Clinical trials have demonstrated a prophylactic role for aspirin in myocardial infarction and in unstable angina pectoris. The Swedish Angina Pectoris Aspirin Trial (SAPAT) is the first prospective study of aspirin in stable angina. 2035 patients were randomised double-blind to treatment with aspirin 75 mg daily or placebo. All patients were treated with sotalol for control of symptoms. The median duration of follow-up was 50 months. Compared with the placebo+sotalol group, the aspirin+sotalol group had a 34% (81 vs 124 patients) reduction in primary outcome events (myocardial infarction and sudden death; 95% confidence interval 24-49%; p = 0.003) and the reduction observed in secondary outcome events (vascular events, vascular death, all cause mortality, stroke) ranged from 22% to 32%. Treatment withdrawal caused by adverse events occurred in 109 patients in the aspirin+sotalol group and 100 in patients in the placebo+sotalol group; major bleeds, including haemorrhagic stroke, occurred in 20 and 13 patients, respectively (not significant). The addition of a low dose of aspirin to sotalol treatment showed significant benefit in terms of cardiovascular events, including a significant reduction in the incidence of first myocardial infarction in patients with symptoms of stable angina pectoris.