Comprehensive Stroke Center Research Articles

Abstract 152: Endovascular Therapy versus Medical Management for Acute Ischemic Stroke With Large Infarct: A Time-Benefit Relationship Analysis

Objective: Recent randomized trials demonstrated the benefit of endovascular thrombectomy for acute ischemic stroke with large infarct. We aimed to characterize the effect of time to treatment on the benefit of endovascular therapy compared to medical management among patients with acute large ischemic stroke. Methods: Analysis the Endovascular Therapy in Acute Anterior Circulation Large Vessel Occlusive Patients with a Large Infarct Core trial (ANGEL-ASPECT), which was a multicenter, randomized trial at 46 comprehensive stroke centers in China from August 2020 to October 2022. Onset to arterial puncture time (OPT) associated with outcomes of endovascular therapy were analyzed as a category and continuous variable. The primary outcome was favorable outcome (modified Rankin scale 0-3) at 90 days. Secondary outcomes included degree of disability (modified Rankin scale range), symptomatic intracranial hemorrhage, any intracranial hemorrhage, and mortality. Results: Among 455 eligible patients, the median age was 68 years, and median Alberta Stroke Program Early Computed Tomography Score was 3 (interquartile range 3-4). Compared with medical management alone, endovascular therapy plus medical management was associated with higher rates of favorable outcome with OPT within 6 hours (44.4% vs 29.9%, adjusted odds ratio[aOR] 2.78 [95% confidence interval [CI] 1.22-6.32]), 6-12 hours (45.7% vs 29.6%, aOR 2.39 [95% CI 1.21-4.71]), but not in OPT beyond 12 hours (51.6% vs 41.4%, aOR 2.05 [95% CI, 0.88-4.77]). The benefit in favorable outcome became nonsignificant after OPT of 13 hours and 22 minutes. In three OPT intervals, the odds of better disability outcome with endovascular therapy plus medical management than medical management alone were observed; the rates of symptomatic intracranial hemorrhage and mortality were similar, though the rates of any intracranial hemorrhage increased. Conclusion: In patients with large cerebral infarction, endovascular therapy plus medical management was efficacious in improving functional outcomes with acceptable safety in a broad time window of 0 to 24 hours, but greater benefit was observed with earlier treatment. A pooled analysis with larger sample size is needed.

Abstract WMP95: Anesthesia Modality in Endovascular Treatment for Distal Medium Vessel Occlusion Stroke: Intention-to-Treat Matched Analysis

Background: The optimal anesthesia modality during endovascular treatment (EVT) for distal medium vessel occlusion (DMVO) strokes is uncertain. We aimed to evaluate the impact of the anesthesia modality on procedural and clinical outcomes following EVT for DMVO strokes. Methods: This is a retrospective analysis of a prospectively collected database from 14 comprehensive stroke centers in the United States and Europe. Patients were included if they had DMVO due to MCA-M3/4, ACA-A1/A2-3, or PCA-P1/P2-3 and underwent EVT. The cohort was divided into two groups: general anesthesia (GA) and non-general anesthesia (non-GA). The primary analysis compared the two groups based on the intention-to-treat principle. The secondary analysis compared both groups according to the as-treated approach. We used propensity scores to balance the two groups at a 1:1 ratio. The primary outcome was the shift in the degree of disability as measured by the 90-day mRS. Secondary outcomes included successful reperfusion, mRS0-1, and mRS0-2 at 90-days. Safety measures included procedural complications, symptomatic intracerebral hemorrhage (sICH), and 90-day mortality. Results: A total of 365 patients were eligible for analysis. In the intention-to-treat analysis (130 matched pairs), baseline demographic and clinical characteristics were balanced. There was no difference in the degree of disability (mRS ordinal shift; acOR 1.64, 95%-CI [0.78-3.46], P=0.19) between the two groups. GA had comparable rates of successful reperfusion (aOR2.66, 95%CI [0.75-9.42],P=0.13), 90-day mRS0-1 (aOR1.07, 95%CI[0.41-2.78],P=0.89), 90-day mRS0-2 (aOR1.46, 95%CI[0.60-3.55],P=0.41), procedural complications (aOR1.08, 95%CI[0.20-5.79],P=0.93), sICH (aOR3.28, 95%CI[0.81-13.34], P=0.10), and 90-day mortality (aOR0.82, 95%CI [0.35-1.95],P=0.66) compared to the non-GA group. Similarly, when comparing 150 matched pairs using the as-treated principle, GA and non-GA showed comparable outcomes. Conclusions: In patients with DMVO undergoing EVT, GA and non-GA had similar procedural and clinical outcomes, as well as safety measures. Further, larger controlled studies are warranted.

