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

Area of Science:

• Cardiology
• Metabolic Syndrome
• Medical Informatics

Background:

• Coronary artery bypass grafting (CABG) carries a significant long-term risk of major adverse cardiovascular and cerebrovascular events (MACCE).
• The triglyceride-glucose (TyG) index is a marker for insulin resistance with predictive value for cardiovascular outcomes.
• Current risk stratification methods do not fully capture the heterogeneity of obesity phenotypes, necessitating novel approaches.

Purpose of the Study:

• To systematically evaluate and compare four novel TyG-adiposity indices (TyG‑CVAI, TyG‑BRI, TyG‑LAP, TyG‑ABSI) for predicting long-term MACCE after CABG.
• To explore the potential mediating role of systemic inflammation in the association between these indices and MACCE.
• To determine if these composite indices offer improved risk stratification compared to the TyG index alone or simple anthropometric measures.

Main Methods:

• A retrospective cohort study of 2547 patients undergoing CABG.
• Calculation of four TyG-adiposity indices from baseline data.
• Assessment of MACCE incidence using multivariable Cox regression, restricted cubic splines, and mediation analysis.
• Evaluation of model performance via Uno's C-index, time-dependent ROC curves, and decision curve analysis.

Main Results:

• Over a median follow-up of 4.25 years, 667 MACCE events occurred.
• All four TyG-adiposity indices were significantly higher in patients experiencing MACCE and independently predicted increased risk.
• TyG‑BRI demonstrated the highest discriminatory ability (Uno's C-index 0.709), outperforming other indices and the TyG index alone.
• C-reactive protein mediated 12.26%-24.20% of the association between the indices and MACCE risk.

Conclusions:

• TyG-adiposity composite indices, particularly TyG‑BRI, are independently associated with long-term MACCE risk post-CABG.
• These novel indices provide incremental predictive value beyond the TyG index or basic anthropometric measures.
• Systemic inflammation partially mediates the relationship, suggesting these indices can refine risk stratification and identify high-risk patients for intensified management.