People who stop taking prescribed aspirin could have a higher risk of heart attacks, a new study has suggested.
Researchers looked at patients with a history of heart disease who had been taking low doses of aspirin to help prevent blood clots.
They found that those who later stopped taking the medication were almost two-thirds more likely to suffer a non-fatal heart attack.
It is believed that up to half of long-term users eventually stop taking aspirin.
Scientists from Spain and Sweden followed 39,513 UK patients aged between 50 and 84 for around three years.
For every 1,000 patients, there were four more non-fatal heart attacks within a year among those who had recently stopped taking their low dose aspirin, compared with those who had continued.
The team concluded: "Reducing the number of patients who discontinue low dose aspirin could...have a major impact on the benefit obtained with low dose aspirin in the general population."
A study has been published online by the British Medical Journal.