Abstract WP35: Outcomes of Mechanical Embolectomy in Patients Treated Beyond 8 hours From Stroke Onset: a Subanalysis of the North American SOLITAIRE Stent-retriever Acute Stroke Registry

Background and Purpose: Endovascular therapy (EVT) with stent-retrievers is safe and effective within 6-8hours of acute ischemic stroke onset; however a large proportion of patients present beyond 8hrs. There is a paucity of data on the safety and effectiveness of EVT in this latter population. Methods: We reviewed demographic, clinical, procedural and clinical outcomes data from consecutive patients treated with the Solitaire™ FR device in the investigator-initiated NASA Registry. Patients were divided into early (≤8hrs) and late (>8hrs) presenting groups. Primary outcomes (90-day mRS 0-2, mortality, and symptomatic ICH) were compared. Results: Three hundred and fifty-four patients from 24 centers were enrolled in NASA. Sixty-three (18%) patients presented >8hrs from onset and were treated. Baseline demographic and procedural factors were comparable between the early and late groups, except for time-to-treatment (271.9±97.3min vs. 754±269.3min, p Conclusions: The NASA Registry has demonstrated that clinical outcomes of patients treated >8hrs from stroke onset are favorable and comparable to the outcomes of patients treated earlier. Later treatment in these selected patients was not associated with an increased risk of symptomatic ICH. Future trials should prospectively evaluate the benefit of EVT beyond 8hrs.