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 Dr Greg Hundley, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, our feature article today looks at the use of Apixaban versus Warfarin, so a trial between the two in patients with atrial fibrillation and advanced kidney disease. But before we get to that, how about if we break away, grab a cup of coffee and go through some of the other important papers in this issue? Dr Carolyn Lam: Yeah, and why not start with talking about our gut and fiber in the diet. Now, we know that a diet poor in fiber is associated with the prevalence of hypertension, but what are the underlying mechanisms? Well, this first paper I want to talk about is from Dr Marques from Baker Heart and Diabetes Institute in Australia and colleagues who basically performed a nice series of mouse experiments and found that a diet lacking prebiotic fiber led to a gut microbiome that was pro hypertenenogenic facilitated the development of cardiac hypertrophy in germ free mice. Even in the absence of fiber, gut metabolites called short chain fatty acids usually produce from the fermentation of prebiotic fiber by the gut microbiota, but they were able to protect against the development of hypertension, cardiac hypertrophy and fibrosis in a preclinical model. This cardioprotection involved short chain fatty acid receptors, and a decrease in the ratio of sodium to potassium excretion and changes in genome white methylation that supported higher levels of T regulatory cells. Dr Greg Hundley: Oh my goodness, Carolyn. So I need to know what I eat for lunch? What's the take home message here? Dr Carolyn Lam: Lots of fiber and definitely not the low fiber westernized diet, which may underlie hypertension. And how? Through deficient short chain fatty acid production and thus the take home is maintaining a healthy, short chain fatty acid producing microbiome is important for the cardiovascular health. Dr Greg Hundley: Wow, Carolyn. I love that article because it really helps provide some perspective on all the diet information that we've been receiving lately. Well, my paper is from doctor ... another Carolyn, but this is Carolyn Ho from Brigham and Women's Hospital- Dr Carolyn Lam: I love her. Dr Greg Hundley: ... And it involves hypertrophic cardiomyopathy and left ventricular systolic dysfunction. So Carolyn, the term end-stage has been used to describe hypertrophic cardiomyopathy with left ventricular systolic dysfunction. And that's defined when someone has hypertrophic cardiomyopathy and the LVEF is less than 50%. The prognosis of patients with this condition has been reportedly poor, but it's very rare in occurrence and therefore, the natural history really remains incompletely characterized. So what did the authors do in this study? They evaluated more than 500 patients from 11 high volume hypertrophic cardiomyopathy specialty centers comprising the international Sarcomeric Human Cardiomyopathy Registry or SHaRe registry. And they were used to describe the natural history of patients with hypertrophic cardiomyopathy and left ventricular systolic dysfunction. Dr Carolyn Lam: Interesting. So what did they find, Greg? Dr Greg Hundley: Number one, first overall, this group of patients, hypertrophic cardiomyopathy with left ventricular systolic dysfunction occurs in about 8% of those with hypertrophic cardiomyopathy. Although the natural history of left ventricular systolic function and hypertrophic cardiomyopathy is variable, 75% of those that have this condition experience adverse events including 35% experiencing a death equivalent at a medium of 8.4 years after developing their systolic dysfunction. In addition to clinical features, the genetic substrate appears to play