Influence of Sex on the Association Between Epicardial Adipose Tissue and Left Atrial Transport Function in Patients With Atrial Fibrillation: A Multislice Computed Tomography Study

BACKGROUND: Epicardial adipose tissue (EAT) is known to play an important role in atrial fibrillation substrate remodeling; however, the influence of sex on the association between EAT and left atrial (LA) transport function has not been elucidated. METHODS AND RESULTS: Of the 514 patients who underwent an index atrial fibrillation ablation procedure, 123 postmenopausal women with no history of hormone replacement therapy and 123 men who were matched for age, body mass index, type of atrial fibrillation, and CHADS (2) score were enrolled. Before the procedure, LA volume, LA emptying fraction, and EAT volume were assessed using multislice computed tomography. Blood samples were obtained from a coronary sinus for analysis of serum adiponectin level before the ablation procedure. There were no differences in baseline demographics and laboratory findings between sexes. Compared with men, women had significantly less total EAT (P<0.001) and higher serum adiponectin levels (P=0.022) but higher proportions of periatrial EAT to total EAT volume (P/T EAT ratio, P<0.001), lower LA emptying fraction (P=0.042), and lower LA voltage (P=0.034). The ratio of periatrial to total EAT volume correlated significantly with LA emptying fraction and LA voltage in both sexes, whereas total EAT volume and serum adiponectin level did not. On multivariate analysis, increased LA volume and higher periatrial:total EAT volume ratio were independent predictors of decreased LA emptying fraction in both sexes. CONCLUSIONS: Compared with matched men, postmenopausal women with atrial fibrillation had higher periatrial adiposity, which was independently correlated with decreased LA voltage and LA transport function.