Stress Hyperglycemia Ratio and Triglyceride–Glucose Index for Predicting In-Hospital Mortality and Heart Failure in Acute Myocardial Infarction

Background: Metabolic dysregulation substantially contributes to adverse outcomes in acute myocardial infarction (AMI). While the triglyceride–glucose (TyG) index reflects chronic insulin resistance, the stress hyperglycemia ratio (SHR) represents acute stress-related glycemic perturbation. Methods: In this retrospective cohort study, 494 patients with STEMI who underwent primary PCI were included. SHR was calculated using admission blood glucose, whereas the TyG index was calculated using glucose and triglyceride levels obtained from routine morning blood samples, generally collected between 04:00 and 06:00 a.m. The primary outcomes were in-hospital mortality and congestive heart failure (CHF). Multivariable logistic regression and receiver operating characteristic (ROC) analyses were performed to evaluate independent associations and discriminative performance. Results: Patients who developed CHF or in-hospital mortality exhibited significantly higher SHR and TyG index levels compared with those without adverse outcomes (all p < 0.05). SHR demonstrated a moderate positive correlation with TyG index (r = 0.441, p < 0.001), supporting the interplay between chronic insulin resistance and acute metabolic stress during AMI. For in-hospital mortality, SHR had a numerically higher area under the ROC curve [AUC: 0.823 (95% CI: 0.727–0.920)] than TyG [AUC: 0.714 (95% CI: 0.605–0.824)]; a formal comparison of the AUCs was not performed. At a cut-off value of 1.45, SHR demonstrated 76.5% sensitivity and 80.0% specificity for in-hospital mortality. In the original multivariable model, the SHR group was associated with in-hospital mortality (OR: 9.61, 95% CI: 2.599–35.578; p = 0.001), although the small number of deaths and incomplete adjustment for established clinical prognostic factors limit interpretation. Conclusions: Among patients with STEMI, both chronic insulin resistance and acute stress-related hyperglycemia were associated with adverse in-hospital outcomes. However, SHR demonstrated superior discriminative capacity and independently predicted mortality, highlighting the dominant prognostic impact of acute metabolic stress during AMI. Integrated assessment of chronic and acute metabolic dysfunction may improve early risk stratification in high-risk myocardial infarction patients.