A major international study has found that clopidogrel, a commonly prescribed blood thinner, is more effective than aspirin at preventing heart attacks and strokes in patients with coronary artery disease (CAD), without an increased risk of major bleeding. The findings, presented at the European Society of Cardiology congress in Madrid and published in the Lancet, could reshape clinical guidelines worldwide.
The comprehensive analysis of nearly 29,000 patients with CAD combined data from seven clinical trials, involving researchers from the US, UK, Australia, Switzerland and Japan. It found that patients taking clopidogrel had a 14% lower risk of major adverse cardiovascular or cerebrovascular events – including heart attack, stroke or cardiovascular death – compared with those taking aspirin. Rates of major bleeding were similar between the two drugs, dispelling concerns about clopidogrel's safety.
Coronary artery disease is the most common form of heart disease and a leading cause of death and disability globally, affecting more than 300 million people, including 2.3 million in the UK. Aspirin has long been the default treatment for preventing serious cardiovascular events in these patients, but the evidence supporting its long-term benefits has been limited.
Writing in the Lancet, the study team said: “This comprehensive synthesis of available evidence indicates that, in patients with CAD, long-term clopidogrel monotherapy offers superior protection against major cardiovascular and cerebrovascular events compared with aspirin, without an excess risk of bleeding. These results support a preference for clopidogrel over aspirin for chronic antiplatelet monotherapy for patients with stable CAD.”
The researchers noted that clopidogrel's widespread availability, generic formulation and affordability support its potential for extensive adoption. The benefits were consistent across key subgroups, including patients with genetic or clinical factors that might predict poorer response to the drug. Further research on cost-effectiveness and broader population studies is still needed to inform changes in treatment standards.
