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Background: Minor ischemic strokes and transient ischemic attacks account for more than a third of ER stroke admissions (21% and 15%, respectively). Most small community hospitals lack adequate coverage by stroke service necessitating transfer of stroke patients to comprehensive stroke centers. Methods: We studied the effect of implementing telestroke service in all regional hospitals and emergency departments affiliated with Promedica Toledo Hospital, a comprehensive stroke center (CSC). This service is carried out by stroke-trained advanced practice providers under supervision of vascular neurologists. Coverage included acute ED assessments of stroke patients, inpatient telestroke consults and follow ups. We propose that this comprehensive telestroke service will improve care of stroke patients presenting to community hospitals, decrease the number of transfers to CSC. It will improve numbers and timing of IV thrombolysis. Results: The total stroke alerts from affiliated locations before implementing telestroke service (2018 and 2019 and first half of 2020), and after implementing the service (since July 2020, 2021, and 2022) were 4817 and 4900, respectively. In pre-telestroke years, about 43% of patients were transferred to the CSC for acute stroke care while during post-telestroke years were 28% with 34.8% reduction on transfers. Among transferred patients, stroke mimickers' percentage decreased from 21% to 8%. There was a 14.5% increase in the number of IVT patients after implementing telestroke service but door to needle time did not change. Conclusion: This is the first reported experience of utilizing stroke-trained APPs to expand telestroke coverage for both ED and inpatient services at community hospitals. There was a decrease in number of transfers to CSC, keeping patients at their local communities. It also increased the number of IV thrombolytic treatments and reduced the number of stroke mimickers' transfers.

Introduction: Hematoma expansion (HE) is a known prognostic indicator of spontaneous intracerebral hemorrhage (sICH). Although several scores exist for prediction of HE, universal adoption has been limited due to their lack of sensitivity and specificity. As machine learning (ML) algorithms have shown promise in the stroke field, here we examine the predictive accuracy of several ML algorithms for HE in sICH patients. Methods: We retrospectively analyzed demographic, clinical data, and radiographic signs of patients with sICH in our 2-hospital database. A total of 61 clinical, imaging, and treatment variables were included in the study. Nine ML models were applied: Adaptive Boost (AdaBoost), Bernoulli Naïve Bayes (BNB), Decision Tree (DT), Gaussian Naïve Bayes (GNB), Logistic Regression (LR), Multi-Layer Perceptron (MLP), Multinomial Naïve Bayes models (MNB), Random Forest (RF), and Extreme Gradient Boosting (XGBoost). All models were trained to predict HE. Model accuracy was assessed using the area under characteristic curve (AUC). Results: Of the 301 patients with sICH, 63 developed HE (21.93%). Of the 9 models studied, MLP had the highest AUC score (0.93±0.042), followed by XGBoost (0.80±0.06). All models demonstrated moderate to high predictive accuracy (AUC 0.64-0.93) for HE. The top predictors in MLP were Baseline NIHSS score, HDL, aPPT, time from last known well to ER, initial hematoma volume, and island sign. MLP had moderate sensitivity of 0.46±0.17 and high specificity of 0.99±0.02. GNB, however, showed the highest sensitivity at 0.86±0.06 and a moderate specificity of 0.65±0.07. Five of the 9 models ranked time last known well to ER presentation as a predictor of HE. Conclusion: In our study, we found all ML models applied had moderate to high predictive accuracy for prediction of HE in sICH, with MLP having the highest accuracy of all models. Future studies examining the use of these algorithms are warranted.

Background and Objectives: Endovascular therapy (EVT) is standard treatment for large vessel occlusion strokes. To reduce inter-hospital times, most patients are usually transferred directly to the angio suite (DTAS) but some transfers are initially taken to the CT scanner (DTCT) to re-evaluate. The objective of our study is to compare outcomes in patients DTAS vs DTCT. Methods: This is retrospective study of LVO stroke from 2017 to 2021 transferred to our CSS from outside hospitals for mechanical thrombectomy (MT). Recruitment was done from the University of Toledo/Promedica stroke database and specific variables were included from chart review. Patients were divided into two cohorts, DTAS and DTCT. Results were calculated with SPSS software. Results: Total of 246 patients were transferred from an outside hospital for MT, 55.6% patients were DTAS vs 44.3% patients to DTCT. There was no significant difference between basic demographics. In both groups, most common vessels involved were M1 (38.4% vs 39.4%), followed by M2 (25.4% vs 29.4%) then ICA terminus (19.6% vs 16.5%). DTAS had significant shorter door to puncture time (35 vs 62 mins, p=0.03), onset to recanalization time (346 vs 583 mins, p=0.012) and onset to groin puncture (329 vs 557 mins, p Conclusion Our study concluded that DTAS has better reperfusion rates, time matrices and decrement of NIHSS compared to DTCT. Functional outcomes at discharge, 90 days and mortality at 90 days was not significantly difference between two groups.

Background: Telemedicine has enabled hospitals without stroke specialists to efficiently triage acute ischemic stroke patients; however, ~10-15% of patients with posterior circulation stroke present with visual loss, visual field deficit, or visual obscuration that can only be detected by thorough bedside examination. We have developed a novel, provisionally patented, device which allows for remote visual field assessment in patients with suspected stroke. The Eye Telestroke Exam Device consists of 3D goggles and custom software that tracks a patient’s eye movements when they respond to visual stimuli within the goggle’s screens and verbal commands given by the remote Neurology specialist. The device system is designed to pair (via Bluetooth technology) with any telemedicine system and will allow the remote examiner to perform a detailed visual field examination remotely. Objective: In this pilot study, we aim to evaluate the sensitivity and specificity of the Telestroke Eye Exam device to evaluate visual fields in healthy individuals and in patients who already have suffered a posterior circulation stroke and have permanent visual field deficits. Methods and Design: The Eye Telestroke Exam Device for Improved Triage in Stroke (EYE-TEST) Pilot study is a 2-arm, prospective study of patients with either a history of posterior circulation stroke with visual disturbances (stroke group) or patients with no visual disturbances (control). A roll in phase of 5 patients in each group will be performed, prior to enrollment of 20 patients into each arm. Investigators performing the device exam will be blinded to patient history. Device performance (sensitivity and specificity) will be compared to conventional bedside visual field assessment in each group. The device exam will be repeated twice for each patient. Results: The roll-in phase of the EYE-STUDY showed 100% sensitivity and specificity for detecting visual field disturbances in the stroke group. No abnormalities were detected in the control group. Conclusion: Enrollment into the study is ongoing and estimated study completion will occur October 2022. Final results of the EYE-TEST study will be presented at ISC 2023. Results of this study will inform future design iterations and studies.

