Pericardial fat is independently associated with human atrial fibrillation.

OBJECTIVES: The purpose of this study was to investigate the association between atrial fibrillation (AF) and pericardial fat.
BACKGROUND: Pericardial fat is visceral adipose tissue that possesses inflammatory properties. Inflammation and obesity are associated with AF, but the relationship between AF and pericardial fat is unknown.
METHODS: Pericardial fat volume was measured using computed tomography in 273 patients: 76 patients in sinus rhythm, 126 patients with paroxysmal AF, and 71 patients with persistent AF.
RESULTS: Patients with AF had significantly more pericardial fat compared with patients in sinus rhythm (101.6 +/- 44.1 ml vs. 76.1 +/- 36.3 ml, p < 0.001). Pericardial fat volume was significantly larger in paroxysmal AF compared with the sinus rhythm group (93.9 +/- 39.1 ml vs. 76.1 +/- 36.3 ml, p = 0.02). Persistent AF patients had a significantly larger pericardial fat volume compared with paroxysmal AF (115.4 +/- 49.3 ml vs. 93.9 +/- 39.1 ml, p = 0.001). Pericardial fat volume was associated with paroxysmal AF (odds ratio: 1.11; 95% confidence interval: 1.01 to 1.23, p = 0.04) and persistent AF (odds ratio: 1.18, 95% confidence interval: 1.05 to 1.33, p = 0.004), and this association was completely independent of age, hypertension, sex, left atrial enlargement, valvular heart disease, left ventricular ejection fraction, diabetes mellitus, and body mass index.
CONCLUSIONS: Pericardial fat volume is highly associated with paroxysmal and persistent AF independent of traditional risk factors including left atrial enlargement. Whether pericardial fat plays a role in the pathogenesis of AF requires future investigation. Copyright (c) 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.