Association of baseline hemoglobin A1c levels with bleeding in patients with non-ST-segment elevation acute coronary syndrome underwent percutaneous coronary intervention: insights of a multicenter cohort study from China

OBJECTIVE To investigate the association between baseline hemoglobin A1c (HbA1c) levels and bleeding in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) who underwent percutaneous coronary intervention (PCI). METHODS This observational cohort study enrolled 6283 consecutive NSTE-ACS patients undergoing PCI from January 1, 2010 to December 31, 2014. Based on baseline HbA1c levels, the patients were divided into the group with HbA1c < 7% ( n = 4740) and the group with HbA1c = 7% ( n = 1543). The primary outcomes are major bleeding (BARC grades 3-5) and all-cause death during follow-up. RESULTS Of patients enrolled, 4705 (74.9%) were male, and 2143 (34.1%) had a history of diabetes mellitus, with a mean (SD) age of 64.13 (10.32) years. The median follow-up duration was 3.21 years. Compared with the patients with HbA1c < 7%, the risk of major bleeding events during follow-up was higher in patients with HbA1c >= 7% (adjusted hazard ratio [HR] = 1.57; 95% confidence interval [CI]: 1.01-2.44; P = 0.044), while the risk of all-cause death during follow-up was not associated with the higher HbA1c levels (adjusted HR = 0.88; 95% CI: 0.66-1.18; P = 0.398). CONCLUSIONS Compared with the lower baseline HbA1c levels, the higher baseline HbA1c levels were associated with an increase in long-term bleeding risk in NSTE-ACS patients undergoing PCI, though higher baseline HbA1c levels were not associated with the higher risk in all-cause death.