'Aspirin a day' advice may put at risk the health of some patients

Published on Thursday 28 May 2009 22:03

HEALTHY people risk internal bleeding if they take a regular dose of aspirin tablets to prevent heart attacks and strokes

Researchers at the Medical Research Council have discovered that while there is an overall health benefit in taking aspirin if individuals have existing heart problems, the risks are too high for the healthy.

An analysis of data from primary and secondary prevention trials, which compared long-term aspirin use, found benefits were offset by an increase in internal bleeding.

Researchers at the Clinical Trial Service Unit at Oxford University found that in primary prevention trials, involving healthy people, aspirin reduced the risk of a non-fatal heart attack by a fifth, the equivalent of five fewer heart attacks each year for every 10,000 people.

However, there was a comparable increase in internal bleeding, which is the equivalent of one extra stroke, caused by bleeding, and three extra gastrointestinal bleeds each year for every 10,000 people.

Previous reviews of primary prevention trials have led to guidelines recommending that aspirin be used widely for primary prevention among healthy people who, for reasons such as raised blood cholesterol or blood pressure, are at above-average risk of coronary heart disease and therefore might be expected to benefit more than others.

However, the new analysis shows many people with above average risk of coronary heart disease are also at above average risk of suffering a bleed.

Yesterday, Professor Colin Baigent, whose study has been published in the Lancet, said: "Drug safety really matters when making recommendations for tens of millions of healthy people. We don't have good evidence that, for healthy people, the benefits of long-term aspirin exceed the risks by an appropriate margin."

The study concludes: "Aspirin is of clear benefit for people who already have cardiovascular disease, but the latest research does not seem to justify guidelines advocating the routine use of aspirin in all healthy individuals above a moderate level of risk for coronary heart disease."

The use of aspirin on a daily basis has increased in recent years. Last month, scientists at Cancer Research UK said people in their forties could reduce their risk of cancer in later life with regular doses of aspirin. However, doctors tend to advise against healthy people taking aspirin in the long term, because it can cause bleeding in the gut, as well as stomach ulcers.

In response to the study in the Lancet, Ellen Mason, a senior cardiac nurse at the British Heart Foundation (BHF), said: "This study on the use of aspirin in primary prevention, partly funded by the BHF, provides further confirmation that, in those without existing heart disease, there is limited benefit from taking aspirin due to the risk of bleeding.

"For this reason, it is better for doctors to weigh up the benefit and risk of prescribing aspirin on an individual basis, rather than develop a blanket guideline suggesting everyone at risk of heart disease is routinely given aspirin."