Association of a Primary Stroke Center Protocol for Suspected Stroke by Large-Vessel Occlusion With Efficiency of Care and Patient Outcomes

Abstract

Importance: While prehospital triage to the closest comprehensive stroke center (CSC) may improve the delivery of care for patients with suspected emergent large-vessel occlusion (ELVO), efficient systems of care must also exist for patients with ELVO who first present to a primary stroke center (PSC).

Objective: To describe the association of a PSC protocol focused on 3 key steps (early CSC notification based on clinical severity, vessel imaging at the PSC, and cloud-based image sharing) with the efficiency of care and the outcomes of patients with suspected ELVO who first present to a PSC.

Design, setting, and participants: In this retrospective cohort study, 14 regional PSCs unfamiliar with the management of patients with ELVO were instructed on the use of the following protocol for patients presenting with a Los Angeles Motor Scale score 4 or higher: (1) notify the CSC on arrival, (2) perform computed tomographic angiography concurrently with noncontract computed tomography of the brain and within 30 minutes of arrival, and (3) share imaging data with the CSC using a cloud-based platform. A total of 101 patients were transferred from regional PSCs to the CSC between July 1, 2015, and May 31, 2016, and received mechanical thrombectomy for acute ischemic stroke. The CSC serves approximately 1.7 million people and partners with 14 PSCs located between 6.4 and 73.6 km away. All consecutive patients with internal carotid artery or middle cerebral artery occlusions transferred over an 11-month period were reviewed, and they were divided into 2 groups based on whether the PSC protocol was partially or fully executed.

Main outcomes and measures: The primary outcomes were efficiency measures including time from PSC door in to PSC door out, time from PSC door to CSC groin puncture, and 90-day modified Rankin Scale score (range, 0-6; scores of 0-2 indicate a good outcome).

Results: Although 101 patients were transferred, only 70 patients met the inclusion criteria during the study period. The protocol was partially executed for 48 patients (68.6%) (mean age, 77 years [interquartile range, 65-84 years]; 22 of the 48 patients [45.0%] were women) and fully executed for 22 patients (31.4%) (mean age, 76 years [interquartile range, 59-86 years]; 13 of the 22 patients [59.1%] were women). When fully executed, the protocol was associated with a reduction in the median time for PSC arrival to CSC groin puncture (from 151 minutes [95% CI, 141-166 minutes] to 111 minutes [95% CI, 88-130 minutes]; P < .001). This was primarily related to an improvement in the time from PSC door in to door out that reduced from a median time of 104 minutes (95% CI, 82-112 minutes) to a median time of 64 minutes (95% CI, 51-71.0 minutes) (P < .001). When the protocol was fully executed, patients were twice as likely to have a favorable outcome (50% vs 25%, P < .04).

Conclusions and relevance: When fully implemented, a standardized protocol at PSCs for patients with suspected ELVO consisting of early CSC notification, computed tomographic angiography on arrival to the PSC, and cloud-based image sharing is associated with a reduction in time to groin puncture and improved outcomes.

Figure 1.. Primary Stroke Center (PSC) Emergent Large-Vessel Occlusion (ELVO) Protocol

The PSC ELVO protocol workflow is focused on early notification of the comprehensive stroke center (CSC; with a goal of <30 minutes), obtaining early vessel imaging (with a goal of <30 minutes) at the PSC, and cloud-based image sharing. CTA indicates computed tomographic angiography of the brain and neck; CT, computed tomography of the brain; EMS, emergency medical services; and IV tPA, intravenous tissue plasminogen activator (alteplase).

Figure 2.. Primary Stroke Center (PSC) Emergent Large-Vessel Occlusion (ELVO) Protocol Efficiency From PSC Arrival to Comprehensive Stroke Center (CSC) Groin Puncture

Kaplan-Meier time-to-event curves with 95% CIs, reflecting transfer efficiency achieved when the PSC ELVO protocol was fully executed vs when it was partially executed. As demonstrated by the steep growth of the grey curve, 9 patients in the fully executed group had a time from PSC arrival to CSC groin puncture of less than 100 minutes. Note that the steep growth of the grey curve implies both greater overall speed and less variability.

Figure 3.. Primary Stroke Center (PSC) Emergent Large-Vessel Occlusion (ELVO) Protocol Care Efficiency Metrics

A, Graphical depiction of key time intervals from onset to reperfusion for a PSC ELVO protocol that is partially vs fully executed. Note that the primary driver of improvement in onset-to-reperfusion times appears to be reduction in time from PSC arrival to PSC departure (from door in to door out [DIDO]). B, Comparison of the partially and fully executed PSC ELVO protocols with other series of patients with ELVO who were either transferred from a PSC or directly admitted to a comprehensive stroke center (CSC). CSCDoor indicates arrival at CSC; CSCPunc, CSC groin puncture; CSCRecan, CSC recanalization; ESCAPE, Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke; HERMES, Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials; IMS3, Interventional Management of Stroke III; PSCDoor, arrival at PSC; SWIFT PRIME, Solitaire with the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke.