Aspirin Versus Clopidogrel Monotherapy for the Treatment of Patients with Stable Coronary Artery Disease: A Systematic Review and Meta-Analysis

INTRODUCTION: Although aspirin (ASA) is the mainstay of treatment for the prevention of recurrent ischemic stroke, the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial showed ASA monotherapy to be inferior to clopidogrel in preventing recurrent adverse cardiovascular outcomes in patients with high cardiac risks. Here, we aimed to systematically compare ASA versus clopidogrel monotherapy for the treatment of patients with stable coronary artery disease (CAD). METHODS: Electronic databases were searched and studies were included if they compared ASA versus clopidogrel monotherapy for the treatment of patients with CAD and they reported adverse clinical outcomes. The latest version of RevMan software (version 5.3) was used as the statistical tool for the data analysis. Odds ratios (OR) and 95% confidence intervals (CI) were generated to interpret the data. RESULTS: A total number of 5497 patients (from years 2003 to 2011) were treated with ASA monotherapy, whereas 2544 patients were treated with clopidogrel monotherapy. Results of this analysis showed no significant difference in composite endpoints (cardiovascular death, myocardial infarction, and stroke) (OR 0.99, 95% CI 0.47–2.10; P = 0.98), all-cause mortality (OR 1.05, 95% CI 0.82–1.33; P = 0.71), cardiac death (OR 0.89, 95% CI 0.17–4.74; P = 0.89, myocardial infarction (OR 0.84, 95% CI 0.52–1.36; P = 0.48), stroke (OR 1.26, 95% CI 0.39–4.06; P = 0.70), and bleeding defined by the Bleeding Academic Research Consortium (BARC [grade 3 or above]) (OR 1.28, 95% CI 0.78–2.12; P = 0.33). CONCLUSION: This analysis did not show any significant difference in all-cause mortality, cardiac death, myocardial infarction, stroke, and BARC grade 3 or above among CAD patients who were treated with either ASA or clopidogrel monotherapy. However, as a result of the limited data, this hypothesis should be confirmed in other major trials.