Long-term Survival in Ischemic Stroke Patients: A Comprehensive Analysis of the TyG-AIP-BMI Composite Index (TabCI) from MIMIC-IV ICU Data

Background Insulin resistance-induced metabolic disorders play a crucial role in exacerbating ischemic stroke. This study aims to explore the association between TabCI and long-term mortality risk in severe ischemic stroke patients. Methods Data from the Medical Information Mart for Intensive Care IV (MIMIC-IV 2.2) database were accessed to retrieve data of ischemic stroke patients. Patients were stratified into four groups based on TabCI quartiles. The study assessed the primary outcome of 180-day all-cause mortality and secondary outcomes including 90-day and 1-year ACM. Kaplan-Meier curves were used to compare outcomes across groups, and lasso regression analysis was employed to select covariates. Multivariable Cox proportional hazards regression models and restricted cubic splines (RCS) were used to explore the association between TabCI and these outcomes. Lastly, interaction and subgroup analyses were conducted to validate the stability of results. Results A total of 1,141 severe ischemic stroke patients were included, with a mean age of 69 years (interquartile range [IQR]: 59-79), and 565 participants (49.5%) were male. Kaplan-Meier analysis indicated significantly lower long-term survival rates in patients in Q1 and Q3 compared to those in Q2 and Q4. Cox proportional hazards regression analysis adjusted for covariates showed a statistically significant increase in 180-day mortality risk in TabCI quartiles, with Q2 and Q4 groups also exhibiting increased risks at 90 days and 1 year. Additionally, RCS analysis revealed a gradual L-shaped correlation between TabCI and 90-day and 180-day all-cause mortality, with a smooth U-shaped trend observed for 1-year mortality, demonstrating significant non-linearity. Subgroup analysis further indicated an inverse correlation between TabCI and long-term mortality risk in non-Caucasian patients and those using aspirin, as well as negative correlations in TabCI among patients not receiving CRRT for 90-day and 180-day mortality. Conclusion TabCI could serve as a marker for stratifying long-term risk among severe ischemic stroke patients, although its clinical predictive efficacy for long-term mortality in these patients is limited.