Impact of Location of Epicardial Adipose Tissue, Measured by Coronary Artery Calcium-Scoring Computed Tomography on Obstructive Coronary Artery Disease

Abstract

Epicardial adipose tissue (EAT) is considered to play a role in the pathogenesis of coronary atherosclerosis. However, whether total EAT volume or location-specific EAT thickness may be a better predictor of obstructive coronary artery disease (CAD) is inconclusive. We investigated whether the total volume or location-specific thickness of EAT measured on computed tomography (CT) could be a useful marker of CAD on top of clinical risk factors and Agatston score. Two hundred eight consecutive subjects with clinical suspicion of CAD receiving coronary arterial calcium (CAC)-scoring CT and CT coronary angiography were retrospectively divided into 2 groups: an obstructive CAD group (n= 97) and a nonobstructive CAD group (n= 111). Total EAT volume and EAT thicknesses at different locations were measured on CAC-scoring CT. Left atrioventricular groove (AVG) EAT thickness was the sole EAT measurement that showed association with increasing number of vessels exhibiting ≥50% stenosis (p for trend <0.001). Logistic regression showed that left AVG EAT thickness was the most important EAT predictor of obstructive CAD (odds ratio 1.16, 95% confidence interval 1.04 to 1.29, p= 0.006; optimal threshold ≥15 mm, odds ratio 4.62, 95% confidence interval 2.24 to 9.56, p <0.001). Adding left AVG EAT thickness on top of clinical risk factors plus Agatston score improved prediction of obstructive CAD (area under the curve from 0.848 to 0.912, p= 0.002). In conclusion, excessive left AVG EAT adiposity is an important risk factor for obstructive CAD, independent of clinical risk factors and Agatston score. However, further trials are needed in investigation of combined assessment of location-specific EAT thickness and Agatston score on CAC scan as to whether this biomarker could improve CAD risk stratification in the general population.