PLATELET INHIBITORS AND ANTIOXIDANT VITAMINS IN CARDIOVASCULAR-DISEASE

Considerable research attention has focused on the possible roles of platelet inhibition, principally using aspirin, and antioxidant vitamins in reducing the risks of cardiovascular disease. Data from large-scale randomized trials indicate that aspirin reduces subsequent vascular events among patients with prior myocardial infarction, stroke, transient ischemic attacks, or unstable angina, as well as among patients with acute evolving myocardial infarction. In primary prevention trials, the Physicians' Health Study showed a clear benefit in decreasing risk of a first myocardial infarction in men; the data on stroke and total number of deaths from vascular causes are inadequate. The Women's Health Study, a trial now under way among apparently healthy women, will provide direct evidence on the balance of risks and benefits of aspirin in primary prevention. Antioxidant vitamins are hypothesized to decrease cardiovascular disease risk by several mechanisms, including inhibition of oxidation of low-density lipoprotein cholesterol and decreasing uptake into the coronary endothelium. Promising results have emerged from observational studies, which show that people with high intakes of antioxidant vitamins through diet or supplements have lowered risks of cardiovascular disease; however, unknown or unmeasured factors associated with high antioxidant vitamin intake may explain all or part of the observed associations. Randomized trials to provide reliable data are now ongoing among apparently healthy men and women, as well as among survivors of prior cardiovascular disease events.