Association of early blood glucose metrics with short- and long-term prognosis in acute myocardial infarction patients: a retrospective cohort study

Acute myocardial infarction (AMI) remains a major cause of morbidity and mortality globally. Recent evidence suggests that beyond single blood glucose measurements, early glycemic fluctuations and stress hyperglycemia may have significant prognostic implications in AMI patients. This study investigates the association between early blood glucose variability indices—including glucose standard deviation (SD), coefficient of variation (CV), mean, and range—and outcomes, as well as the prognostic role of the stress hyperglycemia ratio (SHR) and admission glucose. We conducted a retrospective cohort study using data extracted from the MIMIC-IV database. Blood glucose measurements within the first 48 h of hospital admission were used to calculate glycemic variability metrics and the SHR. Cox proportional hazards regression models, along with restricted cubic spline (RCS) analyses, were employed to evaluate the relationship between these glucose metrics and the primary outcome of 5-year all-cause mortality, as well as the secondary outcome of in-hospital mortality. A total of 2773 AMI patients were included in the final analysis. Higher glycemic variability, as indicated by increased glucose SD, CV, mean, and range, was significantly associated with elevated mortality risk. In contrast, the associations of SHR and admission glucose with mortality exhibited a U-shaped pattern. Notably, the lowest hazard ratios were observed at an SHR of 0.85 and an admission glucose of 96.3 mg/dL, suggesting that moderate levels of these metrics represent cohort-specific risk minima associated with the most favorable prognosis. Additionally, subgroup analyses revealed that older patients and those with diabetes are particularly vulnerable to adverse outcomes related to extreme glycemic deviations. Early glycemic variability and stress hyperglycemia are significantly associated with short- and long-term mortality in AMI patients. Moderate levels of SHR and admission glucose correlate with the lowest mortality risk, underscoring the importance of optimizing glycemic stability.