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 (common OR 0.31[95% CI 0.21-0.47]) and higher odds of mortality at 90 days (OR 2.3 [95% CI 1.5-3.7]) compared to patients with NIHSS 15-25. Successful recanalization was associated with better functional outcome (common OR 3.8 [95% CI 1.4-10.4]), and lower odds of mortality (OR 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.