An association between epicardial adipose tissue and prognosis in acute myocardial infarction: a systematic review and meta-analysis.

Background: Acute myocardial infarction (AMI) remains a leading cause of cardiovascular mortality worldwide. Epicardial adipose tissue (EAT), a metabolically and inflammatorily active visceral fat depot, has been increasingly recognized for its potential role in cardiovascular risk stratification. However, its prognostic significance in patients with AMI remains incompletely understood. This study aimed to systematically evaluate the association between EAT and clinical outcomes in AMI. Methods: This meta-analysis was conducted in accordance with PRISMA 2020 guidelines. Embase, PubMed, Web of Science, and the Cochrane Library were systematically searched up to October 16, 2025. Studies reporting quantitative EAT assessment [e.g., EAT thickness, volume, or density measured by echocardiography, computed tomography (CT), or cardiac magnetic resonance (CMR)] and outcomes in AMI patients were included. Risk of bias was assessed using the National Institutes of Health (NIH) Quality Assessment Tool. Hazard ratios (HRs) were pooled for time-to-event outcomes, including major adverse cardiovascular events (MACE). For continuous outcomes, weighted mean differences (WMDs) were applied when measurements were consistent across studies [e.g., left ventricular ejection fraction (LVEF)], whereas standardized mean differences (SMDs) were used when measurement scales differed (e.g., infarct size). Random-effects models were applied in the presence of heterogeneity. Subgroup analyses were performed to explore potential sources of heterogeneity. Results: A total of 10 studies involving 2,772 patients were included. Higher EAT was significantly associated with an increased risk of MACE [HR 1.96, 95% confidence interval (CI): 1.47-2.63], particularly in studies with follow-up duration ≤12 months. No significant association was observed between EAT and LVEF (WMD -0.04, 95% CI: -2.47 to 2.38). Similarly, EAT was not significantly associated with infarct size (SMD 0.23, 95% CI: -0.38 to 0.84), although substantial heterogeneity was present across studies. Conclusions: Elevated EAT is significantly associated with an increased risk of adverse clinical outcomes in patients with AMI, particularly MACE, suggesting its role as a marker of metabolic and inflammatory burden. However, its association with LVEF and infarct size remains inconclusive. Further large-scale prospective studies are warranted to clarify the clinical utility of EAT in AMI risk stratification.