Abstract
BACKGROUND: The Triglyceride-Glucose (TyG) index is a surrogate marker of insulin resistance and has been associated with cardiovascular outcomes. However, most studies used single-timepoint measurements, failing to capture its dynamic changes after STEMI. METHODS: In this retrospective cohort study, 1,092 STEMI patients undergoing PCI were followed for five years. TyG index was measured at baseline and at 3, 6, 9, and 12 months post-discharge. Group-Based Trajectory Modeling (GBTM) was used to identify TyG index trajectories. Cox regression and Kaplan-Meier analysis evaluated their association with major adverse cardiovascular events (MACE). RESULTS: Three distinct TyG trajectories were identified: persistently high (n = 92), moderate (n = 196), and rapid decline (n = 804). The rapid decline group had significantly lower MACE incidence compared to the persistently high group (P < 0.001). TyG trajectory was an independent predictor of outcomes. CONCLUSION: Distinct TyG trajectories after STEMI are associated with long-term prognosis. A persistently high TyG trajectory indicates elevated cardiovascular risk, suggesting its potential role in secondary prevention.