Hemoglobin A1c and Cardiovascular Outcomes Following Percutaneous Coronary Intervention Insights From a Large Single-Center Registry

OBJECTIVES The aim of this study was to evaluate post-percutaneous coronary intervention (PCI) outcomes in relation to pre-procedural glycated hemoglobin (HbA(1c)) levels from a large, contemporary cohort. BACKGROUND There are limited data evaluating associations between HbA(1c), a marker of glycemic control, and ischemic risk following PCI. METHODS All patients with known HbA(1c) levels undergoing PCI at a single institution between 2009 and 2017 were included. Patients were divided into 5 groups on the basis of HbA(1c) level: <= 5.5%, 5.6% to 6.0%, 6.1% to 7.0%, 7.1% to 8.0%, and >8.0%. The primary endpoint was major adverse cardiac events (MACE), a composite of all-cause death or myocardial infarction (MI), at 1-year follow-up. RESULTS A total of 13,543 patients were included (HbA(1c) <= 5.5%, n = 1,214; HbA(1c) 5.6% to 6.0%, n = 2,202; HbA(1c) 6.1% to 7.0%, n = 4,130; HbA(1c) 7.1% to 8.0%, n = 2,609; HbA(1c) >8.0%, n = 3,388). Patients with both low (HbA(1c) <= 5.5%) and high (HbA(1c) >8.0%) levels displayed an increased risk for MACE compared with those with values between 6.1% and 7.0%. Excess risk was driven primarily by higher rates of all-cause death among those with low HbA(1c) levels, while higher values were strongly associated with greater MI risk. Patterns of risk were unchanged among patients with serial HbA(1c) levels and persisted after multivariate adjustment. CONCLUSIONS Among patients undergoing PCI, pre-procedural HbA(1c) levels display a U-shaped association with 1-year MACE risk, a pattern that reflects greater risk for death in the presence of low HbA(1c) (<= 5.5%) and higher risk for MI with higher values (>8.0%). (C) 2021 Published by Elsevier on behalf of the American College of Cardiology Foundation.