Impact of glycemic gap on 30-day adverse outcomes in patients with acute ST-segment elevation myocardial infarction

Background: Stress-induced hyperglycemia (SIH) generally occurs in critical illness. Recently, glycemic gap (GAP) has been considered to be a superior indicator of SIH. However, data on the association between GAP and prognosis in ST-segment elevation myocardial infarction (STEMI) is limited. This observational study aimed to estimate the prognostic value of GAPmean, defined as the difference between mean blood glucose level within 24 hours after admission and A1c-derived average glucose (ADAG), in patients with acute STEMI. Methods: A total of 4952 patients with acute STEMI were included in the final analysis, and they were divided into four groups according to GAPmean quartiles and diabetes mellitus (DM). The primary outcomes were defined as all-cause mortality and major adverse cardiovascular events (MACEs). Cox proportional hazards regression analysis and net reclassification improvement (NRI) analysis were performed.Results: At 30 days of follow-up, 324 (6.5%) deaths and 569 (11.5%) MACEs occurred. With the elevation of GAPmean, the incidence of all-cause mortality (4.0%, 5.6%, 6.5%, and 10.1%) and MACEs (7.3%, 9.6%, 11.4%, and 17.7%) significantly increased. The receiver operating characteristic curve analysis demonstrated that GAPmean was superior to admission blood glucose (ABG) and GAPadm (defined as the difference between ABG and ADAG) to detect adverse outcomes. Multivariate Cox regression analysis revealed that elevated GAPmean was independently associated with all-cause death and MACEs, with the hazards ratio (HR) for all-cause death in the second, third, and fourth quartiles with the first quartile as reference were 1.50 (95% CI 1.04-2.18), 1.62 (95% CI 1.13-2.32), and 2.18 (95% CI 1.55-3.08), and for MACEs were 1.37 (95% CI 1.04-1.81), 1.56 (95% CI 1.20-2.04), and 2.13 (95% CI 1.65-2.76), respectively, which was independent of the status of DM. Continuous NRI analysis revealed that GAPmean significantly improved risk stratification for all-cause mortality and CEEs by 21.6% and 19.8%, respectively.Conclusion: Glycemic gap between the mean level of blood glucose within 24 hours after admission and ADAG was independently associated with 30-day all-cause death and MACEs in patients with acute STEMI, which was consistent in both DM patients and non-DM patients, and it can provide incremental accuracy in the risk stratification of STEMI.