Effect of antiplatelet pretreatment on platelet aggregation and clinical outcomes in acute ischemic stroke patients treated with recombinant tissue-type plasminogen activator

Early administration of antiplatelet agents in acute ischemic stroke patients (AIS) receiving intravenous thrombolysis (IVT) is a potential therapeutic strategy, however, safety and efficacy are not well established. We hypothesize that antiplatelet pretreatment (AP) before IVT have a similarly role as initiation of AP within the first 24 hours following IVT. We aimed to explore the effect of AP on platelet aggregation and clinical outcomes in thrombolysis-treated AIS patients. We enrolled AIS patients treated with IVT at the Neurology Department of the Nanjing First Hospital from January 2016 to June 2018. Prior use of antiplatelet agent was recorded. Light transmittance aggregometry was used to estimate the maximum platelet aggregation (MPA). Linear regression model was performed to investigate the factors associated with MPA. Multivariate logistic regression was used to analyse the association between AP and clinical outcomes. A total of 59 patients were included; 23 (38.9 %) were taking antiplatelet agent before stroke. Prior AP (β = -20.209, SE mean=6.574; P=0.004) was significantly lower the arachidonic acid-induced MPA at the time point of 3h after thrombolysis. AP did not increase of the risk for sICH (OR=3.41, 95%CI 0.16-7.20, p=0.436) or mortality (OR=3.55, 95%CI 0.39-8.52, p=0.260). There were no associations between AP and improved clinical outcomes (all P>0.05). In thrombolysis-treated AIS patients, AP was associated with lower MPA after thrombolysis. AP is safe in these patients, however, further studies are required to confirm the efficacy.