Abstract WP43: Improving Nurse Retention Through Orientation Restructuring, Planned Professional Development, and Leadership-Employee Support: One Unit’s Journey

Introduction: Increasing RN turnover rates are a noteworthy and nuanced problem for many nurse leaders. It is a particular challenge within specialty units, resulting in the loss of specialty nursing knowledge, assessment, and critical thinking skills relevant to specific patient populations. RN turnover rates increased over a two-year period on a stroke unit in a large teaching hospital that provides specialty care as part of a Comprehensive Stroke Center. Many of the RNs leaving the unit pursued critical care roles, and their knowledge was lost with their attrition. This prompted the nurse leadership to re-examine the orientation process, professional development plan, and leadership-employee support methods that were being utilized. Methods: Using the PDSA model, orientation was reorganized allowing new RNs to be trained solely on the stroke unit for 10-12 weeks then working independently on that unit for 6 months prior to training on the epilepsy monitoring unit, as opposed to training and working on both units from the start of their employment. Professional development plans that included one-on-one resource nurse training with the Assistant Nurse Manager and cross-training to the neuroscience stepdown unit after one year of employment were created for each RN. Each staff member was supported with mentorship check-ins by an assigned Clinical Leader and with bi-monthly check-ins with the Nurse Manager. Quarterly staff meetings were held to promote staff engagement and provide staff members with an opportunity to cascade information on their individual projects, councils, or initiatives to their peers. Results: These changes, including the training of 10 RNs to the stepdown unit, resulted in an 82% decrease in the number of RNs who left their job on the stroke unit in the first year. Conclusion: This process improvement plan demonstrated that thoughtful modifications to the orientation process, a structured professional development plan, and an organized leadership-employee support method can decrease RN turnover. It allowed the preservation of specialty stroke knowledge, thus ensuring that stroke patients continue to receive high-quality, specialized care and that specialty knowledge is transmitted to new staff as they start their careers.

Abstract TP117: Improving Thrombolysis Door-to-Needle Time With a Multi-Pronged Approach

Introduction: Reducing door-to-needle (DTN) times lead to improved patient outcomes in acute ischemic stroke. We sought to use innovative methods to continuously reduce the DTN time, with the specific goal of consistently achieving a median DTN time < 30 minutes. Methods: At an academic Comprehensive Stroke Center, we implemented these strategies to reduce the DTN time: 1) Addition of a virtual DTN timer in the Electronic Medical Record (EMR) to display elapsed time since arrival.2) Creation of a multidisciplinary Thrombolysis Focus Group to analyze data and improve processes. Additional monthly quality improvement meetings were held to discuss all thrombolysis cases with times over our median. 3) Reduction of EMR barriers to recognize metric exclusion criteria and document accordingly. 4) Review of each thrombolysis case with direct provider feedback and an opportunity to appropriately document and clarify delays. 5) Addition of Specialized Neurovascular APPs responding to every Code Stroke with Neurology resident physicians.6) Creation of a “Golden Needle” award to recognize providers who achieved the fastest DTN time in the year. Results: The median DTN time steadily decreased over 3 academic years. The median DTN time was 40 minutes in 2020, 39 in 2021, 38 in 2022 and 36 in year-to-date 2023. Additionally, the percentage of thrombolysis cases meeting the institutional goal of < 30 minutes improved from 21.5% in 2020, to 31.9% in 2021, to 59.6% in 2022, to 88.6% in year-to-date 2023 (figure). Conclusion: Novel multifaceted measures surrounding acute stroke thrombolysis can positively impact both the door-to-needle time and percent of cases within the institutional DTN time goal. Figure: Percentage of Thrombolysis Cases with DTN < 30 Minutes

Abstract WMP30: Real World Experience With Tenecteplase on a Mobile Stroke Unit

Background: Tenecteplase (TNK) administered on a mobile stroke unit (MSU) has demonstrated superior rates of early reperfusion compared to alteplase. Current guidelines include TNK as a second-tier option for large vessel occlusions as TNK has many benefits, including rapid IV administration and ease of dosing. The objective of this study was to describe real world utilization of TNK on a MSU. Methods: This was a retrospective observational study of patients receiving TNK as compared to alteplase between February 2021 and April 2023 at a large academic comprehensive stroke center. Baseline demographics, GCS, NIHSS, as well as time of initial imaging were collected. Primary endpoint was time from MSU door to thrombolytic administration. Secondary endpoints included: MSU door to imaging interpretation, dispatch to thrombolytic administration, and provider decision time to thrombolytic administration. Safety endpoints included symptomatic ICH within 24 hours. Results: During the studied time period 40 patients received alteplase and 32 patients received TNK on the MSU. The median age was 65.7 years and median NIHSS score was 9. There was no difference in time from MSU door to thrombolytic administration (15 vs 17.5, p=0.30). There was also no difference in time from MSU door to imaging interpretation, dispatch to thrombolytic administration, or provider decision time to thrombolytic administration. No hemorrhagic conversion occurred. Conclusion: This is the largest series to date describing real-world utilization of TNK administration in a MSU. There were no significant differences in time to therapy in any of the time points evaluated. This data is promising for the treatment of ischemic stroke in which time to administration of thrombolytic therapy is paramount and TNK is administered as a rapid IV injection as compared to alteplase infusion.

