Background
Pericardial fat has been implicated in the pathogenesis of obesity-related cardiovascular disease. Whether the associations of pericardial fat and measures of cardiac structure and function are independent of the systemic effects of obesity and visceral adiposity has not been fully explored.
Methods and Results
Participants from the Framingham Heart Study (n=997, 54.4% women) underwent chest and abdominal CT and cardiovascular MRI (CMR) between 2002 and 2005. Pericardial fat, intrathoracic fat, and visceral adipose tissue (VAT) quantified from multidetector computed tomography, along with BMI and waist circumference, were examined in relation to CMR measures of left ventricular (LV) mass, LV end diastolic volume (LVEDV), and left atrial dimension. In women, pericardial fat (r=0.20 to 0.35, p<0.001), intrathoracic fat (r=0.25 to 0.37, p<0.001), VAT (r=0.24 to 0.45, p<0.001), BMI (r=0.36 to 0.53, p<0.001), and waist circumference (r=0.30 to 0.48, p<0.001) were directly correlated with LV mass, LVEDV, and left atrial dimension. In men, pericardial fat (r=0.19 to 0.37, p<0.001), intrathoracic fat (r=0.17 to 0.31, p<0.001), VAT (r=0.19 to 0.36, p<0.001), BMI (r=0.32 to 0.44, p<0.001), and waist circumference (r=0.34 to 0.44, p<0.001) were directly correlated with LV mass and left atrial dimension, but LVEDV was not consistently associated with adiposity measures. Associations persisted after multivariable adjustment, but not after additional adjustment for body weight and VAT, with the exception of pericardial fat and left atrial dimension in men.
Conclusions
Pericardial fat is correlated with CMR measures, but the association is not independent of or stronger than other ectopic fat stores or proxy measures of visceral adiposity. An important exception is left atrial dimension in men. These results suggest that the systemic effects of obesity on cardiac structure and function may outweigh the local pathogenic effects of pericardial fat.
