A meta-analysis of seven randomized trials involving nearly 29,000 patients compared the efficacy of clopidogrel and aspirin in the secondary prevention of coronary artery disease[1]. Patients were followed for an average of 2.3 years and most of them underwent percutaneous coronary intervention or had acute coronary syndrome[1]. The results showed that after 5.5 years, there were fewer serious adverse cardiovascular events in patients taking clopidogrel (2.61 per 100 patient-years) than those on aspirin (2.99 per 100 patient-years), representing a 14 percent risk reduction[1]. Mortality and major bleeding did not differ between groups - clopidogrel did not increase the risk of bleeding[1]. These findings suggest that clopidogrel alone is more effective than aspirin in preventing cardiovascular events without an increased risk of complications[1].