Metabolic score for insulin resistance as a predictor of mortality in heart failure with preserved ejection fraction: results from a multicenter cohort study

BACKGROUND: The metabolic score for insulin resistance (METS-IR) has been validated as a novel, simple, and reliable surrogate marker for insulin resistance; however, its utility for evaluating the prognosis of heart failure with preserved ejection fraction (HFpEF) remains to be elucidated. Therefore, we aimed to analyze the association between METS-IR and the long-term prognosis of HFpEF. METHODS: We enrolled a total of 4,702 participants with HFpEF in this study. The participants were divided into three groups according to METS-IR tertiles: (Ln [2 × fasting plasma glucose + fasting triglycerides] × body mass index) / (Ln [high-density lipoprotein cholesterol]). The occurrence of primary endpoints, including all-cause mortality and cardiovascular (CV) death, was documented. RESULTS: There were 3,248 participants with HFpEF (mean age, 65.7 ± 13.8 years; male, 59.0%) in total who were included in the final analysis. The incidence of primary outcomes from the lowest to the highest METS-IR tertiles were 46.92, 86.01, and 124.04 per 1000 person-years for all-cause death and 26.75, 49.01, and 64.62 per 1000 person-years for CV death. The multivariate Cox hazards regression analysis revealed hazard ratios for all-cause and CV deaths of 2.48 (95% CI 2.10-2.93; P < 0.001) and 2.29 (95% CI 1.83-2.87; P < 0.001) when the highest and lowest METS-IR tertiles were compared, respectively. In addition, the predictive efficacy of METS-IR remained significant across various comorbidity subgroups (all P < 0.05). Further, adding the METS-IR to the baseline risk model for all-cause death improved the C-statistic value (0.690 for the baseline model vs. 0.729 for the baseline model + METS-IR, P < 0.01), the integrated discrimination improvement value (0.061, P < 0.01), the net reclassification improvement value (0.491, P < 0.01), and the clinical net benefit. CONCLUSIONS: An elevated METS-IR, which is associated with an increased mortality risk, is a potential valuable prognostic marker for individuals with HFpEF.