Safety and outcomes of endovascular treatment in patients with very severe acute ischemic stroke

Background Patients with anterior circulation ischemic strokes due to large vessel occlusion (AIS-LVO) and very severe neurological deficits (National Institutes of Health Stroke Scale (NIHSS) score > 25) were under-represented in clinical trials on endovascular treatment (EVT). We aimed to evaluate safety and outcomes of EVT in patients with very severe vs. severe (NIHSS score 15-25) neurological deficits. Methods We included consecutive patients undergoing EVT for AIS-LVO between January 2015 and December 2019 at Lille University Hospital. We compared rates of parenchymal hemorrhage (PH), symptomatic intracranial hemorrhage (SICH), procedural complications, and 90-day mortality between patients with very severe vs. severe neurological deficit using univariable and multivariable logistic regression analyses. Functional outcome (90-days modified Rankin Scale) was compared between groups using ordinal logistic regression analysis. Results Among 1484 patients treated with EVT, 108 (7%) had pre-treatment NIHSS scores > 25, 873 (59%) with NIHSS scores 15-25 and 503 (34%) with NIHSS scores < 15. Rates of PH, SICH, successful recanalization, and procedural complications were similar in patients with NIHSS scores > 25 and NIHSS 15-25. Patients with NIHSS > 25 had a lower likelihood of improved functional outcome ((adj)common OR 0.31[95% CI 0.21-0.47]) and higher odds of mortality at 90 days (adjOR 2.3 [95% CI 1.5-3.7]) compared to patients with NIHSS 15-25. Successful recanalization was associated with better functional outcome ((adj)common OR 3.8 [95% CI 1.4-10.4]), and lower odds of mortality (adjOR 0.3 [95% CI 0.1-0.9]) in patients with very severe stroke. The therapeutic effect of recanalization on functional outcome and mortality was similar in both groups. Conclusions In patients with very severe neurological deficit, EVT was safe and successful recanalization was strongly associated with better functional outcome at 90 days.