[Intravenous rt-PA therapy: current status and extending therapeutic time window in Japan]

Several clinical studies carried out in Japan demonstrated that 0.6 mg/kg of intravenous alteplase within 3 hours of stroke onset could be safe and effective in routine clinical practice for Japanese patients. Since the approval, it has become the golden standard for acute ischemic stroke therapy, although there are huge gaps in frequency of use between various areas of Japan.Pooled analyses of randomized controlled trials in USA and Europe and the ECASS III clinical trial indicated the efficacy and safety of rt-PA therapy when expanding therapeutic time window (TTW) from 3 to 4.5 hours. The Japanese Government approved the 4.5 hour time-window in August 2012, and the Japan Stroke Society published the 2nd version of guidelines of rt-PA therapy in October 2012. The author discussed on clinical implications of shortening the door-to-needle time and extending TTW of this therapy.