Triglyceride−glucose index in the prediction of major adverse cardiovascular events in patients with type 2 diabetes mellitus after coronary artery bypass surgery: A retrospective cohort study

Background Insulin resistance (IR) is a significant risk factor for cardiometabolic diseases and a defining feature of type 2 diabetes mellitus (T2DM). This study aimed to examine the potential value of triglyceride-glucose (TyG) index as a predictor of prognosis in coronary heart disease (CHD) patients with T2DM after coronary artery bypass grafting (CABG) surgery and to facilitate the identification of those at high risk of major adverse cardiovascular events (MACEs) for closer monitoring or possible early intervention. Methods This study enrolled 386 T2DM patients who underwent CABG surgery at Nanjing Drum Tower Hospital. Patients were separated into two groups according to the median preoperative TyG Index. The Kaplan-Meier plot was used to compare the rate of MACEs-free survival in T2DM patients after CABG. The independent risk factors for the occurrence of MACEs were investigated using multivariate analysis. Nomogram was used to depict the predictive model. Results Significantly more MACEs occurred in individuals with higher medians of the TyG index (65 (33.7%) vs. 39 (20.2%), p=0.003). TyG index [hazard ratio (HR) 12.926], LVEF [hazard ratio (HR) 0.916], and NYHA functional class III/IV [hazard ratio (HR) 4.331] were identified as independent predictors of MACEs incidence in post-CABG T2DM patients by multivariate analysis. The area under the curve (AUC) for predicting MACEs using the TyG index was 0.89 at five years. Combining the TyG index, LVEF, and NYHA functional class III/IV to build a novel risk assessment model for postoperative MACEs, the AUC climbed to 0.93 at five years. With AUCs, the nomogram comprised of the TyG index, LVEF, and NYHA functional class III/IV demonstrated strong specificity in the training and test sets. Conclusions The incidence of MACEs is high among post-CABG T2DM patients with a high TyG index. TyG index improves the diagnostic accuracy of MACEs, especially at long-term follow-up. A high TyG index may serve as an early warning signal for individuals to undertake lifestyle adjustments that can reduce the progression or incidence of MACEs.