Prognostic value of the stress hyperglycemia ratio in patients with acute coronary syndrome: a systematic review and meta-analysis

Background Elevated admission blood glucose is associated with higher mortality in acute myocardial infarction (AMI). However, it does not distinguish stress-induced hyperglycemia (SIH) from chronic hyperglycemia, particularly in diabetic patients. The stress hyperglycemia ratio (SHR), calculated as admission blood glucose divided by estimated average glucose from glycated hemoglobin, offers a more accurate marker of stress hyperglycemia independent of baseline glycemic status. This systematic review and meta-analysis assessed the prognostic value of SHR for adverse outcomes in patients with acute coronary syndrome (ACS). Methods We systematically searched PubMed, EMBASE, Web of Science, and Scopus from inception to January 2026. Observational cohort studies of ACS patients were included. The primary outcome was all-cause mortality. Secondary outcomes included major adverse cardiovascular events (MACE), cardiovascular mortality, recurrent myocardial infarction (MI), stroke, heart failure (HF), and revascularization. SHR was analyzed as both continuous and categorical variables. Hazard ratios (HRs) for the highest versus lowest SHR categories or per 1-unit increase were pooled using random-effects models with 95% confidence intervals (CIs). Subgroup analyses were performed according to diabetes status. Results Thirty-five studies involving 167,575 participants (mean age 64.4 years, 73.6% male) were included. Higher SHR was strongly associated with increased all-cause mortality (HR: 1.68, 95% CI: 1.52–1.85, p < 0.0001, I² = 0%). Similar association persisted in continuous analyses (HR: 1.39 per unit, 95% CI: 1.06–1.81, p < 0.0001, I² = 86.3%). The highest SHR category was also linked to elevated risks of MACE (HR: 1.55, 95% CI: 1.34–1.79, p < 0.00001, I² = 80.7%), cardiovascular mortality (HR: 1.74, 95% CI: 1.19–2.55, p = 0.004, I² = 84.6%), stroke (HR: 1.73, 95% CI: 1.15–2.60, p = 0.009, I² = 0%), and HF (HR: 1.71, 95% CI: 1.39–2.11, p < 0.0001, I² = 6.6%). Risks of revascularization and recurrent MI did not differ significantly across SHR categories. Associations remained consistent in continuous analyses. The relationship between higher SHR and mortality was consistent across diabetes subgroups. Increased mortality risk was observed among patients with diabetes (HR: 1.52, 95% CI: 1.18–1.95, p = 0.0347, I2 = 61.4%) and those without diabetes (HR: 1.84, 95% CI: 1.45–2.34, p = 0.0846, I2 = 51.2%), with no significant subgroup differences (p for interaction = 0.27). Conclusion SHR offers incremental prognostic value in ACS patients and may serve as a simple, widely available tool for risk stratification independent of diabetes status. Further research is needed to clarify its clinical utility.