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    Life Sciences

    Circulation on the Run

    Each 15-minute podcast begins with an overview of the issue’s contents and main take-home messages for busy clinicians on the run. This is followed by a deep dive into a featured article of particular clinical significance: views will be heard from both author and editor teams for a “behind the scenes” look at the publication. Expect a fun, highly conversational and clinically-focused session each week!

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    Circulation August 20, 2019 Issue Aug 19, 2019
    Show notes

    Dr Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. I'm Dr Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr Gregory Hundley: And I'm Greg Hundley, associate editor from the Pauley Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, this week's feature is from Professor Carl Lindstrom from Helsinki University Hospital and the University of Helsinki and evaluates whether administration of simvastatin via nasogastric tube in brain-dead individuals prior to cardiac transplant donation improves transplant recipient cardiac-related outcomes. It is a randomized trial using an inexpensive therapy, and I look forward to that discussion with Professor Lindstrom. How about we grab a cup of coffee and start off our discussion today. Dr Carolyn Lam: All right, so here goes. The first paper that I want to discuss really looks at the question, is DNA methylation related to incident coronary heart disease? Well, Dr Agha from Columbia University in New York and colleagues looked at this and profiled epigenome-wide blood leukocyte DNA methylation in 11,461 individuals from nine population-based cohorts in the United States and Europe using the Illumina Infinium 450K microarray and prospectively ascertained coronary heart disease events. Dr Gregory Hundley: So Carolyn, what did they find? Dr Carolyn Lam: Well, they found that differences in blood leukocyte DNA methylation at 52 cytosine phosphate guanine sites were associated with incident coronary heart disease or myocardial infarction with a false discovery rate of less than 0.05. Several of the differentially methylated loci mapped to genes related to calcium regulation and kidney function. Exploratory analyses with Mendelian randomization supported a causal effect of DNA methylation on incident coronary heart disease at loci in active regulatory regions with links to noncoding, RNAs and genes involved in cellular and tissue structural components. Very nice Caroline. So what's the summary for us clinically? Dr Gregory Hundley: So, these findings really provide the first evidence that genomic regulation via epigenetic modifications in kidney function and calcium homeostasis related pathways may be involved in the development of coronary heart disease. The findings of epigenetic, loci related non-coding RNAs highlight pathways that have not immersed in genome-wide studies of coronary heart disease and therefore represent novel therapeutic targets, which thus far have not been explored. Dr Carolyn Lam: Very good, Caroline. Well, I've got a basic paper that I want to present and it's from professor Xander Wehrens from the Baylor College of Medicine. And this study addresses factors that promote atrial fibrillation. The investigators found that reduced levels of protein phosphatase-1 regulatory subunit R3A in human atria are causally linked to abnormal calcium handling and atrial fibrillation pathogenesis. In the absence of protein phosphatase-1 regulatory subunit R3A reducing binding of PP1 catalytic subunit increases phosphorylation levels of the ryanodine receptor, R2 calcium release channel, and phospholamban. Complex zone, profiling, a technique that combines native gel electrophoresis with mass spectrometry to obtain the composition of multi protein assemblies revealed that PP1 R3A is part of a macro molecular protein complex containing the ryanodine calcium release channel and the circuit 2APLN calcium uptake transporter. Dr Gregory Hundley: Wow. Complex zone profiling. That's so cool, but what does it all mean for us clinically, Greg? Dr Carolyn Lam: Well reduced levels of PP1 regulatory subunit contribute to abnormal calcium release and re-uptake and atrial monocytes, thereby promoting atrial fibrillation pathogenesis. And thus normalizing levels of PP1R3A phosphatase sub unit may represent a novel therapeutic approach to manage atrial fibrillation. Dr Gregory Hundley: That's so cool. I next have a preclinical paper which contributes really to the understanding of molecular basis of pathological myocardial remodeling in heart failure. And this is from co-corresponding authors, doctors, Jung, Liu, and Lin-Jung from Shanghai East Hospital Tongji University School of Medicine in China. And the paper really focused on Forkhead box transcription factor P1 or Foxp1 in endothelial cells. Dr Carolyn Lam: So Foxp1 Carolyn, tell me a little bit more about that. Dr Gregory Hundley: Is it good that you asked before I asked you. Forkhead box proteins P or Foxp are large modular transcription repressors that bind to DNA via their highly conserved Forkhead DNA binding domains. Fox p1 is highly expressed in vascular endothelial cells and it's essential for normal cardiac development. So, these authors found significantly down regulated Fox P1 expression in cardiac endothelial cells during cardiac remodeling induced by to angiotensin 2. Endothelial cell Fox P1 loss of function resulted in cardiac dysfunction following angiotensin 2 infusion and in the transverse aortic constriction model with severe cardiac fibrosis and mild adaptive cardiac hypertrophy. Whereas endothelial cell Foxp1 gain of function protected against pathological cardiac remodeling and improved cardiac dysfunction transforming growth factor beta 1 signals were identified as Foxp1 direct target genes in endothelial cells which mediated the pathological cardiac fibrosis through cardiac fibroblasts proliferation and myofibroblast formation and maladaptive cardiac hypertrophy through TGF beta 1 promoted endothelial one expression during pathological cardiac remodeling. Dr Carolyn Lam: Wow. Carolyn, this was very sophisticated work. What do we take away from it clinically? Dr Gregory Hundley: These data really identified endothelial Foxp1 mediated TGF beta 1 signal pathway involvement in the promotion of cardiac fibrosis and cardiac hypertrophy via TGF beta 1 induction of the endothelin one pathway. So targeted delivery of TGF beta 1 silencing RNA or small interfering RNA to inhibit endothelial cell specific TGF beta 1 for the improvement of pathological cardiac remodeling may actually represent a future novel therapeutic strategy in managing this maladaptive cardiac fibrosis and hypertrophy during progression of heart failure. Dr Carolyn Lam: That was an excellent summary of a very technical but informative basic science paper. I'm going to shift gears a little bit and talk a little bit about a study relating to clopidogrel and aspirin from the point study. This study comes from Claiborne Johnston at the Dell Medical School and University of Texas. And in patients with acute minor ischemic stroke or high risk transient ischemic attack enrolled in the point trial. The combination of clopidogrel and aspirin for 90 days reduced major ischemic events but increased major hemorrhage compared to aspirin alone. This current paper is a secondary analysis of Point and involves 4,881 subjects in which the investigators assess the time course for benefit and risk from the combination of clopidogrel and aspirin. The primary efficacy outcome was a composite of ischemic stroke, myocardial infarction or ischemic vascular death, and the primary safety outcome was major hemorrhage. Risks and benefits were estimated for delayed times of treatment initiation using left truncated models. Dr Gregory Hundley: So, what did the study show Greg? Dr Carolyn Lam: Well through 90 days, the rate of major ischemic events was initially high, then decreased markedly while the rate of major hemorrhage remained low but stayed constant throughout the study. Using a model based approach the optimal change point for major ischemic events was 21 days with a hazard ratio of 0.65 for clopidogrel aspirin versus aspirin at a P value of 0.0015 compared to later at 22 to 90 days. Where that hazard ratio was 1.38 and the P value only 0.24. And the models showed benefits of clopidogrel aspirin for treatment delayed as long as three days after symptom onset. So Carolyn, the authors conclude that the benefit of clopidogrel aspirin occurs predominantly within the first 21 days and outweighs the low but ongoing risk of major hemorrhage. When considered with the results of the CHANCE study, a similar trial treating with clopidogrel aspirin for 21 days and showing no increase in major hemorrhage. The combined results suggest limiting clopidogrel aspirin use to 21 days may maximize benefit and reduce risk after TIA or minor ischemic stroke. Very practical paper. Dr Gregory Hundley: Indeed. Thanks Greg. That was nice. Dr Carolyn Lam: You bet. Dr Gregory Hundley: Welcome everyone to our podcast and we're very pleased today to have Dr Antti Nykänen from Helsinki University in Finland as well as an associate editor, Justin Ezekowitz from Edmonton, Canada to discuss a very interesting randomized clinical trial related to the administration of simvastatin in those that are donors for heart transplantation and looking at subsequent outcomes in the patients that received the transplants. Antti, we're very excited for you to bring this to circulation. This particular paper and I wonder if you might outline for us what were your hypotheses that you are trying to test and what was your overall study design. Dr Antti Nykänen: These things are routinely admitted to heart transplant recipients starting one to two days after transplantation. As previous clinical studies show that recipient that treatment has beneficial long-term effects on mortality and cardiac allograft vasculopathy. So in this clinical study, we basically tried to answer the question whether having the statin effect on the board even earlier before the transplant procurement by giving statins to the organ donor, if that would protect the transplanted hearts. And this question was based potential rapid vascular and cardioprotective effects of statin and when our previous experimental study showing that treating the organ donor with statins will decreases vascular profusion injury in a heart transplant model. So basically we went on the test donor simvastatin clinically and randomize brain dead heart transplant donors either to a control group or to receive a signal 80 milligram dose of simvastatin before organ procurement. Dr Gregory Hundley: I'm imagining that you would administer the simvastatin through either an intravenous mechanism or perhaps an NG tube, something like that. Maybe tell us a little bit about how you accomplish this and then what were your study results? Dr Antti Nykänen: So, the simvastatin was administered to the donor via a nasogastric tube so there is no intravenous simvastatin formulation available. It needs to be absorbed and then activated through the liver so that can form. So, what we did in our previous experimental study was that we included a few clinical human brain-dead donors and basically investigated whether by giving simvastatin through the nasogastric tube would be metabolized and if you could detect that in in the donor plasma. And that was actually the case. So in a few hours we saw up-regulated levels of simvastatin and also the active form in the donor or so basically showing off that treatment in a clinical brain dead donor of situation would be feasible. So we went on to use that method, clinical study and basically our primary outcome was plasma levels of cardiac injury biomarkers after transplantation. And interestingly by treating the donor with simvastatin decreased and recipients for troponin INT levels six hours after transplant's profusion. Therefore, it seems that organ donor's statin treatment reduces biomarkers of myocardial injury after transplantation in a clinical setting. Dr Gregory Hundley: And did you examine any other functional measures of these patients? For example, ejection fraction by echo or anything, or was it primarily a biomarker study? That's the first question. Second question. Do you have any other information on other organs that also may have been donated? Would the statin have impacted, for example, liver transplantation? Dr Antti Nykänen: That's a good question. So we did follow up cardiac function and the routine and serial measurements with the echocardiographic and we did not find any changes in the left ventricle. It took some traction after transplantation. We did however find the decrease in proBNP levels into recipients. And that was maybe then at one week after transplantation and then it's leveled out after that. And then regarding the next question about other transplanted organs. So once he was in a multi organ donor situation, so the same donor could have donated kidneys or livers, lungs, pancreas. So we did a follow up of the close recipients also. And I can say that there was no adverse effects, no decline in the survival or primary function of the transplanted organs. And interestingly we did find in the liver recipient that if the recipient received the liver from a donor simvastatin treated the liver function tests were better at day seven post-transplant. Dr Gregory Hundley: Very interesting. And then lastly, just another outcome related question. Sometimes I know these patients undergo assessments for rejection by biopsy. Any information that you can share with us on outcomes related to biopsies. Dr Antti Nykänen: We took routine biopsies, myocardial biopsies from the recipients and we did not find any significant differences in the biopsy program rejections either at 30 days or one year after transplantation. We did also monitor, we checked some treatments, so during the first 30 days there was significant decrease in the amount of rejection treatments for hemodynamically rejects it about not for the first year. Dr Carolyn Lam: Wow. Just fabulous results. Thank you so much Antti. So Justin, I wanted to turn the conversation over toward you. Tell us about post-transplant management of these patients and then how do you see these study results integrating into our current standards of care. Dr Justin Ezekowitz: Thanks Greg and Dr Nykänen and thanks for also letting us look at your work, which is terrific and extremely hard to do from the translation of your original 2011 circulation publication in animals and moving forward into the current publication years later. And thinking forward into the next few years of how we translate this into practice so that the current management after transplantation obviously involve multiple anti-rejection medications and many activities around detecting rejection is one of the key ways in which patients are managed other than their hemodynamics and other things that happen early. What I was interested in is the generation of the idea where the simvastatin will really affect the clinical outcomes on the recipient and thinking that into the practice environment is, it's a very simple intervention to think about that would be easily applicable in, I think, most hospitals that do transplantation as either the recipient or the donor. And Dr Nykänen, when you think about translating this into practice over either Europe or in Finland, I don't sense that this is going to be very difficult. Statins are well tolerated. The cardiology and other communities are very familiar with using a statin. But do you anticipate any barriers to translating this into practice as I think the guidelines may pick this up as something of interest. Dr Antti Nykänen: Yes, I think we can show that it's feasible and we did a result on the biomarkers, so indicating that the damage the heart undergoes during the transplantation was smaller after donor statin treatment, so it is feasible, it's very cheap and it generally has a good safety profile. The timeframe for the treatment also feeds into the window of creating a brain dead organ donor. So in that se…

