Abstract MP6: Thrombolysis for Acute Wake-Up And Unclear Onset Strokes With Alteplase at 0.6mg /kg in Clinical Practice: THAWS2 Study

Abstract

Background and Purpose: IV alteplase at 0.6 mg/kg for acute wake-up and unclear onset strokes was recommended in Japanese stroke guidelines in March 2019. We determined the safety and effectiveness of this newly recommended thrombolysis in clinical practice. Methods: This is a multicenter observational study, enrolling acute ischemic stroke patients with a time last-known-well >4.5 h who have a mismatch between DWI and FLAIR treated with intravenous alteplase. The safety outcomes are intracranial hemorrhage (ICH) with neurological deterioration within 36 h after thrombolysis, all cause deaths within 90 days, and adverse events. The efficacy outcomes are functionally independence defined as a mRS score of 0-1 at 90 days, and NIHSS change at 24h from baseline. Results: Between 2019 March and 2020 March, 63 patients (33 females; age, 74±11y; premorbid functionally independence, 50 (82%); median NIHSS on admission, 11) were enrolled at 14 hospitals. Of them, 40 patients (63%) recognized stroke symptoms at wake-up time, and median time between last-known-well and admission was 6.5 h. Baseline MRA showed any vessel occlusion in 52 patients (88%). IV alteplase was disrupted in one patient. Two patients (3%) had symptomatic ICH (≥4 increase in NIHSS) within 36 h. NIHSS change was -5.1±8.1. Twenty-one patients (36%) had functionally independence at discharge and there was no death during acute hospitalization. Of the overall 63 patients, 22 also underwent mechanical thrombectomy (36%, 72±9y, median NIHSS 16), showing no symptomatic ICH, mean NIHSS change of -8.9±7.5, and 8 patients (42%) had functionally independence at discharge. Conclusions: In clinical practice, IV alteplase for wake-up and unclear onset stroke patients with DWI-FLAIR mismatch seemed to be safe and effective compared with previous randomized control trials. Mechanical thrombectomy could be combined with alteplase safely and effectively.