Impact of triglyceride-glucose index on long-term cardiovascular outcomes in patients with myocardial infarction with nonobstructive coronary arteries

Abstract

Background and aims: Triglyceride-glucose (TyG) index has been reported as a novel surrogate marker of insulin resistance and a risk factor in patients with coronary artery disease. We aimed to investigate the prognostic value of TyG index in a distinct entity with myocardial infarction with nonobstructive coronary arteries (MINOCA).

Methods and results: A total of 1179 MINOCA patients were recruited and divided according to tertile levels of TyG index. The primary endpoint was a composite of major adverse cardiovascular events (MACE), including all-cause death, reinfarction, stroke, revascularization and hospitalization for unstable angina or heart failure. Kaplan-Meier, Cox regression and receiver-operating characteristic analyses were performed. Patients with higher tertiles of TyG index had a significantly higher incidence of MACE (9.6%, 14.9%, 18.0%; p = 0.003) over the median follow-up of 41.7 months. After multivariate adjustment, elevated TyG index was significantly associated with an increased risk of MACE (HR 1.33, 95% CI: 1.04-1.69, p = 0.020). The adjusted risk of MACE also increased with rising tertiles of TyG index (tertile 1 as reference; tertile 2: HR 1.64, 95% CI: 1.06-2.53, p = 0.025; tertile 3: HR 1.85, 95% CI: 1.17-2.93, p = 0.008). The TyG index remained a robust risk factor in overall and subgroups of MINOCA patients (all p < 0.05). Moreover, the TyG index yielded a moderate predictive value of MACE (area under the curve 0.66, 95% CI:0.61-0.71, p < 0.001).

Conclusion: Elevated TyG index was independently associated with a poor prognosis after MINOCA. Routine assessment of TyG index may improve risk stratification and facilitate decision making in MINOCA patients.

Keywords: Cardiovascular outcomes; Insulin resistance; Myocardial infarction with nonobstructive coronary arteries (MINOCA); Triglyceride-glucose index.