Air Versus Ground Transport For Interhospital Transfer Prior To Endovascular Stroke Treatment

Introduction: Interhospital transfer for endovascular treatment of large vessel occlusion (LVO) stroke results in significant delays and worse outcomes. We hypothesized that interhospital patient transfer using air transport would result in shorter transit times compared to ground ambulance. Methods: Subjects from the STRATIS registry that underwent interhospital transfer for endovascular treatment were separated by air transport vs. ground ambulance transport and analyzed by transfer distance. The primary endpoint was transfer-time, calculated as the time from imaging at the initial hospital to arrival at the treating hospital. Also assessed was travel-time, calculated as time of departure from the initial hospital to arrival at the treating hospital. Results: There were 232 subjects from 41 sites. Mean transfer-time for all air subjects (n=118) was 147.1 min, and for all ground subjects (n=114) was 130.0 min (p=0.019). Mean travel-time was 45.0 min for air transport and 40.2 min for ground transport (p=0.239); though the average travel distance was longer for air (65.5 miles) vs. ground (27.6 miles; p<0.001). When analyzed by distance, there was no difference between air and ground transfer-time except transfers less than 20 miles, which favored ground transportation (154.4 min vs. 119.5 min; p=0.015; see table). The lack of advantage for air transport may be accounted for by the time between imaging and departure from the initial hospital (mean 89.4 vs. 101.6 min; p=0.075), reflecting additional logistics and/or reduced availability of air transport. Conclusions: In this large, real-world study, interhospital transfer via air transport did not result in faster transfer times compared to ground ambulance. In fact, there was an advantage to ground transportation for distances of less than 20 miles. These results suggest that ground ambulance should routinely be used for interhospital transfer of stroke patients for travel less than 20 miles.