Synergistic Prognostic Value of Epicardial Fat Volume and Triglyceride-Glucose Index in Heart Failure Patients With Glycemic Dysregulation

Background:Glycemic abnormalities are highly prevalent in chronic heart failure (CHF) and exacerbate adverse cardiac remodeling. Epicardial fat volume (EFV) and the triglyceride-glucose (TyG) index may both reflect metabolic-cardiovascular interactions, but their combined prognostic utility in CHF patients with dysglycemia remains unexplored.Methods:We analyzed 516 CHF patients stratified by glycemic status: normal glucose (n = 230), prediabetes (n = 174), and diabetes (n = 112). Baseline characteristics, echocardiography (TTE), and cardiac magnetic resonance (CMR) data were assessed. The primary endpoint was defined as a composite of heart-failure hospitalization or all-cause mortality and was evaluated during a follow-up period of up to 3 years. Associations between EFV, TyG index, and primary endpoint were evaluated using stratified, joint, and incremental prognostic models.Results:Diabetic CHF patients were generally older, had higher smoking rates, worse renal function, and poorer nutritional status. CMR and TTE revealed more severe cardiac structural and functional impairments in dysglycemic groups, including reduced left ventricular ejection fraction (LVEF) and elevated EFV. EFV predicted primary endpoint with increasing accuracy across glycemic strata (AUC: 0.631–0.711 at 1–3 years), with the strongest predictive performance in diabetes. A significant correlation between TyG index and EFV was observed in diabetic patients (r = 0.24, p = 0.00021). Joint EFV (cutoff: 74.68 mL/m²) and TyG (median: 8.48) analysis showed that high TyG alone or combined high EFV/TyG conferred the highest the risk of primary endpoint (p for trend < 0.001), while isolated EFV elevation did not. Incorporating EFV into TyG-based models significantly improved prediction (AUC increased from 0.698 to 0.729 at 1 year). Net reclassification and integrated discrimination improvements confirmed the incremental prognostic value of EFV, particularly in diabetes and over longer follow-up.Conclusion:In CHF patients with glycemic dysregulation, EFV and TyG index synergistically enhance clinical endpoint prediction, with EFV providing significant incremental prognostic value beyond TyG. These metrics may improve risk stratification and personalized management in comorbid heart failure and dysglycemia.