Abstract WP204: Impact of Reperfusion Grade and First Pass Effect in Large vs Small Core Patients Undergoing Mechanical Thrombectomy

Introduction: While patients with small core stroke (SCS) and large core stroke(LCS) benefit from Mechanical Thrombectomy(MT), the impact of reperfusion (Thrombolysis in Cerebral Infarction (eTICI) grade and the first pass effect (FPE)) on clinical outcomes remains poorly understood. We aim to study the interplay between these factors in LCS and SCS patients. Methodology: Retrospective analysis of a comprehensive stroke center prospective database for patients with MCA-M1 or ICA-T occlusions who underwent MT between November 2010-March 2023. Logistic regression models assessed ASPECTS and eTICI score relationships and their impact on outcomes, adjusted for age, NIHSS, tPA, hypertension, general anesthesia and clot location. Results: Of 1548 included patients (mean age 65±16 years, 50.0% males)Table 1, 9.1%(141/1548) were categorized as a LCS (ASPECTS 0-5: 3.5% ASPECTS 0-2 and 96.0% 3-5) while 90.9%(1407/1548) as a SMC (53.0% ASPECTS 6-8 and 47.0% ASPECTS 9-10)(Table1). Lower rates of FPE were achieved in the LCS cohort (26%) compared to the SCS cohort (36%). First pass effect had comparable relative impact on independence rates on LCS and SCS (Figure1A; p>0.05). Final reperfusion rates were comparable LCS and SCS cohorts; In LCS, 5%, 11%, 26%, and 49% achieved eTICI grades 0-2a, 2b50, 2b67, and 2c-3, while in SCS, the percentages were 5.3%, 11%, 18%, and 66%. The relative benefit of final eTICI2c-3 vs 2b50 was comparable between LCS and SCS (p>0.05;Figure1B) Conclusion: The magnitude of benefit of achieving FPE as well as final full reperfusion (eTICI2c-3 vs eTICI2b) is comparable in large and smaller core strokes.

Abstract TMP70: Association of Distal Hyperintense Vessel Sign and Outcomes in Patients With Symptomatic Posterior Circulation Intracranial Atherosclerotic Disease

Objectives: The Distal Hyperintense Vessel (DHV) sign on FLAIR imaging is a radiographic marker of inadequate blood flow due to poor collateral flow distal to the stenotic artery. Previous studies suggest that the DHV sign was associated with early recurrent ischemic stroke in the anterior circulation secondary to intracranial atherosclerotic disease (ICAD). However, its significance in ischemic stroke in the posterior circulation is unknown. Here, we investigate the association of DHV sign in the basilar artery and outcomes at discharge in patients with posterior circulation stroke or TIA secondary to ICAD. Methods: We retrospectively reviewed patients with ischemic strokes or TIA attributed to ICAD of the basilar or vertebral arteries admitted to two comprehensive stroke centers affiliated with UTSW Medical Center from 2010 to 2022. Patients were included if they met VERiTAS criteria (≥50% vertebrobasilar stenosis). The DHV sign was defined as positive when the increased intensity in the basilar artery distal to stenosis was higher than the surrounding CSF signal. The DHV sign was evaluated by blinded vascular neurologists and neuro-radiologists. The primary outcome was mRS at discharge. The secondary outcome was the incidence of clinical deterioration during admission, defined as any worsened neurological exam with associated new infarct or infarct expansion in the posterior circulation. Results: A total of 135 patients were included in the study. A total of 33 (24%) patients had the presence of the DHV sign on admission MRI. Compared to patients without DHV sign, patients with DHV sign had higher NIHSS scores on admission (median 7 vs 2, p<0.001), higher risk of clinical deterioration during hospitalization (27% vs 2%, p<0.001), higher mRS scores at discharge (median 3.45 vs 1.8, p<0.001) and higher mortality rate (24% vs 0%, p<0.001). In multivariate analysis, the DHV sign was an independent predictor of higher mRS scores at discharge. Conclusions: In patients with ischemic stroke or TIA secondary to basilar or vertebral artery atherosclerotic stenosis, the presence of the DHV sign in the basilar artery is associated with more severe disease and poorer outcomes at discharge compared to patients without DHV sign.

Abstract TP190: Higher Pre-Hospital Blood Pressure is Associated With Lower Mismatch Volume and Poorer Collateral Status in Patients With Acute Ischemic Stroke Due to Large Vessel Occlusions

