Prior antiplatelet agent use and outcomes after intravenous thrombolysis with recombinant tissue plasminogen activator in acute ischemic stroke: a meta-analysis of cohort studies and randomized controlled trials.

Abstract

There is uncertainty surrounding the influence of prior antiplatelet agent use on outcomes after intravenous thrombolysis with recombinant tissue plasminogen activator in acute ischemic stroke. We performed a systematic review with a final meta-analysis to evaluate the efficacy and safety of prior antiplatelet use before intravenous recombinant tissue plasminogen activator for acute ischemic stroke. We searched PubMed and Embase databases from 1997 to 2014. Primary outcome was functional outcome at the end of follow-up; secondary outcomes were symptomatic intracranial hemorrhage and recanalization rate. The meta-analysis was performed with Review Manager 5.2 (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2012). Eleven studies with a total of 19,453 patients were included. A total of 6517 (33.5%) patients who had received intravenous recombinant tissue plasminogen activator were taking antiplatelet agent before stroke onset. Pooled analysis demonstrated a clear trend that previous antiplatelet users had a reduced probability of good outcome, although it was not conventionally statistically significant (OR 0.86; 95% CI 0.73-1.01; P = 0.06). There was no difference in recanalization rate between two groups (OR 1.23; 95% CI 0.30-4.99; P = 0.77). The risk of symptomatic intracranial hemorrhage was significantly increased in the antiplatelet group (OR 1.65; 95% CI 1.44-1.90; P < 0.01). In acute ischemic stroke patients receiving intravenous recombinant tissue plasminogen activator therapy, prior antiplatelet agent use did not lead to a significant difference in functional outcome, although it significantly increased the risk of symptomatic intracranial hemorrhage. Recanalization rate was not different between two groups. In the subgroup analysis, prior clopidogrel mono therapy may not increase the risk of symptomatic intracranial hemorrhage, which will need further studies to confirm.