Interhospital Transfer Prior to Thrombectomy is Associated with Delayed Treatment and Worse Outcome in the STRATIS Registry

BACKGROUND—Endovascular treatment with mechanical thrombectomy (MT) is beneficial for acute stroke patients suffering a large vessel occlusion, though treatment efficacy is highly time-dependent. We hypothesized that interhospital transfer to endovascular-capable centers would result in treatment delays and worse clinical outcomes compared to direct presentation. METHODS—STRATIS was a prospective, multicenter, observational, single-arm study of real-world MT for acute stroke due to anterior-circulation large vessel occlusion performed at 55 sites over 2 years, including 1000 patients with severe stroke and treated within 8 hours. Patients underwent MT with or without IV-tPA, and were admitted to endovascular-capable centers via either interhospital transfer or direct presentation. The primary clinical outcome was functional independence (modified Rankin Score 0-2) at 90 days. We assessed 1) real-world time metrics of stroke care delivery, 2) outcome differences between direct and transfer patients undergoing MT, and 3) the potential impact of local hospital bypass. RESULTS—A total of 984 patients were analyzed. Median onset-to-revascularization time was 202.0 minutes for direct vs. 311.5 minutes for transfer patients (p