Impact of EMS bypass to endovascular capable hospitals: geospatial modeling analysis of the US STRATIS registry

BACKGROUND: Routing patients directly to endovascular capable centers (ECCs) would decrease time to mechanical thrombectomy (MT), but may delay intravenous thrombolysis (IVT). OBJECTIVE: To study the clinical outcomes of patients with a stroke transferred directly to ECCs compared with those transferred to ECCs from non-endovascular capable centers (nECCs). METHODS: Data from the STRATIS registry were analyzed to evaluate process and clinical outcomes under five routing policies: (1) transport to nearest nECC; (2) transport to STRATIS ECC over any distance or (3) within 20 miles; (4) transport to ideal ECC (iECC), over any distance or (5) within 20 miles. RESULTS: Among 236 patients, 117 (49.6%) were transferred by ground, of whom 62 (53%) were transferred within 20 miles. Median MT start time was accelerated in all direct transport models. IVT start was prolonged with direct transport across all distances, but accelerated with direct transport to iECC ≤20 miles. With bypass limited to ≤20 miles, the median modeled EMS arrival to IVT interval decreased for both iECCs and ECCs (by 12 min and 6 min, respectively), and median EMS arrival to puncture time decreased by up to 94 min. In this cohort, no patient would have become ineligible for IVT. Bypass to iECC modeling under 20 miles showed a significant reduction in the level of disability at 3 months, with freedom from disability (modified Rankin Scale score 0–1) at 3 months increased by 12%. CONCLUSIONS: Direct routing of patients with a large vessel occlusion to ECCs, especially when within 20 miles, may lead to better clinical outcomes by accelerating the start of MT without any delay of IVT. CLINICAL TRIAL REGISTRATION NUMBER: http://www.clinicaltrials.gov. Unique identifier: NCT02239640.