Epicardial adipose tissue and myocardial ischemia assessed by computed tomography perfusion imaging and invasive fractional flow reserve

Abstract

BackgroundEpicardial adipose tissue (EAT) is a metabolically active fat depot that is associated with incident coronary artery disease (CAD) and major adverse cardiovascular events. The relationship between EAT and myocardial ischemia remains unclear. This study investigated the relationship between EAT volume and the presence of perfusion defects on myocardial computed tomographic perfusion imaging (CTP) and functional stenoses on invasive fractional flow-reserve (FFR). MethodsData were obtained from a previous prospective cross-sectional study in patients with suspected CAD. Patients underwent combined coronary computed tomography angiography (coronary CTA) and CTP followed by invasive coronary angiogram (ICA) and FFR within 14 days. FFR was performed in all major epicardial vessels unless they were angiographically smooth or occluded, with a threshold of <0.8 considered significant. EAT volume was quantified semi-automatically on coronary CTA. ResultsThere were 38 patients included for analysis, mean age 62.5 ± 10.0 years, 68.4% male. Median EAT volume was 82.8 mL (interquartile range (IQR) 49.3 mL). FFR was interrogated in 73/114 (64%) vessels. There was no difference in EAT volumes in patients with and without CTP defects (84.4 mL, IQR: 35.6 mL vs 81.1 mL, IQR: 53.1 mL, p = 0.7). There was also no difference in EAT volumes in patients with and without FFR-significant vessels (86.5 mL IQR: 36.6 mL vs 79.1 mL IQR: 54.5 mL, p = 0.7) and no difference when analysed by number of CTP positive territories or FFR-significant vessels (p = 0.4 and p = 0.8 respectively). ConclusionThis study demonstrated no observable relationship between EAT volume and perfusion defects on myocardial CT perfusion imaging or functional stenosis on invasive FFR.