OXFORD, UNITED KINGDOM. Numerous studies have shown that antiplatelet therapy with aspirin is of benefit for people who have suffered a previous heart attack, stroke or other cardiovascular event. Researchers at the Radcliffe Infirmary have just completed a review of 287 studies, which compared aspirin therapy versus control in 135,000 patients. They conclude that a daily aspirin reduces the risk of a serious cardiovascular event by about 25 per cent. Specifically, the risk of non-fatal stroke was reduced by 25 per cent and the risk of a non-fatal heart attack was reduced by 33 per cent in high-risk individuals.
The researchers found that low doses (75-150 mg/day) of aspirin are just as effective as higher doses for
long-term therapy and that low doses are less likely to cause internal bleeding. At least 150 mg may be
required though to get an immediate effect. A recent European trial observed that patients with atrial
fibrillation who had had a previous stroke reduced their risk of a serious cardiovascular event from 18.4 to
15.3 per cent by taking a daily aspirin. The researchers do point out that regular use of aspirin is associated
with a doubling of the risk of upper gastrointestinal bleeding. They conclude that, "for most healthy
individuals, for whom the risk of a vascular event is likely to be substantially less than one per cent a year,
daily aspirin may well be inappropriate".