Purpose: To investigate health professions student’s awareness, attitude, and perception towards the complementary and alternative medicine (CAM) and also to determine the influence of socio- demographic variables on the descriptive outcomes of this study. Methods: A descriptive, cross-sectional, comparative study was conducted among Undergraduate Health Professions Students (n=398) at King Saud bin Abdulaziz University for Health Sciences at Riyadh campus, through a validated questionnaire. Results: The results of the study revealed that among various modalities of CAM, most students were aware and used prayers/spirituality, followed by nutritional supplements, cupping, massage, herbal medicine and yoga. The least effective modality was aromatherapy, whereas the most harmful modality was acupuncture. The data showed that the students obtained more information from friends/relatives and media and less from formal CAM training/courses. Awareness/self-use and beliefs/attitudes were found to have significant associations (p < 0.05) in regard to gender, parent’s educational level, and family income. Conclusion: The study shows that most of the healthcare students are aware of and demonstrate positive attitudes towards the effectiveness and safety of most CAM modalities. However, the lack of formal training or courses is a major barrier towards its use and practice.

Population health management (PHM) is the holistic process of improving health outcomes of groups of individuals through the support of appropriate financial and care models. Radiologists' presence...

BackgroundAchieving the best possible reperfusion is a key determinant of clinical outcome after mechanical thrombectomy (MT). However, data on the safety and efficacy of intra-arterial (IA) fibrinolytics as an adjunct to MT with the intention to improve reperfusion are sparse.MethodsWe performed a PROSPERO-registered (CRD42020149124) systematic review and meta-analysis accessing MEDLINE, PubMed, and Embase from January 1, 2000 to January 1, 2020. A random-effect estimate (Mantel-Haenszel) was computed and summary OR with 95% CI were used as a measure of added IA fibrinolytics versus control on the risk of symptomatic intracranial hemorrhage (sICH) and secondary endpoints (modified Rankin Scale ≤2, mortality at 90 days).ResultsThe search identified six observational cohort studies and three observational datasets of MT randomized-controlled trial data reporting on IA fibrinolytics with MT as compared with MT alone, including 2797 patients (405 with additional IA fibrinolytics (100 urokinase (uPA), 305 tissue plasminogen activator (tPA)) and 2392 patients without IA fibrinolytics). Of 405 MT patients treated with additional IA fibrinolytics, 209 (51.6%) received prior intravenous tPA. We did not observe an increased risk of sICH after administration of IA fibrinolytics as adjunct to MT (OR 1.06, 95% CI 0.64 to 1.76), nor excess mortality (0.81, 95% CI 0.60 to 1.08). Although the mode of reporting was heterogeneous, some studies observed improved reperfusion after IA fibrinolytics.ConclusionThe quality of evidence regarding peri-interventional administration of IA fibrinolytics in MT is low and limited to observational data. In highly selected patients, no increase in sICH was observed, but there is large uncertainty.

Background and Purpose: The safety and benefit of mechanical thrombectomy in the treatment of acute ischemic stroke patients with M2 segment middle cerebral artery occlusions remain uncertain. Here, we compare clinical and angiographic outcomes in M2 versus M1 occlusions in the STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) Registry. Methods: The STRATIS Registry was a prospective, multicenter, nonrandomized, observational study of acute ischemic stroke large vessel occlusion patients treated with the Solitaire stent-retriever as the first-choice therapy within 8 hours from symptoms onset. Primary outcome was defined as functional disability at 3 months measured by dichotomized modified Rankin Scale. Secondary outcomes included reperfusion rates and rates of symptomatic intracranial hemorrhage. Results: A total of 984 patients were included, of which 538 (54.7%) had M1 and 170 (17.3%) had M2 occlusions. Baseline demographics were well balanced within the groups, with the exception of mean baseline National Institutes of Health Stroke Scale score which was significantly higher in the M1 population (17.3±5.5 versus 15.7±5.0, P ≤0.001). No difference was seen in mean puncture to revascularization times between the cohorts (46.0±27.8 versus 45.1±29.5 minutes, P =0.75). Rates of successful reperfusion (modified Thrombolysis in Cerebral Infarction≥2b) were similar between the groups (91% versus 95%, P =0.09). M2 patients had significantly increased rates of symptomatic ICH at 24 hours (4% versus 1%, P =0.01). Rates of good functional outcome (modified Rankin Scale score of 0–2; 58% versus 59%, P =0.83) and mortality (15% versus 14%, P =0.75) were similar between the 2 groups. There was no difference in the association of outcome and onset to groin puncture or onset to successful reperfusion in M1 and M2 occlusions. Conclusions: In the STRATIS Registry, M2 occlusions achieved similar rates of successful reperfusion, good functional outcome, and mortality, although increased rates of symptomatic ICH were demonstrated when compared with M1 occlusions. The time dependence of benefit was also similar between the 2 groups. Further studies are needed to understand the benefit of mechanical thrombectomy for M2 occlusions. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02239640.

