Association of Diabetic Status and Glycemic Control With Ischemic and Bleeding Outcomes in Patients With Stable Coronary Artery Disease: The 5-Year CORONOR Registry

Background-The relation between diabetes mellitus, glycemic control, and ischemic and bleeding events is poorly described in outpatients with stable coronary artery disease receiving modern secondary prevention. Methods and Results-The multicenter CORONOR (Suivi d'une cohorte de patients Coronariens stables en region Nord-pas-de-Calais) registry enrolled 4184 outpatients with stable coronary artery disease, including 1297 patients (31%) with diabetes mellitus. A recent glycosylated hemoglobin (HbA1c) was available for 1146 diabetic patients, and 48% had HbA1c >= 7%. We analyzed 5-year ischemic (cardiovascular death, myocardial infarction, and stroke) and bleeding (Bleeding Academic Research Consortium >= 3) outcomes, according to diabetic status and glycemic control. When compared with nondiabetic patients, the ischemic risk was higher in diabetic patients with HbA1c >= 7% (hazard ratio [Fin 1.57; 95% confidence interval [CI], 1.25-1.93) but not in diabetic patients with HbA1c <7% (HR, 1.06; 95% CI, 0.83-1.36). Diabetic patients with HbA1c >= 7% were at higher risk than diabetic patients with HbA1c >= 7% (HR, 1.47; 95% CI, 1.09-1.98). When compared with nondiabetic patients, the bleeding risk was higher in diabetic patients, with HbA1c <7% (HR, 1.66; 95% CI, 1.04-2.67) and in those with HbA1c >= 7% (HR, 1.75; 95% CI, 1.07-2.86). No difference in bleeding risk was observed between diabetic patients with HbA1c >= 7% versus those with HbA1c <7%. Similar results were obtained when adjusted for baseline characteristics. Conclusions-The 5-year increased risk of ischemic events in patients with stable coronary artery disease with diabetes mellitus was restricted to those with HbA1c >= 7%. By contrast, the increase in bleeding risk associated with diabetes mellitus was observed in patients with HbA1c >= 7% and in patients with HbA1c <7%. The level of HbA1c should be taken into account for future research and may help physicians to manage prolonged antithrombotic therapies in this high-risk subgroup.