By Dr Jonathan Shurlock
Edited by Dr Ahmed El-Medany
The role of aspirin in primary prevention of cardiovascular disease has been explored previously, with resultant NICE guidance recommending against its use in this role. Dr Geoffrey Cloud has led further research to support this clear stance by formal health policy bodies.
Presented in JAMA Network Open, Dr Cloud carried out a secondary analysis of the Aspirin in Reducing Events in the Elderly (ASPREE) trial. The ASPREE trial randomised almost 20,000 healthy participants to regular aspirin or placebo and found higher all-cause mortality in the aspirin group.
All participants from the ASPREE trial were included, with a total of 19,114 individuals undergoing this secondary analysis (10,782 (56.4%) female; median (IQR) age 74 (71.6-77.7]) years). 9,525 had received aspirin with 9,589 receiving placebo. Primary outcome measures were incidence of ischaemic stroke and incidence of intracranial bleeding.
The authors found no significant reduction in the incidence of ischaemic stroke in the aspirin group when compared with placebo (hazard ratio [HR], 0.89; 95% CI, 0.71-1.11). However, a statistically significant increase in intracranial bleeding was observed among individuals assigned to aspirin (108 individuals [1.1%]) compared with those receiving placebo (79 individuals [0.8%]; HR, 1.38; 95% CI, 1.03-1.84). This occurred by an increase in a combination of subdural, extradural, and subarachnoid bleeding with aspirin compared with placebo (59 individuals [0.6%] vs 41 individuals [0.4%]; HR, 1.45; 95% CI, 0.98-2.16). Haemorrhagic stroke was recorded in 49 individuals (0.5%) assigned to aspirin compared with 37 individuals (0.4%) in the placebo group (HR, 1.33; 95% CI, 0.87-2.04).
The authors concluded that these data do not support the use of low-dose aspirin for primary prevention of stroke in healthy older adults. They noted that the risk of intracerebral bleeding outweighs the potential benefits of aspirin in this population.
The study has several strengths. It is based on a large, well-conducted randomized clinical trial with a long follow-up period. The study was well-designed, and the results were carefully analysed. However, the paper also has some limitations. The study was conducted in a Caucasian population, so the results may not be generalizable to other populations, and did not include people with a history of stroke or other vascular diseases. The study was not powered to detect rare events, so the results may not be reliable for all outcomes.
Overall, the paper provides important evidence on the risks and benefits of low-dose aspirin in healthy older adults and supports the recommendation that low-dose aspirin should not be prescribed for primary prevention in healthy older adults.
Read the full secondary analysis here: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2807630