FOR SOCIAL MEDIA: @AliciaCastongu2, @FazalZaidi9, @oozaidat, @Mouhammad_Jumaa OBJECTIVE: Machine learning (ML) algorithms have emerged as powerful predictive tools in the field stroke. Here, we examine the predictive accuracy of ML models for predicting functional outcomes using 24-hour post-treatment characteristics in the Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke (STRATIS) Registry.ML models, adaptive boost, random forest (RF), classification and regression trees (CART), C5.0 decision tree (C5.0), support vector machine (SVM), least absolute shrinkage and selection operator (LASSO), and logistic regression (LR), and traditional LR models were used to predict 90-day functional outcome (modified Rankin Scale score 0-2). Twenty-four-hour National Institutes of Health Stroke Scale (NIHSS) was examined as a continuous or dichotomous variable in all models. Model accuracy was assessed using the area under characteristic curve (AUC).The 24-hour NIHSS score was a top-predictor of functional outcome in all models. ML models using the continuous 24-hour NIHSS scored showed moderate-to-good predictive performance (range mean AUC: 0.76-0.92); however, RF (AUC: 0.92 ± 0.028) outperformed all ML models, except LASSO (AUC: 0.89 ± 0.023, p = 0.0958). Importantly, RF demonstrated a significantly higher predictive value than LR (AUC: 0.87 ± 0.031, p = 0.048) and traditional LR (AUC: 85 ± 0.06, p = 0.035) when using the 24-hour continuous NIHSS score. Predictive accuracy was similar between the 24-hour NIHSS score dichotomous and continuous ML models.In this substudy, we found similar predictive accuracy for functional outcome when using the 24-hour NIHSS score as a continuous or dichotomous variable in ML models. ML models had moderate-to-good predictive accuracy, with RF outperforming LR models. External validation of these ML models is warranted. ANN NEUROL 2022.

BackgroundThere is little data available to guide optimal anesthesia management during rescue intracranial angioplasty and stenting (ICAS) for failed mechanical thrombectomy (MT). We sought to compare the procedural safety and functional outcomes of patients undergoing rescue ICAS for failed MT under general anesthesia (GA) vs non-general anesthesia (non-GA).MethodsWe searched the data from the Stenting and Angioplasty In Neuro Thrombectomy (SAINT) study. In our review we included patients if they had anterior circulation large vessel occlusion strokes due to intracranial internal carotid artery (ICA) or middle cerebral artery (MCA-M1/M2) segments, failed MT, and underwent rescue ICAS. The cohort was divided into two groups: GA and non-GA. We used propensity score matching to balance the two groups. The primary outcome was the shift in the degree of disability as measured by the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included functional independence (90-day mRS0-2) and successful reperfusion defined as mTICI2B-3. Safety measures included symptomatic intracranial hemorrhage (sICH) and 90-day mortality.ResultsAmong 253 patients who underwent rescue ICAS, 156 qualified for the matching analysis at a 1:1 ratio. Baseline demographic and clinical characteristics were balanced between both groups. Non-GA patients had comparable outcomes to GA patients both in terms of the overall degree of disability (mRS ordinal shift; adjusted common odds ratio 1.29, 95% CI [0.69 to 2.43], P=0.43) and rates of functional independence (33.3% vs 28.6%, adjusted odds ratio 1.32, 95% CI [0.51 to 3.41], P=0.56) at 90 days. Likewise, there were no significant differences in rates of successful reperfusion, sICH, procedural complications or 90-day mortality among both groups.ConclusionsNon-GA seems to be a safe and effective anesthesia strategy for patients undergoing rescue ICAS after failed MT. Larger prospective studies are warranted for more concrete evidence.

BACKGROUND AND PURPOSE: Recent data suggest that intra-arterial thrombolytics may be a safe rescue therapy for patients with acute ischemic stroke after unsuccessful mechanical thrombectomy; however, safety and efficacy remain unclear. Here, we evaluate the use of intra-arterial rtPA as a rescue therapy in the Systematic Evaluation of Patients Treated with Neurothrombectomy Devices for Acute Ischemic Stroke (STRATIS) registry. MATERIALS AND METHODS: STRATIS was a prospective, multicenter, observational study of patients with acute ischemic stroke with large-vessel occlusions treated with the Solitaire stent retriever as the first-line therapy within 8 hours from symptom onset. Clinical and angiographic outcomes were compared in patients having rescue therapy treated with and without intra-arterial rtPA. Unsuccessful mechanical thrombectomy was defined as any use of rescue therapy. RESULTS: A total of 212/984 (21.5%) patients received rescue therapy, of which 83 (39.2%) and 129 (60.8%) were in the no intra-arterial rtPA and intra-arterial rtPA groups, respectively. Most occlusions were M1, with 43.4% in the no intra-arterial rtPA group and 55.0% in the intra-arterial rtPA group (P = .12). The median intra-arterial rtPA dose was 4 mg (interquartile range = 2–12 mg). A trend toward higher rates of substantial reperfusion (modified TICI ≥ 2b) (84.7% versus 73.0%, P = .08), good functional outcome (59.2% versus 46.6%, P = .10), and lower rates of mortality (13.3% versus 23.3%, P = .08) was seen in the intra-arterial rtPA cohort. Rates of symptomatic intracranial hemorrhage did not differ (0% versus 1.6%, P = .54). CONCLUSIONS: Use of intra-arterial rtPA as a rescue therapy after unsuccessful mechanical thrombectomy was not associated with an increased risk of symptomatic intracranial hemorrhage or mortality. Randomized clinical trials are needed to understand the safety and efficacy of intra-arterial thrombolysis as a rescue therapy after mechanical thrombectomy.