Introduction: Immediately after AIS onset, blood pressure variability (BPV) arises as the result of a complex interplay between brain and systemic physiological hemodynamic responses. In this study, we examined the effect of BPV on early infarct growth in patients with large vessel occlusions (LVO) during their prehospital transfer. Methods: We included consecutive patients with AIS-LVO from 2 large comprehensive stroke centers. We collected the BP values from emergency medical services arrival to hospital admission. Patients with <3 BP recordings were excluded. BPV was assessed using the standard deviation (SD) of the systolic (SBPv), diastolic (DBPv), and mean BP (MBPv). Initial infarct volume (IIV) was defined as rCBF <30%, penumbra area as time to maximum concentration (Tmax) >6s, and mismatch volume as the difference between these two volumes (Tmax 6 - rCBF<30%). Collateral status was evaluated using the hypoperfusion intensity ratio (HIR), defined as the Tmax>10s/Tmax>6s ratio. We used linear regression to investigate associations between these variables, using log-transformation to achieve normality, and final exponentiation for a better interpretability of the results. Results: We included 171 patients, mean age was 70.9± 13.7, 51.5% female, 88.3% white, median NIHSS was 15. Mean BP: SBP=12.37 + 6.8, DBP=10.2 + 7.1, and MBP=8.9 + 5.9. CTP values: rCBF >30% (5 [IQR 0.001 - 22]), Tmax >6s (103 [60.5 - 158.5]), and HIR (0.38 [0.17 - 0.54]). Higher SBP variability was significantly associated with lower mismatch volumes. Furthermore, higher SBP tertiles were associated with worse collaterals (high HIR) (Figure) . Conclusion: Pre-hospital BPV is associated with lower mismatch volume, likely mediated by the effect of BP on collateral status. Our findings are consistent with previous studies; the association between higher pre-treatment blood pressure and poorer collaterals might be due to an imbalance in the need of increasing perfusion to the ischemic tissue.

Abstract TP66: Decreased Order to Administration Times Following Transition to Tenecteplase for Acute Ischemic Stroke

Introduction: Alteplase was the first approved tissue plasminogen activator and standard of care for acute ischemic stroke (AIS). The utilization of Tenecteplase as a thrombolytic agent in AIS has offered many organizations several advantages over Alteplase, including ease of preparation and administration. Both thrombolytic agents require a Physician's order and reconstitution by a certified Pharmacist or Registered Nurse prior to administration. Our academic comprehensive stroke center transitioned from Alteplase to Tenecteplase as standard thrombolysis for acute ischemic stroke in November 2022. Treatment times were monitored to explore the benefits of a single bolus administration. Methods: A retrospective chart review was conducted at a single academic comprehensive stroke center. Patients were included if they received thrombolytic therapy in the Emergency Department for a diagnosis of AIS. Patients prior to November 2022 received Alteplase, and those after November 2022 received Tenecteplase. We evaluated the time frame for the medication bolus order for Alteplase and Tenecteplase to the administration time. Results: Of 140 patients screened, 108 were included in the study, with 51 in the alteplase group and 57 in the Tenecteplase group. Mean order to administration times were 10.9 minutes in the alteplase group and 7.37 minutes in the Tenecteplase group, with statistical significance (P=0.0052). There was no significant difference in mean door-to-needle time (59.27 Alteplase vs 53.09 Tenecteplase, P= 0.1803). Conclusions: In a single CSC, the transition from Alteplase to Tenecteplase reduced the order to administration time by 3.53 minutes. The decreased administration time highlights one of Tenecteplase’s potential advantages. Further review is necessary to evaluate additional stroke metrics and clinical outcomes.

Abstract NS9: Nurse-Led Quality Improvement Initiative: Advancing Stroke Awareness in Communities Experiencing Racial and Ethnic Disparities

Background and Purpose: As a Joint Commission Comprehensive Stroke Center, the provision of community education is a priority goal of our program. The majority of our existing community education program takes place in locations where we receive requests to provide these sessions. Analysis of our Get With the Guidelines (GWTG) data reveals gaps in early arrival to the hospital and Emergency Medical Service (EMS) utilization among African American and Hispanic populations. Providing educational resources within these populations may help to close these gaps and foster trust in the healthcare system. The aim of this proposed nurse-led quality improvement project is to improve hospital arrival times of African American and Hispanic stroke patients living in zip codes where GWTG data have identified gaps, through provision of targeted community education. Methods: The top zip codes associated with our target outcomes for improvement will be identified using GWTG pre-data from 2022 and 2023. We will partner with our Community Outreach department. We will identify educational venues and stakeholders among African American and Hispanic populations in these zip codes. We will provide education tailored to our identified populations including early recognition of stroke signs and symptoms, activation of EMS, stroke risk factors, and opportunities for treatment. Post implementation, GWTG data will be reviewed for any changes. Results: Using GWTG data, arrival mode, last known well time, and symptom discovery time to Emergency Department arrival as it pertains to zip codes, race and ethnicity will be reviewed and analyzed. The target zip codes’ data will be compared pre- versus post-implementation of community education efforts. Discussion: Through community education and partnership with the Community Outreach department we hope to improve timeliness of arrival to hospital among disproportionately affected racial minorities in our community for early stroke evaluation and treatment consideration.

