The Relationship and Differences in the Triglyceride-Glucose Index and All-Cause Mortality in Patients with Coronary Heart Disease Combined with Cerebrovascular and Other Comorbidities: An Analysis of the MIMIC-IV Database

Zeng Xiao Xiaoli Liu ^* Peiyuan He Ping Shuai Yuping Liu

• Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China

Objective This study aims to investigate the predictive capability of the triglyceride-glucose index (TyG index) for allcause mortality among patients with coronary heart disease (CHD), particularly in those with cerebrovascular disease (CVD) and other comorbidities, based on the MIMIC-IV database.Methods Using the ICD-9/10 coding standards, eligible CHD patients were identified from the MIMIC-IV database (version 3.0) with defined inclusion and exclusion criteria to ensure sample representativeness. Patients were categorized into CVD and other comorbidity groups. Data on mortality rates at 90 days, 1 year, and overall were collected, along with the TyG index and relevant covariates associated with survival risk. Baseline analyses, Spearman correlation, and restricted cubic splines (RCS) were employed to assess the nonlinear relationship between the TyG index and mortality. Kaplan-Meier curves and Cox proportional hazards models were utilized to evaluate survival risk.Results A total of 1,872 CHD patients were included, with 578 having CVD and a mortality rate of 50.17%; 1,294 had other comorbidities with a mortality rate of 64.91%. RCS analysis indicated a nonlinear relationship between the TyG index and mortality risk. For patients with concurrent CVD, the lowest mortality risk occurred at a TyG index of 9.37 mmol/L, while for those with other comorbidities, the lowest risk was observed at 9.36 mmol/L. Cox regression analysis revealed a significant association between the TyG index and survival risk in all CHD patients (HR = 1.15, 95%CI: 1.04 -1.28, P < 0.01). In patients with other comorbidities, an increase in the TyG index was significantly correlated with elevated mortality risk (HR = 1.21, 95%CI: 1.02 -1.34, P < 0.01).The TyG index exhibits a nonlinear relationship with mortality risk in CHD patients, with elevated levels significantly increasing mortality risk in those with other comorbidities. These findings suggest that the TyG index may serve as a critical metabolic marker for prognostic evaluation in CHD patients, warranting further clinical attention.