Subepicardial adipose tissue and the presence and severity of coronary artery disease

Background: Mechanistic studies suggest that paracrine effects of subepicardial adipose tissue may promote coronary atherosclerosis, but this has not been confirmed in clinical studies. Methods and results: Of 180 consecutive patients who underwent echocardiography and coronary angiography within 1 week (mean 2.5 ± 2.0 days), 139 (80 men, 68 ± 13 years) were studied. Subepicardial adipose tissue on the free wall of right ventricle was measured at end-diastole from parasternal long- and short-axis views of three cardiac cycles. Angiograms were analyzed for the presence, extent and severity of coronary artery disease (CAD), using a 27-segment classification. The number of segments with at least 20% (CAGE ≥ 20) and 50% (CAGE ≥ 50) stenosis was recorded. Age showed a significant correlation with subepicardial adipose tissue thickness measured from parasternal long- (r = 0.25, p = 0.003) and short-axis view (r = 0.23, p = 0.01). No significant correlation was found between subepicardial adipose tissue thickness and any angiographic or other clinical variables (p > 0.05). Neither the proportion of patients with significant or any CAD nor the severity score, CAGE ≥ 20, and CAGE ≥ 50 among each of four quartiles was significantly associated with subepicardial adipose tissue thickness. Conclusions: In this selected population, the amount of subepicardial adipose tissue thickness was not associated with the severity of CAD. Whether subepicardial adipose tissue has any atherosclerotic effect remains to be proven.