Taking a daily low-dose aspirin to prevent blood clots can be disabling or even lethal for people aged 75 and over with a history of heart attacks or strokes, findings released last week from a major UK study show.

The study followed 3,166 patients, including 1,582 aged over 75, who had a first transient ischaemic attack, ischaemic stroke or myocardial infarction and were treated with antiplatelet drugs – mostly aspirin – but did not have a proton pump inhibitor (PPI) prescribed.

Robert Xuereb, chairman of the Department of Cardiology at Mater Dei Hospital, maintains that low-dose aspirin remains a fundamental part of treatment among patients who have already had a heart attack or stroke. Photo: Matthew Mirabelli

Patients were followed up at 30 days, at six months and at one, five, and 10 years to check for recurrent ischaemic events, bleeding and disability.

The results, published in The Lancet medical journal, showed that the risk of major bleeding increased steeply with age, as patients over 75 had three times the risk in younger patients. The risk of fatal bleeds was even higher, as a more than fivefold greater risk was found in older people.

“Previous studies have shown there is a clear benefit of short-term antiplatelet treatment following a heart attack or stroke,” said Peter Rothwell, from the Centre for Prevention of Stroke and Dementia at John Radcliffe Hospital, University of Oxford, and lead author of the study.

“But our findings raise questions about the balance of risk and benefit of long-term daily aspirin use in people aged 75 or over if a proton pump inhibitor is not co-prescribed.”

Commenting on the study, Robert Xuereb, chairman of the Department of Cardiology at Mater Dei Hospital, said: “All medicines come with their side effects. One has to weigh the benefits of using a particular medicine against the risk of side effects which come with its use. Aspirin is no exception.”

Compared with younger patients, older aspirin users in the study were found 10 times more likely to experience disabling or fatal gastrointestinal bleeding.

We are very much aware that its use can result in an increased risk of bleeding, particularly from the stomach

Researchers emphasised that the findings did not mean that older patients should stop taking aspirin. Instead, they recommend broad use of PPI heartburn drugs such as omeprazole, which can cut the risk of upper gastrointestinal bleeding by 70 to 90 per cent.

While aspirin – invented by Bayer in 1897 – is generally viewed as harmless, bleeding has long been a recognised hazard.

“Low-dose aspirin has been used for decades to prevent heart attacks or strokes,” said Xuereb. “However, we are very much aware that its use can result in an increased risk of bleeding, particularly from the stomach.”

The use of aspirin has been reviewed lately. It was formerly used in healthy individuals to prevent a first heartattack or stroke, which is referred to as primary prevention. Its use in this setting is no longer indicated in view of the increased risk of importantbleeding complications.

Experts recommend heartburn drugs to minimise hazard. Photo: Shutterstock.com

“However, low-dose aspirin remains a fundamental part of the treatment in those patients who have already suffered from a heart attack or stroke, which is referred to as secondary prevention,” explained Xuereb.

“The British study confirms that aspirin use comes with a risk of bleeding and this is even more important in those over 75 years of age,” he added.

“A proton pump inhibitor should be considered to reduce the risk of bleeding from the stomach in this group of patients.

“Definitely, all patients of whatever age who have been prescribed low-dose aspirin following a heart attack or stroke should not stop their aspirin since this may result in another heart attack or stroke.”