Background: Machine learning algorithms have emerged as powerful predictive tools in the field of acute ischemic stroke. Here, we examine the predictive performance of a machine algorithm compared to logistic regression for predicting functional outcomes in the prospective Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke (STRATIS) Registry. Methods: The STRATIS Registry was a prospective, observational study of the use of the Solitaire device in acute ischemic stroke patients. Patients with posterior circulation stroke or missing 90-day mRS were excluding from the analysis. A statistical algorithm (logistic regression) and a machine learning algorithm (decision tree) were implemented on the preprocessed dataset using 10-fold cross-validation method where 80% of the data were fed into the models to be trained and the remaining 20% were utilized in the test phase to evaluate the performance of the models for prediction of 90-day mRS score as dichotomous output (0-2=1, 3-6=0). Results: Of the 938 STRATIS patients, 702 with 90-day mRS were included. The machine learning model outperformed the logistic regression model with a 0.92±0.026 Area Under Curve (AUC) score compared to a 0.88±0.028 AUC score obtained by implementing logistic regression. Conclusion: Our machine learning model delivered improved performance in comparison with the statistical model in predicting 90-day functional outcome. More studies are needed to understand and externally validate the predictive capacity of our machine learning model.

Background: Futile recanalization (FR) and symptomatic intracranial hemorrhage (sICH) are adverse outcomes after otherwise successful mechanical thrombectomy (MT). The aim of this study was to evaluate independent predictors of these unfavourable events in the extended time window and to compare imaging modalities (non-enhanced CT (NCCT) alone vs. CT perfusion vs. MRI) regarding patient selection. Methods: The CT for Late EndovasculAr Reperfusion (CLEAR) study was a multicenter, retrospective study of stroke patients undergoing thrombectomy in the extended time window. The primary endpoint of this study was the proportion of patients with FR, defined as a patient with large vessel occlusion achieving near-complete or complete reperfusion (TICI 2c/3) with a 90-day mRS score between 3 and 6. The secondary safety endpoints included the predictors of mortality and symptomatic intracranial hemorrhage. Inclusion criteria for this analysis were baseline NIHSS ≥6, internal carotid artery, M1 or M2 segment occlusion, prestroke modified rankin scale (pmRS) 0-2, time last seen well (TLSW) to treatment 6-24 hours, and mTICI 2c-3. Results: Of 2304 patients in the CLEAR study, 715 patients were included in this analysis. Of these, 364 patients (50.9%) showed FR, 37 patients (5.2%) suffered sICH and 127 patients (17.8%) died within 90 days. Old age, higher baseline NIHSS, higher prestroke disability, transfer to a comprehensive stroke center from another site, and a longer interval from TLSW to puncture were identified as positive predictors of FR. Hypertension was an independent predictor of sICH. The imaging modality (NCCT vs. CT perfusion vs. MRI) was not associated with FR, sICH, or mortality. Conclusions: Older age, higher baseline NIHSS, higher prestroke disability, transfer patients, and a longer interval from TLSW to puncture were predictors of FR in the extended window. Hypertension was a predictor of sICH in successfully reperfused patients. Neither MRI or CT perfusion was superior in predicting FR and sICH compared to NCCT alone. NCCT together with CTA may be sufficient for patient selection in the extended time window. Trial Registration: ClinicalTrials.gov Identifier: NCT04096248

Modified first pass effect (mFPE) of TICI 2B or greater is an independent predictor of clinical outcome in patients who undergo mechanical thrombectomy (MT). Location of the occlusion in the M1 segment may affect the mFPE and may influence clinical outcomes. A comparison of mFPE between occlusions of the proximal and distal (sparing lenticulostriate branches) M1 segments of the MCA has yet to be performed. We aim to examine the interaction between first pass effect and clinical outcomes in proximal versus distal M1 occlusions. We performed retrospective analysis of patients who underwent MT between 2014 and 2020. Patients were included if they were treated for M1 occlusion within 24 hours from last seen normal, and achieved successful recanalization (TICI2b or greater). Patients were excluded if they were not successfully recanalized, or if they had other intracranial or multifocal occlusions. A total of 264 patients were included in this analysis. Ninety two patients had proximal M1 occlusions and 172 had distal M1 occlusions. Patients with proximal M1 occlusions had higher NIHSS (median 18 vs. 16, p=0.003), lower ASPECTS (mean 8.5 vs 9, p=0.02), and were less likely to be females (44.6% vs. 62.8%, p=0.006). Modified first pass effect was achieved in 45.3% of distal M1 occlusions compared to 31.9% of proximal (p=0.047). Excellent clinical outcome, defined as mRS of 0-1 at 90 days was higher in distal occlusion group (38.8% vs. 24.7%, p=0.03). Additionally, the proximal occlusion group was more likely to experience any grade of hemorrhagic transformation (HT) (37.4 vs. 23.3, p=0.02). Other baseline characteristics and time metrics did not differ between the two groups. In a multivariate analysis of predictors of excellent outcome in the overall cohort, ASPECTS (OR=1.39, p = 0.026) and proximal occlusion site (OR=0.485, p=0.037) were the only two independent predictors. Therefore, mFPE was not a predictor of excellent outcome when adjusted for exact location of occlusion.

Background: Previous studies have suggested that 24-hour NIHSS may serve as a surrogate marker for functional outcomes in acute ischemic stroke patients. Here, we examine if 24-hour NIHSS is a predictor of 90-day mRS in the prospective Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke (STRATIS) Registry. Methods: Data from the STRATIS Registry, a multicenter, non-randomized, observational study of AIS LVO patients treated with the Solitaire stent-retriever as the first-choice therapy within 8 hours from symptoms onset, were analyzed. Patients with premorbid mRS>2, posterior circulation stroke, missing 24 NIHSS or 90-day mRS were excluded from the analysis. The ability of 24-hour NIHSS (continuous and thresholds ≤6 and ≤8) to predict 90-day mRS using logistic regression was examined. The models were adjusted for age, baseline NIHSS, hypertension, diabetes, atrial fibrillation, IV-tPA use, time to recanalization, and revascularization status. Results: Of the 938 STRATIS patients, 662 with 24-hour NIHSS and 90-day mRS were included. A model trained with the continuous 24-hours NIHSS had higher predictive power (sensitivity 0.89, specificity 0.76, AUC 0.89±0.013, P Conclusion: When adjusted for covariates, 24-hour NIHSS as a continuous variable was the strongest predictor of dichotomous mRS outcomes in STRATIS patients. Twenty-four hour NIHSS ≤6 and ≤8 present the second and the third best results, respectively.

