Peri-atrial epicardial adipose tissue is associated with new-onset nonvalvular atrial fibrillation.

Background: Atrial fibrillation (AF) is associated with considerable morbidity and mortality in patients with coronary artery disease (CAD). Epicardial adipose tissue (EAT) is recognized as an important inflammatory tissue that may exert deleterious effects on the adjacent left atrial (LA) wall. Multidetector computed tomography (MDCT) can accurately assess EAT's volume and distribution. This study used MDCT to investigate the effect of peri-atrial EAT on new-onset nonvalvular AF.
Methods and Results: The study group consisted of 279 patients (176 men; age, 65±10 years) with no history of AF who underwent MDCT examination for evaluation of CAD. EAT was automatically identified on the basis of threshold attenuation values of -30 to -250 Hounsfield units. EAT volume was calculated as the sum of EAT area and subsequently divided into peri-atrial and peri-ventricular EAT. During follow-up of 3.3±1.0 years, AF occurred in 17 (6.1%) patients. Cox proportional hazards regression analysis indicated that male sex, and the LA and peri-atrial EAT volumes (P=0.03, P<0.001, and P<0.001, respectively) were independent predictors for future AF. The sensitivity and specificity for the prediction of AF using a peri-atrial EAT volume index of ≥27 ml/m(2) were 88% and 92%, respectively.
Conclusions: This is the first study demonstrating that peri-atrial EAT volume estimated by MDCT excellently predicted the development of new-onset AF in patients with CAD, independent of LA enlargement.