Efficacy and safety of clopidogrel and/or aspirin for ischemic stroke/transient ischemic attack: An overview of systematic reviews and meta-analysis

OBJECTIVE: Patients experiencing acute ischemic stroke or transient ischemic attack are commonly treated with clopidogrel and/or aspirin (mono- and dual-antiplatelet therapy) to minimize the risk for recurrent stroke. Updated data from systematic studies can be used to guide practice. The present study aimed to compare findings from systematic reviews and meta-analyses addressing the efficacy and safety of clopidogrel or aspirin – alone or in combination – in patients experiencing acute ischemic stroke or transient ischemic attack. METHODS: The Cochrane Library, PubMed, Ovid, Scopus, EBSCO, and CINAHL databases were searched for relevant studies published from inception to 2020. Data from each study were extracted independently using a predefined data abstraction form. The Risk of Bias in Systematic Reviews tool and A Measurement Tool to Assess Systematic Reviews 2 were used to evaluate risk of bias and the quality of the included studies. RESULTS: Seven studies, published between 2010 and 2020, were eligible for analysis. The included studies evaluated a wide range of outcomes, including recurrent stroke, myocardial infarction, recurrent ischemic stroke, vascular mortality and vascular events, bleeding events, all-cause mortality, functional disability, and quality of life. The risk of bias and methodological validity of the included studies ranged from low to high according to ROBIS and AMSTAR 2 parameters. Results revealed that clopidogrel plus aspirin was more effective than aspirin alone in reducing the risk for recurrent stroke (ischemic or hemorrhagic), with high-quality evidence. However, compared with aspirin, dual treatment increased major bleeding events (intracranial bleeding and extracranial bleeding), supported by high-quality evidence. CONCLUSIONS: High-quality evidence suggested that clopidogrel plus aspirin was more efficient than monotherapy, although the risk for hemorrhagic stroke was relatively higher in combined therapy regimens lasting >1 month.