Non-contrast chest CT-derived epicardial adipose tissue volume index and major adverse cardiovascular events after PCI for acute myocardial infarction: a retrospective cohort study

Background Major adverse cardiovascular events (MACE) remain common after successful percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). Epicardial adipose tissue volume index (EATVI) derived from routine non-contrast chest computed tomography (CT) may reflect residual cardiometabolic and inflammatory risk, but its association with post-PCI MACE and its incremental prognostic value beyond conventional clinical risk markers remain incompletely understood. Methods The final cohort comprised 367 patients with AMI who underwent PCI and non-contrast chest CT between January 2023 and December 2024. EATVI was calculated by indexing semi-automatically segmented EAT volume to body surface area. The endpoint was first major adverse cardiovascular event (MACE), comprising cardiac death, recurrent myocardial infarction, or rehospitalization for heart failure or unstable or progressive angina. Kaplan–Meier analysis, restricted cubic splines, and sequential Cox models assessed associations. Machine-learning-assisted screening informed a four-variable model that was internally validated using 1,000 bootstrap resamples and converted into an integer score. We compared the model with the Global Registry of Acute Coronary Events (GRACE) score alone and GRACE plus EATVI. Results During a median 26.38-month follow-up, 91 patients (24.8%) experienced MACE. Event rates increased from 16.3% to 31.1% across EATVI tertiles (log-rank P = 0.018). Each 22.9 mL/m² increase in EATVI was independently associated with MACE in the fully adjusted model (hazard ratio 1.47, 95% confidence interval 1.18–1.84; P < 0.001). Adding EATVI increased the GRACE C-index from 0.527 to 0.601 ( P = 0.033). The simplified model achieved a C-index of 0.682 (bootstrap-corrected: 0.671) and bootstrap-corrected 6-, 12-, and 24-month areas under the curve of 0.725, 0.709, and 0.690. The integer score separated low-, intermediate-, and high-risk groups, with MACE rates of 11.3%, 24.5%, and 48.1%, respectively (log-rank P < 0.001). Conclusions Routine non-contrast chest CT-derived EATVI identified residual risk after PCI for AMI and improved prognostic assessment beyond GRACE. The simplified model showed moderate internally validated discrimination, but external validation is required before clinical use.