The benefits of aspirin on cardiac morbidity and mortality in patients with coronary artery disease (CAD) are well known. Similar benefits are possible in patients with diabetes mellitus and CAD; however, this population has not been well studied. Harpaz and colleagues evaluated the effects of aspirin on mortality in patients with type 2 (non–insulin-dependent) diabetes mellitus and CAD.

Patients between 45 and 74 years of age who had a documented history of CAD were eligible for the study if they also had a history of diabetes mellitus. Patients with type 1 (insulin-dependent) diabetes were excluded from the study. At the screening visit, blood samples, demographic information, medical history and information about current medications were obtained for all patients. Functional capacity and angina class were also recorded for all patients. Mortality data and cause of death were recorded, with a mean follow-up period of 5.1 years.

Of the approximately 11,000 patients who were screened, 2,368 patients met the criteria for the study. Mean patient age was 60 years, and most of the patients were men (74 percent). Use of aspirin was reported by 52 percent of these patients compared with 56 percent of patients without diabetes. Patients who took aspirin were more like to be younger, male, and to have had a myocardial infarction. Mortality rates in patients with diabetes mellitus were two times higher than in patients without diabetes. However, cardiac and all-cause mortality rates were much lower in patients with diabetes who took aspirin compared with diabetic patients who did not. Overall, the absolute benefit of aspirin use was greater in patients with diabetes and CAD than in the group of CAD patients without diabetes mellitus, even though there was clear benefit in both groups.

The authors conclude that cardiac and all-cause mortality rates are significantly reduced in CAD patients with type 2 diabetes mellitus, and that this benefit is more pronounced than in CAD patients without diabetes mellitus. Unless clearly contraindicated, aspirin should be given to all patients with CAD and type 2 diabetes mellitus.