Abstract
BACKGROUND: Metabolic dysfunction significantly influences cardiovascular outcomes following ST-elevation myocardial infarction (STEMI). The triglyceride-glucose (TyG) index and triglyceride-glucose-body mass index (TyG-BMI) serve as surrogate markers of insulin resistance, whereas B-type natriuretic peptide (BNP) levels reflect cardiac dysfunction. However, the combined prognostic value of these biomarkers for predicting major adverse cardiovascular events (MACEs) in patients with STEMI remains underexplored. METHODS: We conducted a retrospective cohort study of 1177 consecutive patients with STEMI who underwent percutaneous coronary intervention between August 2018 and December 2023. Patients were stratified into four groups based on the TyG index (cutoff: 7.2), TyG-BMI (cutoff: 186), and BNP level (cutoff: 300 pg/mL). The primary endpoint was MACEs, defined as a composite of all-cause mortality, nonfatal myocardial infarction, ischemia-driven repeat revascularization, heart failure hospitalization, and cerebrovascular events. Cox proportional hazards models with progressive adjustment were employed to assess independent and combined prognostic significance. RESULTS: A total of 483 patients (41.0%) experienced MACEs during a median follow-up of 461 days (interquartile range (IQR): 79-672). Patients with both an elevated TyG index (≥7.2) and a high BNP concentration (≥300 pg/mL) demonstrated the highest cardiovascular risk profile and a more than twofold increased MACE risk (hazard ratio (HR) 2.18, 95% confidence interval (CI): 1.57-3.03; p < 0.001) compared with the reference group (those with a low TyG index and low BNP concentration). Similarly, patients with elevated TyG-BMIs (≥186) and BNP levels had an 81% increased risk (HR 1.81, 95% CI: 1.30-2.51; p < 0.001). Meanwhile, the combined TyG index + BNP model demonstrated superior predictive accuracy (area under the curve (AUC): 0.67) compared with the individual biomarkers and the established Global Registry of Acute Coronary Events (GRACE) score (AUC: 0.58). Subgroup analyses revealed particularly pronounced associations in older patients, females, and those with hypertension. CONCLUSIONS: The combination of the TyG index or TyG-BMI with BNP provides enhanced prognostic stratification for predicting MACEs in STEMI patients, offering superior discriminatory capacity compared with that of individual biomarkers. This integrated approach may facilitate personalized risk assessment and guide therapeutic decision-making in clinical practice.