A topic in Clinical Evidence summarizes the evidence on aspirin in unstable angina pectoris. One systematic review (search date 1990, 145 RCTs, 100000 people) compared antiplatelet treatment versus placebo. Seven of these trials included a total of 4000 people with unstable angina. Antiplatelet treatment (mostly aspirin 75 - 325 mg daily) reduced the combined outcome of vascular death, myocardial infarction, or stroke at 6 months (AR 14% on placebo vs 9% on antiplatelet treatment, RR 0.65, 95% CI 0.51 to 0.79, NNT 20, 95% CI 15 to 34).
Clinical evidence category: Beneficial.