Abstract 12578: Pericardial Fat is Associated with Left Atrial Structure and Function: Implications for Atrial Fibrillation

Abstract

Background: There is increasing interest in the pathological role that localised adiposity may have on cardiovascular disease, over and above that of generalised adiposity. We have recently shown that pericardial fat volume is associated with the presence of atrial fibrillation (AF), severity of AF and poorer outcomes after AF ablation.

Methods: Forty patients with AF underwent cardiac MRI. Body mass index (BMI) and body surface area (BSA) were calculated as measures of generalized adiposity. Periatrial, periventricular and total pericardial fat volumes were quantified using a previously-validated ex-vivo technique. Maximum left atrial volume (LAV) and ejection fraction (LAEF) were determined from short-axis slices. All adiposity measures were standardized to a mean of 0 and SD of 1 to facilitate comparison. Multivariable linear regression models were utilised to study the association between adiposity measures and LAV and LAEF. Analyses were undertaken using SPSS 16 and statistical significance set at p<0.05.

Results: In multivariable-adjusted models, periatrial, periventricular and total pericardial fat volumes were significantly associated with both LAV and LAEF, whereas BMI and BSA were not. For every 1-SD increase in periatrial, periventricular and total pericardial fat, LAV was larger by 11.85 (p=0.001), 9.85 (p=0.063) and 12.48 mL (p=0.014) respectively. For every 1-SD increase in periatrial, periventricular and total pericardial fat, LAEF was lower by 10.50 (p<0.001), 10.83 (p<0.001) and 12.20 % (p<0.001) respectively.

Conclusions: Pericardial fat volumes are associated both LAV and LAEF. These associations are stronger than those of generalized adiposity. Our findings suggest pericardial fat has pathological effect on the structure and function of adjacent left atrial myocardium and this may in part explain its association with AF.