    Full show notes at the publisher

    Circulation August 13, 2019 Issue Aug 12, 2019
    Show notes

    Dr Carolyn Lam: Welcome to Circulation On The Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your cohosts. I'm Dr Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr Greg Hundley: And I'm Greg Hundley, associate editor from the Poly Heart Center at VCU health in Richmond, Virginia. Carolyn, oh, this is going to be an exciting featured article today, and we're going to discuss the combination of agents or their administration et al that are best suited for managing both anticoagulation and antiplatelet therapy and those with coronary disease, peripheral arterial disease and heart failure. And, we'll speak with Dr Kelley Branch from the University of Washington. Dr Carolyn Lam: And me! Dr Greg Hundley: Yes. How am I going to interview you? And, we'll discuss the utility of Rivaroxaban with or without aspirin in patients with heart failure or peripheral arterial disease from the compass trial. Dr Carolyn Lam: Well, I'm not going to let you get there until I tell you about this first basic paper I've chosen because it focuses on the unfolded protein response. Dr Greg Hundley: What's that? Dr Carolyn Lam: Well, Greg, I was really hoping you'd ask. The unfolded protein response is a cellular adaptive process to cope with protein folding stress. Now, approximately 40% of human proteins are predicted to be either transmembrane or secretory. The synthesis, the folding, the cellular transportation and location of these proteins rely on proper functioning of this secretory pathway. Numerous studies have established that the unfolded protein response plays versatile roles during development and under physiologic and pathophysiologic conditions. However, the role of this unfolded protein response in the regulation of cardiomyocyte growth is unclear. Dr Greg Hundley: That's fantastic, Carolyn. I've already learned something here. So, what did this paper show? Dr Carolyn Lam: This is from Dr Wang and colleagues from UT Southwestern, and basically, they use both gain and loss of function approaches to genetically manipulate spliced X-box binding protein one or XBP1, which is the most conserved signaling branch of the unfolded protein response in the heart. In addition, primary cardiomyocyte cultures were employed to address the role of XBP1S in cell growth in a cell autonomous manner. They found that XBP1S expression was reduced in both human and Rhode and cardiac tissues with heart failure deficiency of XBP1S lead to decompensation and exacerbation of heart failure progression under pressure overload. On the other hand, cardiac restricted over expression of XBP1S prevented the development of cardiac dysfunction. Mechanistically, they found that XBP1S stimulated adaptive cardiac growth, your activation of mechanistic target of rapamycin or MTOR signaling which is mediated via the FK-506 binding protein 11, which is a novel transcriptional target of XBP1S. So in conclusion, this study really showed a critical role of the XBP1S FKB or FK-506 binding protein 11 and MTOR axis in coupling the unfolded protein response and cardiac cell growth regulation. Dr Greg Hundley: Boy Carolyn, you explained that so well, and I learned a lot from that. I hope I can do as well with this next article from Professor Johann Backs from the University of Heidelberg. Now paradoxically, some glucose lowering drugs have been shown to worsen heart failure, raising the question of how glucose mediates protective versus detrimental cardiac signaling, and this study from his group focused on one of the class two histone deacetylases or HDAC's namely HDAC-4, which functions as an important epigenetic regulator by responding to upstream stress signals, and linking them to downstream gene regulatory programs involved in among other things, metabolic regulation. Dr Carolyn Lam: Very interesting. So what did they find? Dr Greg Hundley: What they found is that HDAC4 acts as an important maintenance factor of cardiac function in diabetes and O-glycine-N0acetylglucosamine of HDAC4 at searing 642 induces the production of cardio-protective HDAC F-end terminal fragment and attenuates cardio detrimental Cam kinase two mediated phosphorylation of HDAC4 at searing 632. Vice versa, Cam kinase two mediated phosphorylation of HDAC4 at searing 632 attenuates HDAC-4 n terminal production. Thus, these findings lay the ground for the development of novel therapeutic strategies for diabetic patients with heart failure by inhibiting Cam kinase phosphorylation at CIHR 632 or enhancing o-glycine and escalation at searing 642. Dr Carolyn Lam: Fascinating, Greg. Well, my next paper is a subgroup analysis of EUCLID and is the first to assess acute limb ischemia in the context of a large-scale clinical trial studying a primary peripheral artery disease population. Dr Greg Hundley: So Carolyn, reminded us what was the EUCLID trial. Dr Carolyn Lam: Okay, so EUCLID stands for Examining Use of Ticagrelor in Peripheral Artery Disease, and this was a randomized clinical trial that included acute limb ischemia as an adjudicated outcome in a primary peripheral artery disease population randomized to ticagrelor versus clopidogrel. Now in EUCLID ticagrelor was not superior to Clopidogrel for the prevention of cardiovascular events in patients with stable peripheral artery disease. However, a EUCLID subgroup analysis of patients with and without prior limb revascularization demonstrated significantly higher risk for acute limb ischemia hospitalization in patients with prior low extremity revascularization. Dr Greg Hundley: So Carolyn, that's interesting. So, what did they find related in this study that focused on the acute limb ischemia? Dr Carolyn Lam: Right. So, today's paper is from Dr Hess and colleagues at University of Colorado School of Medicine and CPC, clinical research in Aurora, Colorado. And, they found that acute limb ischemia occurred in 1.7% of almost 13,900 randomized patients with a median time to hospitalization for acute limb Ischemia of 320 days after randomization. In this population, prior lower extremity revascularization, atrial fibrillation and lower ankle brachial index identified patients at higher risk for acute limb ischemia. Hospitalization for acute limb ischemia was associated with subsequent cardiovascular and limb ischemic events. So, the take home message is providers should monitor for signs and symptoms of acute limb ischemia in patients with stable symptomatic peripheral artery disease, particularly those with prior lower extremity revascularization, atrial fibrillation, and lower ankle brachial index. Dr Greg Hundley: That's very instructive, Carolyn. Fantastic message. So, I'm going to ask you if you could select one lipid biomarker to forecast future adverse cardiovascular events, which would you select? Total cholesterol, HTLC, non-HTLC, direct and calculated LDLC, APO-A1, or APO-B? Dr Carolyn Lam: Well, I'm traditional. I would have chosen LDL. Dr Greg Hundley: Okay. Well, the authors of this study led by Dr Paul Welsh at the University of Glasgow attempted to answer this question by studying participants from the UK Biobank without baseline cardiovascular disease and not taking statins with relevant lipid measurements. They had 346,686 participants. An incident fatal or nonfatal cardiovascular event occurred in 6,200 participants of which 1,656 were fatal, and they occurred over a median time of 8.9 years. So, the associations of non-fasting lipid measurements, total cholesterol, HDLC, non HDLC, direct and calculated LDLC, APO-a1, and APO-B with cardiovascular disease were compared using Cox models, adjusting for classical risk factors and predictive utility was determined by the C-index and net reclassification index. Also, prediction was tested in 68,649 participants taking a statin with or without baseline cardiovascular disease, and that group experienced 3,515 cardiovascular events. Dr Carolyn Lam: Okay, so drum roll. What did they find? Dr Greg Hundley: So, measurement of total cholesterol and HDLC in the non-fasted state is sufficient or was sufficient to capture the lipid associated risk in the cardiovascular disease prediction with no meaningful improvement from addition of APO lipoproteins, direct or calculated LDLC. And, similar findings were reproduced in those taking a statin at baseline. As such, the authors feel like calls for widespread use of APO lipoproteins are not warranted given the negligible difference in risk prediction beyond total cholesterol in HDLC. And, direct LDLC is also not required for risk prediction. Non HDLC is a cheaper or equivalent predictor of risk on and off statins without the requirement of one of us being fasting. This is an excellent article for our listeners to review or download. Dr Carolyn Lam: Wow, that is so cool. So, from one excellent paper to another excellent paper in our feature discussion. Let's go, shall we? Dr Greg Hundley: Welcome everyone to discussion of our featured article. We have Dr Kelley Branch from the University of Washington and our own Carolyn Lam, and they're going to be discussing the compass trial. So Kelley, could you tell us a little bit about the rationale for compass as opposed to the previously published commander study? Dr Kelley Branch: So, in order to understand compass and compare it to commanders, we're going to have to go back a little bit in time here. And recall, you know well over 20 years ago that when we used anticoagulants in coronary artery disease, that was actually shown to be more beneficial than aspirin alone, but because of the excess bleeding risk, warfarin or vitamin K antagonists not used, and aspirin won. Fast forward a number of years, and now we have the non-vitamin K anticoagulants, and the was potentially that we could find the goldilocks, if you will, the good balance of benefit as well as less bleeding maybe used to these new agents. So, the compass trial was really born from an atlas ACS one and Atlas ACS two, which found that a low dose of, in this case, Rivaroxaban 2.5 milligrams VAB as well as five milligrams VAB were shown to be beneficial in patients after acute coronary syndrome. And then, it was thought what happens if we treat these patients with now chronic coronary disease as well as arterial disease? And from this 27,000 patients, 47,395 patients were tested, and our study very specifically looked at patients with a baseline or a history of heart failure when they answered compass. Compass were shown to be beneficial with specifically the use of aspirin plus Rivaroxaban, 2.5 milligrams BAD. And, our idea was to test this in patients with this baseline or history of heart failure. Now, this is in real contradistinction to what the commander tried to do. And the reason why encompass, we actually excluded patients with severe heart failure. This was defined as a New York Heart Association class three or four or an ejection fraction less than 30%. Now if you looked at patients with commander, these patients had ejection fraction less than 40%. That was a criteria to get in. And of course, these patients had to have a recent hospitalization for heart failure. So, these are very different patient populations. Well, both of them, yes, they did have coronary artery disease, but really very different patient populations. Dr Greg Hundley: Very good. So Kelley, tell us specifically, what were your treatment group assignments and the doses and the outcomes that you were going to follow, and then lead us into what did you find? What were the outcomes of your study? Dr Kelley Branch: Sure, so compass was actually developed as a partial three by two factorial. The arm that we're going to be talking about is the rivaroxaban arm. There was also another arm that tested the use of Proton pump inhibitors, and that actually was shown to not be as beneficial as we thought to decreased bleeding. But specifically for rivaroxaban, the baseline was aspirin, and this was on top of guideline based medical therapy. And then patients were randomized to either aspirin alone plus placebo or Rivaroxaban, five milligrams BAD, plus placebo. So, no aspirin at all or aspirin, a hundred milligrams daily, plus Rivaroxaban, 2.5 milligrams BAD. Those were really the three treatments. Patients were going to be followed for about three to four years. That's what we expected to get our 2200 events , an event-driven trial. But, because of the overwhelming benefits at 23 months median follow up, this trial was actually stopped early, so we only had a little over 1300 events at that time. And with that we saw substantial reduction in major adverse cardiovascular events, about 24% mortality was reduced 18%, and there was a bleeding risk along with this, major bleeding, little different way of actually measuring major bleeding, but that was increased by about 70%, and that was the overall trial results. So, looking at the patients with heart failure, though, there was actually a relatively large proportion of patients, so 5,902 patients, about 22% of patients, actually had either baseline heart failure or had a history of heart failure coming in. Now, this was defined specifically by the PI's. These were not rigorously defined as compared to say commander, but these were patients where the PI said this patient has history or has chronic heart failure. So, with these 5,902 patients, we looked specifically at the outcomes of major adverse cardiovascular events similar to what we saw with compass and that is cardiovascular death, myocardial infarction, or any stroke, that combination. And then, looked at some others exploratory analysis like mortality. And, what we found is that in patients with heart failure, the baseline rate was substantially higher for a mate's. Not too surprising because this tends to be a higher risk patient population. But, what we found is that the hazard ratio was about 0.68, so pretty similar to what we've seen the 24% relative risk. In this case, this was a 32% relative risk reduction in those patients with heart failure. Now, if we looked at a patients without heart failure, the hazard ratio is 0.79, so fairly similar and the [conference intervals 00:16:33] overlap. No statistical heterogeneity or no difference between those, but what we did see if we looked at the absolute risk reduction, was an absolute risk reduction in heart failure of 2.4% reduction. That means a number needed to treat of about 42. If you look at the absolute risk reduction for those patients without heart failure, that was 0.9 to 1.0 depending on what the rounding was. We took 1.0 so that means the number needed to treat of 103. So, these were slightly different relative risks, but overall, what we saw is that the hazard ratio is very consistent with the overall effect of compass in the same direction. Interestingly, and actually I think even for me it was surprisingly, we actually looked at the hazard ratios for bleeding, and when we looked at the hazard ratios for bleeding, we fully expected that because it's the higher risk patient population, we actually expected that to go up. What we saw is that the bleeding actually was no difference at all, and if anything in the heart failure population was slightly lower. And, this was fairly surprising to us because we thought that the patients with heart failure, the bleeding would actually trend up because this was a higher risk patient population. So it looks like it's something can be used and really no substantial increase in bleeding. Dr Greg Hundley: Very good. Well Carolyn, as someone that's managing patients with heart failure, what do you see are the clinical implications of this study? Dr Carolyn Lam: That is a beautifully simple, direct question but is not as easy to an…

