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 the setting of acute myocardial infarction (AMI). Epicardial adipose tissue volume index (EATVI) derived from non-contrast chest computed tomography (CT) may reflect residual cardiovascular risk, but its association with post-PCI MACE remains incompletely understood. Methods We enrolled 367 patients with AMI treated with PCI from January 2023 to December 2024 who had available chest CT scans. EATVI was calculated by indexing semi-automatically segmented epicardial adipose tissue volume (EATV) derived from non-contrast chest CT to body surface area. Multivariable Cox regression was used to evaluate the relationship between EATVI and MACE. Incremental prognostic value beyond a clinical model was evaluated using Harrell’s C-index, category-free net reclassification improvement (cNRI), and integrated discrimination improvement (IDI). An exploratory Cox model used least absolute shrinkage and selection operator (LASSO) regression and was internally validated through 1,000 bootstrap resamples of the entire modeling procedure. Results During a median follow-up of 26.38 months, 91 patients (24.8%) experienced MACE. Each 22.91 mL/m² (one standard deviation) increase in EATVI was associated with MACE after adjusting for covariates (HR = 1.45; 95% CI 1.17–1.79; P < 0.001). After EATVI was incorporated into the clinical base model, the C-index increased modestly from 0.676 to 0.690 (ΔC-index = 0.014; 95% CI −0.002–0.048). At 12 months, cNRI was 0.365 (95% CI 0.078–0.720) and IDI was 0.030 (95% CI 0.004–0.074). EATV provided broadly similar incremental prognostic information. The exploratory LASSO-Cox model retained EATVI, diabetes mellitus, Killip class ≥ II, and Gensini score in the full cohort. However, complete-process bootstrap validation demonstrated substantial selection instability, with no predictors retained in 85.2% of resamples. Conclusions Non-contrast chest CT-derived EATVI was associated with post-PCI MACE and provided modest incremental prognostic information beyond conventional clinical factors. Its potential role in post-PCI risk assessment warrants prospective external validation.