EPICARDIAL FAT VOLUME AS A PREDICTOR OF THE SEVERITY OF CAD BY MSCT

Abstract

ABSTRACT Background: Distribution of body fat is known to be more independent and potent predictor of morbidity and mortality than total body adipocity. Each visceral fat storage is anatomically and functionally different and according to its closeness to an organ, it exerts a specific local function for each one. Epicardial adipose tissue (EAT) as a fat depot is further implicated on coronary artery disease (CAD) because of proximity to the adventitia of major epicardial coronary arteries. Epicardial fat volume (EFV) can be evaluated by MSCT even without contrast injection which helps in prediction of the presence and the severity of CAD. Objectives: To evaluate the relationship between epicardial fat volume and the severity of coronary artery disease among patients presented by chest pain with low to intermediate pretest probability for CAD using Multi-Slice CT coronary angiography. Subjects and methods: The study included 100 patients, 94 males and 6 females with mean age 56.03 ± 10.24 years who were referred to the MSCT coronary angiography unit in Zagazig University Hospital and Kobri Elkobba Military Hospital during the period from January 2017 to August 2017. All patients were subjected to through history taking including age, sex, family history of CAD, DM, HTN, smoking, complete clinical examination including BMI and overweight was defined as ≥ 25 kg/m2, standard ECG, analysis of lipid profile, measurement of serum creatinine and random blood glucose level as well as Multi-slice CT angiography. Results: There was significant relationship between EFV and Proximal LAD and D1 lesions (p = 0.020) as regarding segment involvement score (SIS) and segment stenosis score (SSS) by MSCT. Epicardial fat volume (EFV) was 125.34 ± 35.37 cm3 (range from 47.4 to 221.3 cm3 and the median value of EFV in our patients was 123.35 cm3) and Coronary artery calcium score (CACS) was 157.69 ± 352.95 (range from 0 to 2212 and the median value was 29.55) with significant relationship between EFV and Ca score (p = 0.009), highly significant relationship between EFV and SIS score and SSS score (p < 0.001). There was significant relationship between EFV and sex (p = 0.002), highly significant relationship between EFV and hypertension and diabetes mellitus (p < 0.001), no significant relationship between EFV and smoking (p = 0.754) and family history of ischemic heart disease (p = 0.082), significant relationship between EFV and age (p = 0.011), highly significant relationship between EFV and serum cholesterol, LDL, serum triglycerides, LDL/HDL ratio, BMI and inversely proportional to HDL (p < 0.001). Conclusion: we concluded in our study that EFV was associated with coronary atherosclerosis and EFV increased steeply in patients with significant coronary artery stenosis and in those with severe coronary artery calcification as revealed by MSCT angiography. Quantitation of EFV may be useful in addition to coronary artery calcium score as a predictor to identify patients at risk for CAD. Keywords: Epicardial fat volume, coronary artery disease and Multi-slice CT angiography.