Purpose: This study aimed to evaluate the association between metabolic score for insulin resistance (METS-IR) and adverse cardiovascular events in patients with ischemic cardiomyopathy (ICM) and type 2 diabetes mellitus (T2DM).
Methods: METS-IR was calculated using the following formula: ln[(2 × fasting plasma glucose (mg/dL) + fasting triglyceride (mg/dL)] × body mass index (kg/m²)/(ln[high-density lipoprotein cholesterol (mg/dL)]). Major adverse cardiovascular events (MACEs) were defined as the composite outcome of nonfatal myocardial infarction, cardiac death, and rehospitalization for heart failure. Cox proportional hazards regression analysis was used to evaluate the association between METS-IR and adverse outcomes. The predictive value of METS-IR was evaluated by the area under the curve (AUC), continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI).
Results: The incidence of MACEs increased with METS-IR tertiles at a 3-year follow-up. Kaplan‒Meier curves showed a significant difference in event-free survival probability between METS-IR tertiles (P< 0.05). Multivariate Cox hazard regression analysis adjusting for multiple confounding factors showed that when comparing the highest and lowest METS-IR tertiles, the hazard ratio was 1.886 (95% CI:1.613– 2.204; P< 0.001). Adding METS-IR to the established risk model had an incremental effect on the predicted value of MACEs (AUC=0.637, 95% CI:0.605– 0.670, P< 0.001; NRI=0.191, P< 0.001; IDI=0.028, P< 0.001).
Conclusion: METS-IR, a simple score of insulin resistance, predicts the occurrence of MACEs in patients with ICM and T2DM, independent of known cardiovascular risk factors. These results suggest that METS-IR may be a useful marker for risk stratification and prognosis in patients with ICM and T2DM.
Keywords: metabolic score for insulin resistance, ischemic cardiomyopathy, type 2 diabetes mellitus, major adverse cardiac events, prognosis