Prognostic value of the triglyceride–glucose index in patients with premature acute coronary syndrome

Background The triglyceride-glucose (TyG) index has been proposed as an accessible indicator of insulin resistance and cardiometabolic risk. However, its prognostic relevance in patients with premature acute coronary syndrome has not been well defined. We therefore examined baseline clinical features and long-term cardiovascular outcomes in patients with premature acute coronary syndrome (PACS) stratified by TyG status. Methods This retrospective cohort study screened 820 consecutive patients hospitalized with PACS, of whom 804 had complete fasting triglyceride and fasting plasma glucose measurements for TyG calculation. TyG was calculated as ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL) / 2]. Patients were categorized into high and low TyG groups using the 66.7th percentile as the cutoff. The primary outcome was major adverse cardiovascular and cerebrovascular events (MACCE). Results Among 804 eligible patients, 268 (33.3%) were assigned to the high TyG group and 536 (66.7%) to the low TyG group. Patients with high TyG showed a more unfavorable cardiometabolic profile and a higher coronary disease burden at baseline than those with low TyG. During follow-up, MACCE occurred in 17.2% of patients in the high TyG group and in 10.4% of those in the low TyG group. After multivariable adjustment, high TyG remained associated with a higher risk of MACCE (adjusted HR 1.61, 95% CI 1.05–2.47; P = 0.029). TyG analyzed as a standardized continuous variable was also independently associated with MACCE (adjusted HR 1.306, 95% CI 1.039–1.643; P = 0.022). Landmark analysis indicated that the association was more prominent after 365 days. Conclusion In this PACS cohort, elevated TyG was independently associated with an increased risk of MACCE, particularly during longer-term follow-up. TyG may provide a simple adjunctive marker for identifying residual cardiometabolic risk in relatively young patients after ACS.