Abstract 195: Reducing Frequency of Symptomatic Intracranial Hemorrhage in Patients With Acute Ischemic Stroke Treated by Recombinant Tissue-Plasminogen Activator; Interim Result of a Prospective Observational Cohort Study

Abstract

[Introduction] Combination therapy with rt-PA and edaravone, a free radical scavenger, has become a prevalent treatment for acute ischemic stroke in Japan. PROTECT4.5 (Post marketing Registry OnTreatment with Edaravone in acute Cerebral infarction by the Time window of 4.5 hours) is a prospective observational cohort study to evaluate the efficacy and safety of the combination therapy. [Hypothesis] We assessed the hypothesis that combination therapy will reduce frequency of symptomatic intracranial hemorrhage in patients with acute ischemic stroke. [Methods] Patients treated by rt-PA and edaravone within 4.5 hours after onset of ischemic stroke were enrolled. The primary endpoints were proportion of patients with a modified Rankin Scale (mRS) score of 0-1 at 3 months after onset, and frequency of symptomatic intracranial hemorrhage (sICH) within 36 hours after initiating treatment. Mortality at 3 months after onset was assessed as a secondary endpoint. [Results] Between Apr 2010 and May 2012, 2814 patients from 839 institutes received combination therapy with edaravone and rt-PA. The mean age was 71.9 years old; 62.2% were male. The median score of NIHSS at baseline was 13 and the median time from onset to treatment with rt-PA was 2.25 hours. The most common type of stroke was cardioembolic (57.7%). Concomitant hypertension was present in 58.3% and diabetes mellitus in 17.1%. Estimated glomerular filtration rate < 60 mL/min/1.73m 2 was observed in 34.2% of patients. The proportion of patients with mRS 0-1 was 38.8% [709/1826, 95%Confidence Interval 36.6-41.1%]. Frequency of sICH and mortality were 1.7%[48/2814, 1.3-2.3%] and 8.9%[162/1826, 7.6-10.3%], respectively. [Conclusions] The severity and the proportion of mRS 0-1 in the patients enrolled in PROTECT4.5 were similar to those in the prospective single-arm open-label trial and the previous observational studies of rt-PA [J-ACT (Stroke 2006; 37:1810-1815), CASES (CMAJ 2005; 172:1307-12), STARS (JAMA 2000; 283:1145-50)], but frequency of sICH and mortality were lower.