    Full show notes at the publisher

    Circulation August 06, 2019 Issue Aug 05, 2019
    Show notes

    Dr Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your cohosts, I'm Dr Carolyn Lam, associate editor from National Heart Center and Duke National University of Singapore Dr Gregory Hundley: And I'm Greg Hundley, associate editor from the Pauley Heart Center in Richmond, Virginia at VCU Health. Our feature article today really invokes thought regarding LVAD bridging to heart transplantation. I really look forward to the conversation with Dr Veli Topkara from Columbia University, the corresponding author and our associate editor, Dr Mark Drazner from UT Southwestern. And it's regarding the outcomes from their study, evaluating patients waiting for transplant that are bridged with an LVAD versus not. But before we get to that, let's dive into some of our other original articles with our little coffee chat. Do you have an article that you'd like to discuss? Dr Carolyn Lam: You bet I do Greg and I have my coffee here. Have you ever wondered, does microvascular disease, in any location in the body, increase the risk of lower limb amputation? Well, this was looked at in the paper that I chose first today. It's from Dr Beckman from Vanderbilt University Medical Center in Tennessee and his colleagues, and they basically examined 125,674 participants in the Veterans Aging Cohort Study from 2003 to 2014 and analyzed the effect of prevalent microvascular disease defined as retinopathy, neuropathy and nephropathy and peripheral artery disease status on the risk of incident amputation events, of which there were 1,185 amputations over a median of 9.3 years. Dr Gregory Hundley: Wow, Carolyn. What did this study find? What did Josh and his colleagues find? Dr Carolyn Lam: They found that the presence of microvascular disease increases the risk of amputation significantly in the absence of peripheral artery disease. As many as one in six below knee amputations may result from microvascular disease, even without peripheral artery disease. Microvascular disease also potentiates the amputation risk in persons with peripheral artery disease to more than 20-fold, compared to persons with neither peripheral artery disease nor microvascular disease. Further research is really needed to understand the mechanisms by which this occurs. And in the meantime, clinicians should bear this increased risk in mind when screening for and managing lower extremity disease. Dr Gregory Hundley: Ah. Well Carolyn, my first paper is somewhat related because we're going to talk about triglycerides. And this paper is from Zahid Ahmad from UT Southwestern Medical Center. He's the corresponding author. And can you imagine Carolyn an antibody that could correct elevations in serum triglycerides? Dr Carolyn Lam: Tell us about it, Greg. Dr Gregory Hundley: Well, I'm going to give you a little background first. Low levels of triglycerides and other lipids are observed in individuals with loss of function mutations in angiopoietin-like protein 3 which inhibits lipoprotein lipase activity, increasing triglycerides and other lipids, and providing a rationale for development of a monoclonal antibody therapy. Dr Carolyn Lam: Interesting. What did this study do Greg? Dr Gregory Hundley: It evaluated evinacumab. They looked at the safety of this. This is a fully human angiopoietin-like protein 3 antibody, and it was compared with placebo, with no serious treatment emergent adverse events, no events related to death or treatment discontinuation was reported. They did two phase one studies evaluating single and multiple ascending doses. In addition, substantial and sustained percent reductions from baseline versus placebo were observed and triglycerides with absolute levels reaching about 50 milligrams per deciliter for several of the evinacumab doses at specific time points in both studies. And therefore, the data from these two phase one studies in this one paper support further clinical evaluation of this new antibody in larger studies of hypertriglyceridemic individuals. Dr Carolyn Lam: Definitely a space to look out for. Well Greg, my next paper is a basic paper. Genome wide association studies have identified chromosome 14 Q32 as a locus for coronary artery disease. The disease associated variants fall in a hitherto uncharacterized gene called Hedgehog Interacting Protein Like 1, or HHIPL1. the function of this gene and its role in atherosclerosis has previously been unknown, well, until today's paper. But Greg, here's your quiz. What do you know about the hedgehog proteins? Dr Gregory Hundley: Well, I know hedgehogs are friendly little animals and I know they must have great proteins because they're so friendly. Dr Carolyn Lam: Why did I expect that? Oh, let me tell you a little bit about them. The mammalian hedgehog proteins like sonic hedgehog, desert hedgehog, and Indian hedgehog are secreted molecules that exert a concentration and time dependent effect on target cells following binding and complex signal transduction pathways. They induce the transcription of target genes, primarily involved in cell proliferation, survival, and fate specification. Now in adults, the hedgehog signaling is involved in the maintenance of adult vasculature and ischemia induced neovascularization, including after myocardial infarction. Today's authors, however, including Tom Webb from University of Leicester and colleagues, report the first experimental investigation of HHIPL1 and the present evidence that it is a secreted proatherogenic protein that regulates smooth muscle cell proliferation and migration. So, that's novel. Through a series of experiments involving coronary artery disease, relevant human cells and mouse models, they showed that HHIPL1 is a secreted protein that interacts with sonic hedgehog and is a positive regulator of hedgehog signaling. In murine models, HHIPL1 deficiency attenuates the development of atherosclerosis by reducing smooth muscle cell proliferation and migration. The clinical implications are two-fold. First, this study supports HHIPL1 as the causal gene at that 14 Q32 coronary artery disease locus that we did not really understand previously. And secondly, HHIPL1 is a promising therapeutic target that affects a pathogenic mechanism not addressed by current mechanisms for coronary artery disease. Room for novel development. Dr Gregory Hundley: Very interesting Carolyn. Well, I've got another basic science paper, and this is from Dr Kenneth Walsh at University of Virginia and it's going to look at the role of neutrophils, not necessarily macrophages but neutrophils and their role in pressure overload induced cardiac dysfunction. While the complex roles of macrophages in myocardial injury is widely appreciated, the function of neutrophils in nonischemic cardiac pathology has received relatively little attention. This study examined the regulation and function of neutrophils in pressure overload induced cardiac hypertrophy as mice underwent treatment with Ly6G antibody to deplete neutrophils and then subjected them to transverse aortic constriction or TAC. Dr Carolyn Lam: Huh? What did they find? Dr Gregory Hundley Caroline, the study revealed that neutrophils played a critical role in the hypertrophy of the left ventricle that results from pressure overload in this murine model of heart failure and identified that a non-canonical Wnt protein is essential for the recruitment of neutrophils to the injured myocardium. Dr Carolyn Lam: Hmm. What do you think are the clinical implications of this? Dr Gregory Hundley This study demonstrates how neutrophils contribute to the hypertrophy of the left ventricle under conditions that do not involve ischemia or myocardial necrosis. Also, since cardiac hypertrophy is a risk factor for the development of heart failure, this study implicates WnT5a mediated neutrophil infiltration as an early step in the progression of this disease. Dr Carolyn Lam: Wow, thanks Greg. That was so cool. But let's hurry on to our feature discussion, shall we? Dr Gregory Hundley You Bet. Dr Carolyn Lam: Bridge to transplant with left ventricular assist devices is a mainstay of therapy for heart failure in patients awaiting heart transplantation. The criteria for heart transplantation listing does not differ between patients medically managed versus mechanically bridged to heart transplant. However, are there differences in post-transplant outcomes between medically managed and mechanically bridged patients? Well, today's paper provides important data to address this question. So pleased to have with us the corresponding author, Dr Veli Topkara from Columbia University Medical Center, New York Presbyterian as well as Dr Mark Drazner, associate editor from UT Southwestern. Welcome gentleman. Veli, this is an important question. Could you please tell us how you addressed it and what you found? Dr Veli Topkara: We decided to visit an old question of whether bridging with LVAD confers at risk for post-transplant mortality. Because the field and pump technology has been rapidly changing. There has been a significant increase in utilization of devices nationwide to the extent that more than 50% of patients already have an LVAD in place by the time they receive a heart transplant. And patients also wait much longer on these pumps before they could get a heart. Currently, available devices provide continuous flow and patients essentially live without a pulse for many months to years waiting for a heart. And with this unique physiology, they also have unique complications such as RV failure and there has also been pre-survey reports including one from our center suggesting an increase in the primary graft failure rates after heart transplant. And mostly seen in patients who were bridge to transplant with an LVAD. To address some of these questions, we took advantage of the UNOS database, which is the largest prospective transplant data registry in the United States. We were able to identify more than 14,000 patients who are either medically or mechanically bridged to transplant. We then derived a cohort from patients who were LVAD baseline by propensity score and we looked at their outcomes. And what we found was that patients who were mechanically bridged to transplant with an LVAD, had 9.5% mortality at one year, compared to 7.2% in patients who were medically bridged. And this is more than 30% increase in relative risk of death for LVAD patients. When we looked at the specific cause of death at one year, LVAD patients had a higher number of cardiovascular death secondary to primary graft failure, confirming findings of the recent studies at a larger scale. Next, we looked at whether mortality risk factors were similar in the mechanical versus medical bridged patients. And this is a very important question clinically because the criteria for transplant listing do not distinguish between the two patient cohorts. For example, at my center age cutoff transplant listing is less than 72 years of age and that is whether or not patients are on VAD support. And same applies for example, GFR cutoff for renal function or PVR cutoff for pulmonary hypertension. And all the cutoffs that are utilized are essentially identical for transplant candidates irrespective of the bridging strategy. But what we found in this paper, however, what's quite different that if we apply the same thresholds for mechanical versus medical bridged patients, for some of these risk factors, you end up having outcomes that are remarkably different. For example, for patients with a normal renal function, the mortality risk is similar going into transplant with or without an LVAD, but for patients with borderline renal function observed mortality has more than doubled for those going into transplant with an LVAD, as opposed to medical therapy. And we also observed similar trends for recipient age, BMI and PVR, in which numerical increase in these factors would translate to high risk of mortality in LVAD patients going into heart transplant. Despite the limitations of this large registry analysis, I think these findings suggest that we may need to think of it differently when it comes to listing or transplanting patients who are on LVAD. And there seems to be a group of patients who are perhaps maybe better served by staying on an LVAD as opposed to moving on to heart transplant and we need to better identify who these patients are. Dr Carolyn Lam: Oh Wow. Veli, thank you. First, congratulations on a very important paper and also how you beautifully summarized. Mechanically bridging patients associated with a higher risk of early post-transplant mortality and even providing data on the cause and risk factors associated with that mortality. Mark, could I bring you in here? Not just as AE (associate editor), but as a doc[tor] who manages many of these patients. What were your perspectives? Dr Mark Drazner: As I step back and as Veli said, there's an increasing number of patients who are being bridged with a VAD, so the question clearly is important, and we don't really have any randomized data available to us in terms of how the bridging strategy may impact outcomes. When you look at the groups of patients who are supported with VADs or not, they're very different and so you need to do some statistical manipulation which here they did propensity matching, to try to come up with equal groups as you look at their outcomes. That was nicely done. And then theoretically I think you could argue there may be reasons why patients bridged with VADs may do better or they may do worse. They may do better because you may restore their functionality, you may improve renal function and, but they may do worse because they have coagulopathies, the VAD itself may lead to complications and so it's a question you can't really answer just logically. You really need some data which is I think the best study that's been brought forward so far as the one we're discussing today. Veli, let me ask you because the obvious question then is why do you think the outcomes are worse among the patients who are bridged? Dr Veli Topkara: I think they are doing worse for multiple different reasons. Having an LVAD is clearly an additional surgery which technically makes the second transplant surgery more complicated. But when we looked at the risk factors for primary graft failure at our institutions, the predictors of primary graft failure in LVAD patients were also very similar to factors we identified in this nationwide analysis which included renal failure, RV dysfunction, as well as trans-transplant and increased time on device support. I think it's clear that some subset of LVAD patients who have these risk factors are at higher risk for increased post-transplant mortality for some of the mechanistic reasons are unclear at this point. Dr Mark Drazner: Do you think their continuous flow exposure is part of it? Dr Veli Topkara: That's clearly one of the hypotheses that we have been talking about because as we discussed, these patients are exposed to continuous flow for a long time and one of the concerns is whether they lose their peripheral arterial venous-reactivity over time. And this could potentially also be the reason why patients who are on pump support for longer times are at higher risk for PGF. That's a possible underlying mechanism. But in this data set, we didn't have fair data with regards to pulse pressure and pulsatility, which could have helped answering this question. Dr Mark Drazner: And just for clarification for the listeners, this was pre-HeartMate 3 data, is that correct? Dr Veli Topkara: Yes. This analysis doesn't include any HeartMate 3 patients. Dr Carolyn Lam: And Mark, if you don't mind, could you also clarify for the listene…

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    Circulation July 30, 2019 Issue Jul 29, 2019
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    Dr Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your cohosts. I'm Dr Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr Greg Hundley: I'm Greg Hundley, Associate Editor of Circulation, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr Carolyn Lam: Greg, guess what? We are going to be talking later about non-inferiority trials. Now, you're going to go like, "Huh? What?," but then we see more and more non-inferiority cardiovascular trials. And do we really know the advantages and limitations of this type of trial design? Which is so important to understand, because we need to understand the factors that may impact our confidence and interpretation of these results. So, that's going to be a really important feature discussion, coming up right after our coffee chat. Greg, what are your papers? Dr Greg Hundley: Thanks Carolyn. Boy, I can't really wait to get to that feature discussion. That's something that we deal with all the time, and I look forward to that explanation and that discussion. I'm going to talk a little bit of basic science, with two papers right in a row. And the first one involves catecholaminergic polymorphic ventricular tachycardia through inhibition of calcium/calmodulin-dependent kinase II. The lead author is Dr Vassilios Bezzerides from Boston Children's Hospital. Carolyn, this paper focuses on treatment of catecholaminergic polymorphic ventricular tachycardia, an underlying diagnosis in at least 12% of pediatric patients who present with unheralded cardiac arrest. ICDs, as you know, are frequently implanted, but are problematic because of increased complication rates in pediatric patients, failure to convert ventricular arrhythmias, and the risk of fatal ICD-induced electrical storm. Modulating CaM Kinase II within the heart shows promise to treat this, but CaM Kinase II is essential in other tissues, most notably the brain. Dr Carolyn Lam: How interesting. So, what did the study show? Dr Greg Hundley: Well, the investigator used adeno-associated viral gene therapy, which is proven to be a safe and efficient vector for sustained gene transfer into many cell types to selectively inhibit CaM Kinase II in cardiomyocytes. They were able to express the specific CaM kinase II inhibitory peptide AIP in cardiomyocytes without significant extra cardiac expression, and an inhibition of CaM Kinase II effectively suppressed ventricular arrhythmias in a murine model of catecholaminergic polymorphic ventricular tachycardia after a single therapeutic dose. So thus, in animal models, delivery of a CaM Kinase inhibitory peptide by AAV represents a novel single dose gene therapy for catecholaminergic polymorphic ventricular tachycardia. How about that? Dr Carolyn Lam: Wow. You've got a second paper? Dr Greg Hundley: I sure do. So now we're going to jump into, again, looking at polymorphic VT from engineered human heart tissue. And this article is from Kevin Parker at Harvard University, "Modeling of Human Arrhythmias Using Induced Pluripotent Stem Cell-Derived Cardiomyocytes has Focused on Single-Cell Phenotypes." With this said, it is important to realize that arrhythmias are emergent properties of cells assembled into tissues and the impact of inherited Arrhythmia mutations on tissue level properties of human heart tissue. And therefore, newer technologies are needed to develop more satisfactory therapeutic interventions. Ones that encompass all of the tissue, not just single cells. Dr Carolyn Lam: Interesting. So, what did this particular study do? Dr Greg Hundley: So, Carolyn, in this study, the investigators report on an optogenetically-based human-engineered tissue model of catecholaminergic polymorphic VT, which as we have discussed in the previous article is promoted by mutation of the cardiac ryanodine channel 2, which is promoted by mutation of cardiac ryanodine channel and triggered by exercise. They developed a human IPSC cardiomyocyte-based platform to study the tissue level properties and investigated pathogenic mechanisms in polymorphic VT by combining this novel platform with genome editing. The authors found that engineered heart tissue, fabricated from human pluripotent stem cell derived cardiomyocytes, effectively modeled catecholaminergic polymorphic VT caused by dominant mutations in the cardiac ryanodine receptor, including induction of arrhythmias by conditions that stimulate exercise. Using selective pharmacology and genome editing, the authors identified activation of calcium/calmodulin-dependent kinase II, or CaM Kinase II, and CaM Kinase II mediated phosphorylation of ryanodine at Serine 2814 as critical events that are required to unmask the latent arrhythmic potential of catecholaminergic polymorphic VT, causing ryanodine mutations, highlighting a molecular pathway that links beta adrenergic stimulation to arrhythmogenesis in this disease. Dr Carolyn Lam: Wow Greg! So, two very interesting and important linked genetic papers. Well, we're going to switch tracks a little bit and talk about, well, my favorite topic: heart failure with preserved ejection fraction and the whole complex issue of the diagnosis of this syndrome. Now we know that the diagnosis is kind of complex and there is currently no consensus but several proposed definitions. So how do the clinical and hemodynamic profile of patients vary across the different definitions of HFpEF? So, this question was answered by Dr Jennifer Ho from Massachusetts General Hospital and her colleagues, who examined consecutive patients with chronic exertional dyspnea and an ejection fraction above 50% who are referred for comprehensive cardiopulmonary exercise testing with invasive hemodynamic monitoring. They applied societal and clinical trial HFpEF definitions and compared the clinical profiles, exercise responses, and cardiovascular outcomes by these different definitions. So, of 461 patients, 416 met the ACC/AHA definition, 205 met the ESC definition, and 55 met the HFSA criteria for HFpEF. The clinical profiles and exercise capacity varied vastly across the definitions, with peak oxygen uptake averaging 16.2 for those with the ACC/AHA definition and down to 12.7 in those satisfying the HFSA definition. Dr Greg Hundley: Wow. What a difference from these societies. Dr Carolyn Lam: Mm-hmm (affirmative). Dr Greg Hundley: So Caroline, it sounds like they looked at all comers with exertional dyspnea. Now how about those that had hemodynamic evidence of heart failure with preserved ejection fraction? Dr Carolyn Lam: Yeah, good question Greg. So, you caught me telling you that all these patients had hemodynamic cats as well, and a total of 243 had hemodynamic evidence of HFpEF, which was defined as an abnormal rest or exercise feeling pressure. Of these, 222 met the ACC/AHA criteria, 161 met the ESC criteria, and only 41 met the HFSA criteria. Over a mean follow-up of 3.8 years, the incidents of cardiovascular outcomes range from 75 for the ACC/AHA criteria to 298 events per thousand-person years for the HFSA criteria. The application of clinical trial definitions of HFpEF similarly resulted in distinct patient classification and prognostication. So in summary, the authors demonstrated significant diversity in the number of patients meeting HFpEF criteria. And using different HFpEF classifications variably enriched for future cardiovascular events, but at the expense of not including up to 85% of individuals with physiologic evidence of HFpEF. Comprehensive phenotyping of patients with suspected heart failure really highlighted the limitations and heterogeneity of current HFpEF definitions and may help to refine HFpEF sub-grouping to test therapeutic interventions. Now, these are all discussed in an important accompanying editorial by Michele Senni, Sergio Caravita, and Walter Paulus. Dr Greg Hundley: Wow Carolyn. It appears, depending upon the definition, we could really classify patients drastically differently. Dr Carolyn Lam: Yeah, an important paper indeed. And again, I would strongly encourage everyone to read that editorial as well. For my second pick, we're going to switch to CPR in children. So these authors, now led by Dr Rohan Khera from UT Southwestern, examined the prevalence and predictors of survival of children who progress from bradycardia to pulselessness in in-hospital cardiac arrest despite cardiopulmonary resuscitation. So they looked at almost 5,600 pediatric patients age more than 30 days to under 18 years of age, who received CPR at hospitals participating in the Get With The Guidelines - Resuscitation during 2000 to 2016 each CPR event was classified as bradycardia with pulse, bradycardia with subsequent pulselessness, and initial pulseless cardiac arrest. And the authors assessed for risk adjusted rates of survival to hospital discharge. Dr Greg Hundley: So Carolyn, what did they find? This is really interesting. Dr Carolyn Lam: Well, among hospitalized children in whom CPR was initiated, half had bradycardia with poor perfusion at the initiation of chest compressions and nearly one third of these progressed to pulseless in-hospital cardiac arrest despite CPR. Survival was significantly lower for children who progressed to pulselessness despite CPR compared to those who were initially pulseless. So, these findings suggest that pediatric patients who lose their pulse despite CPR are at particularly high risk and require a renewed focus on post resuscitation care. Dr Greg Hundley: Very interesting, Carolyn. Dr Carolyn Lam: Well, that wraps it up for our discussion. Let's go onto the featured discussion. Shall we, Greg? Dr Greg Hundley: You bet. Dr Carolyn Lam: Non-inferiority cardiovascular trials are increasingly being published and in the highest impact journals. Yet how much do we really know about these designs of the trial, of the non-inferiority trials? Well, I have to admit not much in my point of view, and I was so pleased to see our feature discussion paper really published in this week's journal, which really digs deep into non-inferiority trials and talks about time trends and perhaps some lessons that we should all bear in mind when we look at these. I'm so pleased to have the first author, Dr Behnood Bikdeli, to tell us about the study. And he is from Columbia University Medical Center, New York Presbyterian Hospital, Yale Center of Outcomes, Research and Evaluation Core, as well as the Cardiovascular Research Foundation in New York. We also have Dr Naveed Sattar, associate editor from the University of Glasgow. Behnood, could you tell us, so what made you look at this question and what did you find? Dr Behnood Bikdeli: For a while we've been very interested in profiling the cardiovascular trials, trying to understand a little better, what are the specific characteristics of the major child that we rely upon for research but also for clinical practice? Years ago, we did some studies for surrogate outcome trials and this, let's just say subsequent piece, where we tried to look into a randomized cardiovascular trial that use a non-inferiority design. We had a series of features in terms of quality metrics and methodological metrics that we wanted to look into. The over eight almost 27-year period, we identified 111 of these trials. Reassuringly, most of these trials inherited several important quality and methodological metrics that we were looking into. However, we also saw a significant room for improvement. There were quite a few quality or methodological metrics that some of these trials were not adhering to and we think it's important because ultimately for the design reporting and last reading of these trials, knowing these pluses and minuses would help inform people. Dr Carolyn Lam: That's great, Behnood. Now for those of us listening who don't think about this every day, could you give us some examples of the top errors perhaps to look out for? Dr Behnood Bikdeli: For example, in the typical superiority trials, when we want to test an intervention a versus intervention B, all that matters is we do a very good and adequately sized trial and rest of it is up to the study and how it goes to see whether or not something panned out. There was a significant difference between the new intervention versus the older ones, but in non-inferiority trials we have something called the non-inferiority margin and that's very highly relevant when it comes to the outcome that you're assessing when it comes to the ultimate results of the trial. If the investigators choose a very lenient y non-inferiority margin, they may end up calling an intervention non-inferior. They may give it a pass. While in reality the intervention has quite a lot of a risk or harmful profile compared with standard of care. But in the other side, as a clinical example, we have several interventional tools at hand, like transcatheter aortic valve replacement. Most of the indications where it's currently used came from large bell designed non-inferiority trials. Where they showed that it was almost as good as surgery, in some cases better, but also it had a lot of ancillary advantages. Dr Carolyn Lam: Thanks, Behnood. And you know here, I just want to call out to the readers. You have to look at this paper. Look at the tables and figures which are really so helpful. And Naveed, can I bring you in on this now? I mean, I just love this paper. It's such an important topic and I've never seen it addressed like this before. Could you tell us a little bit about what the editors discussed when we looked at this? Dr Naveed Sattar: I've been involved in a few non-inferiority trials and some of the factors that many of us discuss and some of course associated, sort of our clinical trials, and I've been involved normally in superiority trials, but increasingly we have cut our teeth in non-inferiority trials. So, some of the points that the paper picks up resonated well with us in terms of, one of the examples was Behnood and his team found that around about 40% of trials didn't even justify what their non-inferiority margin was. And that's something I've actually had detailed discussions involved in various trials with. And that's a really important point, but it isn't a, you have to be able to justify why you choose particular margin and what that margin would mean to the community. Otherwise you potentially could just pick something out there which really doesn't allow you to make a really strong non-inferiority claim. And I think that's one of the factors that you found, Behnood. Is that correct? Behnood Bikdeli: Absolutely. And that's a great point. Thank you. To us, there were two things about it. One was whether or not they provided any detailed justification for it exactly as you said, not that they're just picking up something because that's the sample size that they could achieve or that's the number that they felt comfortable with. But also the second piece of it, a respective of how they calculated or came up to the number, their readers have a right to know how this was calculated or were this came from, so it's the reporting part of it. Sometimes they reported both in the published paper and a study protocol or a design paper. Sometimes it was only in one of them. Sometimes as you mentioned, it was not mentioned in either, which puts the reader in a very difficult situation. So we think, and these were the best of the best trials in the highest impact journals. Probably if we look high and low elsewhere it's going to be even more challenging. So, we think there's a lot of room for improvement for the readers to expect cleaner, mo…

