Predictive Value of the Triglyceride-Glucose Index (TyG Index) for Major Cardiac Events in Patients With Chronic Heart Failure and Type 2 Diabetes: A Prospective Observational Study

INTRODUCTION: Chronic heart failure (CHF) with coexisting type 2 diabetes mellitus (T2DM) confers a markedly elevated risk of major adverse cardiac events (MACEs). Insulin resistance plays a central pathophysiological role in this excess risk, yet direct assessment remains impractical in routine care. The triglyceride-glucose (TyG) index, a straightforward surrogate indicator of insulin resistance derived from fasting glucose and triglyceride levels, has emerged as a potential prognostic tool. This study evaluated the predictive value of the TyG index for MACE in patients with CHF and T2DM. METHOD: This prospective observational study was conducted at a tertiary care cardiology center in Bangladesh from July 2023 to August 2024. Eighty-three adults with confirmed CHF and T2DM were enrolled and followed for six months. Baseline clinical, echocardiographic, and biochemical parameters were recorded, and the TyG index was calculated using a validated formula. Major adverse cardiac events, including cardiovascular death, heart-failure-related hospitalization, and ischemic cardiac events, were adjudicated by blinded cardiologists. Group comparisons, quartile analysis, and receiver operating characteristic (ROC) curve analysis were performed to evaluate the prognostic performance. RESULTS: Major adverse cardiac events occurred in 69 (83.1%) of patients, predominantly due to heart-failure-related hospitalization in 67 (80.7%). The TyG index was significantly higher in patients with MACE compared with those without MACE (6.8 ± 0.7 vs. 5.8 ± 0.6; p=0.001). Higher TyG quartiles were significantly associated with mortality and heart-failure hospitalization (p<0.05). ROC analysis demonstrated excellent predictive accuracy for MACE (AUC=0.890; 95% CI: 0.818-0.962), with an optimal cutoff of ≥6.30 yielding 53/69 (76.8%) sensitivity and 13/14 (92.9%) specificity. CONCLUSION: The TyG index is a strong and clinically useful predictor of major adverse cardiac events in patients with coexisting CHF and T2DM. Its simplicity and accessibility support its integration into routine risk stratification, particularly in resource-limited settings.