Epicardial fat volume and concurrent presence of both myocardial ischemia and obstructive coronary artery disease.

OBJECTIVE

Epicardial fat volume (EFV) is linked to cardiovascular event risk. The aim of this study was to evaluate whether EFV is independently related to concurrent presence of both myocardial ischemia and obstructive coronary stenosis.

METHODS

We studied 92 consecutive patients without known coronary artery disease (CAD) who underwent Rb-82 PET, coronary calcium scoring (CCS) and invasive coronary angiography (ICA) within 6 months. EFV was computed from non-contrast CT by validated software and indexed to body surface-area (EFVi, cm(3)/m(2)). Ischemia was defined by ≥ 5% difference of total perfusion deficit (quantified by validated software) between stress and rest. Obstructive stenosis was defined ≥ 50% luminal diameter stenosis.

RESULTS

Fifty three patients had both ischemia and stenosis. Compared to those without, patients with both having ischemia and stenosis had significantly higher CCS (1125 ± 1230 vs. 626 ± 690, p = 0.02) and EFVi (64.6 ± 20.6 vs. 49.7 ± 14.2 cm(3)/m(2), p=0.0002). On multivariable analysis after adjusting age, gender, cardiovascular risk factors, chest pain, and CCS (≥ 400), only elevated EFVi (>68.1cm(3)/m(2)) significantly predicted concurrent presence of both ischemia and stenosis (odds ratio 6.18, 95% confidence interval 1.73-22.01, p = 0.005). Area under the receiver-operator-characteristic analysis demonstrated a trend towards improved incremental prediction of concurrent myocardial ischemia and obstructive stenosis over age, gender, chest pain, and high CCS (0.73 vs. 0.65, p = 0.09).

CONCLUSIONS

Our study suggests that elevated EFVi measured using non-contrast CT may be related to concurrent presence of both ischemia and stenosis.