Aspirin should be recommended to reduce the risk of heart attack in men aged 45 – 79 and to reduce the risk of stroke in women aged 55 – 79 who do not have heart disease, the US Preventive Services Task Force (USPSTF) has recommended.(1)
The USPSTF(2) states that men aged 45 – 79 should be encouraged to take aspirin when the potential benefit of a reduction in the risk of a heart attack outweighs the potential harm of an increase in gastrointestinal bleeding; women aged 55 – 79 should be encouraged to take aspirin when the potential benefit of a reduction in the risk of ischaemic stroke outweighs the potential harm of an increase in gastrointestinal bleeding.
The recommendations are based on the latest evidence of the benefits of aspirin. If implemented in Europe, they would greatly increase the number of people taking aspirin to prevent heart attack or stroke.
Taking aspirin to prevent heart attack or stroke by people who are not known to have heart disease is known as primary prevention. An individual’s risk is estimated from their sex, age, smoking status, blood pressure and cholesterol level. European guidelines recommend primary prevention with aspirin when the risk of a heart attack exceeds 10% per year;(3) in the UK, primary prevention is recommended for people over 50 years old when the 10-year risk exceeds 20%.(4) Aspirin is universally recommended for people who have already had a heart attack or stroke (secondary prevention).
The USPSTF provides estimates of the numbers of cardiovascular events avoided by primary prevention with aspirin and the risk of gastrointestinal bleeding and stroke. Assuming aspirin reduces heart attacks by 32%, its benefits for men aged 45 – 79 outweigh the risks when the 10-year risk of a heart attack is 4%. For women aged 55 – 59, the benefit:risk ratio becomes favourable when the 10-year risk of stroke is 3%. The USPSFT says the benefits of aspirin are not proven for men or women in younger age groups, among people aged 80 or over, or for reducing the risk of heart attack among women.(1)
The decision to take aspirin should be made jointly between doctors and patients, the USPSFT emphasises, but the recommendation should be stronger as the potential benefit increases.