Safety and Efficacy of Intravenous Recombinant Tissue Plasminogen Activator Administered in the 3-to 4.5-hour Window in Korea

Background: The safety and efficacy of intravenous tissue plasminogen activator (IV-TPA) in the 3- to 4.5-hour window were largely driven from Western populations, but have not been systematically explored in Korean population. Methods: We compared outcomes of acute ischemic stroke patients treated in the 3- to 4.5-hour window versus those in the 0- to 3-hour window, using a prospective multicenter registry database. Safety outcomes included symptomatic intracranial hemorrhage (SICH) and 3-month mortality and efficacy outcomes were the proportions of modified Rankin Scale (mRS) 0-1 and mRS 0-2 and the overall mRS distribution at 3 months. Results: Among 723 patients consecutively treated with IV-TPA alone, 616 were treated within 3 hours and 107 treated between 3 and 4.5 hours. The median onset-to-treatment time was 115 minutes for 0- to 3-hour group and 217 minutes for 3- to 4.5-hour group. The SICH rate was higher in the 3- to 4.5-hour group than in the 0- to 3-hour group (4.7% vs. 3.1%), but the difference was not significant (adjusted odds ratio [OR] [95% confidence interval {CI}], .81 [.20-3.35]). There were no significant differences between the 3- to 4.5-hour and 0- to 3-hour groups in the 3-month mortality (19.6% vs. 12.0%), mRS 0-1 (39.3% vs. 42.9%), mRS 0-2 (48.6% vs. 55.7%), and the overall mRS distribution (adjusted proportional OR [95% CI], .94 [.63-1.41]) after adjusting for covariates. Conclusions: IV-TPA treatment can be safely and efficaciously administered to eligible Korean patients up to the extended time window of 4.5 hours. However, efforts to expedite the treatment should not be neglected.