Impact of initial glycosylated hemoglobin level on cardiovascular outcomes in prediabetic patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Background: The prognostic value of the glycemic control level, as measured using glycosylated hemoglobin (HbA1c) level, in prediabetic patients with acute coronary syndrome is still undetermined. The aim of this study was to demonstrate the influence of HbA1c level at admission on the incidence of major adverse cardiac events (MACE) in prediabetic patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

Methods And Results: Using data from the Korea Working Group on Myocardial Infarction (February 2008-December 2011), this observational study included 2470 STEMI patients undergoing primary PCI who had not been diagnosed with diabetes mellitus either before or after admission (HbA1c at admission <6.5%). Patients were divided into two groups based on HbA1c at admission: prediabetic (5.7% ≤ HbA1c ≤ 6.4%, n=1475, 59.5%) and nondiabetic (HbA1c<5.7%, n=995, 40.5%). After analyzing the matched cohort, 1-year cumulative MACE incidence, defined as a composite of mortality, nonfatal myocardial infarction, repeated PCI, or coronary artery bypass graft, MACE was not found to differ significantly between the two groups (6.7 vs. 6.0%, P=0.616). Using multivariate logistic analysis, HbA1c level at admission was not significantly associated with the occurrence of MACE (odds ratio 0.925, 95% confidence interval 0.618-1.384, P=0.925).

Conclusion: This study demonstrated that HbA1c level at admission was not significantly associated with cardiovascular outcomes in prediabetic Korean populations with STEMI undergoing primary PCI.