An overview by a Yale researcher
of four studies examining the use of aspirin and the reduction of heart
attacks in persons with no previous history of cardiovascular disease shows
aspirin remains a good preventive measure.
The studies included more than 51,000 people and 2,284 "vascular events":
vascular disease-related death, cardiac or cerebral; nonfatal heart attack, or
nonfatal stroke. The overview article was published in the Archives of
"The results reconfirm that aspirin is beneficial in preventing a first
myocardial infarction," said Patricia Hebert, associate research scientist in
the Department of Medicine, Cardiology, at Yale School of Medicine. "We
really did not have enough events to assess the effects of aspirin on overall
stroke, ischemic stroke, or cardiovascular death. There was an increase in
the risk of hemorrhagic stroke from taking aspirin, which also has been
detected in secondary prevention trials."
Individuals that took aspirin had a 32 percent reduction in nonfatal heart
attacks. Aspirin did not appear to reduce the number of vascular disease-
related deaths, nor lead to any significant decrease in the number of overall
or ischemic strokes. There was, however, a slight increase in the risk of
hemorrhagic stroke associated with aspirin use.
The overview included four primary prevention trials of aspirin and
cardiovascular disease: The Physicians Health Study, The British Doctors'
Trial, The Thrombosis Prevention Trial, and The Hypertension Optimal Treatment
"In primary prevention, there is conclusive benefit of aspirin in reducing
risk of a first myocardial infarction and any important vascular event,"
Hebert said. "Whether there are any beneficial effects on risks of vascular
deaths, overall stroke, or ischemic stroke remains uncertain due to inadequate
numbers of events in the primary prevention trials completed to date. While
based on small numbers, the available evidence suggests an increased risk of
hemorrhagic stroke that needs to be further investigated."
Hebert said more randomized trial data, especially in women, is needed to
help formulate a rational public health policy for individuals at usual risk
of suffering a heart attack or stroke. In the meantime, she said, these data
provide evidence for a significant benefit of aspirin therapy in the primary
prevention of myocardial infarction.
Co-author of the study was Charles Hennekens, M.D., visiting professor of
Medicine & Epidemiology and Public Health at the University of Miami School of