Aspirin for primary prevention of cardiovascular events in people with diabetes: a position statement of the American Diabetes Association, a scientific statement of the American Heart Association, and an expert consensus document of the American College of Cardiology Foundation.

The burden of cardiovascular disease (CVD) among patients with diabetes is substantial. Individuals with diabetes are at twoto fourfold increased risk of cardiovascular events compared with ageand sex-matched individuals without diabetes. In diabetic patients over the age of 65 years, 68% of deaths are from coronary heart disease (CHD) and 16% are from stroke (1). A number of mechanisms for the increased cardiovascular risk with diabetes have been proposed, including increased tendency toward intracoronary thrombus formation (2), increased platelet reactivity (3), and worsened endothelial dysfunction (4). The increased risk for cardiovascular events and mortality in patients with diabetes has led to considerable interest in identifying effective means for cardiovascular risk reduction. Aspirin has been shown to be effective in reducing cardiovascular morbidity and mortality in highrisk patients with myocardial infarction (MI) or stroke (secondary prevention) (5). The Food and Drug Administration has not approved aspirin for use in primary prevention, and its net benefit among patients with no previous cardiovascular events is more controversial, for both patients with and without a history of diabetes (5). The U.S. Preventive Services Task Force recently updated its recommendation about aspirin use for primary prevention. The Task Force recommended encouraging aspirin use in men age 45–79 years and women age 55–79 years and not encouraging aspirin use in younger adults. They did not differentiate their recommendations based on the presence or absence of diabetes (6,7). In 2007, the American Diabetes Association (ADA) and the American Heart Association (AHA) jointly recommended that aspirin therapy (75–162 mg/day) be used as a primary prevention strategy in those with diabetes at increased cardiovascular risk, including those who are over 40 years of age or who have additional risk factors (family history of CVD, hypertension, smoking, dyslipidemia, or albuminuria) (8). These recommendations were derived from several older trials that included relatively small numbers of patients with diabetes. Results of two recent randomized controlled trials of aspirin performed specifically in patients with diabetes raised questions about the efficacy of aspirin for primary prevention in diabetes (9,10). Because of the scope of the problem of CVD in patients with diabetes and the conflicting evidence about the efficacy of aspirin for primary prevention in people with diabetes, the ADA, AHA, and the American College of Cardiology Foundation (ACCF) convened a group of experts to review and synthesize the available evidence and use this information to create updated recommendations. The group considered and organized this report around the following questions: