Relationship of epicardial adipose tissue by echocardiography to coronary artery disease

Objective: To study the relationship of echocardiographic epicardial adipose tissue (EAT) with coronary artery disease (CAD) risk factors and the extent of coronary atherosclerosis. Methods: EAT thickness was measured in 527 patients undergoing their first coronary angiography. EAT was defined as an echo-lucent area on the free wall of the right ventricle on the still image of the two-dimensional echocardiogram at end diastole in the parasternal long-axis and parasternal short-axis views. A CT scan at the umbilicus was acquired to measure abdominal visceral adipose tissue (VAT) from a random sample of 30 patients. The extent of coronary atherosclerosis was assessed using a coronary atherosclerosis score based on the quantitative coronary angiography results. Results: EAT thickness was correlated with abdominal VAT (r(s) = 0.626, p < 0.001), age (r(s)= 0.480, p < 0.001), waist circumference (r(s)= 0.309, p < 0.001), body mass index (rs= 0.233, p, 0.001), C reactive protein (r(s)= 0.224, p < 0.001), and the homoeostasis model assessment score (r(s)= 0.249, p < 0.001). EAT was thicker in subjects with CAD than in those without CAD (4.0 vs 1.5 mm, p, 0.001). Patients with unstable angina had thicker EAT than those with stable angina or atypical chest pain (4.0, 3.0, and 1.5 mm, respectively, p, 0.001). EAT (>= 3.0 mm) was an independent factor of CAD on multiple logistic analysis (odds ratio = 3.357; 95% CI 2.177 to 5.175, p < 0.001). Conclusions: These results suggest that EAT may reflect the amount of visceral fat, which is associated with insulin resistance and inflammation. The echocardiographic measurement of EAT may provide additional information for assessing CAD risk and predicting the extent and activity of CAD.