STRATIS Registry Evaluates Effects of Interhospital Transfer on Stroke Patients Before Thrombectomy
December 13, 2017—Findings from the STRATIS registry were published by Michael T. Froehler, MD, et al in Circulation (2017;136:2311–2321). STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter, observational, single-arm study of real-world mechanical thrombectomy for acute stroke due to anterior circulation large vessel occlusion.
The investigators concluded that interhospital transfer was associated with significant treatment delays and a lower chance of favorable outcomes. They advised that strategies to facilitate more rapid identification of large vessel occlusion and direct routing to endovascular-capable centers for patients with severe stroke may improve outcomes.
As summarized in Circulation, the treatment in the registry was performed at 55 sites during a period of 2 years and included 1,000 patients with severe stroke and treated within 8 hours. Patients underwent mechanical thrombectomy with or without intravenous tissue plasminogen activator 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. The STRATIS investigators assessed (1) real-world time metrics of stroke care delivery, (2) outcome differences between direct and transfer patients undergoing mechanical thrombectomy, and (3) the potential impact of local hospital bypass. The findings include an analysis of a total of 984 patients.
The investigators reported that median onset-to-revascularization time was 202 minutes for direct versus 311.5 minutes for transfer patients (P < .001). Clinical outcomes were better in the direct group, with 60% (299/498) achieving functional independence compared with 52.2% (213/408) in the transfer group (odds ratio, 1.38; 95% confidence interval, 1.06–1.79; P = .02).
Likewise, excellent outcome (modified Rankin score 0–1) was achieved in 47.4% (236/498) of direct patients versus 38% (155/408) of transfer patients (odds ratio, 1.47; 95% confidence interval, 1.13–1.92; P = .005). Mortality did not differ between the two groups (15.1% for direct, 13.7% for transfer; P = .55).
Additionally, the investigators noted that intravenous tissue plasminogen activator did not impact outcomes. Hypothetical bypass modeling for all transferred patients suggested that intravenous tissue plasminogen activator would be delayed by 12 minutes, but mechanical thrombectomy would be performed 91 minutes sooner if patients were routed directly to endovascular-capable centers. If bypass is limited to a 20-mile radius from onset, then intravenous tissue plasminogen activator would be delayed by 7 minutes and mechanical thrombectomy performed 94 minutes earlier, reported the investigators in Circulation.
In July 2016, Dr. Froehler, the registry's Lead Investigator, presented the STRATIS findings at the Society of NeuroInterventional Surgery's (SNIS) 13th Annual Meeting in Boston, Massachusetts.
At that meeting, SNIS President Donald Frei, MD, commented, “We are committed to improving patient outcomes and organizing more effective systems of care across the country. This study shows us we have to improve our processes for getting patients to the right center directly. We need to implement this valuable insight so we can give patients the timely response they deserve for the best possible outcomes.”
In May 2016, SNIS announced the launch of the Get Ahead of Stroke campaign, which is focused on organizing stronger stroke systems of care nationwide, based on critical observations of studies similar to the STRATIS registry.