Abstract 93: Upgrading to Endovascular Therapy-Performing Hospital Increases Acute Ischemic Stroke Admissions

Abstract

Introduction: Given the impact of endovascular therapy (EVT) on clinical outcomes and the use of pre-hospital bypass protocols to route acute ischemic stroke (AIS) patients to EVT-performing hospitals (EPHs), there is substantial interest in upgrading stroke center certification to become EPHs. Here, we assess trends in patient volumes of AIS admissions at three hospitals after upgrade, in comparison to one long-standing EPH and six non-EPHs within the same urban area. Methods: From our prospectively collected, multi-institutional registry, we identified consecutive AIS admissions at ten hospitals in the Houston metropolitan area from November 2017 through March 2022. One hospital had been an EPH throughout the study period (Group A: EPH 0), three transitioned to EPHs in November 2017 (Group B: EPH 1, EPH 2, EPH 3), and six were non-EPHs (Group C). Primary outcomes were trends in volume of total AIS admissions over time determined by linear regression. Secondary outcomes included trends in volumes of tPA usage, LVO admissions, and mechanical thrombectomy (MT) determined by linear regression. Results: Among 13,099 patients with AIS presenting to ten hospitals, median age was 67 [IQR 57-78], 45% were female, median NIHSS was 4 [IQR 1-11], 17.5% were given tPA, 22% had LVO, and 9.5% underwent mechanical thrombectomy. Centers that became EPH in 2017 experienced an overall increase in AIS admissions (p=0.0007) at rates of 8 per year for EPH 1 (p=0.005), 5 per year for EPH 2 (p<0.001) and 4 per year for EPH 3 (p=0.11). AIS admissions did not change significantly at the original EPH (p=0.13) nor at three of the non-EPHs (p=0.24, 0.39, 0.82), and volumes decreased at the other three non-EPHs (p=0.009, 0.02, 0.09). Changes in LVO volumes did not reach significance for any group. Volumes of tPA use and MT increased for group B (p<0.005) but did not change significantly for group A (p>0.18), and tPA use decreased for group C (p=0.03). Conclusions: In this observational cohort study, upgrading to EPH status resulted in increasing AIS admissions over time, as well as increases in tPA use and MT. Volumes at the previously established EPH did not change significantly over the study period, while AIS admissions decreased slightly at the non-EPHs in the surrounding area.