Methods: The SOS Trial is a prospective, single-arm, multicenter study based in the United Kingdom and Germany. Patients can be enrolled presenting with symptoms of acute ischemic stroke within 8 hours from symptom onset from a large vessel occlusion and a NIHSS of at least 10. The primary endpoint is functional outcome at 90 days as defined by mRS of 0-2. Interim data was collected and analyzed. The secondary endpoints include good neurological outcome as defined by an NIHSS score of 0-1 or a 10 points or more improvement in this scale at discharge, all cause mortality, and the incidence of hemorrhage.
Results: To date, 137 patients were enrolled at 16 centers. Data was available for 42/137 (30.7%) patients. The mean age was 62.4+21.2; median admission NIHSS was 18 (10-31). Occlusions were in the MCA (71.4%), ICA (21.4%), ACA (4.8%), and other (2.4%). Good 90-day outcome was achieved in 13.9% (5/36); 15.0% (6/40) died. The serious adverse event rate was 24.4 (32/131). A total of 7 (17.1%) patients suffered intracerebral hemorrhage. Good neurological outcome rate was 14.7% (5/34).
Conclusion: Preliminary data showed that large vessel acute ischemic stroke leads to poor patient outcomes if untreated. With further data collected from the remaining patients enrolled, this can help advance our knowledge of the natural course of stroke and serve as a benchmark for future endovascular trials.