Abstract
▪ Abstract Aspirin irreversibly inhibits cyclooxygenase in platelets for their entire lifespan, raising the possibility of clinical benefits by decreasing risks of occlusive vascular events. In secondary prevention among patients with a wide range of prior occlusive vascular events, including myocardial infarction (MI), stroke, transient ischemic attacks (TIAs), as well as unstable and chronic stable angina, aspirin therapy is associated with a reduction in risks of subsequent MI, stroke, and vascular deaths. In acute MI, aspirin also confers clear benefits on subsequent MI, stroke, and vascular deaths. In primary prevention, the available randomized trial data, which to date are limited to men, indicate a clear reduction in risk of a first MI; the current data are inconclusive concerning aspirin's effect on stroke and total vascular mortality. A currently ongoing trial among 40,000 apparently healthy women will provide reliable data concerning the balance of benefits and risks of aspirin in primary prevention.