Epicardial Adipose Tissue Is Associated With Left Atrial Dysfunction in People Without Obstructive Coronary Artery Disease or Atrial Fibrillation

Background: Epicardial adipose tissue (EAT) is a metabolically active visceral fat depot. Although EAT volume is associated with the incidence and burden of atrial fibrillation (AF), its role in subclinical left atrial (LA) dysfunction is unclear. This study aims to evaluate the relationships between EAT volumes, LA function, and LA global longitudinal strain. Methods: One hundred and thirty people without obstructive coronary artery disease or AF were prospectively recruited into the study in Australia and underwent cardiac computed tomography and echocar-diography. EAT volume was quantified from cardiac computed tomography. Echocardiographic 3-dimensional (3D) volumetric measurements and 2D speckle-tracking analysis were performed. Results: Using the overall median body surface areaeindexed total EAT volume (EATi), the study cohort was divided into 2 groups of larger and smaller EATi volume. Subjects with larger EATi volume had significantly impaired LA reservoir function (3D LA ejection fraction, 46.1% +/- 8.9% vs 49.0% +/- 7.0%, P = 0.044) and reduced LA global longitudinal strain (37.6% +/- 10.2% vs 44.1% +/- 10.7%, P < 0.001). Total EATi volume was a predictor of impaired 2D LA global longitudinal strain (standardized beta = -0.204, P = 0.034), reduced 3D LA ejection fraction (standardized beta = -0.208, P = 0.036), and reduced 3D active LA ejection fraction (standardized b = -0.211, P = 0.017). Total EATi volume, rather than LA EATi volume, was the more important predictor of LA dysfunction. Conclusions: Indexed EAT volume is independently associated with subclinical LA dysfunction and impaired global longitudinal strain in people without obstructive coronary artery disease or a history of AF.