6 research outputs found
Role of epicardial adipose tissue in human atrial fibrillation
Abstract A recent metaâanalysis among which four reports were conducted in Japan demonstrated that epicardial adipose tissue (EAT) is closely associated with an increased risk of atrial fibrillation (AF) recurrence after catheter ablation. We previously investigated the role of EAT in AF in humans. Left atrial (LA) appendage samples were obtained from AF patients during cardiovascular surgery. Histologically, the severity of fibrotic EAT remodeling was associated with LA myocardial fibrosis. Total collagen in the LA myocardium (i.e., LA myocardial fibrosis) was positively correlated with proinflammatory and profibrotic cytokines/chemokines, including interleukinâ6, monocyte chemoattractant proteinâ1, and tumor necrosis factorâα, in EAT. Human periâLA EAT and abdominal subcutaneous adipose tissue (SAT) were obtained by autopsy. EATâ or SATâderived conditioned medium was applied to the rat LA epicardial surface using an organoâculture system. EATâconditioned medium induced atrial fibrosis in organoâcultured rat atrium. The profibrotic effect of EAT was greater than that of SAT. The fibrotic area of the organoâcultured rat atrium treated with EAT from patients with AF was greater than in patients without AF. Treatment with human recombinant angiopoietinâlike protein 2 (Angptl2) induced fibrosis in organoâcultured rat atrium, which was suppressed by concomitant treatment with antiâAngptl2 antibody. Finally, we attempted to detect fibrotic EAT remodeling on computed tomography (CT) images, which demonstrated that the percent change in EAT fat attenuation was positively correlated with EAT fibrosis. Based on these findings, we conclude that the percent change in EAT fat attenuation determined using CT nonâinvasively detects EAT remodeling