Key Points Question In patients with proximal anterior circulation occlusion stroke presenting in the extended window, are rates of favorable outcomes at 90 days comparable in the patients selected for thrombectomy with noncontrast computed tomography vs patients selected with computed tomography perfusion or magnetic resonance imaging? Findings In a multicenter cohort of 1604 patients in the extended window with large-vessel occlusion, patients selected by noncontrast computed tomography had comparable clinical and safety outcomes with patients selected by computed tomography perfusion or magnetic resonance imaging. Meaning These findings suggest noncontrast computed tomography alone may be used as an alternative to advanced imaging in selecting patients with late-presenting large-vessel occlusion for mechanical thrombectomy., This cohort study compares the clinical outcomes of patients with stroke who presented 6 to 24 hours after symptom onset and were selected for mechanical thrombectomy by noncontrast computed tomography vs those selected by computed tomography perfusion or magnetic resonance imaging., Importance Advanced imaging for patient selection in mechanical thrombectomy is not widely available. Objective To compare the clinical outcomes of patients selected for mechanical thrombectomy by noncontrast computed tomography (CT) vs those selected by computed tomography perfusion (CTP) or magnetic resonance imaging (MRI) in the extended time window. Design, Setting, and Participants This multinational cohort study included consecutive patients with proximal anterior circulation occlusion stroke presenting within 6 to 24 hours of time last seen well from January 2014 to December 2020. This study was conducted at 15 sites across 5 countries in Europe and North America. The duration of follow-up was 90 days from stroke onset. Exposures Computed tomography with Alberta Stroke Program Early CT Score, CTP, or MRI. Main Outcomes and Measures The primary end point was the distribution of modified Rankin Scale (mRS) scores at 90 days (ordinal shift). Secondary outcomes included the rates of 90-day functional independence (mRS scores of 0-2), symptomatic intracranial hemorrhage, and 90-day mortality. Results Of 2304 patients screened for eligibility, 1604 patients were included, with a median (IQR) age of 70 (59-80) years; 848 (52.9%) were women. A total of 534 patients were selected to undergo mechanical thrombectomy by CT, 752 by CTP, and 318 by MRI. After adjustment of confounders, there was no difference in 90-day ordinal mRS shift between patients selected by CT vs CTP (adjusted odds ratio [aOR], 0.95 [95% CI, 0.77-1.17]; P = .64) or CT vs MRI (aOR, 0.95 [95% CI, 0.8-1.13]; P = .55). The rates of 90-day functional independence (mRS scores 0-2 vs 3-6) were similar between patients selected by CT vs CTP (aOR, 0.90 [95% CI, 0.7-1.16]; P = .42) but lower in patients selected by MRI than CT (aOR, 0.79 [95% CI, 0.64-0.98]; P = .03). Successful reperfusion was more common in the CT and CTP groups compared with the MRI group (474 [88.9%] and 670 [89.5%] vs 250 [78.9%]; P

Background Prehospital triage scores aim to identify large vessel occlusions (LVOs) in the field; however, their real‐world performance and accuracy across a 24‐hour period remains unknown. In this study, we compare the positive predictive value of the prehospital Rapid Arterial occlusion Evaluation (RACE) score for the detection of LVO during working hours and nonworking hours. Methods We performed a retrospective review of all patients presenting with a RACE score of ≥5 at one comprehensive and one thrombectomy‐capable hospital between July 2015 and December 2019. Patients were dichotomized to those presenting during “working hours” (7:00 am to 6:00 pm on weekdays) or “nonworking hours” (6:01 pm to 6:59 am on weekdays or anytime during weekends). The primary outcome was diagnosis of LVO. Secondary outcomes included diagnosis of acute neurovascular syndromes, door‐to‐treatment time metrics, and a modified Rankin Scale of ≤2 in those undergoing mechanical thrombectomy. Results Of the 701 patients with RACE score ≥5, 687 patients were included (355 nonworking hours and 332 working‐hours cohorts). Mean age was 71 and 72 years in the nonworking hours and working hours groups, respectively ( P =0.13). Median National Institutes of Health Stroke Scale and baseline demographics were comparable between the 2 groups. There was no significant difference in the diagnosis of LVO (36.3% versus 34.6%; P =0.69) or final discharge diagnosis. The positive predictive value of the RACE score for the detection of an acute neurovascular syndrome (transient ischemic attack and stroke) was improved during nonworking hours (76.3% versus 67.8%; P =0.01). In patients undergoing mechanical thrombectomy, rates of good clinical outcome were similar (44.7% versus 48%; P =0.76), despite the shorter door‐to‐groin‐puncture and revascularization times during working hours. Conclusions The RACE score shows a consistent positive predictive value in determining LVO during working and nonworking hours. However, it is more accurate in determining acute neurovascular syndromes during nonworking hours, which is driven by a decrease in stroke mimics during this time.

