Purpose: Interhospital transfer is necessary to facilitate endovascular therapy (EVT) for patients with emergent large vessel occlusion (ELVO) who present to nonendovascular centers. We hypothesized that interhospital transfer would accelerate following 2014 pivotal randomized controlled trials (RCTs) demonstrating benefits of EVT.
Methods: We analyzed trend of interhospital transfer for EVT using Get With The Guideline (GWTG)-Stroke from January 2012 to September 2016. Analyses of transfer-in trend for the hospitals consistently providing EVT were restricted to hospitals with >1 EVT/quarter in last 4 study quarters (250 sites). We analyzed trend of interhospital transfer for all ischemic stroke (IS) patients and following subgroup: NIHSS ≥6 and arrival to the EVT-providing hospital within 7 hours of last known well.
Results: During the study period 31425 patients received EVT. Transfer-in EVT cases increased from 334 to 912 from Q3 2014 to Q3 2016 (p<0.001 for change in linear trend, Figure 1A). Interhospital transfer for EVT is common (44% in Q3 2016) and increasing proportion of IS patients are arriving to EVT-providing hospitals as transfers, especially among the subgroup of NIHSS ≥6 and arrival to the EVT-providing hospital within 7 hours of last known well (Figure 1B). Since RCT announcement, transfer-in patients receive EVT at a significantly higher rate (5.2% in Q3 2014 vs. 10.8% in Q3 2016, Figure 1C). Hospitals with a higher % transfer-in EVT (comparing top quartile to bottom quartile) were more likely to have more beds and be in an urban location, with comprehensive stroke center certification and higher annual EVT volumes.
Conclusions: Interhospital transfer of IS patients has accelerated markedly in the past two years, highlighting the need to develop protocols and quality metrics to ensure efficient systems of care for this subset of patients.