Triglyceride glucose index for predicting cardiovascular outcomes in patients with coronary artery disease

Background: Triglyceride glucose (TyG) index is a novel marker for metabolic disorders and recently it has been reported to be associated with cardiovascular disease (CVD) risk in apparently healthy individuals. However, the prognostic value of TyG index in patients with stable coronary artery disease (CAD) is not determined. Methods: We conducted a nested case-control study among 3,745 patients with stable CAD. Patients were followed up for 11,235 person-years. The cardiovascular events (CVEs) were defined as all-cause death, non-fatal myocardial infarction (MI), stroke and post-discharge revascularization [percutaneous coronary intervention (PCI) coronary artery bypass grafting (CABG)]. In total, 290 (7.7%) patients with CVEs and 1,450 controls were matched according to age, gender, previous history of PCI or CABG and the duration of follow-up. TyG index was calculated as formula: ln[fasting triglycerides (mg/dL) x fasting plasma glucose (mg/dL)/2]. Results: Multivariable Cox proportional hazards models revealed that TyG index was positively associated with CVEs risk (hazard ratio: 1.364, 95% confidence interval: 1.100-1.691, P=0.005). The Kaplan-Meier analysis indicated that patients within the highest quartile of TyG index presented the lowest event-free survival (P=0.029). Moreover, a 1-standard deviation (SD) increment in TyG index was associated with 23.2% [hazard ratio (HR): 1.232, 95% confidence interval (95% CI): 1.084-1.401] higher risk of CVEs, which was superior to other triglyceride or glycemic related markers. Conclusions: The present study, firstly, showed that TyG index was positively associated with future CVEs, suggesting that TyG may be a useful marker for predicting clinical outcomes in patients with CAD.