Introduction: In an effort to maximize provision of acute stroke therapies, the Emergency Medical Services (EMS) in Orange County, CA (6th most populous U.S. county) established a system of care whereby patients with suspected acute stroke are taken to hub sites with endovascular treatment (EVT) capability or to spoke hospitals. Patients at spokes with acute ischemic stroke (AIS) and suspected large vessel occlusion (LVO) are transferred by EMS to hubs. Here we examined the relationship between stroke features, hospital transfers, and mortality; and their change over time.
Methods: All patients during 2013-2015 were included for whom 911 was called within 7 hours of onset, and EMS personnel declared “acute stroke" at end of initial evaluation.
Results: A total of 6,188 patients (mean age 72) had suspected stroke, of which 54.9% were AIS and 19.4% hemorrhagic stroke. Across all patients, transfer rates into hub sites increased over time (OR 1.12 per 3-months, p<0.0001) and differed by diagnosis (p<0.0001), with transfer in 12.0% of hemorrhages (n=122) but only 3.5% of AIS (n=101). Among patients with AIS only, transfer rates into a hub site increased over time (OR 1.08, p<0.0001), spiking mid-2015. Acute reperfusion therapy was given to 28.3% (20.9% IV tPA only, 3.6% IA therapy only, 3.8% IV tPA+IA), but its usage was unrelated to transfer status, and only 11% of all transferred AIS patients received EVT. Across all patients, mortality during acute hospitalization was 8.2% and did not differ by transfer status, but did differ by diagnosis (p<0.0001): 23.6% of hemorrhages vs. 5.4% of AIS. Over time, mortality decreased only among patients with AIS (OR 0.95, p=0.03).
Conclusions: There were several favorable features of this acute stroke care system, including that 28.3% of AIS patients received reperfusion therapy and that mortality decreased over time. However, while transfer to EVT-ready sites increased, rates of IA therapy were low. Continued efforts to optimize acute stroke systems of care should be tailored toward increasing EVT by early recognition of LVO and timely triage to hub facilities.