Abstract WP139: Impact of Intracranial Atherosclerosis Burden on Vasospasm Risk and Outcomes in Aneurysmal Subarachnoid Hemorrhage

Background: Cerebral vasospasm is a well-known complication after aneurysmal subarachnoid hemorrhage (aSAH) and occurs more commonly in younger patients. We hypothesized that intracranial atherosclerosis, which is seen predominantly in older patients, affects vasospasm risk in aSAH. We sought to determine association between intracranial atherosclerosis burden with vasospasm and outcomes in aSAH. Design/Methods: We performed a retrospective study of a prospectively collected cohort of consecutive patients with aSAH admitted to a Comprehensive Stroke Center between July 2016 and April 2023. Intracranial atherosclerosis burden was quantified by using modified Woodcock (MW) score on CT angiograms measured by trained assessors. Vasospasm was defined based on transcranial Doppler (TCD) criteria. Worse outcome was defined as 3-month modified Rankin Scale 4-6. Univariable and multivariable logistic regression were used to test the association of predictors with outcomes. Results: We reviewed 302 cases of aSAH (mean age 56.8 years [SD 13.3], 65% female and 70% white). Cerebral vasospasm was reported in 46% of patients and was more common in younger patients (OR 0.91 for each year increase, 95% CI 0.89-0.94; p<0.001). MW scores were measured with excellent intra-rater and inter-rater reliability (Cohen’s kappa coefficient 0.9 and 0.83 respectively) ranging from 0 to 3 (median 0, IQR 0-1) with higher scores in older patients (beta coefficient 0.019, 95% CI 0.009-0.028; p<0.001). Higher MW calcification score was associated with lower risk of vasospasm (odds ratio 0.52 per point increase, 95% CI 0.36-0.78; p=0.001). There was an inverse correlation between MW scores and severity of vasospasm (beta coefficient -0.29, 95% CI -0.48, -0.1; p=0.003). However, MW score was not independently associated with worse functional outcome (p=0.62) when adjusted for age, Hunt and Hess grades, modified Fisher scores. Conclusions: Intracranial atherosclerosis is a potential mechanism for lower vasospasm rate in older SAH patients, however, it may not impact functional outcome. This may suggest intracranial atherosclerosis may affect TCD velocities without any clinical correlation. Larger prospective studies are needed to confirm our findings.

Abstract WP136: Impaired Venous Outflow Impacts Functional Outcomes in Acute Small Subcortical Infarcts: A Single-Center Retrospective Analysis

Introduction: Acute small subcortical infarcts (SSI), colloquially acute lacunar stroke, are a radiographic diagnosis representing a myriad of pathophysiologic processes. One such pathophysiologic subgroup is venous collagenosis which serves as a pathologic indicator that aberrant venous outflow may contribute to SSI development. We aimed to identify whether impaired venous outflow (IVO) impacted functional outcomes in individuals presenting with SSI. Methods: We performed a single-center retrospective study of individuals who presented to the Rhode Island Hospital Comprehensive Stroke Center. Included individuals were ≥ 18 years with the diagnosis of SSI, as defined per consensus criteria, on brain MRI diffusion weighted imaging. The primary exposure is the presence of impaired venous outflow (IVO) defined radiologically in accordance with prior studies, as hyperintensity of the jugular, sigmoid, or transverse sinuses along the skull base on MR angiogram time of flight, Figure. The primary outcome was a favorable function outcome at hospital discharge defined as a modified Rankin Scale (mRS) of ≤ 3. Standard descriptive and regression statistical techniques were used for data interpretation. Results: We identified 39 patients who met criteria with 12 (30.8%) with IVO. Age and vascular risk factors did not significantly differ amongst the cohort. Twenty-six (66.7%) had a favorable hospital discharge outcome favorable functional outcome with IVO being less common [IVO present: 5/26 (19.2%) versus LVO absent: 21/26, (80.8%), p = 0.034]]. After adjusting for age and hypertension, IVO was associated with an odds ratio of 8.33 (95%CI 1.41-49.3, p =0.019). Conclusion: We found that IVO may be an independent contributor to fewer favorable functional outcomes. This data highlights that not only the arterial vessels are of relevance in acute SSI.

Abstract WMP7: Impact of Telestroke Access in a Rural Setting

Background: Despite decades long adoption as the standard-of-care for ischemic stroke, the majority of eligible patients do not receive intravenous thrombolysis (IVT), with underutilization especially pronounced in rural areas. Telestroke, however, may help alleviate this geographical healthcare disparity. The current study aims to identify the impact of implementing a mature telestroke network within a rural setting. Methods: Retrospective review of a prospectively maintained telestroke database from a large rural tertiary care comprehensive stroke center covering 31 spoke hospitals spanning critical access hospitals to primary stroke centers between 10/2021-02/2023. Data was compared to a previous review period (01/2016-12/2018; comprised of 8 spokes) and the statewide IVT rates recorded in GWTG. Data analysis conducted via descriptive statistics and Fisher’s (two-tailed) exact test. Results: 1801 telestroke consults were performed; 41.4% (746/1801) were ineligible for acute stroke intervention. 39% (410/1055) of eligible patients were treated with IVT (vs. 33% [317/959] previously, p = 0.068), representing 58% (410/708; vs 24% [107/448] previously, p < 0.001) of statewide total IVT administration. Symptomatic hemorrhage (sICH) was 3.0%, overall 30-day mortality was 5.6%, and sICH mortality was 1.0%. IVT deferred most commonly: low NIH (44%), mimics (21%), coagulopathy (8%), followed by other. 22% (396/1801) of total consults were transferred from the originating site (vs. 34% [305/890] previously, p < 0.0001) of which 10% (42/396) underwent EVT. Discussion: The impact of expanding a rural telestroke network continued to produce high IVT rates (nearly double the national average) with safety outcomes (sICH, mortality) at or below national standards. Additionally, a large network has significantly increased the proportion of patients remaining at originating sites, optimizing both tertiary and local centers’ resources. The value of a regional telestroke hub is further underscored by the significant increase in statewide IVT attributed to network consults. However, further strategies are needed to better educate rural providers on acute stroke to reduce the rate of ineligible consults and streamline use of telestroke services.

