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<0.0001), IV tPA utilization (52.6% vs. 11.1%, <0.0001), baseline diastolic BP (77.9±16.8mmHg vs. 83.8±20.2mmHg, p=0.03), and frequency of vertebrobasilar occlusions (7.1% vs. 19.1%, p=0.0034). Procedural aspects were similar except for time to recanalization (early 73.8±84.5min vs. late 53.6±32min, p=0.0074). Recanalization success (TICI≥2b) was comparable (early 74.4% vs. late 76.2%, p=0.76). The primary outcome measures including symptomatic ICH (11.6% vs. 4.8%, p=0.11), mortality (29.9% vs. 29.3%, p=0.93), and mRS 0-2 (44.4% vs. 34.5%, p=0.17) were similar between the early and late groups, respectively. When only anterior circulation strokes were included (N=301), the data did not change significantly and the primary endpoints of symptomatic ICH (12.1% vs. 5.9%, p=0.2), mortality (27.9% vs. 27.7%, p=0.97) and mRS 0-2 (44.6% vs. 36.2%, p=0.29) remained comparable between the early and late groups, respectively.
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.
Response to Letter Regarding Article, “Balloon Guide Catheter Improves Revascularization and Clinical Outcomes With the Solitaire Device: Analysis of the North American Solitaire Acute Stroke Registry”