Antiplatelet pretreatment and outcomes in intravenous thrombolysis for stroke: a systematic review and meta-analysis

Since there are contradictory data regarding the association of antiplatelet pretreatment (AP) with safety and efficacy outcomes of intravenous thrombolysis (IVT) for acute ischemic stroke (AIS), we conducted a systematic review and meta-analysis of available randomized-controlled clinical trials (RCTs) to investigate the association of AP with outcomes of AIS patients treated with intravenous alteplase. The outcome events of interest included symptomatic intracranial hemorrhage (sICH), fatal ICH, complete recanalization (CR), 3-month favorable functional outcome (FFO, mRS score 0-1), 3-month functional independence (FI, mRS score 0-2), and mortality. The corresponding odds ratios (ORs) were calculated for all the outcome events using random-effects model. The adjusted age and admission NIHSS OR (OR_adjusted) were also estimated for all available outcomes. We included 7 RCTs (4376 patients, 33.7% with AP). In unadjusted analyses, AP was associated with higher likelihood of sICH (OR = 1.89, 95% CI 1.40-2.56), death (OR = 1.59, 95% CI 1.24-2.03), and lower likelihood of 3-month FI (OR = 0.69, 95% CI 0.56-0.85). No association was detected between AP and fatal ICH (OR = 1.53, 95% CI 0.75-3.15), 3-month FFO (OR = 0.79, 95% CI 0.58-1.07), and CR (OR = 0.64, 95% CI 0.04-11.66). After adjustment for age and admission stroke severity, AP was not related to sICH (OR_adjusted = 1.67, 95% CI 0.75-3.72), 3-month FI (OR_adjusted = 0.88, 95% CI 0.54-1.42), or death (OR_adjusted = 1.01, 95% CI 0.55-1.86) in adjusted analyses. In conclusion, after adjusting for confounders, AP was not associated with a higher risk of sICH and worse 3-month functional outcome in AIS treated with intravenous alteplase. Antiplatelet intake prior to tPA-bolus should not be used as a reason to withhold or lower alteplase dose in AIS patients treated with IVT.