Effects of aspirin treatment on survival in non-insulin-dependent diabetic patients with coronary artery disease

PURPOSE: The benefit of aspirin treatment among diabetic patients with chronic coronary artery disease is not well established. The purpose of this study was to assess the effect of aspirin on cardiac and total mortality in a large cohort of diabetic patients with established coronary artery disease and to compare it with the effect of aspirin in nondiabetic counterparts. PATIENTS AND METHODS: In this observational study among patients screened for participation in the Bezafibrate Infarction Prevention Study, the effects of aspirin treatment in 2,368 non-insulin-dependent diabetic patients with coronary artery disease were compared to those in 8,586 nondiabetic patients. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated with proportional hazards models. RESULTS: Fifty-two percent of diabetic patients and 56% of nondiabetic patients reported aspirin therapy. After 5.1 ± 1.3 (mean ± SD) years of follow-up, the absolute benefit per 100 patients treated with aspirin was greater in diabetic patients than in nondiabetic patients (cardiac mortality benefit: 5.0 versus 2.1, and all-cause mortality benefit: 7.8 versus 4.1). Overall cardiac mortality among diabetic patients treated with aspirin was 10.9% versus 15.9% in the nonaspirin group (P<0.001), and all-cause mortality was 18.4% and 26.2% (P<0.001). After adjustment for possible confounders, treatment with aspirin was an independent predictor of reduced overall cardiac (HR = 0.8; 95% CI: 0.6–1.0) and all-cause mortality (HR = 0.8; 95% CI: 0.7–0.9) among diabetic patients, similar to those in nondiabetic patients. CONCLUSION: Treatment with aspirin was associated with a significant reduction in cardiac and total mortality among non-insulin-dependent diabetic patients with coronary artery disease. The absolute benefit of aspirin was greater in diabetic patients than in those without diabetes.