THE ECASS 3-HOUR COHORT - SECONDARY ANALYSIS OF ECASS DATA BY TIME STRATIFICATION

Objectives: (1) To determine whether and how outcome measurements in t he ECASS trial are influenced by a shorter time window (0-3 vs. 3-6 h) between onset of symptoms and start of thrombolytic therapy using rec ombinant tissue plasminogen activator (rt-PA) in acute ischemic stroke . (2) To discuss the results of the ECASS 0- to 3-hour cohort with the results of the National Institute of Neurological Disorders and Strok e Study (NINDSS). Design and Analysis: Analysis of the 0- to 3-hour an d the 3- to 6-hour cohort in accordance with the ECASS protocol. Compa rative analysis of the ECASS and NINDSS results following the NINDSS p rotocol using dichotomized endpoints. Main Outcome Measures: Primary e ndpoints: modified Rankin Scale, Barthel Index; secondary endpoints: c ombined Barthel/Rankin, long-term Scandinavian Stroke Scale, National Institutes of Health Stroke Scale, mortality at 30 and 90 days, occurr ence of intracranial hemorrhage. NINDS trial endpoint: favorable outco me as defined in the NINDS trial. Results: In ECASS, 87 patients were randomized within 3 h of stroke onset. Differences in favor of rt-PA t reatment can be found for all primary and secondary outcome measures i n the ECASS O- to 3-hour cohort, except for mortality at day 30, which is somewhat higher in the rt-pA-treated group. However, due to the sm all sample size, the differences do not reach statistical significance . Early infarct signs (as defined by the ECASS protocol) are found as early as 2 h after stroke onset. Parenchymal hemorrhages are found sig nificantly more often among rt-PA-treated patients. The results in the ECASS O- to 3-hour cohort fit well with the results in NINDSS. Conclu sion: Data from the 3-hour ECASS cohort support the efficacy of early thrombolytic therapy in acute hemispheric stroke patients. Comparing b leeding complications between the ECASS and NINDSS is difficult becaus e of differences in the definition and occurrence of hemorrhagic event s.