ObjectiveTo investigate the predictive value of the triglyceride glucose (TyG) index in major adverse cardiovascular events (MACE) in patients after coronary artery bypass graft (CABG) surgery. MethodsA retrospective collection of patients with coronary atherosclerotic heart disease who underwent CABG treatment in the Department of Cardiac Surgery Ward 1, the 7th People’s Hospital of Zhengzhou, from 2015 to 2024 was conducted. The X-tile software was used to calculate the nearest cutoff value of the TyG index, and patients were divided into groups based on this optimal cutoff value. The association between the TyG index and MACE was explored through univariate analysis, Kaplan-Meier survival curve analysis, and Cox regression analysis. The predictive ability of the TyG index was evaluated by important factor ranking and the area under the receiver operating characteristic curve (AUC). ResultsA total of 998 patients were included, with 630 patients having a TyG index ≤8.80, including 438 males and 192 females, with a median age of 55 (60, 65) years; and 368 patients with a TyG index >8.80, including 236 males and 132 females, with a median age of 57 (63, 69) years. Cumulative survival curves showed that the incidence of MACE in the TyG≤8.80 group was significantly lower than in the TyG>8.80 group (log-rank test, P<0.001). Cox regression analysis indicated that TyG>8.80 was an independent risk factor for MACE [HR=2.581, 95%CI (1.201, 5.549), P<0.001]. In the important factor ranking, the TyG index had the greatest impact on MACE. The TyG index could enhance the predictive ability of the MACE prediction model, with the AUC increasing from 0.712 to 0.872. ConclusionThe TyG index can serve as an effective predictive indicator for MACE after CABG surgery.