Abstract WP162: Primary Results Of Mechanical Thrombectomy For Acute Ischemic Stroke In Clinical Practice: K-net Registry

Abstract

Background: Endovascular treatment (EVT) for acute large vessel occlusion has been found to be effective in several randomized controlled trials. We conducted a prospective cohort study to evaluate the real-world efficacy of EVT in patients with acute ischemic stroke in a metropolitan area with a high population density and a large number of comprehensive stroke centers. Methods: We analyzed the Kanagawa Intravenous and Endovascular Treatment of Acute Ischemic Stroke registry, a prospective, multicenter observational study of patients treated by EVT and/or intravenous tissue-type plasminogen activator (tPA), in Kanagawa, Japan. Of the 2488 patients enrolled from January 2018 to June 2020, 1764 patients treated with EVT were included. The primary outcome was a good outcome, which was defined as a modified Rankin Scale (mRS) of 0 to 2 at 90 days. Secondary analysis included predicting a good outcome using multivariate logistic regression analysis. Results: The median age was 77 years and the median National Institute of Health Stroke Scale (NIHSS) score was 18. Pretreatment mRS score 0-2 was 87%, and direct transport was 92%. The rate of occlusion in anterior circulation was 90.3%. Successful recanalization was observed in 88.7%. The median time from onset to recanalization was 193 minutes. Good outcomes at 90 days were 43.3% in anterior circulation and 41.9% in posterior circulation. Furthermore, 49.3% of patients with anterior circulation obstruction who had pre-stroke mRS 0-2 had good outcome, which was higher than the HERMES trial. Overall mortality was 12.6%. Significant predictors for a good outcome were: age, male, direct transfer, NIHSS score, Alberta Stroke Program Early Computed Tomography Score, intravenous tPA, and successful recanalization. Conclusions: EVT in routine clinical use in a metropolitan area showed comparable good outcomes and lower mortality compared to previous registries and RCTs, despite the high proportion of patients with older age, pretreatment mRS score of > 2, posterior circulation occlusion, and higher NIHSS. Those results may have been associated with more direct transport and faster onset-to-recanalization times.