Abstract TP45: A Nurse-Driven Pre-hospital Telemedicine Program Supports Care of Patients With Suspected Stroke

Background: Because of the time-sensitive nature of stroke treatment, extensive efforts focus on reducing treatment time in the hospital and prehospital setting. Recent studies exploring the use of telemedicine within the ambulance setting report positive results. Non-recordable paramedic-assisted videos allowed patients to be examined by an ED physician while in route to the receiving hospital, improving stroke treatment times. Ambulance teleconsultations are reported to be reliable and a good method to aide emergency triage facilitating accurate diagnosis. To the best of our knowledge, these studies have used EMS tele-health services to connect with a physician. In this study we assessed the treatment benefits of a nurse-driven pre-hospital telemedicine program in a community comprehensive stroke center (CSC). Methods: Telemedicine services was installed in 4 ambulance units. A tablet was supplied to highly specialized stroke nurses. Using the current dispatch notification system, the stroke nurse was alerted to an incoming suspected stroke patient and prepared to receive the telemedicine video connection. During the telemedicine video call a paramedic-assisted assessment occurred, patient history, contact information, and pre-thrombolytic consent was obtained. Upon arrival, the stroke alert proceeded as normal. Telemedicine data was retrospectively matched with data extracted from the medical record to evaluate treatment volume (thrombolytics (TNK), endovascular procedure (EP), or both), treatment times [door to CT(D2CT), door to needle (D2N), door to puncture(D2P), door to device(D2D)], and coded stroke volume for all EMS-telemedicine cases between Jan 2020-May 2022. Results: Over the course of the pilot, 41 cases were successfully matched, and pre-hospital video assessments occurred for 17 (41%) cases. Treatment rates were 20% (n=8), 15% (n=6), and 10% (n=4) for TNK, EP, and both respectfully. Median times were 7 min (4-21), 20min (12-32), 58min (48-124), and 82 min (64-140) for D2CT, D2N, D2P, D2D respectively. Lastly, 71% (n=29) received a stroke diagnosis. Conclusion: This study shows that a nurse-driven prehospital telemedicine system can be successfully implemented in a community CRC with excellent treatment time metrics.

Abstract WP110: DEVIATING: Determining Variability in Antiplatelet Timing in Stroke by Gender

Background: Antiplatelet administration within 48 hours of acute stroke presentation is standardized as it reduces mortality and recurrent ischemic stroke rate. Gender disparities have been noted in acute stroke care, including IV tPA and thrombectomy. Limited data exists for gender disparities in antiplatelet administration by day 2 of hospitalization. Methods: In an IRB-approved analysis, we retrospectively assessed patients admitted with acute ischemic strokes from the prospectively collected UC San Diego Stroke Registry from 2013 to 2023. We reviewed baseline demographics, whether an antiplatelet agent was initiated by hospital day 2, and choice of antiplatelet agent. We grouped patients based on their gender identification: male versus female. Patients who transitioned to comfort care, had an embolic source, were treated with a therapeutic dose of anticoagulation, had hemorrhagic conversion of infarct, or had a contraindication to antiplatelet use were excluded. Chi-squared, Kruskal-Wallis and Fisher tests were utilized. Results: 471 patients were included in this analysis (179 female, 292 male). We found no significant differences in medical history except diabetes (60 female, 69 male, p = 0.03). We found a significant difference in age (female 69.3 years, male 64.3 years, p < 0.01). We found a significant difference in patient race (p = 0.01). There was no significant difference in antiplatelet administration by hospital day 2 (171 female, 287 male, p = 0.14) or choice of antiplatelet (aspirin p = 0.29, clopidogrel p = 0.12, ticagrelor p = 0.67, dual antiplatelet p = 0.22). Conclusions: These findings suggest equality of care in antiplatelet administration for acute ischemic stroke between genders, which is reassuring. This data was collected at an academic comprehensive stroke center. Further studies should be completing including patients who were treated at various levels of stroke centers.

