Abstract: Objective：To assess whether epicardial adipose tissue (EAT) thickness is associated with coronary flow reserve (CFR) and could be used to detect coronary microvascular dysfunction. Methods: We enrolled 62 nondiabetic patients who underwent computed tomography angiography or invasive coronary angiography and had no obstructive coronary artery disease. CFR and EAT thickness were measured by transthoracic Doppler echocardiography (TTDE). Results: In the study, a total of 62 patients were enrolled, echocardiographic coronary flow reserve were obtained in 61 of the patients with a mean age of (59±10) years. 34 patients (56%) had reduced CFR (CFR＜3, 2.52±0.32) suggesting microvascular dysfunction and 27 patients (44%) had normal CFR (CFR≥3, 3.56±0.52). EAT thickness was significantly increased in the patients with microvascular dysfunction as compared with those without ［(3.4±0.8) mm vs. (2.3±0.6) mm, P＜0.001］. EAT thickness was strongly related to CFR (r=-0.668, P＜0.001). By Logistic regression analysis, EAT thickness was the independent predictor of coronary microvascular dysfunction (OR=7.78, 95%CI: 2.44-24.79). EAT thickness＞2.9 mm had 82.4% sensitivity and 92.3% specificity to detect CFR＜3 (area under ROC curve 0.860, P＜0.001). Conclusion: EAT thickness was significantly increased in patients with coronary microvascular dysfunction. EAT thickness was independently associated with impaired CFR. EAT＞2.9 mm had high sensitivity and specificity to detect coronary microvascular dysfunction.

Key words: Echocardiography, Epicardial fat, Coronary flow reserve, Coronary circulation, Microcirculation