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    Circulation July 23, 2019 Issue Jul 22, 2019
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    Dr Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts, I'm Dr Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr Greg Hundley: And I'm Greg Hundley, Associate Editor at the Pauley Heart Center at VCU Health in Richmond, Virginia. Well Carolyn, did you ever wonder whether cardiovascular drug effects could be investigated through natural variation in the genes for the protein targets? In our feature discussion today, investigators from the British Isles, Germany, and the United States use this approach to explore the potential side effects and repurposing potential of antihypertensive drugs. Sound interesting? Well listeners, we look forward to the results later in our program, but Carolyn, how about we chat about some of the other papers in this issue? Dr Carolyn Lam: You bet Greg. So, have you ever asked yourself "What is the role of protein glycosylation in regulating LDL metabolism?" Dr Greg Hundley: That was going through my mind when we were playing basketball just the other night. Dr Carolyn Lam: Well this is truly a great study from Dr Holleboom at Academic Medical Center Amsterdam and Dr Lefeber from Radboud University Medical Center, both in the Netherlands. And their colleagues will study 29 patients of the two most prevalent types of Type 1 Congenital Disorder of Glycosylation, and these are the ALG6 and PMM2 types. They also study 23 first and second-degree relatives with a heterozygote mutation and measured their plasma cholesterol levels. LDL metabolism was studied in three cell models. They found that patients with type 1 congenital disorder of glycosylation have hypobetalipoproteinemia through increased LDL receptor expression. Carriers of the mutation in glycosylation enzymes affected in this syndrome had decreased LDL cholesterol levels compared to controls, and defects in glycosylation enzymes could play, therefore, an important role in LDL cholesterol metabolism. Dr Greg Hundley: Boy, this is pretty insightful I think, Carolyn. So, what are the clinical implications? Dr Carolyn Lam: Well, given that LDL cholesterol was also reduced in a group of clinically unaffected heterozygotes, the authors propose that increasing LDL receptor mediated cholesterol clearance, by targeting N-glycosylation in the LDL pathway, may therefore represent a novel therapeutic strategy to reduce LDL cholesterol, and of course prevent cardiovascular disease. Dr Greg Hundley: Very interesting work. You know, we just keep learning more and more about LDL. I'm going to switch and jump back with Empagliflozin. And this is a study in diabetic mice that really has an interesting in-vivo imaging component. As an imager, I was really excited about this. The article is from Dr Kengo Kidokoro from Kawasaki Medical School. And we don't often talk about it, but listeners, if you have a chance, there's a very interesting video-enhanced file associated with this article, and if you can download it, it's really just so cool with multiple image clips demonstrating an operative mechanism of SGLT2 inhibition on renal function. And it really gives us an opportunity to revisit renal function. Quick quiz Carolyn. In diabetic kidney disease, is glomerular hyperfiltration good or bad? Dr Carolyn Lam: Bad. Dr Greg Hundley: Yeah, absolutely. So, hyperfiltration is characteristically observed at earlier stages of diabetic kidney disease and involves activation of the renin-angiotensin-aldosterone system at the efferent arteriole and tubuloglomerular feedback mechanisms, especially at the afferent arteriole. So, as they go through this, just picture in your mind that glomerulus and afferent is arriving, and efferent is leaving. So, SGLT2 upregulation in diabetes is thought to play an important role in TGF signaling by increasing sodium reabsorption at the proximal tubule, thereby decreasing distal delivery to the sodium sensing macula densa at the juxtaglomerular apparatus. This decline in distal sodium delivery is interpreted as a decline in effective circulating volume, leading to inappropriate afferent vasodilation in an effort to preserve intra-glomerular pressure and GFR. In diabetes, these TGF effects lead to intra-glomerular hypertension and hyperfiltration. You got that quiz right, Carolyn. Which promotes diabetic kidney disease progression and impaired kidney function, ultimately increasing overall cardiovascular risk and mortality. Conversely, blocking SGTL2 pharmacologically reduces renal hyperperfusion and hyperfiltration in animals and humans, which may preserve renal function, thereby reducing risk associated with diabetic kidney disease progression. Dr Carolyn Lam: You know what, Greg? I kind of had an unfair advantage in this quiz. I work with a lot with the SGLT2 inhibitors, but I just love that you asked us to picture it and look at that video. Anyways, so this article really allows us to review SGLT2 inhibition at the glomerular level, which is truly hot. So, tell us what did they find? Dr Greg Hundley: So, this is the first report of changes in renal hemodynamic function by SGLT2 inhibition using direct in-vivo visualization techniques in a diabetic animal model. The videos, they're spectacular, and they're excellent so that you can download them for educational purposes. Afferent arteriolar vasoconstriction, and reduced hyperfiltration occurred within a few hours after a single dose of a SGLT2 inhibitor. And Adenosine signaling, through tubuloglomerular feedback, is a key pathway to prevent diabetic hyperfiltration via SGLT2 inhibition. Clinically, Carolyn, now I know you would ask me about that, so I got ready, this study highlights another potential mechanism for the benefits of SGTL2 inhibition. The SGLT2 inhibitor-related mechanism's responsible for reducing cardiovascular risk in clinical trials may be due to protection against diabetic kidney disease progression, thereby attenuating risk factors for heart failure, such as volume overload and hypertension. Dr Carolyn Lam: Ah. That is just so cool, and really just so consistent with the clinical data that's emerging too. Thank you, Greg. So, have you ever asked yourself this other question, what role do platelets play in ischemia reperfusion injury? So, I'm not going to quiz you. I'm actually kind and loving and a good person. And so, I will tell you about ischemia reperfusion injury, which is a common complication of cardiovascular disease. Now, resolution of the detrimental effects of ischemia reperfusion injury generated prothrombotic and proinflammatory responses, is essential to restore homeostasis. Now, although platelets are known to play a crucial role in the integration of thrombosis and inflammation, their role as participants in the resolution of thrombo-inflammation is really under-appreciated. And hence, this other paper that I chose today, and it's from Dr Gavins from Louisiana State University Health Sciences Center Shreveport, and her colleagues, who used pharmacological and genetic approaches, coupled with murine and clinical samples to uncover key concepts underlying this role for platelets. Dr Greg Hundley: So Carolyn, what did they find? Dr Carolyn Lam: Well, they found that exacerbation of thrombo-inflammatory responses occurred in ischemia reperfusion injury mouse models of middle cerebral arterial occlusion, as well as lower plasma levels of the anti-inflammatory pro-resolving protein Annexin A1. And this was a lower plasma level of this Annexin A1 among patients with acute ischemic stroke. Administration of Annexin A1 promoted cerebral protection against thrombo-inflammation and the development of subsequent thrombotic events post-stroke. Annexin A1 was also able to reduce platelet activation and thrombosis, via the suppression of integrins. So, overall, these data reveal a novel multi-faceted role for Annexin A1 to act both as therapeutic and prophylactic drug via its ability to promote endogenous pro-resolving anti-thrombo, anti-inflammatory circuits in the cerebral ischemia reperfusion injury. And collectively, these results further enhance our understanding in the field of platelet and ischemia reperfusion injury biology. Dr Greg Hundley: Oh wow. So, another important insight from this author group on platelet activation and thrombosis in key clinically relevant syndromes. Well, my last paper is going to be talking about a risk prediction score for life-threatening ventricular tachyarrhythmias. And they're going to study this in laminopathies, and the lead investigator is Dr Karim Wahabi from Cochin Hospital in France. To estimate the risk of life-threatening ventricular tachyarrhythmia in patients with LMNA mutations, and thus select candidates for implantable cardiac defibrillators, the investigators evaluated 444 patients of about 40 years in age in a derivation sample. And then, 145 patients that are about the same age, 38 years, in a validation sample, for the occurrence of a) sudden cardiac death or b) ICD-treated or hemodynamically unstable ventricular tachyarrhythmias. Dr Carolyn Lam: Oh. Very important. These laminopathies are really not that uncommon. So what did they find, Greg? Dr Greg Hundley: Carolyn, predictors of events included male sex, non-missense LMNA mutations, first-degree and higher AV block, non-sustained ventricular tachycardia, and LVEF. The authors developed a new score to estimate the 5-year risk of life-threatening ventricular tachyarrhythmias in patients with LMNA mutations. And compared to the current standard of care, the proposed risk prediction model offered more accurate prediction of life-threatening ventricular tachyarrhythmias, and correctly re-classified almost 30% of the patients in the study. Nicely, the authors have made this available, and the score can be derived from readily collected clinical and genetic parameters and estimated using an online calculator that's provided in the journal. But, it's https://lmna-risk-vta.fr. Future prospective studies should focus on the estimation of the clinical benefit conferred by the use of this score in terms of sudden cardiac death prevention. Dr Carolyn Lam: That is super cool, Greg. But, I am so excited now to move to our feature discussion. Shall we? Dr Greg Hundley: You bet. Dr Carolyn Lam: Can we use natural variations in our genes for the protein targets as a way to look at cardiovascular drug effects? Man, this is going to be such an important and exciting discussion, because this is what our feature paper talks about. I am so pleased to have with us our corresponding author, Dr Dipender Gill from Imperial College London, as well as our Associate Editor, Dr Wendy Post from Johns Hopkins. So, first of all, Dipender, please, could you give us a background on what you did? This is really very novel in approach. Dr Dipender Gill: It was also a lot of fun to conduct. I think, currently, we're living in an era where there's been a recent explosion in the availability of genetic data, and this really inspired us to think about how we could use that to learn more about commonly prescribed drugs. The implementation of genetics, or genetic variance, to study drug effects isn't entirely novel. It's actually been undertaken for some years now. Most of the work has been related to lipid lowering drugs, for example, statins, where people can take genetic variance, or versions of genes, corresponding to the drug effect, and study these to investigate what effects these drugs might have, both on the intended target, but also potential side effects. To my knowledge, this hadn't previously been done for anti-hypertensive drugs. But yet, the data for this was available. And therefore, we thought that actually we could very well go ahead and do this, and perhaps find some interesting things. Dr Carolyn Lam: Oh, that's so interesting thing, Dipender. You know, there was this term in your abstract, and mentioned multiple times, Mendelian randomization. Now, for those of us that don't think about this every day, could you tell us a little bit what that means? Dr Dipender Gill: Yeah. So, I'll actually give a little bit of background. One of the main limitations of traditional epidemiological research is that any association, it's sometimes difficult to infer causation. They can be confounded by environmental factors, lifestyle factors. In the Mendelian randomization technique, what we do is we use randomly allocated genetic variants to study the effect to an exposure. So, we select these genetic variants because they are related to the exposure of interest. And because these genes are randomly allocated at conception, they're not subject to confounding from environmental or lifestyle factors. Whether you have a gene or not, is not necessarily related to your lifestyle or your environment. And therefore, the association of these genetic variants with certain outcomes isn't subject to confounding. Dr Carolyn Lam: That makes so much sense, and I suppose that, not to allow cause and effect to be determined. So please, tell us, in this particular case of the anti-hypertensive drugs, what did you do and what did you find? Dr Dipender Gill: First, we decided specifically which drugs we wanted to look at, and we thought, actually, let's start off with the most commonly prescribed anti-hypertensive drugs. So, we short-listed these based on recent consensus guidelines, and we looked at ACE inhibitors, beta-blockers, calcium channel blockers, thiazide type diuretics. And then, we went back to various online databases to identify which genes correspond to the target protein of these drugs. We took these genes, and we then identified genetic variants at their specific genetic loci, their specific region of the genome, and we identified the variants in these regions that were also related to systolic blood pressure. And in this way, we inferred that genetic variants, at the protein coding targets of these genes, that were also related to systolic blood pressure, likely represented the effect of variations in these proteins that also implicated blood pressure, and therefore, could serve as proxies, or instruments, to study the effect of these drug targets. We then went ahead to validate the selection of these genetic variants by forming Mendelian randomization, and specifically, we checked whether people that have genetic variants that correspond to, say, ACE inhibitor activity, or beta-blocker activity, or calcium channel blocker activity, if they also have correspondingly lower risk of coronary heart disease and stroke, to the same degree that we would observe in randomized control trials against placebo. And indeed, we found that actually, the results were fairly similar, and this gave us confidence. And studying these genetic variants that mimic the effect of these drugs could be used as a proxy or as a surrogate to study their clinical effect of taking these drugs. So, that was the first phase. Dr Wendy Post: Dipender, congratulations to you and our team. This is a really exciting paper, and the editors were especially interested in the novelty, and the potentially impactful findings, especially of the second part of the study, which I think you'll describe briefly next. And that was using an approach that many who are listening may not have heard about too much before called PheWAS, or a phenome wide association study. And maybe you could tell us briefly what you found in that part of the analysis. Dr Dipender Gill: The first part, it was very cool, because it allowed us to identify versions of genes that corresponded to the effect of these drugs. But in itself, it didn't tell us anything novel. It didn't tell us anything new. So, the real question…