Objective Intensive blood pressure (BP) management after mechanical thrombectomy (MT) may be beneficial in patients with acute anterior circulation (AC) Ischemic stroke (IS) due to large vessel occlusion (LVO). We sought to evaluate the efficacy of Nicardepine (NCR) vs. Clevidipine (CLV) in IS patients with LVO who underwent successful MT. Methods With IRB approval, we retrospectively collected data on consecutive patients with isolated MCA M1 occlusion who underwent successful MT (TICI score of 2B or 3). Patient demographics, baseline characteristics, time efficiencies, procedural data, incidence of hemorrhagic transformation (HI) and symptomatic ICH per ECASS II criteria on 24H head CT, and clinical outcomes were recorded. We also recorded duration from recanalization to optimal BP control (ROBP), IV drip utilized (NCR vs. CLV), number of SBP excursions, and total duration of time outside the target SBP in first 24H. Results We identified 111 patients between 2017 and 2020, 57 patients required a drip (43 NCR, 14 CLV), and 54 patients were managed with prn medications. Median NIHSS was higher in the drip group (18, IQR 13-21) vs. 15.5 (IQR 9-20), p value= 0.03. There was no significant difference in the rate of good clinical outcome defined as mRs of 0-2 or return to baseline (47.4 vs 61.1%, p value=0.18); rate of any HI (29.8% vs. 27.8%, p value=0.84) and sICH(5.3% vs 0%, p value=0.24) between the two groups ( drip vs. no drip). When comparing the NCR to CLV groups, median ROBP was significantly shorter in the CLV group, 5min (IQR 0.75-7) vs. 17min (IQR 6-35), p value= 0.003; and total duration of time outside the pre-specified BP range was 37.5 min (IQR 19-120) vs. 118 min (57-227) consecutively, p value=0.045. HT rates (14.3% vs. 34.9%, p value=0.19), sICH rates (0 vs. 7%, p value=0.57), and rate of good clinical outcome (64.3% vs. 41.9%, p value=0.22) were similar between the two groups (CLV vs. NCR). In a Multivariate analysis, after adjusting for age, gender, IV tPA administration, drip used and time out of range; NIHSS (OR 0.8, CI 0.70-0.91, p=0.0008) and ROBP (OR=1.05, CI 1.0-1.1, p value=0.032) were independent predictors of good clinical outcome. Conclusion CLV achieved faster ROBP time and better BP control after MT. Further prospective studies are needed. Disclosures M. Oliver: None. J. Shawver: None. H. Salahuddin: None. S. Desai: None. S. Zaidi: None. M. Jumaa: None.

Introduction Endovascular therapy for large vessel occlusion has become the standard of care for appropriate patients treated under 24 hours from onset. Despite being superior to standard medical management, roughly 50% of patients still do not achieve independent neurological functioning. Therapeutic hypothermia (TH) impacts multiple pathways to provide neuroprotection in stroke by lower metabolic demand. Prior trials with TH may have failed due to inconsistent reperfusion therapies at that time. The RECCLAIM II study was designed to test if the addition of TH to endovascular reperfusion is feasible and safe. We intend to provide an update on the progress and status of the study as enrollment continues. Methods Prospective, multi-center, randomized-controlled study with a target enrollment of 120 patients to assess the safety and feasibility to achieve rapid hypothermia to under 34 degrees C with the ZOLL Intravascular Proteus system prior to achieving reperfusion. Cooling will be maintained for 6 hours with rewarming to 36.5-37 degrees C over the next 3-6 hours. CT studies will be assessed for hemorrhagic complications 24 hours post-procedure and 90-day blinded outcomes will be obtained on each patient. Up to ten centers will enroll up to 120 patients for the study. Each center will perform 4 Roll-in cases prior to entering the randomization phase. The primary feasibility endpoint is that the majority of patients will achieve a temperature of 34 degrees C within one hour of arterial puncture without significant delays to reperfusion when comparing the control and treatment arms. The secondary endpoints include rates of hemorrhage and clinical outcomes in both arms. Results A total of 30 patients have been enrolled to date. Times for each procedure, ability to achieve rapid hypothermia, 90 day blinded Modified Rankin, and core lab adjudicated hemorrhagic complication rates will be evaluated. The DMC will review significant adverse events and mortalities. Workflow time metrics will be assessed for both arms to assess for how quickly TH can be commenced in conjunction with thrombectomy. These results will serve as the basis for powering a phase III study to assess the efficacy of TH in conjunction with reperfusion therapy compared to reperfusion therapy alone. Conclusion There is limited evidence demonstrating the clinical benefit or impact of neuroprotection in conjunction with endovascular reperfusion therapy for acute ischemic stroke. Combining intravascular therapeutic hypothermia with endovascular reperfusion therapy may provide an opportunity to enhance clinical outcomes in patients with large vessel occlusion. Disclosures R. Gupta: 1; C; Stryker Neurovascular PI ASSIST Registry, Zoll PI RECCLAIM II (No compensation), Cerenovous Steering Committee MEMBRANE study, Medtronic Steering Committee ELEVATE Study, Penumbra CEC MIND Trial, Vesalio PI CLEAR Study, Rapid Medical PI Tiger Study. S. Zaidi: None. M. Jumaa: None. N. Badjatia: None. A. Yoo: 1; C; Medtronic, Cerenovous, Penumbra, Stryker, Genentech. 2; C; Cerenovous, Genentech. 6; C; Insera Therapeutics.

