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Circulation May 05, 2020 Issue

Circulation May 05, 2020 Issue

FromCirculation on the Run


Circulation May 05, 2020 Issue

FromCirculation on the Run

ratings:
Length:
19 minutes
Released:
May 4, 2020
Format:
Podcast episode

Description

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, associate editor from the Pauley Heart Center at VCU health in Richmond, Virginia. Well Carolyn, our feature this week really examines long-term efficacy of drug eluting stents versus coronary artery bypass grafting in those patients with left main disease. Really looking at long-term extended follow up from the PRECOMBAT trial but before we get to that, how about we grab a cup of coffee and jump into some of the other articles in the issue? And I'll start off. My first article is a basic science paper looking at catecholamine sensitive and ventricular tachycardia in ARVC. And it comes from Dr Long-Sheng Song from the University of Iowa Carver College of Medicine. So, the study from Dr Song used protein mass spectrometry analyses and that identified integrin beta one is downregulated in those patients with arrhythmogenic right ventricular cardiomyopathy hearts without changes to calcium handling proteins as adult cardiomyocytes express only the beta-1 D isoform, they generated a cardiac specific beta-1 D knockout mouse model and perform functional imaging and biochemical analyses to determine the consequences from integrin beta-1 D loss of function in hearts in vivo and in vitro. Dr Carolyn Lam: Nice, very elegant design. So what were the results Greg? Dr Greg Hundley: Well Carolyn, the authors found that integrin beta- 1D deficiency and RyR2 serine 2030 hyper phosphorylation were detected by Western blotting in left ventricular tissues from patients with ARVC but not in patients with ischemic or hypertrophic cardiomyopathy. And in the mouse experiments, beta-1 D negative or knockout mice exhibited normal cardiac function and morphology, but presented with catacholamines sensitive polymorphic ventricular tachycardia consistent with increased RyR2 serine 2030 phosphorylation and apparent calcium handling in beta-1 D knockout cardiomyocytes. So Carolyn, in conclusion, the authors found their data suggest that integrin beta-1D deficiency represents a novel mechanism underlying the increased risk of ventricular arrhythmias in patients with ARVC. Dr Carolyn Lam: Okay. You told us about integrin beta-1 D and I'm going to tell you about apolipoprotein M. So Greg, what do you know about apolipoprotein M? Dr Greg Hundley: Well, Carolyn, at seven o'clock the morning, I seem to have forgotten a little bit about that. Can you remind me what apolipoprotein M is? Dr Carolyn Lam: Sure Greg, very happy to. So apolipoprotein M or apoM mediates the physical interaction between high density lipoprotein particles and sphingosine 1-phosphate and exerts an anti-inflammatory and cardio-protective effects in animal models. Now listen on, listen on. So authors, Dr Chirinos from Perelman Center for Advanced Medicine, University of Pennsylvania and Dr Javaheri from Washington University School of Medicine and co-authors hypothesized that reduced levels of apoM would be associated with worse outcomes in human heart failure. Specifically, they tested the hypothesis that reduced circulating apoM would be associated with the risk of death, a composite of death, ventricular assist, device implantation or heart transplantation and a composite of death, heart failure related hospitalization among adults with heart failure and rolled in a large multicenter Penn heart failure study. They did stratified analysis in patients with heart failure with reduced and preserved ejection fraction and even replicated these findings in two independent cohorts, the Washington University heart failure registry and a subset of the TOPCAT trial. What they found was that reduced apoM plasma protein levels indeed were associated with adverse outcomes in heart failure including both HFpF and HFrF. The relat
Released:
May 4, 2020
Format:
Podcast episode

Titles in the series (100)

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!