Published in JAMA Network Open, this study represents the first comprehensive investigation into the risk-versus-benefit analysis of aspirin as a primary prevention measure for older individuals, who are often vulnerable to head trauma from falls and other head injuries. Aspirin is known to have bleeding as a side effect.
Researchers analysed data from the ASPREE (ASPirin in Reducing Events in the Elderly) trial, which involved over 19,000 initially healthy older adults, with the majority being over 70, predominantly from Australia and the USA.
The participants, who had no known cardiovascular disease at the beginning of the trial, were randomly assigned to take either a 100 mg daily aspirin or a placebo tablet for an average of five years.
The secondary analysis study found no statistically significant difference in the occurrence of ischemic stroke (the most common type of stroke caused by blood vessel blockage in the brain) between the aspirin and placebo groups.
Both groups reported strokes at a similar percentage, with 4.6 per cent in the aspirin group and 4.7 per cent in the placebo group. However, brain bleeding events were 38 per cent higher in those who took aspirin than those who took the placebo.
Based on these findings, the researchers concluded that the risk of brain bleeding outweighed any potential benefits of aspirin in reducing strokes. This includes brain bleeds due to head trauma, which is often associated with falls.
Senior Author Professor John McNeil emphasised that although the overall incidence of bleeding was not common, it does highlight the additional risk of low-dose aspirin use, especially for older individuals prone to head trauma.
“These findings do not apply to older adults taking aspirin on medical advice, such as after a heart attack and ischaemic stroke. In secondary prevention, the balance of risks and benefits generally favours aspirin. It’s important to consult with your GP before making any changes to your medicine intake,” McNeil said.
First author and Director of Stroke Services at Alfred Health, Professor Geoffrey Cloud, suggested that instead of relying on daily aspirin, older individuals concerned about reducing their risk of a first stroke should focus on lifestyle risk factor modification and blood pressure control under the guidance of their healthcare providers.