Effect of antiplatelet pretreatment on safety and efficacy outcomes in acute ischemic stroke patients after intravenous thrombolysis: a systematic review and meta-analysis.

Background: About 40% of acute ischemic stroke patients are under antiplatelet pretreatment. Previous studies have shown conflicting results on the effect of prior antiplatelet agents on post thrombolytic clinical outcomes.
Methods: A systematic search using PubMed and EMBASE databases for eligible studies. Prior antiplatelet safety was measured by symptomatic intracerebral hemorrhage (sICH) and mortality. Efficacy was measured by functional independence and favorable functional outcome.
Results: Crude analysis indicated that antiplatelet pretreatment was associated with sICH and mortality. In adjusted analysis, the results confirmed a nonsignificant association between antiplatelet pretreatment and a higher risk of sICH and mortality, but demonstrated that antiplatelet pretreatment tended to improve functional independence and favorable functional outcome. Subgroup analysis detected a racial disparity in prior antiplatelet effect on sICH and the association between antiplatelet pretreatment and sICH was dependent on different antiplatelet regiments.
Conclusion: There was no significant difference in sICH and mortality between patients with and without antiplatelet pretreatment. Besides, antiplatelet pretreatment did not adversely affect the efficacy outcomes. The prevalence of sICH among Asians receiving antiplatelet pretreatment was relatively high. Additionally, it needs to be noticed that the effect of preexisting antiplatelet on clinical outcomes may be dependent on post thrombolytic antiplatelet regiments.