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    Circulation July 16, 2019 Issue Jul 15, 2019
    Show notes

    Dr Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts, I'm Dr Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr Greg Hundley: And I'm Dr Greg Hundley: Hundley, Associate Editor from the Pauley Heart Center in Richmond, Virginia at VCU Health. Well Carolyn, our featured article this week addresses the age at which to initiate clinical screening of relatives for hypertrophic cardiomyopathy. Our guidelines suggest screening of relatives from age ten and onwards but data are lacking to substantiate this suggestion. I look forward to the authors' discussion of their findings regarding initiation of screening in children. For now though, do you have an article that you'd like to share? Dr Carolyn Lam: You bet, Greg. So, the first paper I chose really demonstrates that patients inducible pluripotent stem cells or IPSC cardio derived myocytes can be used as a disease modeling platform to delineate the functional mechanisms that underlie cardiac hypertrophy and in this particular case they looked at Noonan Syndrome and showed that how these techniques can be subsequently used to identify novel molecular and genetic therapeutic targets. So, Greg, here's your quiz. The genetics of Noonan Syndrome. Dr Greg Hundley: I remember it was on our board exam. Dr Carolyn Lam: Let me tell you about it. So more than 90% of patients with Noonan Syndrome have a mutation in the hinge region CR2 domain of Raf-1 and they exhibit severe hypertrophic cardiomyopathy for which there is no treatment. Authors, Dr Jaffrey from Cornell University and Dr Kontaridis from Masonic Medical Research Institute in Utica in New York and their colleagues used Noonan Syndrome Raf-1 patient and CRISPR corrected IPSC cardiomyocytes to recapitulate the Noonan Syndrome cardiac phenotype. These Noonan Syndrome IPSC derived cardiomyocytes exhibited the same hypertrophy and myofibrillar disarray that's really observed in Noonan Syndrome patient hearts, so mechanistically the authors showed that activation of mitogen-activated protein kinase or mech-1 or -2, but not the extracellular regulated kinase, which is ERK1 or 2 triggered abnormal cardiomyocytes structure and conversely ERK5 mediated increased cell size in these Noonan Syndrome mutant IPSC derived cardiomyocytes. RNA sequencing further identified genes dysregulated in the Noonan Syndrome cardiomyocytes that may underlie hypertrophic cardiomyopathy downstream if the mech-1 or -2 and ERK5 genes. Dr Greg Hundley: So, Carolyn, that's a lot of genetic information, so what can I take home as I think about this further and what may come down the line as we manage patients with Noonan Syndrome? Dr Carolyn Lam: Thanks, Greg. The real take home message is that these pathways could serve as novel therapeutic targets to treat hypertrophic cardiomyopathy in patients with Noonan Syndrome and Raf-1 mutations. Overall, the elucidation of rare disease mechanism of hypertrophic cardiomyopathy may further unravel and reveal causes of other more common idiopathic congenital disorders and hypertrophic diseases. Dr Greg Hundley: Oh, very good. Well, I'm going to switch gears and talk a little bit about infective endocarditis prophylaxis and this article comes from Pallavi Garg at the London Health Scientist Center. Carolyn, as you may recall, given the lack of proven efficacy and concerns about the perceived risks of antibiotic prophylaxis like development of antibiotic resistance, the American Heart Association in 2007 and the European Society of Cardiology in 2009 published revised guidelines recommending cessation of antibiotic prophylaxis prior to dental procedures for patients at moderate risk of infective endocarditis while continuing the practice in high risk patients. This Canadian study was conducted from 2002 to 2014 among all adults and those at high and moderate risk for infective endocarditis and they were stratified by age. Prescriptions for antibiotic prophylaxis were obtained from the Ontario Drug Benefit Database for adults 65 and older and outcomes regarding antibiotic prophylaxis prescription rates and the incidents of infective endocarditis related hospitalization were assessed. Dr Carolyn Lam: Ooh, interesting. What did they find? Dr Greg Hundley: The authors found a sustained reduction in antibiotic prophylaxis prescriptions among individuals at moderate risk for infective endocarditis that coincided with the change in guidelines. In contrast, while there was a decreasing trend in antibiotic prophylaxis among individuals at high risk of infective endocarditis and a minimal drop following the guidelines released, the overall rates of prophylaxis prescribing in this group continued to climb since early 2007, and collectively, these findings suggest that appropriate uptake of the revised AHA guidelines occurred. Furthermore, over the thirteen-year study period, the authors identified an increase in hospitalizations for new episodes of endocarditis approximately three years after the AHA guidelines were revised. This timeline along with the rise of endocarditis incidents in both the high and moderate risk groups suggests that this observed increase in endocarditis is likely unrelated to the change in the prescribing practice of antibiotic prophylaxis. This conclusion is further supported by the overall decrease in endocarditis cases attributable to streptococcal infections over time, a finding contrary to what might be expected as a result of the reduction in antibiotic prophylaxis. Dr Carolyn Lam: Oh, very interesting, Greg. At first a little bit scary and then after when you described it more, it does seem a little bit more reassuring. Very interesting. Well, thank you. My next paper deals with functional tricuspid regurgitation, which as you know is really common in heart failure with reduced ejection fraction or HFrEF and mostly consequent to pulmonary hypertension. However, what is the access mortality associate with functional tricuspid regurgitation in HFrEF? Well, this paper from Dr Maurice Serrano from Mayo Clinic and colleagues looked at all Mayo Clinic patients from 2003 to 2011 diagnosed with heart failure stage B and C and an ejection fraction less than 50% who had functional tricuspid regurgitation grading and systolic pulmonary artery pressure measured by Doppler echocardiography. Now among more than 13,000 patients meeting these inclusion criteria, functional tricuspid regurgitation was detected in 88%. Functional tricuspid regurgitation was independently associated with more dyspnea, more impaired kidney function, and lower cardiac output. For the long term outcomes, the higher the degree of functional tricuspid regurgitation compared with a group with trivial tricuspid regurgitation was independently associated with a higher mortality hazard. The five year survival was substantially lower with increasing severity of tricuspid regurgitation so it was 68% on average for trivial functional tricuspid regurgitation versus 34% for severe functional tricuspid regurgitation. Importantly, this access mortality observed with moderate or severe functional tricuspid regurgitation was independent of pulmonary hypertension and any other clinical characteristics. Dr Greg Hundley: Hmm, interesting but Carolyn, wouldn't we expect this? Dr Carolyn Lam: You know what, you may expect it, but this is really the largest series, I think, that has shown this and shown this in the systematic way that functional tricuspid regurgitation in and of itself may play an important pathophysiologic role and thus, may represent a potential therapeutic target in HFrEF. In other words, the present study really advocates for a trial to test treating functional tricuspid regurgitation in patients with HFrEF. Dr Greg Hundley: Oh wow, you really put that in great perspective, Carolyn. Well, your reward is going to be a quiz. Dr Carolyn Lam: Oh my gosh, Greg. Dr Greg Hundley: We're going to talk about ... Dr Carolyn Lam: What now? Dr Greg Hundley: Caveolin-1, an atherogenesis and nitric oxide and this is from Professor Carlos Fernandez Hernando at the Yale University School of Medicine. Okay, multiple choice. What are caveolae? Now I'm going to give you some choices, you get to pick A. Are they crypts within the walls of vessels. B. Crypts within the membranes of endothelial cells. Or C. Crypts within the border zones of infarcts. Dr Carolyn Lam: Wait a minute, Greg. I'm not even sure we're pronouncing it the same. You're asking about caveolae like ... Potato potata. They're invaginations of cell membranes, that's all I know. Dr Greg Hundley: Oh wow, fantastic. This study focused on the effect of Caveolin-1, a protein integral to the formation of caveolae. The investigators found in a series of mouse experiments that A. The athero-protection observed in mice lacking Caveolin-1 is independent of endothelial nitric oxide synthase activation and nitric oxide production. B. Endothelial Caveolin-1 controls lipoprotein infiltration in vascular inflammation in early stage atherosclerotic lesion. C. Endothelial Caveolin-1 promotes pro-atherogenic matrix deposition leading to endothelial cell activation in atheroprone regions of the aorta and finally, D. Atheroprone regions of the aorta are characterized by increased intracellular and basolateral caveolae distribution in endothelial cells compared to athero-resistant areas. Dr Carolyn Lam: Wow, I like the way you broke that down into four points, but could you summarize what it means clinically? Dr Greg Hundley: Yeah, so I think if you had to summarize all of this in a sentence, perhaps the suppression of Caveolin-1 expression in endothelial cells might prevent the progression and promote the regression of atherosclerosis so in the future perhaps an interesting target to treat atherosclerosis. Well, now Carolyn, I guess we should proceed to that talk with our featured discussion. Dr Carolyn Lam: Absolutely. Thanks, Greg. Hypertrophic cardiomyopathy is an inheritable myocardial disease with age-related penetrance. Current guidelines recommend that clinical screening of relatives start from the age of ten years onwards by the European Society of Cardiology and twelve years onwards by the American College of Cardiology or American Heart Association. There are of course caveats for earlier screening but the clinical value of this approach has really not been systematically evaluated. That is until today's feature paper and we are so pleased to be here discussing it. This is Greg Hundley and Carolyn Lam and we're your co-hosts for Circulation on the Run. So happy to welcome Dr Juan Pablo Kaski who's the corresponding author of today's feature paper from Great Ormand Street Hospital in London and we also have Dr Gerald Greil, Associate Editor from UT Southwestern. Welcome, everyone. Juan, if you don't mind, could you start by summarizing this very important study of yours? Dr Juan Pablo Kaski: Thank you very much. Hypertrophic cardiomyopathy is a genetic muscle condition that is characterized by hypertrophy and is most commonly inherited as a dominant trait. Previous studies have suggested that in familial disease at least ventricular hypertrophy doesn't usually present until adolescence and this has led to the current guidelines which do not recommend routine screening of children below the age of twelve according to the American guidelines below the age of ten and the European guidelines for hypertrophy cardiomyopathy but own clinical experience was different and suggested that perhaps sarcomeric disease and familial disease could present in younger children, so what we aimed to do with this study was to assess the validity of this approach and tried to assess the yield of clinical screening in children from families of hypertrophic cardiomyopathy. Dr Juan Pablo Kaski: We took our collective experience in our institution over a period of many years and recruited just on the 1,200 consecutive children all aged less than eighteen years at the time of initial assessment coming from just under 600 families and these were children who were referred for clinical screenings because a first degree relative had been diagnosed with hypertrophic cardiomyopathy. What we found was that in 5% of these children and in fact, in 8% of the families that we screened, we were able to pick up early phenotypic features of hypertrophic cardiomyopathy. In 72% of patients, we made a diagnosis before the age of twelve, so before current clinical screening guidelines we'd recommend and importantly, a third of these patients during follow up had a change in their management as a result of the diagnosis. Their medication was commenced, they underwent procedures or implantations of defibrillators. Dr Greg Hundley: Juan, this is Greg Hundley and I was wondering when did the participants that were enrolled experience events? Did those that were say under fourteen or even under twelve, did they experience events relative to those that were a little older? Dr Juan Pablo Kaski: The events that our participants experienced were relatively few. Many of these occurred during the childhood age but some occurred once the children had transitioned into the adult age. We did look to see whether there was any difference in terms of early diagnosis and subsequent events, but we didn't find anything, we didn't identify two separate populations in that respect. Dr Greg Hundley: And then did you perform genetic analyses? I know you described phenotypic characterization of the patient population but how about genetically? What results did you find there? Dr Juan Pablo Kaski: The main aim of the study really was to determine a yield of clinical screenings, so this is a reflection of a real-world practice where genetic testing may not necessarily be routinely available. Having said that, we did have genetic data in a third of our families and in fact, in maybe 70% of those children who made clinical diagnosis of hypertrophic cardiomyopathy was made and what we find in those individuals who have undergone genetic testing is that the vast majority of those had mutations in sarcomeric protein genes and pathogenic or likely pathogenic variants in sarcomeric genes in just under 70% and these were well characterized mutations that are very similar to those that are seen in adolescence or adult onset hypertrophic cardiomyopathy. I think what was interesting about these genetic results is that we seem to have identified a population of early onset sarcomeric disease that genetically appears to be indistinguishable from a sort of later onset adult disease but with the clinical presentation and natural history curve shifted somewhat to the left. Dr Greg Hundley: Gerald, just switching over, can you tell us some of your thoughts about how the results of this study will impact clinical practice, both in the European countries as well as U.S.? Dr Gerald Greil: I mean, I was obviously delighted to see the study being submitted to circulation because there's a very important message particularly for pediatric cardiologists which is potentially influencing the guidelines and Dr Kaski may comment on this as well as the next step meaning that it seems like screening patients older than ten or twelve years and once again, there's a slight discrepancy between the European and U.S. guidelines, seems to be ... Can be questioned and potentially we should screen these patients earlier. Another amplification of this study is that we should think about how much genetic screening can be an essential tool in our methods in looking at these patients and I want to point out that because of these discrepancies we also initiated an editorial letter for this publication d…

