Association of Triglyceride-Glucose Index With In-Hospital Malignant Arrhythmias in Older Patients With Diabetes Mellitus and Left Ventricular Aneurysm: A Retrospective Study.

Background: Left ventricular aneurysm (LVA), a severe post-myocardial infarction (MI) complication, predisposes patients to malignant arrhythmias. The triglyceride-glucose (TyG) index, a marker of insulin resistance, is linked to adverse cardiac outcomes. Nevertheless, the association between the TyG index and in-hospital malignant arrhythmias in older, diabetic patients with LVA remains unclear. Methods: This retrospective study (the First Affiliated Hospital of Wenzhou Medical University, China) consecutively enrolled 655 patients with LVAs (aged ≥60 years with confirmed diabetes) from 2004 to 2024. The relationship between the TyG index quartiles and in-hospital malignant arrhythmias was evaluated using Kaplan-Meier (K-M) curves, Cox regression, and restricted cubic spline (RCS) analyses. Mediation analysis was employed to investigate underlying inflammatory pathways. Results: Participants had a median age of 75 years, and 57.56% were males. The RCS analysis indicated that elevated TyG index values were associated with a higher risk of in-hospital malignant arrhythmias; compared with the lowest quartile (Q1), the highest quartile (Q4) showed a nearly threefold higher risk (hazard ratio [HR] = 2.99; 95% confidence interval [CI]: 1.26-7.13). Exploratory pathway analyses indicated that neutrophils (NEs), white blood cells (WBCs), and the systemic inflammation response index (SIRI) partially accounted for this association. Subgroup analyses revealed no significant interactions. Conclusions: This study shows that the TyG index is independently associated with in-hospital malignant arrhythmias in older patients with LVA, serving as a simple, clinically relevant marker to identify high-risk individuals and guide targeted management.