Association Between C-Reactive Protein-Triglyceride Glucose Index and Adverse Cardiovascular Outcomes in Acute Coronary Syndrome Patients With Prior Coronary Artery Bypass Grafting.

backgroundPatients with acute coronary syndrome (ACS) who have previously undergone coronary artery bypass grafting (CABG) represent a complex, high-risk population characterized by a substantial burden of atherosclerosis and a marked propensity for recurrent ischemic events. The pathophysiological interplay between systemic inflammation and insulin resistance serves as a key mediator driving the progression of atherosclerosis and the destabilization of atherosclerotic plaques. However, the prognostic impact of their combined effect, quantified by a novel composite biomarker-the C-reactive protein-triglyceride glucose index (CTI)-remains uncertain in this specific high-risk population.

methodsWe enrolled 1195 ACS patients with prior CABG who underwent percutaneous coronary intervention (PCI). The CTI was calculated as 0.412 × ln (high-sensitivity C-reactive protein [mg/L]) + ln (fasting triglycerides [mg/dL] × fasting blood glucose [mg/dL]/2). Patients were divided into three groups based on their CTI tertiles. The primary endpoint was defined as the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE), which encompassed all-cause death, nonfatal stroke, nonfatal myocardial infarction (MI), and unplanned revascularization.

resultsOver a median follow-up of 3 years, 366 patients experienced MACCE. The incidence of MACCE progressively increased across CTI tertiles (log-rank p  < 0.001). In the multivariable Cox proportional hazards model adjusted for the GRACE (Global Registry of Acute Coronary Events) risk score and a comprehensive panel of clinical, procedural, and laboratory confounders, the highest CTI tertile remained an independent predictor of MACCE (adjusted hazard ratio [HR]: 3.864, 95% confidence interval [CI]: 2.710-5.511, p  < 0.001). When CTI was analyzed as a continuous variable, each unit increase was found to confer an 80.1% greater risk of MACCE (adjusted HR: 1.801, 95% CI: 1.556-2.085, p  < 0.001). This association remained consistent across all predefined subgroups. Adding CTI tertiles to the baseline model-which encompassed the GRACE risk score and other confounders-yielded a modest but statistically significant improvement in predictive performance (C-statistic increased from 0.605 to 0.655, p  < 0.001; continuous net reclassification improvement [cNRI]: 0.740, p = 0.032; integrated discrimination improvement [IDI]: 0.145, p = 0.020).

conclusionsThe CTI-a composite biomarker that captures both systemic inflammation and insulin resistance-emerged as a significant and independent predictor of long-term MACCE in ACS patients with prior CABG who underwent PCI. Its integration into risk stratification models may improve prognostic assessment and potentially facilitate more personalized and intensive secondary prevention strategies.