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    Circulation July 09, 2019 Issue Jul 08, 2019
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    Dr Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. I'm Dr Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr Greg Hundley: And I'm Greg Hundley, also Associate Editor from the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr Carolyn Lam: I'm so excited about our feature discussion today, Greg, because it is about a familiar but very important problem of hypertension, and we will be looking at trial results of a new drug, a first in its class type of drug. And tackling a problem that is particularly important perhaps in black patients with hypertension. Well, more very soon. First, let's discuss some papers, shall we? Do you have one? Dr Greg Hundley: My paper is from Joseph Burgoyne from King's College in London and pertains to resveratrol. Now, resveratrol is a non-flavonoid polyphenolic compound that has been found in the skin of several fruits, with the most notable being grapes. The compound exhibits beneficial effects, including the prevention of cardiovascular neurologic diseases, cancer, metabolic syndrome, as well as it promotes bone and eye health. And in this study, the investigative team explains how resveratrol may mediate its numerous beneficial effects including lowering of blood pressure by direct thiol oxidation. Also, they demonstrate that resveratrol can counter-intuitively induce direct protein oxidation, a process that is enhanced under pro-oxidative conditions associated with disease. The oxidation of cyclic GMP dependent protein kinase 1 alpha, or PKG1 alpha, by resveratrol lowers blood pressure in hypertensive mice. Dr Carolyn Lam: Okay. But what does that mean for us clinically, Greg? Dr Greg Hundley: Well, the results demonstrate how blood pressure can be lowered by using resveratrol, and targeting cysteine 42, or PKG1 alpha, may provide a new class of anti-hypertensive agents. In addition, identifying additional proteins modified by resveratrol may provide new targets for therapy to treat cardiovascular disease. Carolyn, how about your first paper? Dr Carolyn Lam: We are going to look at the further results of the ODYSSEY OUTCOMES trial. And as a reminder, ODYSSEY OUTCOMES was a double-blind randomized comparison of the PCSK9 antibody Alirocumab with placebo in almost 19,000 patients who had an acute coronary syndrome 1-12 months previously and elevated at the atherogenic lipoproteins despite intensive statin therapy. And that trial found that Alirocumab reduced the risk of the primary composite outcome of coronary heart disease, death, ischemic stroke, myocardial infarction, or unstable angina requiring hospital admissions. The current paper looked further at the effects of Alirocumab on death. Dr Greg Hundley: So Carolyn, what did they find? Dr Carolyn Lam: Well, there are quite a number of findings here. The first, there were fewer deaths in total that occurred with the PCSK9 inhibitor Alirocumab versus placebo, and this resulted from a non-significantly cardiovascular and non-cardiovascular deaths with Alirocumab. The second finding was that in a pre-specified analysis of more than 8,200 patients eligible for 3 or more years of follow-up, Alirocumab reduced death. And then, the third finding was that patients with non-fatal cardiovascular events were at increased risk for both cardiovascular and non-cardiovascular deaths, and a post-Hoc analysis found that compared to patients with a lower LDL, those with a baseline LDL above 100 had a greater absolute risk of death, and a larger mortality benefit with Alirocumab. In the Alirocumab group, all cause death declined with a lower achieved LDL achieved at 4 months of treatment to a level of approximately 30. So in summary, Alirocumab added to intensive statin therapy, has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for 3 or more years, and if baseline LDL is 100 or more, or if achieved LDL is low. Dr Greg Hundley: That's great, Carolyn. My next paper is going to talk a little bit about endothelial cells. And what I think we're going to learn is that not all endothelial cells are alike. This comes from Dr Rajat Gupta from Brigham and Women's Hospital, and I really thought this was an interesting article that used single-cell RNA sequencing to make it possible to identify and characterize cellular sub-populations. Dr Greg Hundley: The investigative team performed enzymatic dissociation of 4 whole mouse aortas, followed by single-cell sequencing of over 10,000 cells. Dr Carolyn Lam: Wow. What did they find? Dr Greg Hundley: Well using cluster analysis of gene expression from the aortic cells, they identified 10 populations of cells representing each of the main arterial cell types. There were fibroblasts, vascular smooth muscle cells, endothelial cells, immune cells, including monocytes, macrophages, and lymphocytes. And importantly, there were 3 distinct endothelial cell sub-populations with differences in them driven by major functional gene programs including adhesion and lipid handling. Comparison of aortic single-cell RNA sequence data sets from normal and Western diet-fed mice suggested that these sub-populations exist under both dietary conditions and have some unified responses to diet alteration. Also, immunofluorescence using single marker genes to identify endothelial cell sub-populations showed that the VCAM1 positive population was spatially located in regions of disturbed flow like the lesser curve of the aorta. Dr Carolyn Lam: Okay. So bring it home for us, Greg. What does this mean clinically? Dr Greg Hundley: Yeah exactly, Carolyn. So, characterizing functional sub-populations may serve as a novel method for understanding endothelial health in patients with vascular disease. And although aortic endothelial cell sub-populations demonstrate some unified responses to vascular disease relevant stimuli, like a Western diet, functionally different sub-populations may contribute differentially to vascular diseases, enabling sub-population targeted therapies to perhaps be implemented in the future. Dr Carolyn Lam: Cool. So Greg, cardiomyopathies have often been seen as genetic in origin, but what about potentially modifiable causes? So, this next paper that I picked looked at that, and it's from corresponding author Dr Rosengren from Sahlgrenska University in Gothenburg, Sweden, who with her colleagues, sought to investigate a potential link between obesity in adolescence and being diagnosed with cardiomyopathy in adulthood. So, this was a nation-wide register-based prospective cohort study of almost 1 million 690,000 adolescent men who were enlisted for compulsory military service from 1969 to 2005. Now at baseline, body mass index, blood pressure, and medical disorders were registered, along with test results for fitness and muscle strength. Cardiomyopathy diagnosis was then identified from the National Hospital Register and Cause of Death Register. So, they found that during a median follow-up of 27 years, 4,477 cases of cardiomyopathy were identified, of which 59% were dilated, 15% were hypertrophic, and 11% were alcohol or drug-induced. Increasing body mass index, or BMI, was strongly associated with elevated risk of cardiomyopathy, especially dilated cardiomyopathy, starting at levels considered normal, meaning a BMI of 22.5 to less than 25 kilograms per squared meters. And this was even after adjusting for age, years, center, and baseline comorbidities. There was a more than 8 fold increased risk of cardiomyopathy at a body mass index of 35 and above, compared with a BMI of between 18.5 and less than 20. Dr Greg Hundley: So, it sounds like BMI elevations and cardiomyopathies don't go together. So, what are the clinical implications? Dr Carolyn Lam: This really shows that even mildly elevated body weight in late adolescence may contribute to being diagnosed with cardiomyopathy in adulthood. So, the already marked importance of weight control in youth is really further strengthened by these findings, as well as the greater evidence for obesity as a potential important cause of adverse cardiac remodeling that is independent of clinically evident ischemic heart disease. Dr Greg Hundley: Outstanding. So, BMI, not good. Dr Carolyn Lam: Nope, Greg. High BMI, not good. That was fun, Greg. So, shall we move on to our feature discussion? Dr Greg Hundley: Absolutely. Dr Carolyn Lam: For our feature discussion today, we are talking about a familiar problem, but just so very important, and that is hypertension. And guess what? Our feature paper discusses a new first in class centrally-acting renin-angiotensin system blocker that has such remarkable initial results. I am so pleased to have with us the corresponding author for the paper, Dr Keith Ferdinand from Tulane University School of Medicine, as well as our Guest Editor, Dr David Calhoun from University of Alabama and Birmingham. Keith, could you start by telling us a little bit about the kinds of patients you see there in New Orleans that struggles with hypertension control perhaps? And then, please tell us about Firibastat. Dr Keith Ferdinand: I'm in New Orleans. In fact, I'm a native New Orleans. And as you know, most of the south and southeast and part of the United States has a high proportion of African American or US blacks. This population has higher rates of hypertension, increased prevalence, more severe hypertension, and more uncontrolled hypertension. We also note in the south that there tends to be an increase in obesity, which is a powerful risk factor for all patients with hypertension, regardless of race or ethnicity. And unfortunately, the rates of obesity appear to be increasing. So based on the fact that we have an increase in obesity, we have many patients whose blood pressures are not controlled, and some of the previous data have suggested less response to first step or monotherapy with ACE inhibitors and angiotensin receptor blockers, I initiated a trial with a first in its kind oral active brain aminopeptidase A inhibitor. Dr Carolyn Lam: Wow. Could you tell us a little bit more about brain aminopeptidase, and this new drug Firibastat? Dr Keith Ferdinand: Most people don't know anything about this molecule, because this is something that was discovered by some French physiologists. They approached me to design the clinical trial here in the United States. And what it does is, it blocks the conversion of angiotensin II to angiotensin III in the brain. Angiotensin III is actually the active component of the renin-angiotensin system centrally, and if you block angiotensin III production, it has a triple therapy effect. One is that it causes the diuresis. It decreases sympathetic tone, and it stimulates the carotid artery, such that you have, again, a decrease in sympathetic tone. Now, why choose it for patients who are obese, and why want to include a large proportion of non-Hispanic blacks here in the United States? Well, the reasons are that when you look at some of the bench research using rats, it appears to have a more beneficial effect in DOCA-salt rats, which is a model for salt-resistant hypertension. Salt-resistant hypertension is more common in blacks, more common in patients with obesity, and may indeed be one of the reasons why monotherapy or first-step with conventional renin-angiotensin system agents, specifically ACE inhibitors and ARBs, have not been as effective in the past. Dr Carolyn Lam: Gosh. That is so interesting, and it's really making me think about my patients too here in Asia, where we have a lot of salt-sensitive hypertension. Now, could you please tell us about the trial you did, and what you found? Dr Keith Ferdinand: We looked at a cohort of patients. All of the patients were overweight and obese. They were washed out for 2 weeks, and had a systolic blood pressure of 145-170, and a diastolic of less than 105. We wanted to get at least 50% self-identified blacks or Hispanics, and I suspect that any patient who meets this phenotype, and that would include Asians, or even Whites, may respond similarly. We then placed them in an open label format, and I can discuss why we used an open label, with monotherapy with Firibastat. After 2 weeks, we then titrated the dose level from 250 twice daily to 500 twice daily if needed, and we had a low dose thiazide and hydrochlorothiazide 25 mg addition, if needed, for escape, if patients had a blood pressure greater than 160/100. The other thing that was interesting and unique about this particular trial is that we used the automatic office blood pressure, where the blood pressure was taken 6 times. The first time was discarded, and then averaged, without a particular doctor or a nurse being there to do the blood pressure. We felt that this was a valid means of getting blood pressure loaded. It tends to mimic, to a large extent, what you see in 24 hour inventory daytime systolic blood pressure. So, this was a valid means of measuring blood pressure loads. This was a relatively high risk patients. And these were patients whom, previously, probably would not have responded as well to monotherapy with ACE inhibitors or ARBs. Dr Carolyn Lam: That's really clear, and clever design. I would love to hear a little bit more about why the open label, and of course, the results. Dr Keith Ferdinand: Well, that's one of the criticisms of this study, but actually, we presented to the FDA when we were discussing designing this trial, perhaps doing a placebo control trial. And we were told by the FDA that if you use a valid means of measuring blood pressure load, so that would be ambulatory blood pressure, or automated office blood pressure, that a placebo would not be necessary, because those means of checking blood pressure load would be considered a true valid means of finding a blood pressure effect. The other thing is, dealing with minority patients, and really dealing with patients in general, for blood pressure, if they have substantial hypertension, the message has been out there that this is a killer and cause of cardiovascular disease. It would probably have been very difficult to enroll the patients, you've got 254 patients in a national study. It would have been very difficult to enroll these patients, who would have known easily that they had substantial elevation of blood pressure, and we said, "You know, 50% chance you're going to get a sugar pill that has no effect." Dr Carolyn Lam: Right. Right. Very nice. The results? Dr Keith Ferdinand: Well, the results were a robust 9.7 mm reduction in systolic blood pressure. At day 56, the p-value was less than 0.0001. And when you do a sub-group analysis of patients who were in the study, it was effective for persons who are under 65, or over 65, male or female. All patients were overweight, and the patients who were obese, with a BMI of 30 or above, had a trend towards even a better blood pressure effect, which again, is not seen with first step with conventional ACE and ARBs. We also did an analysis based on black and non-black, and there was no difference, again with the trend towards the black patients actually doing fairly well. So, the take home from the particular study was this is the first in its kind, new approach to central Ras blockage with aminopeptidase A inhibitor, that was effective in a population which was overweight and obese, with over 50% minority, and showed substantial blood pressure reduction using a valid means of checking blood pressure, the automated blood pressure in the clinic. Dr Carolyn Lam Keith, congratulations. A very important study. David, could I bring you in here? What were your thoughts as you were managing this paper, and what do you think are the future steps here? Dr David Calhoun: Looking at the su…

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    Circulation July 2, 2019 Issue Jul 01, 2019
    Show notes

    Dr Greg Hundley Welcome back everyone from our week hiatus for this July 2nd issue of Circulation On the Run. I'm Dr Greg Hundley, from the Pauley Heart Center at VCU health in Richmond, Virginia. Dr Carolyn Lam: And I'm Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. So good to be back, Greg. Dr Greg Hundley Absolutely. So Carolyn, our featured articles going to focus on amyloid and transthyretin amyloid is recognized in middle age and older individuals with increases in LV mass and heart failure. And in our featured article from the United Kingdom, Dr Gilmore and colleagues are going to discuss the natural history of this disease and compare outcomes of those with acquired versus hereditary forms of the disease. But before we get to that interview, how about we discuss several other original articles? Dr Carolyn Lam: For sure, Greg. Thanks. I want to pick two genetic papers in this issue. They're really exciting. The first one is actually the first study to consider the association between rare genetic variance in a large set of cardiomyopathy genes and the occurrence of cancer therapy induced cardiomyopathy. So this paper is from co-corresponding authors, Dr Garcia-Pavia from hospital Universitario Puerta de Hierro from Madrid, and Dr Christine Seidman from Harvard Medical School in Boston, Massachusetts. The authors studied 213 patients with cancer therapy induced cardiomyopathy from three cohorts. The first retrospectively recruited adults with diverse cancers, the second prospectively phenotyped breast cancer patients. And then the third prospectively phenotyped children with acute myeloid leukemia. They showed an increased prevalence of rare variants in cardiomyopathy genes, particularly the truncating variants of the TTN gene in both adults and pediatric cancer patients with cancer therapy induced cardiomyopathy. They confirmed the human genetic data with experimental analyses showing that anthracyclines induced protracted left ventricular dysfunction in mice with truncating variants of TTN genes but not in the wild type mice. Dr Greg Hundley Aha. So what are the clinical implications of this study, Carolyn? Dr Carolyn Lam: Well, the findings show that variance in cardiomyopathy genes contribute to cancer therapy induced cardiomyopathy susceptibility among adult and pediatric cancer patients. And thus the identification of genetic risk factors really opens the door to new opportunities to define patients at high risk of cancer therapy induced cardiomyopathy and associated adverse outcomes. I want to go onto the next paper because it's so related. It's another genetic paper. This time looking further at the truncating variants of the TTN genes and a very novel approach, they aim to assess a genomics first approach to assess the consequences of these TTN variants. So, this was from corresponding author Dr Zoltan Arany from Perelman School of Medicine in University of Pennsylvania where he and his colleagues reviewed whole exome sequence data for more than 71,000 individuals to identify anyone with truncating variants of TTN genes. They further selected individuals with these variants in exons highly expressed in the heart and using a linked electronic health record, they evaluated the associations of these truncating variants of TTN genes with the diagnosis and quantitative echocardiographic measures. They also reviewed data from the Jackson Heart study to validate specific analyses for individuals of African ancestry. Dr Greg Hundley Interesting. So we're hearing a little bit about different ancestry and TTN genes. What did they find? Dr Carolyn Lam: So, I should have first clarified that that first look was in individuals of European ancestry. And they found there that the individuals of European ancestry identified through this genomics VERSE approach had a much greater odds of developing dilated cardiomyopathy and had lower left ventricular function than their peers, whether or not a clinical diagnosis of dilated cardiomyopathy was present. They also found that the association of the TTN variants and dilated cardiomyopathy was much weaker in individuals of African ancestry. So in summary, truncating genetic variants of TTN had a measurable effect in large clinical populations with respect to both strong associations with cardiomyopathy and with associations with quantitative differences in cardiac structure and function. Given the caveat though, that these association appeared strongest in individuals of European ancestry. So Greg, what did you have? Dr Greg Hundley Well, Carolyn, the overlap of inflammatory processes operating in atherosclerosis and the rich presence of macrophages within plaques make macrophages a strong candidate for therapeutic targeting in atherosclerosis. And so this study comes from Levent Akyürek at the Institute of Biomedicine and involves targeting filament A to reduce macrophage activity in atherosclerosis. So filament A is a large actin binding protein that has been implicated in atherosclerosis and this study tested the hypothesis that targeting filament A in macrophages would impair atherosclerosis in vivo in mice and the investigators evaluated the expression of filament A in human atherosclerotic plaques. Dr Carolyn Lam: Huh, interesting. So what did it show? Dr Greg Hundley: Well, in humans, expression of filament A is increased in macrophages and advanced atherosclerotic plaques of human carotid arteries. In mice, in the absence of filament A, macrophages displayed impaired migration, proliferation and lipid uptake and secreted lower levels of inflammatory IL 6, also lack of filament A and macrophages in vivo reduced aortic plaque size and atherogenic mice. There were additional mechanistic findings and that the C terminal fragment of Filament A produced by calpain cleavage regulated IL 6 secretion in macrophages and treatment with calpeptin, which inhibits calpain cleavage, reduced aortic plaque size and atherogenic mice. And so therefore, filament A might serve as a prognostic biomarker and atherogenesis and perhaps targeting the C terminal proteolytic fragment of filament A could be a strategy to reduce inflammation and atherosclerotic plaque development. Carolyn, I've got another paper, but guess what? This one has our first quiz of the academic new year. This is a paper about Nexclin, and it discusses a new component of junctional membrane complexes required for cardiac T-tubule formation. The corresponding authors are led by professor Zhou Shen from the University of California, San Diego. So, Carolyn in this quiz, what is a T-tubule? Dr Carolyn Lam: Greg, that is mean! T-Tubules, something inside the cell. Something to do with membranes folding over. Dr Greg Hundley Yeah, you know this is one of those, it's not multiple choice. It's an open ended question. You need your little blue book. You've got to write the answer. So T, or transverse, tubules are extensions of the cell membrane that penetrate into the center of cardiac muscle cells and interact with the sarcoplasmic reticulum to facilitate calcium release and thus help modulate myocardial contraction. T-tubule uncoupling and remodeling are known features of heart failure. Dr Carolyn Lam: Alright, so that's T-tubules. Guess what Greg, I'm going to ask you before you ask me. So, what's Nexilin? Dr Greg Hundley I read the paper like a good student of the American Heart Association. This was answered by the investigative team of Chen and his associates. Nexilin has been identified as an actin binding protein and multiple mutations in the nexin gene are associated with cardiac diseases. In this study, Nexilin was required for initiation of T-tubule invagination and overall T-tubule formation, with a loss of next sullen leading to impaired calcium handling. Clinically, these results identified Nexilin as a new possible target for T-tubule remodeling and provide mechanistic insight into molecular pathways leading to cardiomyopathy in patients with mutations in Nexilin. So Carolyn, great job on our first quiz of the academic new year. And how about we move on to that featured discussion? Dr Carolyn Lam: Absolutely. Dr Greg Hundley Welcome everyone to our featured article discussion on this July 2nd and we are going to discuss with Dr Julian Gilmore from London, and our editor Dr Justin Grodin from Dallas, regarding amyloid. And Julian, I understand this particular study you have investigated a natural history of transthyretin amyloidosis cardiomyopathy. Can you tell us a little bit about transthyretin amyloid as opposed to light chain amyloid? And then also I think there's two types of transthyretin amyloid, both a hereditary and then a wild type. Dr Julian Gilmore: Amyloidosis is a disorder of protein misfolding, and there are in fact many different proteins that can misfold and form amyloid fibrils. When they form fibrils they become insoluble and tend to build up and cause damage to whichever organ they're depositing in. Two of the proteins that form amyloid fibrils in humans in vivo are transthyretin, known as TTR for short, or immunoglobulin light chains, known as immunoglobulin light chains, and those two proteins cause transthyretin amyloidosis and AL amyloidosis or immunoglobulin light chain amyloidosis respectively. Those are the main two types of amyloid that affect the heart or cause a cardiomyopathy and they behave very differently in terms of their natural history in that AL amyloidosis is a very aggressive, rapidly fatal cardiomyopathy if untreated. Whereas cardiac transthyretin amyloidosis tends to be a more gradual albeit progressive cardiomyopathy. Transthyretin amyloidosis, as you alluded to, can either be acquired, known as wild type or hereditary and in the hereditary version it's associated with mutations in the transthyretin gene of which there are more than 130 now that are recognized to cause disease. The wild type version of the disease, the non-hereditary version of the disease, is now an increasingly recognized cause of heart failure, mainly in older individuals and particularly older males. And the hereditary version essentially remains a rather rarer disease, although the mutation that is associated or it is associated with a risk of developing this disease occurs in certain populations and in particular occurs in 4% of people of African descent, as a particular genetic mutation that occurs in 4% of individuals of African descent. So and that is associated with risk of developing this hereditary transthyretin cardiomyopathy. Dr Greg Hundley: And so, there's the UK National Amyloidosis Center. Tell us a little bit from that center, what did you do with this particular study in terms of its design and what were your results? Dr Julian Gilmore: Essentially the UK National Amyloidosis Center is the single center in the UK, which is commissioned centrally to diagnose and type, stage, and provide treatment FYS for patients with amyloidosis. And that includes all parts of amyloidosis. We studied a large number of patients with cardiac transthyretin amyloidosis, so cardiac ATTR amyloidosis, who referred to our center and studied them longitudinally, if you like, over the course of many years. So this was a natural history study for a condition for which at the time of the onset of the study and until the end of the study there was no disease modifying treatment and essentially what we found is that there was a great delay in diagnosis amongst most patients diagnosed with the disease and in fact the median number of attendances in hospital for patients diagnosed with the disease before they were actually diagnosed with 17 which is quite amazing and unsurprisingly in a gradually progressive disease, by the time they were diagnosed, their quality of life was very poor. We found that their quality of life symptoms gradually progressed and that they became more and more functionally impaired and had relatively poor survival with a median survival of somewhere in the region of five years. What we did find is that patients with a particular type of hereditary, ATTR amyloidosis, the type that I alluded to earlier, the mutation for which is present in 4% of people of African ancestry, he planted the V122I mutation. Patients carrying that particular mutation actually have more aggressive disease and survive for shorter than patients with the wild type disease. So, 17 hospitalizations before diagnosis and the proceeding three years. Were there factors in your study that you could identify that we should now be looking for to try and make this diagnosis earlier? Absolutely. So one of the reasons for not diagnosing the condition is basically the poor sensitivity and specificity of echocardiography, which is generally the first investigation that a cardiologist will request when a patient presents with symptoms of heart failure. There are some particular features on echocardiography that can provide clues such as strain measurement on tissue doppler imaging, where one can get a bullseye pattern, that's been reported in the literature. So there are particular features on echocardiography that one can look at to increase the chance of picking up this disease. And in particular the big increase in the number of diagnoses over recent years has been because of cardiac MRI scanning, which has become an increasingly used tool for the investigation of heart failure in which one gets a very characteristic picture of late gadolinium enhancement when it's performed in a patient with cardiac amyloidosis, which immediately triggers people to think, ah, here it is, we've got amyloid. And the other sort of novel diagnostic technique as being bone scintigraphy. In the UK we use a bone tracer called DPD and in the US a bone tracer called PYP, and those bone tracers have exquisite sensitivity for cardiac amyloidosis. So if one injects these tracers in a patient with cardiac amyloidosis one gets cardiac uptake into the heart, which can't really be missed on a planar scan. So those two techniques basically, the increasing needs of cardiac MRI and the increasing use of bone scintigraphy to investigate patients with heart failure have resulted in a great increase in the number of diagnoses. The last thing to say is that a huge proportion of patients with amyloid or transthyretin amyloid cardiomyopathy have actually had carpal tunnel syndrome previously. The median time from carpal tunnel syndrome to presentation with heart failure is about seven years, but that is another red flag, if you like, that ought to at least trigger a doctor to think could be amyloid. A thick walled heart in the context of someone whose had previous carpal tunnel syndrome. So there are a few clues there as to how one might make an earlier diagnosis, which is absolutely necessary given the nature of our data, sharing the delays that I outlined down here. Dr Greg Hundley And Julian, last quick question before we get with Justin here. In your data, can you describe for us the importance of that earlier diagnosis related to long-term outcomes as opposed to the group that was diagnosed much later, you know, beyond your median. What was the difference in prognosis in those two groups? Dr Julian Gilmore: There is no doubt that if patients are diagnosed earlier, they survived for longer, reflecting the natural history of the disease. So these patients, as I mentioned earlier, did not receive any disease modifying therapy and we did divide the patients into pre 2012, when patients were essentially diagnosed by endomyocardial biopsy, or the vast majority of them were diagnosed by endomyocardial biopsy, and post 2012 by which time most patients were diagnosed via an imaging, if you like, algorithm that we published in 2016 in the same journal in circulation. And the patients who were d…

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    Circulation Subspecialty Journal's Editors-in-Chief June 2019 Jun 24, 2019
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    Dr Amit Khera: Welcome to Circulation On The Run. Our weekly podcast summary and backstage pass to the Journal. I'm Dr Amit Khera, associate editor and digital strategies editor from UT Southwestern Medical Center in Dallas, and I had the distinct privilege of standing in for Dr Carolyn Lam and Greg Hundley this week. Twice a year, we are very fortunate to have some unique podcasts when we don't have circulation issues, and in the past we've met with many fellows in training and heard about some interesting studies that they're doing. Today we have a very special podcast we have not done before, and that is one where we had the opportunity to learn about our Circulation Family of Journals, and more importantly to hear from the dynamic editors in chief of these various journals. I think you're really going to enjoy it, we'll walk through and hear from each one of them, hear about some of the innovative things that are happening, some of the future that they see for their journal in their field, and I really enjoyed it, and I'm sure you will as well. So, without further ado, we'll start with our first editor. Dr Sunil Rao: I'm Sunil Rao. I'm an intervention cardiologist at Duke, and I'm the Editor-in-Chief for Circulation Cardiovascular Interventions, which is one of the daughter journals of the Circulation Family. We publish articles really related to the broad spectrum of interventional cardiology, from coronary interventions to peripheral arterial disease, and Endovascular interventions to structural heart disease interventions. We also published review articles in all of those areas, as well as any health policy or outcomes studies that are in that space. Dr Amit Khera: Tell us what are some of the innovative things that your journal is doing this year. Dr Sunil Rao: We're really excited about two things, one is our extremely successful Assistant Editor program that we launched last year at A.H.A. 2018. This is a program where we have five early career individuals that are within five years of completing their fellowship program who joined the editorial team at Circulation Cardiovascular interventions, and in that role they really learn a lot about the mechanics of how scientific publishing works, they commit to doing manuscript reviews, and receive feedback on improving their peer review process, and even independently handles some manuscripts as well, that are in their areas of interest. This is our way, I think, of encouraging the next generation to stay engaged with science, and with the scientific publishing process. It's been extremely successful. Assistant editors are part of our team for a two year term. So, in 2020, we will be selecting the next class of assistant editors, and after their term is ended, they join our editorial board as editorial board members. So, we're really excited about that, it's been an overall positive experience, for I think everybody involved. The second thing that we're really excited about is that we launched a social media presence for the journal, which it previously did not have. So, we have a very active Circulation Cardiovascular Interventions Twitter handle, I encourage all the listeners to join Twitter if you're not on Twitter, and if you are on Twitter please follow at Cirque intervened. It's " at C.I.R.C.I.N.T.V.". That is the official Twitter handle for our journal. Dave Fishman is our social media editor, and Chadi Alraies is our assistant social media editor, and we're not just tweeting out the articles, and providing summaries when the papers get published, we're holding Twitter journal clubs once a month ,and these have been extremely successful, it's an hour long Twitter journal club where the discussion gets very intense, and there's a lot of back and forth. We try to have the authors on as well, so that they can explain the rationale for their study, some of the challenges that they face when they are doing the study, and hopefully provide some implications for clinical practice, and what the next steps are. That's a way for us to engage our readership, it's almost a form of post publication peer review, which I think is becoming very popular. In addition, remember we don't have a print format of our journals, so this is a way to get the readership more engaged with the Web site, and to come to our website and learn what elsewhere publishing, and how they can get involve with the Journal as well, both as authors who submit their work, or if they want a peer review for us, please contact us and let us know. Dr Amit Khera: I really love hearing about the Twitter journal club, I know that they are well received, and certainly getting a lot of traction. Tell us about what initiatives or topics you're most excited about this year, and maybe some things that are coming later in the year. Dr Sunil Rao: We're really excited about the big areas in interventional cardiology, which are coronary physiology, we've published quite a few papers on looking at different physiological parameters, and how they can drive the appropriate use of PCI and how that affects outcomes. I think that's going to continue to be a huge topic over the next year, Certainly such a heart disease has exploded, and with the data on low risk patients undergoing TAVR, and having really good outcomes, we're seeing a lot more submissions in the low risk TAVR space, the other area that's really exploding right now is Mitral and Tricuspid Valve Interventions, one of the areas that I think has seen a tremendous amount of device innovation. So, we're seeing a lot of submissions from really high quality papers in that space, but I think it's also important to note, that unlike previous iterations of the Journal, we're actually having a review article, we're trying to have a review article every month on a major area that is burgeoning, so that the readership can understand the overall lay of the land, with respect to evidence, how that guy's clinical practice, and what's coming next. So, we've published quite a few review articles already, and there are more to come, and I think that's a really important way for the readership to keep current with what's going on in Interventional Cardiology. Dr Amit Khera: What about the advancing aspects of your subspecialty? There's so much going on in interventional cardiology, it's a bit dizzying, just tell us a little bit about some of the ways that your journal's helping advance that mission, not just now but perhaps in the future. Dr Sunil Rao: I think one of the challenges that we have at Interventional Cardiology, and maybe this is true across Cardiology, is that the evidence is developed very rapidly, and oftentimes it almost seems like the field is lurching back and forth in certain areas, a prime example of that is the drug coated balloon controversy for Peripheral Interventions. The Journal Of The American Heart Association published a meta-analysis, showing that there may be an association between the use of these devices and increased mortality, that has led to a lot of discussion in the interventional community, and quite frankly I think there's a fair amount of confusion out there about whether we should be using these devices, should we put a moratorium on these devices, is the signal real, if it is, what's the mechanism of death. So, a lot of conversation around that, in fact, it's led to what's going to be a focused FDA meeting in June, specifically on the drug coated balloon controversy. Where I see our journal playing a role is really in trying to, not only publish the latest science, which is rigorous in the field for controversial topics such as this, but also to help provide some context for that science, and I think our integrated strategy of original science review articles, and social media really helps us to communicate with the readership, and with the Interventional Cardiology community writ large, meaning not just physicians, but also Cath lab staff, nurses, noninvasive cardiologists who obviously have patients who are undergoing interventions, and even policymakers, to keep them abreast of what's going on, so that they can have the same level or base of knowledge, so that the conversation is on a level playing field. Dr Amit Khera: Okay, well you heard it from Dr Sunil Rao. Thank you for your time. Dr Kiran Musunuru: I'm Kiran Musunuru, I'm the outgoing Editor-in-Chief of Circulation Genomic and Precision Medicine. Let me start by saying a little bit about the content of the journal, it considers all types of articles related to, as the name implies, Genomic and Precision Medicine, and more specifically, Clinical Genetics, the molecular basis of complex cardiovascular disorders, considered at a variety of levels, that can include a lot of different, what we would call Omics Techniques, from Genomics to Transcriptomics, Proteomics, Metabolomics, Metagenomics, and, so forth. It also deals with big data applications, that includes Electronic Health Record Data, Patient generated data combined with any of the things I've already mentioned, Genome Wide Association Studies, Pharmacogenomics, Gene Therapy, Therapeutic Gene Editing, Systems Biology. So, it's a pretty comprehensive look at all the various topics that would fall under the rubric of Genomic and Precision Medicine. Dr Amit Khera: Now, Dr Musunuru, you mentioned the outgoing Editor-in-Chief, let's introduce the incoming Editor-in-Chief, Thatcher Christopherson Semsarian. Dr Chris Semsarian: I'm the incoming Editor-in-Chief. My name is Chris Semsarian, I'm a cardiologist at the Royal Prince Alfred Hospital in Sydney, Australia. Dr Amit Khera: What are some of the innovations you and the Journal are doing this year, or, what are some of the things you see coming in the future? Dr Kiran Musunuru: Something I'm very excited about, is that we are just starting a pilot project with the American Heart Association's Institute for Precision Cardiovascular Medicine. The institute has a very nice platform called the Precision Medicine platform, and, in brainstorming last year, we realized there was a very nice opportunity to try to create a new type of journal article. There's also a big move in science nowadays to improve transparency, and rigor, and reproducibility, especially in science. The idea being that ideally other investigators should be able to take one team's work, and be able to run through the entire analytical process, and reproduce the original findings, and perhaps even find ways to improve upon those original findings, and, so we realized working with the institute's Precision Medicine Platform, we had the opportunity to actually make a new type of article, we think of, as the paper of tomorrow, a virtual article. The idea would be, that we would have primary data on the Precision Medicine Platform, the analytical tools used to process the data would also be on the Precision Medicine Platform, the analytical plan, in the form of a so-called Jupiter notebook, that basically takes people step by step through exactly which tools were used in which order, in which way, with which parameters, would be on the Precision Medicine Platform, and then there would be some verbal explanation, some background, to explain the context of these analysis, and to really put it into perspective, as how it fits into the body of literature, and so the idea would be, this would live on the Precision Map Platform in a virtual format, and then anyone else who is interested in this work could come, and actually directly interact with the data, and the tools, and the analytical plan, and could actually rerun the entire papers work from scratch, thus reproducing it, and then could actually tweak the analytical plan, or install tools of their own, and be able to build upon the work that had already been done. It's a very different way of thinking about journal articles, more as living entities rather than static work that just lives on a page, and is there as reported, and then never has an opportunity to be fully produced or improved upon. Dr Amit Khera: There's so much happening in the space of genomics, and obviously, we hear the word "Precision Medicine" so commonly. Tell us a bit about how your journal in specific is advancing the mission of your area. Dr Kiran Musunuru: I'll say a little bit, and then maybe turn it over to Chris, give his perspective as the incoming Editor-in-Chief. I think it's a vibrant field, but it's also a very new field, it's evolving rapidly, and I think the Journal has a very important role to play, and not only reporting the results that are coming out of studies in this field, but actually having a role to play in helping to shape the field, helping to define the field, it's very exciting, it's very much in rapid evolution. Just ten years ago or so, when the Journal first started, we were just starting to see the first Genome Wide Association studies, and now we've gone so far beyond that. Now, again, we're talking about these large bio banks, we're talking about Precision Medicine, we're talking about applying this information in health care, we're talking about combining all of these various streams of data and many levels to be able to do studies, that are, I would even say, exponentially advanced beyond what we able to do just ten years ago, and so, it's very exciting times for the journal, then maybe I can ask Chris to share his thoughts on that. Dr Chris Semsarian: Yeah Kiran, I mean, it's a great honor system to follow in your amazing footsteps, and what you've done for the Journal, and as the incoming Editor-in-Chief, I really want to sort of try, and build on the platform that you've established over the last few years, and really, one of the areas that I'm particularly interested in is the area of Translation of Genomic Findings. I mean, ultimately what we do in our lives, as clinicians, is to help patients improve diagnosis, to improve the treatment of these patients, and to be able to do studies with very basic understanding of how our genomes work, and how Narcotic Genes interact, and translating those findings into these improved diagnostic approaches, and even in guiding management is really exciting, I think, in terms of clinical medicine, and improving patient care as we look ahead. I really want to be able to continue to publish really, state of the art, novel, innovative, research areas, that you've already covered, Kiran, which would lead to better care of our patients, who are ultimately the beneficiaries of this type of amazing work. So, I'm really excited looking at the Journal, it's a tremendous area of interest and research, where there's twenty-two thousand genes approximately now genomes, and we really don't understand most of them in terms of their intricate function, and I figured it's a great time ahead, in terms of Precision Medicine. Dr Amit Khera: Okay, well, that was Dr Kiran Musunuru, and Christopher Semsarian, we appreciate both of your time today for Circulation on the Run. Dr Paul Wang: I'm Dr Paul Wang, I'm the Editor-in-Chief of Circulation Arrhythmia and Electrophysiology. Our Journal covers really the expanse of our field, going from basic mechanisms of arrhythmias, so very basic science work, to really clinical practice, clinical outcomes, to population based studies, and genetic based considerations in our field. So, we really feel we encompass the entire range, and there really isn't any topic within our area, that we don't feel is outside our realm. Dr Ami…