Introduction Multiple studies have shown that faster treatment times for ischemic strokes result in improved clinical outcomes. Pre-hospital triage scores aim to identify large vessel occlusions in the field and allow earlier activation of stroke teams in the hospital. Objective To compare the sensitivity of the pre-hospital Rapid Arterial oCclusion Evaluation (RACE) score for the detection of large vessel occlusions during working hours and non-working hours. Methods We retrospectively reviewed all patients presenting with a RACE score of ≥ 5 to one comprehensive and one thrombectomy capable hospital between July 2015 and December 2019. Baseline demographics, time of hospital arrival, presenting NIHSS score, intravenous tPA and mechanical thrombectomy metrics, ninety day modified Rankin scores, discharge disposition, and final discharge diagnosis were recorded. Patients presenting between 7 AM to 6 PM during weekdays were considered to present during ‘Working hours’ whereas patients presenting between 6 PM - 7 AM on weekdays or anytime during weekends were considered to present during ‘Non-working hours’. The primary outcome of interest was diagnosis of large vessel occlusion. Secondary outcomes included diagnosis of neurovascular event, discharge diagnosis, and good clinical outcome defined as ninety day modified Rankin Scale (mRS) of ≤ 2. Results Over a 4.5 year period, this study analyzed 687 patients who presented to the hospital via Emergency Medical Services with a RACE score of 5 or more. The average age of the cohort was 71.4 years and women comprised 55% of the cohort. Median NIHSS was comparable in the Working (13) and Non-working (14; p=0.48) groups. Intravenous tPA administration (21.7% vs. 26.5%; p=0.15) and risk factors including hypertension, diabetes mellitus, previous stroke, and prevalence of atrial fibrillation were comparable between the two groups. There was no significant difference in the diagnosis of large vessel occlusion (36.4% vs 34.6%) or final discharge diagnosis. Sensitivity of the RACE score for detection of neurovascular events (TIA, ischemic stroke, intracranial hemorrhage) was improved during non-working hours (75.1%) compared to working hours (67.2%; p=0.02). Although door to groin puncture & recanalization times were shorter during working hours, there was no significant difference in the rate of good clinical outcomes (54.1% vs. 51.5%; p=0.76) in patients undergoing mechanical thrombectomy. Conclusion The sensitivity of the RACE score for detecting large vessel occlusions does not vary significantly during working and non-working hours. However, patients who present with high RACE scores during working hours are more likely to have a diagnosis of a stroke mimic than those presenting off hours. Disclosures E. Hitomi: None. M. Jumaa: None. S. Zaidi: None. J. Shawver: None. A. Korsnack: None. A. Castonguay: None. R. Burgess: None. V. Kung: None. H. Salahuddin: None.

Population health management (PHM) is the holistic process of improving health outcomes of groups of individuals through the support of appropriate financial and care models. Radiologists' presence at the intersection of many aspects of health care, including screening, diagnostic imaging, and image-guided therapies, provides the opportunity for increased radiologist engagement in PHM. Furthermore, innovations in artificial intelligence and imaging informatics will serve as critical tools to improve value in health care through evidence-based and equitable approaches. Given radiologists' limited engagement in PHM to date, it is imperative to define the PHM priorities of the specialty so that radiologists' full value in improving population health is realized. The purpose of this expert review is to explore programs and future directions for radiologists in PHM.

Background and Purpose— Mechanical thrombectomy (MT) devices have led to improved reperfusion and clinical outcomes in acute ischemic stroke patients with emergent large vessel occlusions; however, less than one-third of patients achieve complete reperfusion. Use of intraarterial thrombolysis in the context of MT may provide an opportunity to enhance these results. Here, we evaluate the use of intraarterial rtPA (recombinant tissue-type plasminogen activator) as rescue therapy (RT) after failed MT in the North American Solitaire Stent-Retriever Acute Stroke registry. Methods— The North American Solitaire Stent-Retriever Acute Stroke registry recruited sites within North America to submit data on acute ischemic stroke patients treated with the Solitaire device. After restricting the population of 354 patients to use of RT and anterior emergent large vessel occlusions, we compared patients who were treated with and without intraarterial rtPA after failed MT. Results— A total of 37 and 44 patients was in the intraarterial rtPA RT and the no intraarterial rtPA RT groups, respectively. Revascularization success (modified Thrombolysis in Cerebral Infarction ≥2b) was achieved in more intraarterial rtPA RT patients (61.2% versus 46.6%; P =0.13) with faster times to recanalization (100±85 versus 164±235 minutes; P =0.36) but was not statistically significant. The rate of symptomatic intracranial hemorrhage (13.9% versus 6.8%; P =0.29) and mortality (42.9% versus 44.7%; P =0.87) were similar between the groups. Good functional outcome (modified Rankin Scale score of ≤2) was numerically higher in intraarterial rtPA patients (22.9% versus 18.4%; P =0.64). Further restriction of the RT population to M1 occlusions only and time of onset to groin puncture ≤8 hours, resulted in significantly higher successful revascularization rates in the intraarterial rtPA RT cohort (77.8% versus 38.9%; P =0.02). Conclusions— Intraarterial rtPA as RT demonstrated a similar safety and clinical outcome profile, with higher reperfusion rates achieved in patients with M1 occlusions. Prospective studies are needed to delineate the role of intraarterial thrombolysis in MT.

BackgroundEndovascular thrombectomy is a promising treatment for acute ischemic stroke in children, but outcome and technical data in pediatric patients with large-vessel occlusions are lacking.ObjectiveTo assess technical and clinical outcomes of thrombectomy in pediatric patients.MethodsWe undertook a retrospective cohort study of pediatric patients who experienced acute ischemic stroke from April 2017 to April 2019 who had immediate, 30-, and 90-d follow-up. Patients were treated with endovascular thrombectomy at 5US pediatric tertiary care facilities. We recorded initial and postprocedural modified Thrombolysis in Cerebral Infarction (mTICI) grade≥2b, initial and postprocedural Pediatric National Institutes of Health Stroke Scale (PedNIHSS) score, and pediatric modified Rankin scale (mRS) score 0 to 2 at 90 d.ResultsThere were 23 thrombectomies in 21 patients (mean age 11.6±4.9 yr, median 11.5, range 2.1-19; 52% female). A total of 19 (83%) thrombectomies resulted in mTICI grade≥2b recanalization. The median PedNIHSS score was 13 on presentation (range 4-33) and 2 (range 0-26) at discharge (mean reduction 11.3±6.1). A total of 14 (66%) patients had a mRS score of 0 to 2 at 30-d follow-up; 18/21 (86%) achieved that by 90 d. The median mRS was 1 (range 0-4) at 30 d and 1 (range 0-5) at 90 d. One patient required a blood transfusion after thrombectomy.ConclusionIn this large series of pediatric patients treated with endovascular thrombectomy, successful recanalization was accomplished via a variety of approaches with excellent clinical outcomes; further prospective longitudinal study is needed.