Abstract WMP96: When to Change? Altering Strategies in Mechanical Thrombectomy May Impact Reperfusion Rates

Introduction: Earlier and greater reperfusion in mechanical thrombectomy (MT) leads to better clinical outcomes. The timing and potential benefit of switching thrombectomy techniques after failed device passes remains unclear. Methods: Retrospective analysis of a prospective comprehensive stroke center database including patients with intracranial ICA, MCA M1/M2, or Basilar occlusions undergoing MT with either Stent-Retriever (SR), Contact Aspiration (CA) or Combined technique (CT) from 2015 to 2023. Our primary endpoint was complete/near-complete reperfusion (eTICI 2c-3) at pass #2 (after pass #1 failure). Secondary endpoints included 1) eTICI2b-3 at pass#2, and 2) eTICI2c-3 with pass #3 (following failure in two consecutive passes with the same technique). We used logistic or Firth regression to compare reperfusion rates and Kaplan-Meier analysis for cumulative rates. Results: Among 3130 MTs in the study period, 1810 met inclusion criteria. Median age [IQR] was 65 [55 - 76] years and 51.5% were male. Following a failed first pass, switching from CA to either CT or SR was associated with higher eTICI 2c-3 (aOR [95%CI] 2.8 [1.3 - 6.5] and 7.4 [1.4-54.8], respectively). Changing from CT or SR to any other technique was not associated with higher reperfusion. Secondary endpoint analysis for eTICI2b-3 yielded comparable results. For the third pass, switching to CT after two repeated failed SR or two repeated failed CA attempts was associated with higher eTICI 2c-3 as compared to repeating the original strategy (SR aOR 5.8 [1.4 - 33.3]; AC aOR 5.6 [1.1 - 41.2]). We did not observe benefit in switching to alternative technique following one or two consecutive passes with CT. After three repeated attempts with the same technique, CT led to greater eTICI 2c-3 as compared to SR and CA (83% vs. 72% vs. 64%, p < 0.001). Conclusions: While limited by small subgroup sample sizes, our study strengthens the hypothesis that early changes in MT technique may have an impact on reperfusion. Our data indicates that if CA fails on first pass, transition to SR or CT should be considered. After two failed consecutive SR or CA passes, transition to CT should be contemplated.

Abstract WP153: Factors Affecting Length of ICU Stay After Endovascular Thrombectomy for Acute Large Vessel Ischemic Stroke

Introduction: The advent of endovascular thrombectomy (EVT) for acute large vessel occlusion (LVO) ischemic stroke has reduced the overall ICU length of stay (LoS), especially for patients undergoing successful reperfusion. Prolonged ICU LoS is reported to be associated with worse clinical outcomes, but factors associated with prolonged LoS after MT are not established. Methods: A retrospective analysis of 499 patients undergoing EVT at a single large comprehensive stroke center from January 2015 to May 2020 was performed. Demographics, procedure variables, ICU LoS, ICU complications, and modified Rankin scale at discharge were collected. Multiple regression was used to identify independent variables affecting the ICU LoS. Additional analysis using t-test assuming unequal variances was performed for select variables. Results: The median age was 72 [61-82], 254 (51%) male & median NIHSS was 16 [10-20]. The average door-to-puncture time was 104 ±28 mins and the average procedure time 43.9 ±28.7. General anesthesia (GA) was administered in 257 (51%) patients. Successful reperfusion (TICI 2c-3) was achieved in 334 (67%) patients. Median ICU LoS was 3 days [1-5]. Patients with mRS 0-2 at discharge (33%) had shorter ICU LoS (2.8 vs 5.7, P<0.001). ASPECTS < 7 (6.9 vs 4.6, P=0.03), use of GA (6.2 vs 3.3 days, P<0.001) and ICU complications such as pulmonary embolism (PE) and pneumonia (10 vs 4 days; p <0.001) significantly increased the ICU LoS. Successful reperfusion significantly reduced ICU LoS (4.2 vs 5.8 days, p=0.015). After adjusting for age, sex, baseline NIHSS and ASPECTS, both the procedure time (b= 0.03, P=0.02) and final TICI score (b= -0.76, P=0.001) were independently associated with prolonged ICU LoS (R2=0.1, F=4, P<0.001). Conclusion: Pre-procedural factors such as poor ASPECTS (< 7), procedural factors such as the use of GA, prolonged procedure time, and TICI 0-2b reperfusion, and ICU complications such as pneumonia and PE are associated with prolonged ICU LoS.

Abstract TP10: Artificial Intelligence Algorithm as a Diagnostic Tool for Aneurysms

Viz Aneurysm is an artificial intelligence engine created to detect aneurysms from CT-Angiography (CTA) scans. As with any new technology, it should be measured against the current standard of care. Here, we compared Viz.ai ‘flagging’ of an aneurysm against interpretation reports by faculty radiologists in order to understand accuracy and precision of the technology as a diagnostic tool. In this study, CTA scans were analyzed by Viz Aneurysm from October 2022 to June 2023 at a single Comprehensive Stroke Center. Information regarding each subject was collected through Epic, and the presence of an aneurysm was verified by a radiologist. Although Viz.ai states that the algorithm is limited to detecting aneurysms that are 4 mm in diameter or greater, we have included all aneurysms discovered by radiologists. These ranged in diameter from 0.8 to 22 mm. A total of 963 scans were analyzed, with 70 aneurysms detected total. Approximately 51.10% scans were performed on male patients, and our population ranged in age from 23 to 94 years. The algorithm performed well in flagging scans containing definite aneurysms, with a specificity of 96.78% (95% CI 0.95-0.98) and a negative predictive value of 97.23% (95% CI 0.96-0.98). It was less accurate in excluding scans without aneurysms, showing a sensitivity of 63.64% (95% CI 0.51-0.75) and a positive predictive value of 60.00% (95% CI 0.50-0.69). When aneurysms smaller than 4 mm were excluded, the sensitivity and specificity increased to 81.25% (95% CI 0.64-0.93) and 96.90% (95% CI 0.96-0.98), respectively. The algorithm was successful in identifying all cases (n = 5) of ruptured aneurysms. In several cases (n = 27), radiologists were unable to definitively diagnose an aneurysm, frequently citing the possibility of an infundibulum. It should be noted that there was one case where the algorithm detected an aneurysm, but the patient was diagnosed with a 23-mm pituitary macroadenoma. This suggests that the algorithm may be susceptible to neuroanatomical mimics. We have shown that Viz Aneurysm is a highly specific diagnostic tool that may help medical professionals to identify definite aneurysms. More studies of this nature should be conducted in a variety of populations to confirm these results.

