Abstract
AIM: The triglyceride-glucose (TyG) index, a biomarker commonly used to evaluate metabolic health status, can predict unfavorable outcomes. Thus, we aimed to explore evidence regarding the prognostic value of the TyG index in patients with ischemic cardiomyopathy and heart failure with preserved ejection fraction (HFpEF). METHODS: We enrolled 277 consecutive participants with new-onset ischemic cardiomyopathy and HFpEF who underwent coronary artery bypass grafting (CABG). The primary study endpoint was major adverse cardiovascular events (MACEs), defined as cardiac death, acute myocardial infarction, graft failure, and stroke. RESULTS: During a median follow-up of 43.34 months, 70 patients (25.1%) experienced MACEs. A multivariable Cox regression analysis identified the TyG index as an independent risk factor for MACEs, with a higher baseline TyG index associated with greater risk after adjusting for confounding factors. A restricted cubic spline showed that the TyG index had a linear relationship across the range. The optimal cut-off value of 9.167 for the TyG index demonstrated a sensitivity of 70% and specificity of 84.1%, with an AUC of 0.820 (p＜0.001, 95% CI: 0.762-0.878), thus effectively stratifying participants into lower TyG index (TyG ＜9.167, n = 182) and higher TyG index groups (TyG ≥ 9.167, n = 95), while subgroup analyses confirmed a robust association with MACEs across various populations. Furthermore, the time-dependent area under the curve, calibration curve, and decision curve analyses demonstrated that incorporating the TyG index into the traditional cardiovascular risk factor model significantly enhanced the prediction of MACE risk. Additionally, significant net reclassification improvement (0.335, 95% confidence interval [CI]: 0.136-0.518, p＜0.05) and integrated discrimination improvement (0.178, 95%CI: 0.089-0.270, p＜0.001) were also observed. CONCLUSION: The TyG index is a reliable prognostic indicator for MACEs after CABG in patients with ischemic cardiomyopathy and HFpEF and it serves as a valuable complement to traditional cardiovascular risk factors by providing metabolic-related insights.