Taking aspirin to prevent heart attacks: worth the risk?

Frequent use of aspirin to prevent heart attacks can increase the risk of major bleeding by more than 40%, research has shown.

A study focused on more than 1,000 people with no evidence of heart or artery disease.

Some were taking aspirin, others a non-active placebo, and a third group no treatment at all.

Aspirin use was associated with an 11% lower risk of cardiovascular events.

Around 250 patients needed to be treated with aspirin for five years to prevent a single heart attack, stroke or death caused by cardiovascular disease, said researchers.

However, people taking aspirin were 43% more at risk of a major bleeding episode than those not using the drug.

This meant that roughly one in 200 people treated with aspirin could expect a major bleed.

Taking too much aspirin is well known to thin blood and increase the risk of intestinal bleeding.

Lead researcher Dr Sean Zheng, from King’s College London, said: “This study demonstrates that there is insufficient evidence to recommend routine aspirin use in the prevention of heart attacks, strokes and cardiovascular deaths in people without cardiovascular disease.

“There has been more uncertainty surrounding what should be done in patients who are at higher risk of cardiovascular disease and in patients with diabetes. This study shows that while cardiovascular events may be reduced in these patients, these benefits are matched by an increased risk of major bleeding events.

“Aspirin use requires discussion between the patient and their physician, with the knowledge that any small potential cardiovascular benefits are weighed up against the real risk of severe bleeding.”

Commenting on the findings published in the Journal of the American Medical Association, Professor Stephen Evans, from the London School of Hygiene & Tropical Medicine, said: “The message for healthy patients is that taking aspirin has a small benefit to prevent heart disease but also at least as large a harm in terms of serious bleeding.

“For some individual patients the balance may tip more clearly in either direction.”

Professor Helen Stokes-Lampard, who chairs the Royal College of GPs, said: “Aspirin can be an inexpensive and effective drug for reducing risks of recurrence in patients who have suffered a stroke or heart attack, but we have known for many years that there are risks and side effects involved with its long-term use, and this study highlights the importance of managing its use carefully and effectively.

“It is important that this research is considered as clinical guidelines are updated and developed, in the best interests of our patients.

“Patients who regularly take aspirin – either as prescribed by their doctor or who have self-medicated – should not panic as a result of this research. But if they are concerned about taking the drug they should discuss it with their GP at their next routine appointment, or with their local pharmacist.”