Abstract WP22: “Chopperlysis:” Improved Functional Outcomes Associated With Helicopter Transport in Large Vessel Occlusion Stroke Patients Treated With Tenecteplase

Introduction: Tenecteplase (TNK) is increasingly being utilized for IV thrombolysis in acute ischemic stroke, including for patients with large vessel occlusion (LVO) prior to transfer to an endovascular thrombectomy (EVT) capable center (TCC). However, there is limited data regarding factors that influence functional outcome between the time of TNK administration and TCC arrival. The purpose of this analysis is to characterize the effect of the arrival method on the effectiveness of TNK to improve patient outcomes. Methods: A retrospective registry of stroke patients between 2019-2023 at a single comprehensive stroke center was queried. Patients with LVO stroke who had complete data for method of arrival (i.e. ground transportation versus helicopter), TNK treatment, and available 90-day modified Rankin score (mRS) were included. The primary outcome was a favorable 90-day mRS of 0-2. Categorical variables were reported as frequencies, and associations across variables were analyzed using Chi-square test or Fisher's exact test. Odds ratios were calculated with univariate logistic regressions. Results: Of 2675 patients meeting inclusion criteria, 14.4% arrived by helicopter and 85.6% arrived by ground transportation. 174 (6.5%) were treated with TNK, including 5.1% of ground transported patients and 14.1% of air transported patients. Irrespective of EVT, patients arriving by ground did not differ in likelihood of achieving the primary outcome whether they did or did not receive TNK (53.9% TNK vs. 48.4% no TNK, p=0.35). However, patients arriving by helicopter had a significantly higher likelihood of achieving the primary outcome with TNK, regardless of EVT (60% TNK vs. 41.2% no TNK, p=0.04), and in patients transported by helicopter who did not undergo EVT, there was an even higher likelihood of good functional outcome associated with TNK treatment (69.2% TNK vs. 40.1% no TNK, p=0.049). Conclusion: In our cohort, treatment with TNK was associated with improved functional outcomes in helicopter transported patients but not in those transported by ground, and this benefit was found to be even more robust in patients who did not undergo EVT. Future studies are needed to validate these findings and investigate the underlying pathophysiological mechanism.

Abstract 77: A Regional Transfer Center Pilot Improves Door-in-Door-out Time in a Large Integrated Healthcare System

Background: Successful treatment of patients with large vessel occlusions (LVO) is time dependent, yet timely transfers between hospitals for endovascular therapy (EVT) can be challenging. At Kaiser Permanente Northern California (KPNC) a wide variety of ambulance and EMS agencies may be involved in Urgent interfacility transfers. We evaluated a region-wide pilot utilizing a central transfer center to facilitate these transfers within a large integrated healthcare system. Methods: KPNC implemented a regional transfer center (TC) in March 2023, which arranged transfers for 17 of 19 primary stroke centers (PSC) from 8am to 9pm. Two centers were excluded as they were utilizing 911 transport rather than interfacility ambulance hub transfers. The study cohort included all stroke patients arriving to a PSC with LVO who were transferred to one of our Comprehensive Stroke Centers for EVT from 3/6/23 through 8/4/23. Data were compared to a similar cohort 10/6/23 through 3/5/23 (pre-TC). All patients were evaluated by teleneurologists on arrival, who requested initiation of ambulance transfer. Before TC, the ambulance request was made by the local ED facility; after the implementation of the TC, ambulance was arranged by the TC and communicated with teleneurology and the local ED. Door in door out (DIDO) times were measured for all transfers. Results: The pre-TC group had 81 transfers. The post-TC group had 68 patients. After TC, median DIDO dropped from 105 minutes to 83.5 minutes (p=0.02). The percent of patients transferred within 90 minutes rose from 41% to 57% (p=0.04) and the percent transferred with 75 minutes rose from 25% to 35% (p=0.14). Similar improvements were seen regardless of sex or ethnicity [Table]. Conclusions: Preliminary results show a significant improvement in DIDO times with initiation of a centralized TC to facilitate LVO transfers in a large integrated delivery system. Systems wishing to improve DIDO performance should consider implementing a similar TC.