The physician who, in keeping with stereotyped jokes, puts off a night visit by instructing the caller to take aspirin may no longer be able to do so. The distressed caller may already be taking the drug as a participant in a cohort study of its efficacy in preventing thrombosis. A number of these studies have been initiated since the discovery that aspirin inhibits platelet aggregation. Although some of them relate to the peripheral vasculature,1 the majority address themselves to thrombosis in the coronary and the cerebral circulation.
A report of one such study, the randomized prospective Coronary Drug Project Aspirin Study,2 disclosed a substantially lower death rate in the aspirin- than in the placebo-treated group. In a more recent, retrospective, case-controlled study, Hennekens et al3 found no association between the frequent use of aspirin and the mortality from coronary heart disease. Still in progress are the Aspirin