There is so far only limited information on the effects of antithrombotic regimens on the incidence of angina pectoris. However, because angina is a powerful predictor of major events of coronary heart disease, these effects should be evaluated. Warfarin has an immediate effect on blood coagulability and thrombosis, and recent evidence suggests that it may exert some of its benefit through a delayed effect, perhaps on the vessel wall. The study by Knottenbelt et al provides some, though far from conclusive, support for a delayed effect and also suggests that low-dose aspirin may increase rather than reduce the incidence of angina. However, the value of aspirin in the prevention of nonfatal myocardial infarction is reemphasized, as is the benefit of combined treatment with low-intensity anticoagulation and aspirin in preventing both fatal and nonfatal events of coronary heart disease.