Abstract 3275: Early Neurological Improvement After Intravenous Thrombolysis in Acute Stroke Predicts Long-Term Functional Outcome

Abstract

Background: Intravenously administered tissue plasminogen activator (IV-TPA) remains the only approved therapeutic agent for arterial recanalization in acute ischemic stroke (AIS). Wide variations in the rates and timing of neurological recovery are observed in thrombolyzed patients. While all IV-TPA treated patients are routinely evaluated for neurological recovery at 24-hours, considerable improvement occurs in some cases within 2-hours of treatment initiation. We evaluated whether early neurological improvement at 2-hours after IV-TPA bolus (ENI-2) can predict functional outcomes in thrombolyzed AIS patients at 3-months. Methods: Data for consecutive stroke patients treated with IV-TPA within 4.5 hours of symptom-onset during 2007-2010 were prospectively entered in the thrombolyzed registry maintained at our tertiary care center. Data were collected for demographic characteristics, vascular risk factors, stroke subtypes and blood pressure levels before IV-TPA bolus. National Institute of Health Stroke Scale (NIHSS) scores were obtained before IV-TPA bolus and at 2-hours. ENI-2 was defined as a reduction in NIHSS score by more than 10-points from baseline score or an absolute score of 4-points or less at 2-hours after IV-TPA bolus. Functional outcomes at 3-months were determined by modified Rankin scale (mRS). Data were analyzed by SPSS 19.0. Results: Of the 2238 AIS patients admitted during the study period, 240 (11%) received IV-TPA within 4.5-hours of symptom-onset. Median age was 65yrs (range 19-92), 63% males, median NIHSS 17points (range 3-35) and median onset-to-treatment time 149 minutes. Overall, 122 (50.8%) patients achieved favorable functional outcome (mRS 0-1) at 3-months. Factors associated with favorable outcome at 3-months on univariable analysis were younger age, female gender, presence of atrial fibrillation, baseline NIHSS, onset-to-treatment time (OTT) and ENI-2. However, multivariable analysis demonstrated NIHSS at onset (OR per 1-point increase 0.907, 95%CI 0.848-0.969) and ENI-2 (OR 4.926 95%CI 1.66-15.15) as independent predictors of favorable outcome at 3-months. Conclusion: Early Neurological improvement at 2-hours after IV-TPA bolus is a strong predictor of the functional outcome at 3-months in acute ischemic stroke patients.