Circulation : Clinical Summaries

Abstract

HomeCirculationVol. 133, No. 17Circulation: Clinical Summaries Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessResearch ArticlePDF/EPUBCirculation: Clinical SummariesOriginal Research Put Into Perspective for the Practicing Clinician Originally published26 Apr 2016https://doi.org/10.1161/CIR.0000000000000413Circulation. 2016;133:1629–1630Ablation Versus Amiodarone for Treatment of Persistent Atrial Fibrillation in Patients With Congestive Heart Failure and an Implanted Device: Results From the AATAC Multicenter Randomized TrialHeart failure and atrial fibrillation are common cardiac conditions that often coexist. This is the first randomized study to show that, in patients with heart failure and persistent atrial fibrillation, catheter ablation is superior to amiodarone (the most used drug in these patients) in achieving freedom from atrial fibrillation at long-term follow-up. Importantly, ablation reduced rehospitalization and overall mortality and improved quality of life and exercise capacity. This study suggests that clinicians should consider catheter ablation sooner in this patient population. See p 1637.Circulating Biomarkers of Dairy Fat and Risk of Incident Diabetes Mellitus Among Men and Women in the United States in Two Large Prospective CohortsDiabetes mellitus is a major preventable cause of morbidity and mortality. Growing evidence suggests that dairy foods, and even dairy fat, could reduce risk of diabetes mellitus. Most previous studies used self-reported dietary questionnaires that could be prone to subjective reporting and might not fully capture dairy fat intake, particularly from mixed dishes. Circulating fatty acid biomarkers, such as odd-chain saturated fats (15:0, 17:0) and certain natural trans fats (t-16:1n-7), may provide more objective measures of dairy fat intake. We prospectively evaluated the relationship between plasma concentrations of 15:0, 17:0, and t-16:1n-7 and new-onset diabetes mellitus among 3333 men and women aged 30 to 75 years in 2 separate US cohorts. Incident diabetes mellitus was confirmed by validated methods based on symptoms, diagnostic tests, and medical therapy. After adjusting for demographics, metabolic risk factors, lifestyle, diet, and other circulating fatty acids, we found that all 3 of these circulating fatty acids were associated with substantially lower risk of diabetes mellitus, with ≈45% to 50% lower risk comparing the top versus bottom quartiles of their levels. Potential limitations include the misclassification of fatty acid measurements because of laboratory error and within-person variation over time, which would attenuate results toward the null; and residual confounding because of unmeasured or mismeasured covariates, although this would seem unlikely to fully explain the magnitudes of observed associations. Our findings suggest that dairy foods, and specifically dairy fat, could help prevent diabetes mellitus, highlighting the need for intensive experimental and mechanistic evaluation on the health effects of dairy fat, and as the determinants of these circulating fatty acids, as well. See p 1645.Changes in Arterial Access Site and Association With Mortality in the United Kingdom: Observations From a National Percutaneous Coronary Intervention DatabaseAdoption of the transradial access site (TRA) for percutaneous coronary intervention (PCI) has been shown to reduce mortality and major adverse cardiovascular events in high-risk patient groups undergoing PCI in several randomized, controlled trials and national observational databases. The present analysis is the first to systematically study the change in access site practice over time from a national perspective during a period of time when TRA transitioned to become the predominant access site used for PCI in England and Wales. We estimate the potential clinical benefit during this change in practice. We report marked heterogeneity in TRA adoption nationally even once we adjust for differences in populations. Our analysis suggests that through a national change in access site practice, 450 lives have been saved in England and Wales over 8 years. Marked differences in TRA adoption across different regions have meant that an additional 264 mortalities may have been avoided if TRA adoption had uniformly occurred nationally. Although TRA has become the default access site used in PCI procedures nationally, significant challenges remain in a more uniform adoption of TRA both in the United Kingdom and internationally, particularly in patients at highest risk of bleeding complications who have most to benefit. Our analysis suggests that a large-scale national change in access site practice can lead to significant mortality gains. More uniform access to training opportunities nationally may be needed to drive more uniform adoption and to maximize the clinical benefit for patients undergoing PCI. See p 1655.Doxorubicin Blocks Cardiomyocyte Autophagic Flux by Inhibiting Lysosome AcidificationDoxorubicin is an efficacious and commonly used chemotherapeutic agent with clinical utility that is limited by dose-dependent cardiotoxicity. Numerous studies have probed molecular mechanisms of doxorubicin cardiomyopathy, but a single, unifying model of pathogenesis remains elusive. Autophagy is a highly conserved mechanism of intracellular protein and organelle recycling. In many contexts, autophagy participates in the cellular response to the same events triggered by doxorubicin such as redox injury and mitochondrial damage. In fact, previous studies addressing a possible role of cardiomyocyte autophagy in doxorubicin cardiotoxicity have emerged with conflicting interpretations, with doxorubicin-induced autophagy reported to be either increased or decreased. In this report, we addressed the role of cardiomyocyte autophagy in doxorubicin cardiotoxicity based on a novel model of low-dose doxorubicin treatment that results in modest but progressive cardiomyopathy that mimics events occurring in patients. We uncover a doxorubicin-induced defect in autophagic flux that may explain the earlier conflicting interpretations of autophagic flux. Furthermore, our findings point to a novel means of mitigating doxorubicin-elicited pathological remodeling. See p 1668.Evolution of Mitral Valve Prolapse: Insights From the Framingham Heart StudyMitral valve prolapse (MVP) remains the most important cause of primary mitral regurgitation requiring surgery. Nondiagnostic MVP morphologies have been described in the familial context and may represent early expression of MVP in those genetically predisposed. Longitudinal studies of MVP progression among unselected individuals in the community, including those with nondiagnostic MVP morphologies, are lacking. We demonstrate that nondiagnostic MVP morphologies may evolve into MVP, highlighting the clinical significance of mild MVP expression in the community. In addition, we demonstrate that a quarter of MVP cases in the Framingham Heart Study progress to significant mitral regurgitation or need for valve surgery over 3 to16 years, suggesting that the natural history of MVP-related mitral regurgitation may not be as benign as previously depicted in cross-sectional studies. Overall, our observations highlight the need to identify the genetic determinants and the environmental factors associated with the variability of MVP progression. See p 1688. Previous Back to top Next FiguresReferencesRelatedDetails April 26, 2016Vol 133, Issue 17 Advertisement Article InformationMetrics © 2016 American Heart Association, Inc.https://doi.org/10.1161/CIR.0000000000000413 Originally publishedApril 26, 2016 PDF download Advertisement