Background and Purpose- In Japan, nearly half of ischemic stroke patients receive edaravone for acute treatment. The purpose of this study was to assess the effect of edaravone on neurological symptoms in patients with ischemic stroke stratified by stroke subtype. Methods- Study subjects were 61 048 patients aged 18 years or older who were hospitalized ≤14 days after onset of an acute ischemic stroke and were registered in the Japan Stroke Data Bank, a hospital-based multicenter stroke registration database, between June 2001 and July 2013. Patients were stratified according to ischemic stroke subtype (large-artery atherosclerosis, cardioembolism, small-vessel occlusion, and cryptogenic/undetermined) and then divided into 2 groups (edaravone-treated and no edaravone). Neurological symptoms were evaluated using the National Institutes of Health Stroke Scale (NIHSS). The primary outcome was changed in neurological symptoms during the hospital stay (ΔNIHSS=NIHSS score at discharge-NIHSS score at admission). Data were analyzed using multivariate linear regression with inverse probability of treatment weighting after adjusting for the following confounding factors: age, gender, and systolic and diastolic blood pressure at the start of treatment, NIHSS score at admission, time from stroke onset to hospital admission, infarct size, comorbidities, concomitant medication, clinical department, history of smoking, alcohol consumption, and history of stroke. Results- After adjusting for potential confounders, the improvement in NIHSS score from admission to discharge was greater in the edaravone-treated group than in the no edaravone group for all ischemic stroke subtypes (mean [95% CI] difference in ΔNIHSS: -0.46 [-0.75 to -0.16] for large-artery atherosclerosis, -0.64 [-1.09 to -0.2] for cardioembolism, and -0.25 [-0.4 to -0.09] for small-vessel occlusion). Conclusions- For any ischemic stroke subtype, edaravone use (compared with no use) was associated with a greater improvement in neurological symptoms, although the difference was small (<1 point NIHSS) and of limited clinical significance.
Keywords: aspirin; blood pressure; cause of death; database; free radical scavengers.