Clinical significance of epicardial fat in suspected angina pectoris: an observational study

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Epicardial adipose tissue (EAT) is the visceral fat between pericardium and visceral epicardium and is the source of several endocrine and inflammatory mediators. It also has paracrine affects in the neighboring coronary arteries. Objective To evaluate the association of EAT with subclinical atherosclerosis (carotid intima media thickness & flow mediated vasodilation), ultrasonic and anthropometric measures of abdominal fat, metabolic syndrome and coronary artery disease (CAD) concurrently. Material and methods Patients who underwent computed tomography (CT) coronary angiography for suspected CAD were prospectively included. All underwent anthropometric measurements, laboratory investigations, ultrasonic measurement of liver fat grade & B-mode hepatorenal ratio, carotid intima media thickness (CIMT), flow mediated vasodilation (FMD), CT measurement of epicardial fat thickness (EFT) & epicardial fat volume (EFV) along with CT coronary angiography. Study population was divided into 2 groups on the basis of presence or absence of CAD and were compared. The relationship between risk factors and presence of CAD was assessed by logistic regression analysis. To define EFT and EFV value predictive of the presence of significant CAD, the area under (AUC) the receiver operating characteristic (ROC) curve was calculated. Correlation between EFT as well as EFV with anthropometric and laboratory parameters, CIMT and FMD were assessed by Pearson correlation coefficient. Results Total 54 patients were included in study. Mean age was 54 years, 66% were diabetic and 33% were hypertensive. Mean CIMT, FMD, EFT and EFV were 0.70 + 0.27 cm; 5.64 + 2.64%; 5.51 + 2.50 mm and 60.6 + 28.6 cc, respectively. Total 34 (62.96%) patients were detected to have CAD. EFT as well as EFV were significantly higher in CAD group (3.31 + 2.34 vs 6.24 + 1.91mm; p= <0.001, 72.5 + 22.3 vs 40.4 + 27.1cc; p= <0.001); in patients with metabolic syndrome (83.3 + 18.4 vs 49.2 + 26.1cc; p < 0.001, 7.13 + 1.49 vs 4.16 + 2.32mm; p < 0.001). Both, EFV & EFT were significantly correlated with the abdominal fat, CIMT and FMD. Smoking, age and EFV were the independent predictors for CAD. EFV >31.65cc predicted the presence of CAD (sensitivity 91.25%, specificity 60%, AUC = 0.798, 95% CI = 0.665-0.930) and EFT >2.85mm predicted the presence of CAD (sensitivity 94.1%, specificity 65%, AUC= 0.820, 95% CI= 0.687-0.953). Conclusions Epicardial fat is significantly associated with presence of CAD, metabolic syndrome, visceral fat, CIMT and FMD. CT measured epicardial fat may be included with CT based CAD lesion assessment and CT coronary calcium score to screen the patients of suspected angina pectoris. Abstract Figure. Epicardial adipose tissue Abstract Figure. EFV and CAD