The primary efficacy endpoint (composite outcome of time to first occurrence of cardiovascular death, myocardial infarction, unstable angina, stroke, or transient ischaemic attack. occurred in 269 (4.29%) patients in the aspirin group versus 281 (4.48%) patients in the placebo group (HR 0.96; 95% CI, 0.81–1.13; p=0.6038). The researchers suggest these findings probably reflect contemporary risk management strategies.
According to a commentary, the overall findings replicate those from previous studies of aspirin for primary prevention in patients at low cardiovascular disease risk. On the one hand, these findings reinforce recommendations against use of aspirin in this setting but, on other hand, leave unanswered the role of aspirin for primary prevention in patients without diabetes who have at least moderate CVD risk. It notes that European guidelines do not recommend using antiplatelets in individuals without cardiovascular disease because of the increased risk of major bleeding, whereas the US Preventive Services Task Force advocates initiating aspirin on the basis of age and a 10-year cardiovascular disease risk of at least 10%, as defined by available risk estimators. It adds that this study highlights the weakness and over-estimation of current methods to define the 10-year risk of cardiovascular disease, which are still based on historical data, underscoring the need for more reliable and contemporary estimates of cardiovascular risk. It also highlights that the study provides insight into the challenge of doing pragmatic trials of aspirin in an era characterised by other preventive and therapeutic interventions. It concludes that overall, the consistent trend in negative results from trials of aspirin in primary prevention, particularly in patients without diabetes, suggests that new avenues of research are needed for the prevention of cardiovascular events.