Antiplatelet effect of ticagrelor with aspirin in acute minor stroke and transient ischemic attack stratified by CYP2C19 metabolizer status: subgroup analysis of the PRINCE trial

The association of CYP2C19 LoF alleles with adverse clinical outcomes in stroke patients taking clopidogrel: An updated meta-analysis

The aggregated risk of recurrent stroke in stroke/transient ischemic attack (TIA) patients carrying CYP2C19 LoF alleles who take clopidogrel has not been investigated recently, and the available research is limited. This study aimed to perform an updated meta-analysis to assess the association between CYP2C19 LoF alleles and the risk of recurrent stroke in patients taking clopidogrel. Databases were searched for the literature on eligible studies. The end points were recurrent stroke, composite vascular events, and bleeding events. Odds ratios (ORs) were calculated using RevMan software, where p < 0.05 was considered statistically significant. Patients carrying CYP2C19 LoF alleles who were treated with clopidogrel had a significantly increased risk of recurrent ischemic stroke compared with non-carriers (OR 2.18, 96% CI 1.80-2.63; p < 0.00001). The risk of recurrent stroke was only significantly different in Asian patients (OR 2.29, 96% CI 1.88-2.80; p < 0.00001) but not in patients of other ethnicities; however, there were a limited number of studies in other ethnic groups. Both observational studies (OR 2.83, 96% CI 2.20-3.65; p < 0.00001) and RCTs (OR 1.48, 96% CI 1.10-1.98; p = 0.009) found associations with a significantly increased risk of recurrent ischemic stroke. Asian stroke patients or TIA patients carrying CYP2C19 LoF alleles and taking clopidogrel were at a significantly higher risk of recurrent ischemic stroke than non-carriers. Significantly increased risk of recurrent ischemic stroke was found in both observational studies and RCTs.

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.