Beyond luminal stenosis: Epicardial adipose tissue volume reflects coronary plaque burden according to CAD-RADS 2.0

To evaluate the association between epicardial adipose tissue (EAT) volume (EAV) and CAD-RADS 2.0-based coronary plaque burden, and to explore its relationship with stenosis severity, plaque phenotype, and high-risk plaque (HRP) features.

In this retrospective study, 221 patients undergoing same-day ECG-gated non-contrast cardiac CT and coronary CT angiography were included. Stenosis severity, plaque phenotype, HRP features, and plaque burden were classified according to CAD-RADS 2.0, including P-score assessment. EAV was semi-automatically quantified on non-contrast CT using an attenuation threshold of - 200 to - 30 HU. Associations between EAV and imaging parameters were evaluated using multivariable analyses adjusted for traditional cardiovascular risk factors. Incremental predictive value for extensive plaque burden was assessed using nested models incorporating traditional risk factors, coronary artery calcium (CAC) score, and EAV.

EAV was significantly higher in patients with CAD than in plaque-free individuals and remained independently associated with CAD after adjustment for traditional risk factors and CAC. CAD prevalence increased across EAV quartiles, from 70.2 % in the lowest quartile to 92.9 % in the highest quartile. Among patients with CAD, the prevalence of extensive plaque burden increased from 15.6 % to 46.7 % across EAV quartiles. EAV improved prediction of extensive plaque burden beyond traditional risk factors; however, its incremental value beyond CAC was limited. EAV was not consistently associated with plaque phenotype or HRP features. Inter- and intraobserver agreement for EAV quantification was excellent (ICC: 0.969-0.998).

EAV is associated with CAD presence, stenosis severity, and overall plaque burden, supporting its role as a complementary imaging biomarker of atherosclerotic burden on non-contrast cardiac CT.