Hemoglobin A1c as a prognostic marker in patients undergoing primary angioplasty for acute myocardial infarction.

ABSTRACT

OBJECTIVES: We sought to determine the effect of hemoglobin A1c (HbA1c) on the outcomes of primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Diabetes mellitus (DM) can be diagnosed from a level of at least 6.5% on two separate occasions according to the American Diabetes Association (ADA) definition, which was updated in 2010. No data are available for the value of HbA1c in patients with STEMI treated with primary PCI. METHODS: A total of 374 consecutive patients with STEMI (mean age 55.9±12.6 years, 318 men), undergoing primary PCI between December 2009 and June 2010, were prospectively enrolled in this study. Blood samples for HbA1c were obtained on the first 24 h after admission. In-hospital follow-up was performed. By using new ADA criteria, patients were classified into three groups group I (HbA1c ≤5.6%, n=112); group II (HbA1c 5.7-6.4%, n=180); and group III (HbA1c ≥6.5%, n=82). RESULTS: In-hospital mortality was higher in group III (11%) compared with group II (2.8%) and group I (0.9%; P=0.001). Major adverse cardiac events in the hospital were also higher in group III (12.2%) compared with other groups (group II, 5.6% vs. group I, 0.9%, P=0.003). After adjusting the baseline characteristics, HbA1c remained a strong independent predictor of the in-hospital mortality (odds ratio 1.412; 95% confidence interval 1.031-1.935, P=0.03). Hospital stay was also longer in group III than others (P=0.007). A total of 196 (63.6%) patients without a history of diabetes mellitus had elevated HbA1c of more than or equal to 5.7%, with 31 (10.1%) of them having HbA1c of more than or equal to 6.5%. CONCLUSION: HbA1c is an independent predictor of the in-hospital mortality in STEMI treated with primary PCI. Apart from prognostic value, high HbA1c could be used for diabetes mellitus diagnosis, which is supported by ADA definitions.