Impact of diabetes mellitus and hemoglobin A1c level on outcomes among Chinese patients with acute coronary syndrome

Abstract

Background: The impact of different glycemic control conditions on in-hospital and long-term outcomes among patients with acute coronary syndrome (ACS) is less well defined. Hypothesis: Diabetes mellitus (DM) with different admission hemoglobin A1c (HbA1c) levels (different glycemic control) could affect outcomes among Chinese patients hospitalized as ACS. Methods: We categorized 8961 Chinese ACS patients into one of the following three groups: “no DM” (group 1, n = 3773; no DM history and admission HbA1c < 6.5%), “DM with optimal control”(group 2, n = 2241; DM with admission HbA1c < 7.0%), “DM with suboptimal control”(group 3, n = 2947; DM with admission HbA1c ≥ 7.0%). The primary outcome was in-hospital major adverse cardiovascular events (MACEs). 6098 patients were followed for a median of 3.85 years. Adjusted associations of these three groups with in-hospital MACEs and long-term mortality were determined. Results: DM with suboptimal control (group 3) was associated with greater in-hospital MACEs (OR 1.46, 95% CI 1.17-1.81, P =.001) than “no DM” (group 1). DM patients (group 2 and group 3) also had higher in-hospital MACEs (OR 1.42, 95% CI 1.16-1.73, P =.001) than “no DM” patients (group 1). It showed no significantly different in-hospital MACEs between optimal (group 2) and suboptimal (group 3) control group (OR 1.06, 95% CI 0.84-1.34, P =.63). Both optimal control (group 2) and suboptimal control (group 3) had a higher long-term mortality (HR 1.26, 95% CI 1.02-1.56, P =.03; HR 1.42, 95% CI 1.16-1.73, P =.001). Conclusions: ACS patients with DM were associated with higher in-hospital MACEs and long-term mortality. Moreover, lower HbA1c level seems to have limited impact on cardiovascular events and long-term mortality in this high-risk population.