Abstract 1122‐000137: Characteristics and Utilization of Acute Reperfusion Therapy after Transfer of In‐Hospital LVO Strokes

Introduction : Acute repercussion therapy for acute ischemic stroke is a crucial tool in the tertiary care setting for patients presenting with large vessel occlusion (LVO). While strokes that present from the community have favorable outcomes compared to in‐hospital strokes, it is unclear if this is because of greater access to endovascular therapy. We aim to characterize the utilization of endovascular reperfusion therapy for in‐house LVO and compare outcomes of in‐house LVOs to those presenting from the community. Methods : From the period of December 2013 to December 2019, all stroke patients with an LVO who presented to a primary stroke center (“spoke” hospital) who were transferred to a comprehensive stroke center (“hub”) were analyzed. Univariate and multivariate analyses were performed to compare baseline characteristics and clinical outcomes. Results : A total of 181 in‐house strokes were transferred from a peripheral center to our comprehensive stroke center. About 16% (29) received IV‐tPA at the OSH and 2 additional patients received IV‐tPA at the CSC [17%; n = 31]. 163 patients harbored an intracranial acute vessel occlusion. Anterior LVO (ICA, M1,M2) and basilar artery occlusion was observed in 64% (n = 116) patients and 6% (n = 11) patients, respectively [Total LVO‐ 70%; n = 127]. 20% (n = 27) of LVO received IV‐tPA and 72% (n = 91) of LVO underwent thrombectomy. Reasons for not receiving included symptoms improved (25%), repeat imaging made reperfusion inadvisable (72.2%) and poor baseline (2.8%). Rates of mRS 0–2 in patients with ICA/M1/M2 receiving EVT were 13% (13/100) and the mortality rate was 45% (46/103). Rates of mRS 0–2 were significantly lower [13% vs 38%, p<0.01] and mortality was significantly higher [45% vs 18%, p<0.01] amongst anterior LVO in‐house transfer patients receiving EVT compared to all anterior LVO patients receiving EVT in the given time period. Conclusions : A relatively large proportion of in‐house LVO stroke patients underwent thrombectomy (70%). Most common cause of not receiving thrombectomy was imaging findings showing completed or large infarct. Compared to their community stroke counterparts, in‐house LVO strokes had lower efficacy outcomes and higher mortality. Further study in required to understand these findings.

Pre- and Interhospital Workflow Times for Patients With Large Vessel Occlusion Stroke Transferred for Endovasvular Thrombectomy

Background: Patients with large vessel occlusion (LVO) stroke are often initially admitted to a primary stroke center (PSC) and subsequently transferred to a comprehensive stroke center (CSC) for endovascular thrombectomy (EVT). This interhospital transfer delays initiation of EVT. To identify potential workflow improvements, we analyzed pre- and interhospital time metrics for patients with LVO stroke who were transferred from a PSC for EVT.Methods: We used data from the regional emergency medical services and our EVT registry. We included patients with LVO stroke who were transferred from three nearby PSCs for EVT (2014–2021). The time interval between first alarm and arrival at the CSC (call-to-CSC time) and other time metrics were calculated. We analyzed associations between various clinical and workflow-related factors and call-to-CSC time, using multivariable linear regression.Results: We included 198 patients with LVO stroke. Mean age was 70 years (±14.9), median baseline NIHSS was 14 (IQR: 9–18), 136/198 (69%) were treated with intravenous thrombolysis, and 135/198 (68%) underwent EVT. Median call-to-CSC time was 162 min (IQR: 137–190). In 133/155 (86%) cases, the ambulance for transfer to the CSC was dispatched with the highest level of urgency. This was associated with shorter call-to-CSC time (adjusted β [95% CI]: −27.6 min [−51.2 to −3.9]). No clinical characteristics were associated with call-to-CSC time.Conclusion: In patients transferred from a PSC for EVT, median call-to-CSC time was over 2.5 h. The highest level of urgency for dispatch of ambulances for EVT transfers should be used, as this clearly decreases time to treatment.

Ambulance waiting and associated work flow improvement strategies: a pilot study to improve door-in-door-out time for thrombectomy patients in a primary stroke center

BackgroundRapid access to thrombectomy for patients with large vessel occlusion (LVO) acute ischemic stroke (AIS) is critical for improving outcome. A major challenge for the ‘drip and ship’ model is reducing the door-in-door-out time (DIDO). We propose a new protocol with the aim of reducing DIDO, without adversely affecting emergency service usage time.MethodsConsecutive patients with suspected LVO AIS admitted to a Primary Stroke Center (PSC) from October 2018 to January 2021 were included. On arrival, the ambulance crew remained with the patient. Following immediate clinical and radiological evaluation, patients were transferred to the Comprehensive Stroke Center (CSC) by the same waiting crew. Key time metrics were collected and compared with historical data prior to the new protocol.Results27 patients had an LVO amenable for mechanical thrombectomy during the time period. There was a significant reduction in the DIDO times compared with the historical group (median 45 min vs 96 min; p<0.0001). There was no significant difference in ambulance usage time between the two time periods (median 53 min vs 45 min; p=0.530). There was an increase in ambulance usage time in FAST-positive patients not for transfer in the pilot group compared with FAST-positive patients not for transfer in the historical group (27 min vs 58 min; p<0.001). In addition, door-to-needle times (24 min vs 40 min; p=0.018) and door-to-CT times (11 min vs 25 min; p<0.0001) improved between the two groups.ConclusionOur data show a significant reduction in the DIDO for patients transferred for thrombectomy, with no adverse effects on ambulance usage time.

Central Triage of Acute Stroke Patients Across a Distributive Stroke Network Is Safe and Reduces Transfer Denials

Background and Purpose: Mechanical thrombectomy has dramatically increased patient volumes transferred to comprehensive stroke centers (CSCs), resulting in transfer denials for patients who need higher level of care only available at a CSC. We hypothesized that a distributive stroke network (DSN), triaging low severity acute stroke patients to a primary stroke center (PSC) upon initial telestroke consultation, would safely reduce transfer denials, thereby providing additional volume to treat severe strokes at a CSC. Methods: In 2017, a DSN was implemented, in which mild stroke patients were centrally triaged, via telestroke consultation, to a PSC based upon a simple clinical severity algorithm, while higher acuity/severity strokes were triaged to the CSC. In an observational cohort study, data on acute ischemic stroke patients presenting to regional community hospitals were collected pre- versus post-DSN implementation. Safety outcomes and rate of CSC transfer denials were compared pre-DSN versus post-DSN. Results: The pre-DSN cohort (n=150), triaged to the CSC, had a similar rate of symptomatic intracerebral hemorrhage and discharge location compared with the post-DSN cohort (n=150), triaged to the PSC. Time to stroke unit admission was faster post-DSN (2 hours 40 minutes) versus pre-DSN (3 hours 29 minutes; P <0.001). Transfer denials were reduced post-DSN (3.8%) versus pre-DSN (1.8%; P =0.02), despite an increase in telestroke consultation volume over the same period (median, 3 calls pre-DSN versus 5 calls post-DSN; P =0.001). No patients who were triaged to the PSC required subsequent transfer to the CSC. Conclusions: A DSN, triaging mild ischemic stroke patients from community hospitals to a PSC, safely reduced transfer denials to the CSC, allowing greater capacity at the CSC to treat higher acuity stroke patients.

In-Hospital Stroke Care: A Six-Year Community-Based Primary Stroke Center Experience

Background and purpose: In-hospital stroke-onset assessment and management present numerous challenges, especially in community hospitals. Comprehensive analysis of key stroke care metrics in community-based primary stroke centers is under-studied. Methods: Medical records were reviewed for patients admitted to a community hospital for non-cerebrovascular indications and for whom a stroke alert was activated between 2013 and 2019. Demographic, clinical, radiologic and laboratory information were collected for each incident stroke. Descriptive statistical analysis was employed. When applicable, Kruskal-Wallis and Chi-Square tests were used to compare median values and categorical data between pre-specified groups. Statistical significance was set at alpha = 0.05. Results: There were 192 patients with in-hospital stroke-alert activation; mean age (SD) was 71.0 years (15.0), 49.5% female. 51.6% (99/192) had in-hospital ischemic and hemorrhagic stroke. The most frequent mechanism of stroke was cardioembolism. Upon stroke activation, 45.8% had ischemic stroke while 40.1% had stroke mimics. Stroke team response time from activation was 26 minutes for all in-hospital activations. Intravenous thrombolysis was utilized in 8% of those with ischemic stroke; 3.4% were transferred for consideration of endovascular thrombectomy. In-hospital mortality was 17.7%, and the proportion of patients discharged to home was 34.4% for all activations. Conclusion: The in-hospital stroke mortality was high, and the proportions of patients who either received or were considered for acute intervention were low. Quality improvement targeting increased use of acute stroke intervention in eligible patients and reducing hospital mortality in this patient cohort is needed.

Changes in Patient Volumes and Outcomes After Adding Thrombectomy Capability

Background and Purpose: With the rising demand for endovascular thrombectomy (EVT) and introduction of thrombectomy-capable stroke centers (TSC), there is interest among existing stroke hospitals to add EVT capability to attract and retain stroke patient referrals. In this work, we quantify changes in patient volumes and outcomes when adding EVT capability to an existing stroke center. Methods: In MATLAB 2017a Simulink, we simulate a 3-center system comprising an EVT-capable comprehensive stroke center, an EVT-incapable primary stroke center, and an EVT-incapable primary stroke center that gains EVT capability (TSC). We model these changes in 2 geographic settings (urban and rural) using 2 routing paradigms (Nearest Center and Bypass). In Nearest Center, patients are sent to the nearest center regardless of EVT capability. In Bypass, patients with severe strokes are sent to the nearest EVT-capable center, and all others are sent to the nearest center. Probability of good clinical outcome is determined by type and timing of treatment using outcomes reported in clinical trials. Results: Adding EVT capability in the Bypass model produced an absolute increase of 40.1% in total volume of patients with stroke and 31.2% to 31.9% in total volume of acute stroke treatments at the TSC. In the Nearest Center model, the total volume of patients with stroke did not change, but total volume of acute stroke treatment at the TSC had an absolute increase of 9.3% to 9.5%. Good clinical outcomes saw an absolute increase of 0.2% to 0.6% in the whole population and 0.3% to 1.8% in the TSC population. Conclusions: Adding EVT capability shifts patient and treatment volume to the TSC. However, these changes produce modest improvement in overall population health. Health systems should weigh relative hospital and patient benefits when considering adding EVT capability.