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    Circulation June 18 Issue Jun 17, 2019
    Show notes

    Dr Gregory Hundley: Welcome everyone to the June 18th edition of Circulation on the Run. I am Dr Greg Hundley, Professor of Internal Medicine and Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. In today's issue we're deviating from our common format due to some scheduling difficulties. So, rather than our traditional coffee chat in this program I'm going to have a large gulp of coffee and present results from several exciting papers. Then we'll turn over the second half of our program to Dr Carolyn Lam for our feature discussion. Now, I promise this is a one-time deviation and we will return to our common chat format in early July. But, before I launch into my presentations I did want to introduce what will transpire with Carolyn. She will be discussing an exciting paper from the Adelaide Medical School at the University of Adelaide in Australia. Some have wondered whether the persistence of a patent arterial venous fistula post-kidney transplant may contribute to ongoing maladaptive cardiovascular remodeling. To address this issue Carolyn will be discussing with authors whether ligation of this AV fistula may reverse this maladaptive remodeling. And like you, I'm excited to listen to that discussion. But before that let me review several of the other distinctive papers on this issue. The first one is entitled "Individual Treatment Effect Estimation of Two Doses of Dabigatran on Stroke and Major Bleeding in Atrial Fibrillation." They are the results from the RE-LY trial. The corresponding author is Professor Frank Visseren from the University Medical Center of Utrecht in Utrecht University. The study emanates from the randomized evaluation of long-term anticoagulation therapy or the RE-LY trial. In which high dose dabigatran, that's 150 milligrams twice daily, was found more effective in prevention of ischemic stroke and systemic embolism than low dose dabigatran which is 110 milligrams twice daily. But this occurred at that expense of an increased risk of gastrointestinal bleeds. Importantly however, the absolute treatment effect of dabigatran in both doses, likely differs between individuals. And therefore, individual treatment effect estimation has the potential to identify patients who have a favorable trade off and absolute benefit and harm from dabigatran compared with no treatment, and to select the optimal dose for each individual patient. So in this study, the investigative team derived and validated a prediction model for ischemic stroke and systemic embolism and major bleeding in patients with atrial fibrillation from three treatment arms of the RE-LY study. They had 11,955 individuals in the derivation cohort and 6,158 in the validation cohort. And they evaluated the patient characteristics of sex, age, smoking, anti-platelet drugs, prior vascular disease, diabetes, blood pressure, estimated glomerular filtration rate, and hemoglobin. Dr Gregory Hundley: Well, what were the results? Well the five-year absolute risk reduction, for ischemic stroke and systemic embolus minus the five-year absolute risk increase for major bleeding, when comparing the high to the low dose of dabigatran yielded a net benefit in 46% of patients. And therefore, the authors conclude that the absolute treatment benefits and harms of dabigatran in atrial fibrillation can be estimated based on readily available patient characteristics. And perhaps down the road such treatment effect estimations can be used for shared decision making before starting dabigatran treatment and to determine its optimal dose of administration. Well, how 'bout that? And let's go on to the second paper entitled "Empagliflozin and the Risk of Heart Failure Hospitalization in Routine Clinical Care: A First Analysis from the Empagliflozin Comparative Effectiveness and Safety, or EMPRISE Study. And the corresponding author for this study is Elisabetta Patorno from Brigham and Women's Hospital in the Harvard Medical School. So, as a background in a different study to this, the EMPA-REG OUTCOME trial showed that Empagliflozin an SGLT2 inhibitor was found to reduce the risk of hospitalization for heart failure by 35% on top of standard of care in patients with Type 2 diabetes and established cardiovascular disease. Well, the current study, The Empagliflozin Comparative Effective and Safety or EMPRISE Study was designed to assess empagliflozin's effectiveness, safety, and health care utilization in routine care from the period of time between August of 2014 through September of 2019. And the author's report on the first interim analysis in which they investigated the risk of hospitalization for heart failure among Type 2 diabetic patients initiating empagliflozin vs. sitagliptin. The investigators used two commercial and one federal Medicare claims data source from the U.S. and identified a one-to-one propensity score matched cohort of 16,443 pairs of Type 2 diabetes patients that were greater than 18 years of age initiating empagliflozin or sitagliptin. The average age of the participants was approximately 59 years. And almost 54% of the participants were males and approximately 25% had records of existing cardiovascular disease. So compared to sitagliptin the initiation of empagliflozin decreased the hospitalization for heart failure risk by 50% over a mean follow-up of 5.3 months. And the results were consistent in patients with and without baseline cardiovascular disease for both the empagliflozin 10 milligram or 25 milligram daily dose. Or analysis comparing empagliflozin vs. dipeptidyl peptidase-4 inhibitor class all comers. Thus, in conclusion, in this first interim analysis from EMPRISE, the investigative team showed that compared with sitagliptin the initiation of empagliflozin was associated with a decreased risk of hospitalization for heart failure among patients with Type 2 diabetes as treated in routine care with and without a history of cardiovascular disease. Dr Gregory Hundley: Well, now we're going to turn our attention to red meat. And this next study was entitled, The Consumption of Meat, Fish, Dairy Products, Eggs, and Risk of Ischemic Heart Disease. It's a Perspective study of 7,198 incident cases among 409,885 participants in the Pan European Epic Cohort. And the corresponding author is Professor Timothy Key from The University of Oxford. Some of the background here, met analysis of previous prospective studies have suggested that intake of processed meat maybe associated with a higher risk of ischemia heart disease whereas, unprocessed red meat might not. For dairy products and eggs, systematic reviews of prospective studies have reported no consistent evidence that higher intakes are associated with a higher risk of ischemic heart disease. Other studies have shown that fatty fish consumption may reduce the risk of ischemic heart disease, it is a rich source of long chain N3 fatty acids. And meta-analysis has suggested even an inverse association between overall fish consumption and mortality from ischemic heart disease. So, hear in this cohort: we're going to evaluate all of these. Accordingly Key, and his co-authors report the relationships of these foods with risk of ischemic heart disease in the European prospective investigation into cancer and nutrition, the EPIC study, and that again is a cohort of a half million men and women from nine European countries followed for 12 years to examine the association between the intake of animal foods and the occurrence of ischemic heart disease. The author's found that higher consumption of red, unprocessed and processed meat was positively associated with the risk of ischemic heart disease. None of the other animal foods examined were positively associated with this risk. And intakes of fatty fish, yogurt, cheese and eggs were modestly, inversely associated with the risk. In addition, the red and processed meat were associated with plasma non-HDL cholesterol and systolic blood pressure. And this finding is of interest as possibly these other variables could serve as mediator of the association between red or processed meat and future ischemic heart disease. It is important to note that while these results are of interest to those concerned with the future adverse cardiovascular effects related to the consumption of red meat, one cannot infer causality and other studies would need to be designed to address causal relationships. The last paper that I'm going to present during the coffee gulp, emanates from the basic science arena. And it is entitled The "Shear-Induced CCN1 Promotion of Atheroprone Endothelial Phenotypes and Arthrosclerosis. And the corresponding author is Dr Fan-E Mo from the National Cheng Kung University College of Medicine. Dr Gregory Hundley: The matricellular protein CCN1 has been implicated in arthrosclerosis based on its expression in arterial segments with evidence of arthrosclerosis. And this study evaluated the relationship between sheer stress, both laminar and oscillatory at the site of atherosclerotic liaisons and molecular markers of pathophysiologic process involved in the progression of arthrosclerosis. The authors found that sheer induced CCN1 and its receptor integrin, alpha six, beta one, instigate atheroprone phenotypic changes in endothelial cells via activating NF kappa beta. Because the activation of NF kappa beta further up regulates the expression of CCN1, alpha six, and beta one, atheroprone flow creates a positive feedback to sustain atherogenesis. In addition, disrupting CCN1, alpha 6 beta one engagement by a specific CCN1 mutation, or by a peptide antagonist unhindered atherogenesis in mice. So what are the clinical implications of these findings? That's something Carolyn would ask me. Well, it appears that CCN1 alpha 6 beta one engagement represents a novel therapeutic target for arthrosclerosis. These data demonstrate a causative role of CCN1 in atherosclerosis via modulating endothelial phenotypes. And CCN1 binds to its receptor integrin alpha 6 beta one to activate NF kappa beta, thereby instigating a vicious cycle to persistently promote atherogenesis. Perhaps in the future T1 me medics may further be optimized to treat arthrosclerosis. Well everyone, that concludes the first portion of this June 18 edition of Circulation on the Run and now it's time to move on to Carolyn's discussion of our featured paper. Dr Carolyn Lam: Cardiovascular disease remains the major cause of death in kidney transplant recipients. And today's featured paper has important implications for the management of this cardiovascular risk following kidney transplantation. I'm so excited to be discussing it, and I'm going to let the corresponding author Dr Toby Coates from Royal Adelaide Hospital tell us all about it, and so happy to also welcome our editorialist Dr Patrick Mark from University of Glasgow. Toby, could you please tell us what inspired you to do this remarkable study? Dr Toby Coates: We're very interested in obviously our patients surviving as long as they possible can after kidney transplantation. And we noticed that many of them having had a successful kidney transplant, still had functioning AV fistulas. Now of course the AV fistula, is a connection between the artery and the vein that enabled us to access the circulation after hemodialysis. Which around the world is probably the most, is the most common form of dialysis practice performed. So many of these patients sustained 20 years down the track after successful transplants still had these very large functioning left to right shunts, on the basis of their dialysis history. So we had a couple of patients who developed quite severe cardiac failure and we noticed that when we ligated the AV fistula, their back got dramatically better. So, as a consequence of that, we went to look at the ligature and we couldn't find any randomized control trial that told us what the best thing was to do, post-transplant with these fistulas. So we decided that what we would do be use the state of the art cardiac magnetic resonance imaging, or cardiac MRI to assist the cardiac function with myocardium thickness in our patients and then randomize a group of stable transplant patients to ligation or not. And then follow that up with cardiac MRI six months down the track to see what happened. And so that was the basis of the study that we performed. The first randomized controlled trial of the effect of ligation of the AV fistula on the left ventricular mass, that was the prominent one for trial. Dr Carolyn Lam: You know, Toby, just to let you know right there, I thought it was so incredibly novel. So I'm a heart failure specialist and we know that shunts are associated with high output cardiac failure, and yet, I personally had never questioned this, so I thought this is incredibly novel and it's important. But please, tell us all about the results. Dr Toby Coates: We were delighted to say that there was a very significant reduction in the left ventricle mass. In fact, the main decrease was 22.1 grams compared to the control arm in whom the cardiac mass actually went up 1.2 grams. So, then we mobilized the body surface area, the reduction of the left ventricular mass index dropped by 11.8 grams per metered square. Now, this is quite remarkable for me doing the study because I've never seen an intervention, I've never seen an intervention where every single patient improved with the ligation, every single patient there was an improvement in the cardiac parameters. Never seen anything like it in the pre and post of the ventricular mass it really came down. So that was quite remarkable. And the second thing that really impressed me at the time, was the improvement in the BMP's, and we measured the brain maturated peptide, and being a methodologist that's clearly something that's of interest to us and we saw a substantial reduction. It's statistically significant reduction in BMP as well. The patient themselves, some of them recorded quite significant improvement in exercise tolerance afterwards. And we had, as I mentioned before in a couple of patients, not in the study but outside of the study, subsequently when they're presented with profound right heart failure, the ligation of the AV fistula made a huge difference to them symptomatically. So that was sort of confirming all of the things that we thought along the way. Pleasingly we didn't see any change in kidney function. So, we were concerned that there might have been on the basis of some non-controlled studies in the past, that there might have been a deterioration in the estimated glomerular filtration rate, or eGFR. We didn't see that. And we didn't see any significant change in the blood pressure either. Which is some of us have previously reported. Closing the fistula itself, is a very trivial procedure. It's usually done as an outpatient, so a day procedure. So it's not resulting in coming to the hospital. And the only complications, really were lots of local redness and some pain, potentially from the fistula where in the ligated. So, we thought this was remarkable. An outpatient procedure that could significantly reduce the left ventricular mass by 22.1 grams over the six month period that was associated with minimal side effects and complications. And when you think about that, that's sort of equivalent really to taking an anti-hypertensive medication for six months. That magnitude of reduction with ventricular mass which clearly from the patient's point of view is much preferable to adding more medication to an already over-burdened tablet loading in your patients with kidney transplants. So we were very pleased with that result altogether. Dr Carolyn Lam: Thank you Toby, and we in turn were very pleased…

    Full show notes at the publisher

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