Relationships Between Periventricular Epicardial Adipose Tissue Accumulation, Coronary Microcirculation, and Left...

Obesity is related to left ventricular (LV) diastolic dysfunction, although its pathophysiological mechanism remains unclear. Epicardial adipose tissue (EAT) is an ectopic fat with paracrine effects on coronary circulation and myocardium. We hypothesized that left ventricle-specific (periventricular) EAT may deteriorate diastolic function by impairing coronary microcirculation.

In protocol 1, 74 patients without obstructive narrowing of the left anterior descending artery on multidetector computed tomography (MDCT) underwent coronary flow reserve (CFR) examination to evaluate the relationship between EAT and coronary microcirculation. In protocol 2, 372 patients who underwent both MDCT and serial transthoracic Doppler echocardiographic (TTDE) examinations were enrolled to investigate the impact of periventricular EAT on changes in diastolic function. EAT volume was measured by MDCT. CFR and diastolic function were assessed by TTDE. Deterioration of LV diastolic function was defined as a ≥ 20% decrease in early diastolic mitral annular velocity.

CFR was significantly correlated with periventricular EAT volume (r = -0.37; P = 0.001), but not with total EAT volume (r = -0.21; P = 0.071). Periventricular EAT volume (P = 0.010) was significantly associated with CFR independent of cardiovascular risk factors. Among the 372 patients who had serial TTDE examinations, the frequency of deteriorated LV diastolic function was lowest in the lower tertile of periventricular EAT, intermediate in the middle tertile, and highest in the upper tertile (12.9%, 21.0%, and 25.8%, respectively; P = 0.037). Age, diabetes mellitus, and periventricular EAT volume were significantly associated with deterioration of LV diastolic function (all P < 0.05).

This study demonstrated the close association of periventricular EAT with impaired CFR and deteriorated LV diastolic function.