Clinical Outcomes of On-Site Versus Off-Site Endovascular Stroke Interventions

Abstract

Objectives: The aim of this study was to assess whether offering local endovascular stroke therapy (EST) rather than transferring patients off-site to receive EST would improve outcomes.

Background: There are limited data to determine whether offering EST on-site rather than transferring patients to receive EST off-site improves clinical outcomes.

Methods: A large academic consortium database was queried to identify patients with acute ischemic stroke who received EST between October 2015 and September 2019. Primary endpoints were in-hospital mortality and poor functional outcomes. Secondary endpoints were major complications, length of stay, and cost. Baseline characteristics were adjusted for using propensity score matching and multivariate risk adjustment.

Results: A total of 22,193 patients with acute ischemic stroke who underwent EST (50.8% on-site, 49.2% off-site) were included. Mean ages were 67.9 ± 15.5 years and 68.4 ± 15.5 years, respectively (p = 0.03). In the propensity score matching analysis, mortality and poor functional outcomes were higher in the off-site EST group (14.7% vs. 11.2% and 40.7% vs. 35.9%, respectively; p < 0.001). In the risk-adjusted analyses with different models, in-hospital mortality and poor functional outcomes remained significantly higher in the off-site EST group. In the most comprehensive model (adjusting for age, sex, demographics, risk factors, tissue plasminogen activator use, and institutional EST volume), in-hospital mortality and poor functional outcomes were significantly higher in the off-site EST group, with odds ratios of 1.38 (95% confidence interval: 1.26 to 1.51) and 1.26 (95% confidence interval: 1.18 to 1.34), respectively (p < 0.001). The incidence of intracranial hemorrhage and mechanical ventilation was higher in the off-site group, but cost was higher in the on-site group in both the propensity score matching and risk-adjusted analyses.

Conclusions: In contemporary U.S. practice, patients with acute ischemic stroke treated with EST on-site had lower in-hospital mortality and better functional outcomes compared with those transferred off-site for EST.

Keywords: endovascular stroke therapy; ischemic stroke; mechanical thrombectomy; on-site.