Aspirin, NSAIDS, and Cardiovascular Risk U.S. Preventive Services Task Force. Aspirin for the primary prevention of cardiovascular events: Recommendation and rationale. Ann Intern Med 2002;136(2):157-60.

Haydan M, Pignone M, Phillips C, et al.: Aspirin for the primary prevention of cardiovascular event: A summary of the evidence for the U.S. Preventive Services Task Force. Ann Intern Med 2002;136(2):161-72.

Ray W, Stein C, Hall K et al.: Non-steroidal anti-inflammatory drugs and risk of serious coronary heart disease: An observational cohort study. Lancet 2002;359(9301):118-23.

Aspirin reduces myocardial infarction but increases gastrointestinal (GI) and intracranial bleeding. Researchers have found daily aspirin doses of 75 mg, 100 mg, and 325 mg effective in preventing cardiovascular disease; researchers haven't found benefits from higher doses. Enteric-coated aspirin doesn't clearly reduce adverse GI effects of aspirin. Those with known heart disease receive more benefits than harm from aspirin. For patients with risk factors but no known coronary heart disease (CHD), use algorithms to determine 5-year risk for CHD. When making aspirin therapy decisions, consider overall CHD risk.

In 1,000 patients with a 5% risk of CHD events over 5 years, aspirin would prevent 6 to 20 myocardial infarctions but would cause up to 2 hemorrhagic strokes and 2 to 4 major GI bleeding events. For patients with a CHD event risk of 1% over 5 years, aspirin would prevent 1 to 4 myocardial infarctions but would cause up to 2 hemorrhagic strokes and 2 to 4 major GI bleeding events.

In a case-control study, Ray and colleagues used data from the Tennessee Medicaid program to compare serious CHD risk in persons ages 50 to 84 who were new users of nonaspirin, nonsteroidal anti-inflammatory drugs (NANSAIDs) to an equal number of nonusers. During 532,634 person-years of follow-up, 6,362 cases of serious CHD occurred. Researchers did not find protective effects of naproxen or other NANSAIDs on CHD risk, indicating that clinicians shouldn't use these drugs for cardioprotection.