Role of Epicardial Adipose Tissue Volume and Attenuation on Computed Tomography Angiography as Independent Predictors of Major Adverse Cardiovascular Events in Patients with Stable Coronary Artery Disease and Preserved Ejection Fraction

✅ Abstract Background: Epicardial adipose tissue (EAT) is a metabolically active visceral fat depot that plays a crucial role in coronary atherosclerosis through paracrine and inflammatory mechanisms. Quantification of EAT volume and attenuation using coronary computed tomography angiography (CCTA) has emerged as a promising noninvasive marker of cardiovascular risk. However, the prognostic significance of EAT characteristics in patients with stable coronary artery disease (CAD) and preserved left ventricular ejection fraction (LVEF) remains insufficiently characterized. Objectives: To investigate whether EAT volume and attenuation measured by CCTA independently predict major adverse cardiovascular events (MACE) in patients with stable CAD and preserved LVEF. Methods: This prospective observational study included 520 patients with stable CAD confirmed by CCTA and preserved LVEF (≥50%). EAT volume was quantified using semiautomated software, and EAT attenuation was assessed in Hounsfield units (HU). Patients were followed for a median of 36 months. The primary endpoint was a composite of MACE, including cardiovascular death, nonfatal myocardial infarction, unstable angina requiring revascularization, and hospitalization for heart failure. Multivariable Cox proportional hazards models were used to evaluate the independent prognostic value of EAT parameters after adjustment for traditional cardiovascular risk factors, coronary plaque burden, and inflammatory biomarkers. Results: During follow-up, MACE occurred in 68 patients (13.1%). Patients who experienced MACE demonstrated significantly higher EAT volume and lower EAT attenuation values compared with event-free patients (p < 0.001 for both). Increased EAT volume was independently associated with higher MACE risk (hazard ratio [HR] 1.34 per 10 mL increase; 95% confidence interval [CI], 1.18–1.52; p < 0.001). Lower EAT attenuation, suggestive of greater inflammatory activity, was also independently associated with adverse outcomes (HR 1.27 per 5 HU decrease; 95% CI, 1.11–1.45; p = 0.002). Incorporation of EAT parameters into risk prediction models significantly improved discrimination and reclassification metrics beyond conventional clinical and imaging variables. Conclusions: EAT volume and attenuation assessed by CCTA are independent predictors of adverse cardiovascular outcomes in patients with stable CAD and preserved LVEF. These findings highlight the potential value of EAT characterization as a novel imaging biomarker for risk stratification and personalized therapeutic strategies in stable CAD populations. Further studies are warranted to determine whether targeted interventions aimed at modulating EAT inflammation can improve clinical outcomes.