The CHARISMA Study has been made available online by the New England Journal of Medicine.
The study compared clopidogrel and aspirin to aspirin alone in 15,603 patients who had clinical cardiovascular disease or were at high risk of suffering a first event. These patients were then followed up for about 2 years for myocardial infarction, stroke or cardiovascular death.
At the end of the study there was no significant difference between the two groups in the primary outcome. There was a tendency to harm in the group that received clopidogrel and aspirin as there were a greater number of cases of severe bleeding, however this was not statistically significant.
Clopidogrel and aspirin therapy is of benefit in certain situations such as following a stent insertion but this study demonstrates that there is no reason to add clopidogrel to aspirin therapy as there is no incremental benefit for the patient but there may be an increased risk of harm.
Action: Clinicians who prescribe antiplatelets for primary and secondary prevention of uncomplicated cardiovascular disease should avoid using clopidogrel and aspirin in combination.