Association between the triglyceride-glucose index and major adverse cardiovascular and cerebrovascular events after percutaneous coronary intervention.

BACKGROUND: The triglyceride-glucose (TyG) index is a simple surrogate marker of insulin resistance (IR), but its prognostic value in patients undergoing percutaneous coronary intervention (PCI) remains incompletely defined. This study investigated the association between the TyG index and major adverse cardiovascular and cerebrovascular events (MACCE) after PCI. METHODS: This single-center retrospective cohort study included 4,366 patients who underwent PCI between October 2018 and September 2021. The TyG index was calculated from fasting triglyceride (TG) and fasting blood glucose (FBG) levels and analyzed both as a continuous variable and according to quartiles. The primary endpoint was MACCE, defined as a composite of all-cause death, hospitalization for heart failure (HF), recurrent myocardial infarction (MI), stent thrombosis, unplanned repeat revascularization, and stroke. Multivariable Cox regression, restricted cubic spline (RCS) analysis, subgroup analysis, and incremental prognostic value analysis were performed. RESULTS: During a median follow-up of 30 months, 431 patients experienced MACCE. MACCE rates across TyG quartiles were 10.2%, 8.4%, 9.1%, and 11.8%, respectively. In the fully adjusted model, each 1-unit increase in the TyG index was associated with a higher risk of MACCE [hazard ratio (HR) =1.297, 95% confidence interval (CI): 1.114-1.512, P<0.001]. Compared with the lowest quartile, the highest TyG quartile was associated with increased MACCE risk (HR =1.597, 95% CI: 1.204-2.119, P=0.001). RCS analysis showed an overall association without statistically significant non-linearity. Subgroup analyses showed generally consistent directions of association. Adding the TyG index modestly improved the C-index from 0.6564 to 0.6629, with a continuous net reclassification improvement (NRI) of 0.0971 and an integrated discrimination improvement (IDI) of 0.0019. CONCLUSIONS: The TyG index was modestly but independently associated with MACCE after PCI. The increased risk was mainly observed in the highest TyG quartile, without evidence of a clear nonlinear or threshold effect. The TyG index may serve as a convenient marker of residual metabolic risk after PCI, although further external validation is warranted.