Relationship Between Epicardial Fat Volume and Coronary Microvascular Dysfunction

Coronary microvascular dysfunction (CMD) is associated with myocardial ischemia in patients without obstructive coronary artery disease (CAD). Epicardial fat volume (EFV) has been reported to be associated with epicardial CAD and diastolic dysfunction. However, because its impact on CMD remains unclear, we aimed to investigate the relationship between CMD and EFV.

This study included 103 patients without obstructive CAD who underwent assessment of CMD and EFV. CMD was defined as either coronary flow reserve (CFR) <2.0 or index of microcirculatory resistance (IMR) ≥25. EFV was quantified using computed tomography and the EFV index was calculated. CMD was identified in 34 (33%) patients. The EFV index was significantly larger in the CMD group than in the non-CMD group (86.1±27.9 vs. 65.8±20.0 cm³/m²; P<0.01). Notably, patients with low CFR (<2.0) and high IMR (≥25) had a larger EFV index (102.1±33.4 cm³/m²). Univariable logistic regression analysis indicated a significant relationship between CMD and the EFV index (odds ratio (OR): 1.04; P<0.01). In the multivariable model, EFV index was significantly associated with CMD (OR: 1.03; P<0.01). The EFV index significantly correlated with CFR (r=-0.39, P<0.01) and IMR (r=0.32, P<0.01).

EFV was associated with CMD in patients without obstructive CAD.