Abstract WP021: Mobile Stroke Arrival to Thrombolytic Administration 25 minutes Best Approaches Golden Hour Treatment Outcomes

Background: We sought to determine a data-based time metric for mobile stroke unit arrival to thrombolytic administration. Methods: The Mobile Stroke Treatment Unit (MSU) of metropolitan Columbus, Ohio, provides emergency stroke coverage for 445 square miles spanning over 50 zip codes. Our MSU is operational from 0700-1900 daily and is dispatched for all 911 calls designated as probable or definite strokes. Our MSU defines arrival as the documented time of MSU arrival to the patient location. The time of arrival to thrombolytic needle time is recorded. We retrospectively reviewed all patients treated with thrombolytic therapy and brought to our CSC from May 2019 to March 2025. Patients were separated into the following time intervals: treatment within the first 60 minutes of symptoms (golden hour), MSU arrival to needle time < 25 minutes, MSU arrival to needle time < 26-35 minutes, MSU arrival to needle time > 36 minutes. Golden hour patients were separated from the other patient groups to avoid overlap. The endpoint was a mRS 0-1 at 90 days. The outcome ratio of the golden hour treatment group was considered the standard. We compared the ratio of patients achieving the primary endpoint in each separate time interval with the golden hour group using a pairwise Fisher's exact test for significance. We defined goal MSU arrival to needle time as less than any time interval with statistically significant lower clinical outcomes than that of the golden hour cohort. Results: During out study period, 166 patients were treated with thrombolytics and brought to our CSC. Patients were treated and achieved the primary endpoint as follows: 39/64 patients in the golden hour, 16/27 patients in < 25 minutes, 23/43 patients between 26-35 minutes, 8/10 patients in > 36 minutes. We could not identify a specific time interval where outcomes statistically diverged from those treated within the golden hour. However, patients treated < 25 minutes demonstrated the best trend of equivalency with golden hour treated patients (OR 1.07, CI-0.20-0.21, p=1.07). Conclusions: We propose the definition of onsite to needle time as a time metric for MSUs. We encourage the goal of treatment to be within the golden hour when possible. Although a data-based metric was not identified, treatment within 25 minutes of arrival appears most similar to this group. We advocate for a larger mutlicenter study.