Selection and results of antiplatelet therapy in the prevention of stroke and myocardial infarction.

Four antiplatelet drugs have been evaluated in cerebrovascular disease and in coronary heart disease--dipyridamole, clofibrate, sulfinpyrazone, and aspirin. There is no evidence that dipyridamole or clofibrate is beneficial in patients with stroke or myocardial infarction. Aspirin is effective in reducing stroke and death in patients with transient cerebral ischemia. Although aspirin has not been reported to significantly (statistically) reduce mortality or frequency of ischemic events in patients with acute myocardial infarction, five of six randomized trials showed a similar favorable trend. Sulfinpyrazone seems to be ineffective in the treatment of transient cerebral ischemia, but there is evidence that it decreases the incidence of sudden death in patients with myocardial infarction. In patients with prosthetic heart valves, the combined use of aspirin or dipyridamole with an oral anticoagulant is more effective in preventing systemic embolism than an oral anticoagulant alone.