Abstract 329: Mobile Stroke Unit and Mechanical Thrombectomy Workflow: A Single Center 5‐Year Experience.

Background and purpose: Mobile Stroke Units have been demonstrated to significantly reduce time to treatment and increase the chances of early intravenous thrombolysis (IVT) with positive effect on clinical outcomes. The evidence of its impact on the treatment time metrics and outcomes in endovascular treatment (EVT)‐eligible patients outside of large clinical trials is limited. Method Retrospective review of a single‐center prospectively maintained mechanical thrombectomy database spanning June 2018‐November 2023. Patients receiving endovascular treatment (EVT) for large‐vessel occlusion (LVO) strokes were divided in two groups: MSU‐transported and EMS‐transported (mothership) presenting within MSU operating days/hours. Treatment time metrics and clinical outcomes were compared. Results Among patients undergoing EVT during MSU operating days/hours, 565 were included (66 were in MSU and 499 in EMS groups). Median overall age was 66 years, 55% were male. Median baseline ASPECTS and NIHSS were comparable between the groups. Witnessed onset of stroke was more common in the MSU group (42% vs 27%, p=0.007) while time from symptom recognition to ED door was shorter for EMS‐transported patients (84 vs 103 min, p=0.001). More patients in MSU group were within IVT window and received alteplase or tenecteplase (45% vs 24%, p<0.001). MSU patients were more likely to bypass further imaging and go direct to angio upon hospital arrival (12% vs 2.2%, p<0.001), and more patients in the EMS group had multimodal imaging before EVT (95% vs 83%, p=0.001). The LKW‐to‐puncture times were shorter in the MSU group (237 vs 389 min, p=0.021), which also had significantly faster times from ED door to CT and multimodal imaging completion (9 vs 17 min, and 17 vs 27 min, respectively, p<0.001). Regarding the EVT procedure, all time metrics favored MSU‐ transported patients, including door‐to‐angio (41 vs 62min, p<0.001), door‐to puncture (58 vs 82 min, p<0.001) and door‐to‐reperfusion (96 vs 127 min, p<0.001). A sensitivity analysis excluding DTA patients indicated that all time metrics, except for LKW‐to‐puncture time, remained faster in the MSU group. Results were unchanged after adjustment for witnessed symptom onset (yes/no), and time from last known normal to symptom recognition. Mediation analyses showed that the association between MSU and lower door‐to‐puncture time was substantially explained by a difference in rates and time to completion of multimodal imaging, which was responsible for 49% (95% CI: 28% to 75%) of the difference between MSU and EMS. Functional outcomes at 90 days and rates of intracerebral hemorrhage were similar between the two groups. Conclusions: In this single center analysis, MSU‐transported patients demonstrated improved EVT time metrics, with shorter treatment times when compared to EMS‐transported patients. Outcomes and safety parameters did not differ between the two groups.