Insulin resistance predicts the risk for recurrent coronary events in post-infarction patients

BACKGROUND: We investigated the risk for recurrent coronary events associated with insulin resistance in post-infarction patients from the Thrombogenic Factors and Recurrent Coronary Events (THROMBO) study. METHODS: The association between insulin resistance expressed by Homeostatic Model As-sessment 2 for Insulin Resistance (HOMA2-IR) and the risk for recurrent coronary events was investigated in a cohort of 1,032 patients evaluated 2 months after myocardial infarction (MI) with a follow-up of 26 months. The endpoint for the study was recurrent coronary event defined as cardiac death, nonfatal MI, or unstable angina, whichever occurred first. We used time dependent survival analysis and Cox proportional hazards regression method to determine the association between HOMA2 categorized as high > 75th percentile and endpoints after adjustment for relevant clinical covariates and series of thrombogenic and dyslipogenic factors. RESULTS: High HOMA2-IR defined as in fourth quartile (≥ 2.4) was associated with increased risk for recurrent coronary events (HR 1.44; CI 1.03-2.01; p = 0.03) after adjustment for the clinical covariates: age, gender, diabetes, prior MI, pulmonary congestion, coronary artery bypass grafting and percutaneous transluminal coronary angioplasty. The highest risk of cardiac events was observed in non-obese patients (body mass index [BMI] ≤ 30 kg/m2) with high HOMA2-IR (HR 1.5; CI 1.02-2.22; p = 0.038). The plasma level of plasminogen activa-tor inhibitor-1 was associated with higher risk for recurrent coronary events in patients with insulin resistance (HR 1.79; CI 1.05-3.03; p = 0.03, interaction p = 0.018). CONCLUSIONS: In conclusion, insulin resistance predicts recurrence of coronary events in post-infarction population. HOMA2-IR is better than BMI in stratifying risk of recurrent coronary events.