Major Causes for Not Performing Endovascular Therapy Following Inter-Hospital Transfer in a Complex Urban Setting

Introduction: Endovascular therapy (EVT) has emerged as the standard of care for emergent large vessel occlusion (ELVO) acute ischemic stroke. An increasing number of patients with suspected ELVO are being transferred to stroke centers with interventional capacity. Not all such inter-hospital transfers result in EVT. Aim: To identify the major causes for not performing EVT following transfer. Methods: An analysis of 222 consecutive patients with suspected ELVO transferred for potential EVT between January 2015 and-December 2017 within a New York City health system was performed. About 36% (80/222) were deemed EVT ineligible and compared to an EVT cohort. Results: Major causes for not performing EVT were established infarct (34%), no or recanalized ELVO (31%), and mild or clinically improved symptoms (21%). In the established infarct subgroup, 28% (7/27) arrived at a stroke center with interventional capacity within 5 h of last known well, compared to 61% (83/142) in the EVT cohort (p = 0.003). In the no or recanalized ELVO subgroup, 40% (10/25) received computed tomographic angiography at the primary stroke center (PSC), compared to 73% (104/142) in the EVT cohort (p = 0.001). Among patients treated with intravenous thrombolysis, 6% (6/104) improved from a NIHSS of ≥6 to <6 following transfer. Conclusions: Established infarct, no or recanalized ELVO, and mild or clinically improved symptoms were the major causes for not performing EVT for patients transferred for ELVO management. These may be addressed by decreasing stroke onset to treatment times and timely ELVO detection at the PSC and/or pre-hospital triage.