Abstract WP42: Early Dramatic Improvement on the National Institutes of Health Stroke Scale Predicts Favorable Outcome 90 Days After Thrombectomy in the DEFUSE 3 Study

Abstract

Introduction: Thrombectomy in late time windows leads to improved outcomes in patients with ischemic stroke due to large vessel occlusion (LVO). We determined if patients with a dramatic improvement in their National Institutes of Health Stroke Scale (NIHSS) score 24 hours (24h) after thrombectomy were more likely to have a favorable clinical outcome than patients without a dramatic change in NIHSS in the DEFUSE 3 study. Methods: All patients who underwent thrombectomy in DEFUSE 3 were included. Dramatic improvement (DI) was defined as a reduction of ≥8 NIHSS or NIHSS 0-1 24h after thrombectomy. Clinical outcomes were assessed by an ordinal analysis modified Rankin Scale (mRS) score and a dichotomous analysis for functional independence (mRS 0-2) at 90 days. Pre- and post-thrombecotmy core infarction was quantified by the DEFUSE 3 core laboratory. Results: 91 patients in DEFUSE 3 underwent thrombectomy with follow up data; 31 patients (34%) experienced DI (DI+) after thrombectomy and 60 patients (66%) did not (DI-). There were no differences in age, medical comorbidities, right sided infarction, LVO location, presentation NIHSS, treatment with intravenous tPA, or time of thrombectomy treatment between DI+ and DI-. Presentation ASPECTS and baseline infarct core and penumbra volumes were similar between these groups. Reperfusion (TICI IIB-III) after thrombectomy was achieved in 26 (84%) DI+ and 43 (72%) DI- (p=0.2). Symptomatic intracranial hemorrhage occurred in no DI+ and 8% of DI- patients (p=0.2). DI was associated with a favorable mRS shift at day 90 (OR 3.8 [CI 1.7-8.6]; p=0.001) and higher rates of mRS 0-2 (61% vs 37%) OR 2.7 [CI 1.1-6.7]; p=0.03. Mortality was 3% in DI+ vs 18% in DI- (p=0.05). DI+ patients has lower median 24h NIHSS (5 [IQR 1-7] vs 13 [IQR 7.5-21]; p<0.001), smaller 24h infarction volume (21 ml [IQR 5-32] vs 65 [IQR 27-145]; p<0.001), and less 24h infarct growth (8 ml [IQR 1-18] vs 37 [IQR 16-105]; p<0.001) compared to DI- patients. Hospital stay was shorter in DI+, 3.7 days [IQR 2.9-7.1] vs 7.4 [IQR 5.2-12.1] in DI-, p<0.001. Conclusions: DI following thrombectomy correlates with favorable clinical and radiographic outcomes and reduced hospital length of stay. DI was a favorable prognostic sign following late window thrombectomy in the DEFUSE 3 cohort.