Effects of Extending the Time Window of Thrombolysis to 4.5 Hours

Background and Purpose— The European Cooperative Acute Stroke Study (ECASS) III trial and Safe Implementation of Thrombolysis in Stroke–International Stroke Thrombolysis Register (SITS-ISTR) data were published in 2008. Riks-Stroke, the Swedish Stroke Register, was used to explore how thrombolysis in the 3- to 4.5-hour window has been spread in different hospitals and patient groups and what effects this has had on treatment within 3 hours. Methods— All 76 hospitals in Sweden admitting patients with acute stroke participate in Riks-Stroke. During the study period, January 2003 to June 2010, 92 150 18- to 80-year-old patients were hospitalized for acute ischemic stroke. Results— After the publication of the ECASS III results in the third quarter of 2008, thrombolysis in the 3- to 4.5-hour window increased from 0.5% before publication to 2.1% in 2010. Thrombolysis in the 3- to 4.5-hour window spread somewhat faster in men than women ( P =0.04) but at a similar rate in different age groups. The use of thrombolysis within 3 hours after onset of symptoms increased successively from 0.9% in 2003 to 6.6% in late 2008 and then it stabilized at 6%. The median time from arrival to the hospital to start of treatment remained unchanged at 66 to 69 minutes before and after 2008 ( P =0.06). Conclusions— Since the end of 2008, there has been a rapid nationwide dissemination of thrombolysis in the 3- to 4.5-hour window, whereas rates in the <3-hour window have leveled off. The extended time window has not affected door-to-needle time.