Relation of Epicardial Fat Thickness by Multi-Detector Computed Tomography Scan and Coronary Artery Disease

Abstract

BACKGROUND Coronary artery disease is one of the major causes of morbidity and mortality in the world as well as in Nepal and are associated with several risk factors and predictors. Epicardial fat thickness (EFT) is also a predictor of obstructive coronary artery disease based on various studies done elsewhere. Epicardial fat, the adipose tissue located between the visceral pericardium and myocardium of the heart serves as both pro-inflammatory and anti-inflammatory roles in various physiological and pathological states. Measurement of EFT and its analysis may help to predict the likelihood of obstructive coronary artery disease and help to use preventive measures to prevent or delay the occurrence of obstructive coronary artery disease.

AIMS  This study was done to assess relation of epicardial fat thickness by multi-detector computed tomography scan with coronary artery disease and its severity.

METHODS This was a hospital based observational study conducted in Shahid Gangalal National Heart Centre and total 524 patients undergoing MDCT coronary angiography were included from Jun 21, 2024 to Jun 20, 2025 (12 months). 320 slice MD CT coronary angiography was done using standard protocol. Reconstruction was done and epicardial fat thickness was measured at basal short axis view in RV at 25%,50% and 75% level at RV free wall at 75% of RR interval. Mean of three measurement was taken as mean epicardial fat thickness. Patients were grouped into 4 groups based on the luminal stenosis: no CAD, Mild , Moderate and Severe stenosis, with no stenosis, luminal stenosis < 50%, 50-70% >= 70% stenosis in any or all 3 major coronary arteries respectively. Luminal stenosis of 50% or greater taken as obstructive CAD.

RESULTS Among 524 patients undergoing CT coronary angiography, 81 (15.5%) had obstructive coronary artery disease (CAD), while 443 (84.5%) had no obstructive disease. The mean epicardial fat thickness (EFT) was 2.75 ± 0.72 mm. Patients with obstructive CAD had higher mean EFT compared to those without disease (3.9 ± 0.6 vs. 2.5 ± 0.5 mm, p < 0.001). EFT progressively increased with disease severity: 2.33 mm in normal coronaries, 3.17 mm in mild CAD, 3.80 mm in moderate CAD, and 4.06 mm in severe CAD (p < 0.001). Similarly, EFT rose with vessel involvement, from 3.7 mm in single-vessel disease to 4.4 mm in triple-vessel disease (p < 0.001).ROC curve analysis showed EFT of 3.15 mm as optimal cut-off for predicting obstructive CAD, with an AUC of 0.969, sensitivity 96.3%, and specificity 86.9%. On multivariate regression, EFT ≥3.15 mm was the strongest independent predictor of CAD (AOR 91.3; 95% CI 23.3–357.0, p < 0.001), followed by higher coronary artery calcium score (CACS ≥400: AOR 7.08, p = 0.012). EFT demonstrated a moderate positive correlation with CACS (r = 0.566, p < 0.001).

CONCLUSION Higher epicardial fat thickness measured by multidetector CT in patients undergoing CT coronary angiography was strongly associated with obstructive coronary artery disease.