TyG-adiposity composites predict long-term MACCE after CABG: Evidence for partial mediation by CRP

Coronary artery bypass grafting (CABG) is associated with a significant long-term risk of major adverse cardiovascular and cerebrovascular events (MACCE). The triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, has demonstrated predictive value for cardiovascular outcomes but does not account for the heterogeneity of obesity phenotypes. Integrating the TyG index with measures of visceral adiposity may improve risk stratification in patients after CABG.

This study aimed to systematically evaluate and compare the ability of four novel TyG‑adiposity indices (TyG‑CVAI, TyG‑BRI, TyG‑LAP, and TyG‑ABSI) to predict long‑term MACCE following CABG, and to explore the potential mediating role of systemic inflammation in this association.

In a retrospective cohort of 2547 consecutive patients undergoing CABG, the four TyG‑adiposity indices were calculated from baseline clinical and laboratory data. The primary endpoint was the incidence of MACCE. Associations were assessed using multivariable Cox regression, restricted cubic splines for dose‑response relationships, and mediation analysis. Model performance was evaluated using Uno's C‑index, time‑dependent ROC curves, and decision curve analysis.

Over a median follow‑up of 4.25 years, 667 MACCE events occurred. All TyG‑adiposity indices were significantly higher in patients who experienced MACCE. After full adjustment, each index independently predicted increased MACCE risk, with strong dose‑response relationships (all P for trend <0.001). TyG‑BRI demonstrated the highest discriminatory ability (Uno's C‑index 0.709, 95 % CI 0.681-0.737), outperforming TyG‑CVAI (0.685), TyG‑LAP (0.651), TyG‑ABSI (0.587), and the TyG index alone (0.576). C‑reactive protein mediated 12.26 %-24.20 % of the association between the indices and MACCE risk.

TyG‑adiposity composites, particularly TyG‑BRI, are independently associated with long‑term MACCE risk after CABG and provide incremental predictive value over the TyG index or simple anthropometric measures. The association is partly mediated by systemic inflammation. These indices may help refine risk stratification across metabolic phenotypes and identify high‑risk patients for intensified management.