Background: Limited prospective data exists on the use of intra-arterial (IA) thrombolytics as rescue therapy(RT) after failed mechanical thrombectomy(MT) in acute ischemic stroke(AIS) patients with large vessel occlusions LVO). The aim of this study is to investigate the use of IA recombinant tissue plasminogen activator(IA-rtPA) as RT in the prospective STRATIS Registry. Methods: Data from the STRATIS Registry, a multicenter study of AIS patients treated with the Solitaire stent-retriever as the first choice therapy within 8 hours from symptoms onset, were analyzed. Clinical and angiographic outcomes were compared between patients treated with and without IA-rtPA. Both anterior and posterior circulation occlusions were included in this substudy. Results: Of the 938 STRATIS patients with IA-tPA use reported, 809 and 129 were in the no IA-rtPA(83.2%) and IA-rtPA(13.8%)groups, respectively. No difference was seen in baseline demographics. Site of occlusion was similar between the groups, with the majority occurring in the MCA(72.4% versus 73.6%, p=0.74). IV-rtPA was administered in 63.0% and 70.5% of no IA-rtPA and IA-rtPA patients(p=0.11). Median IA-rtPA dose was 4mg(IQR 2-12). Mean onset to arterial puncture time was shorter in the IA-rtPA group(200.2±104.6 versus 228.2±98.5 minutes, p=0.003); however, mean puncture to procedure end time was longer in the IA-rtPA group(78.7±43.1 versus 63.1±35.9 minutes). Mean number of passes (2.2±1.4 versus 1.8±1.2,p=0.001) and rate of distal embolization(67.8% versus 54.5%, p=0.007) was significantly higher in the IA-rtPA group. Core lab adjudicated substantial reperfusion (mTICI≥2b) was achieved in 88.4% and 84.7% of no IA-rtPA and IA-rtPA patients(p=0.16). No difference was observed in rates of symptomatic intracranial hemorrhage(sICH) (1.4% versus 1.6%,p=0.70), good functional outcome (mRS≥2, 57.3% versus 59.2%, p=0.86), or mortality (15.5% versus 13.3%,p=0.80) at 90-days. Conclusion: Use of IA-rtPA after failed thrombectomy was not associated with an increased risk of sICH or mortality in the STRATIS Registry. These results suggest that IA thrombolysis may be a safe option as rescue therapy in select patients.

Background: Limited data exists on the benefits of mechanical thrombectomy (MT) in acute ischemic stroke patients on new oral anticoagulants (NOAC). The aim of our study is to examine the safety and efficacy of MT in NOAC patients at our center. Methods: A retrospective review of our prospective MT database was performed for this study. Baseline characteristics, National Institutes of Health Stroke Scale (NIHSS) score, revascularization rate, symptomatic intracranial hemorrhage rate (sICH), and 90-day mortality and favorable outcomes were compared in MT patients on NOAC (MT-NOAC) versus those who were not on NOAC (MT). Results: From July 2012 to December 2018, 553 AIS patients underwent treatment with MT, with 36 patients on NOAC (6.5%). Median age was similar (73 versus 74), with 52.8% and 52.0% (p=0.8) female in the MT-NOAC and MT groups, respectively. Median baseline NIHSS score (17 IQR10-21 versus 17 IQR 12-21, p=0.75) and ASPECTS (9 IQR 8-9, p=0.80) were similar between the groups. Atrial fibrillation was more prevalent in the MT-NOAC group (80.6% versus 37.7%, p= Conclusion: MT in patients on NOAC appears to be safe and efficacious. As our study is limited by sample size, larger prospective studies are needed to understand the safety and efficacy of MT in AIS patients on NOAC.

Background and Purpose: The role of intra-arterial (IA) thrombolysis in modern endovascular therapy is not well-understood. Here, we surveyed neurointerventionalists to understand their current clinical practices and opinions of IA thrombolysis in the new era of mechanical thrombectomy (MT). Method: A 24-question anonymous survey was distributed via email to the members of the Society of Vascular and Interventional Neurology. Results: One hundred and four responses were included in the analysis. Most respondents were interventional neurologists (76.9%) and had ≥5-years in neuro-interventional practice (80.8%). IA thrombolytics are presently used by 60.6%. Aspiration plus stent-retriever was the most common MT approach used with IA-thrombolysis (66.0%). IA-thrombolysis was used in mainly three approaches: (1) treatment of primary distal occlusions, (2) as rescue after proximal occlusion thrombectomy, and (3) or as adjunct therapy to primary MT approach. The most frequent IA-rtPA dose was 3-10 mg, with 1 mg/min infusion rate (56.6%). 84.9% do not have a standardized protocol for administering IA-rtPA. About half (50.9%) believed there should be no time limit for administering IA lytic if there is a favorable imaging profile, while 30.2% indicated ≤6 h. Most respondents (76.5%) would consider using IA-tenecteplase in a trial setting. Only 12.9% felt there was no role for IA thrombolysis in modern endovascular practice. Respondents with ≥10-years' experience were less supportive of the future of IA lytic (98.0 vs. 76.4%, p = 0.006). Conclusion: IA-thrombolysis is currently used in clinical practice; however, there is no clear consensus on best practices or criteria for administration. Further studies are needed to define the role of IA-thrombolysis in the context of MT.

Introduction Aneurysmal subarachnoid hemorrhage is a neurological emergency that is associated with significant morbidity and mortality. There are multiple factors both modifiable and non-modifiable that contribute to the rupture of an aneurysm. Laboratory experiment has shown that orientation of the dome of aneurysm downwards, parallel to the force of gravity, has a higher risk of thrombosis and rupture because of turbulence.1 Another experiment revealed that red blood cells tend to settle in aneurysms that are oriented downwards.2 This could trigger thrombus formation and eventual rupture. We aim to study the effect of the orientation of dome of the aneurysm on the presenting severity and outcome of the sub-arachnoid hemorrhage. Methods A retrospective review of medical records of 38 subjects (with a total of 41 saccular aneurysms) who presented with aneurysmal subarachnoid hemorrhage between 2012 and 2018 was performed. The information collected for the study included the age of the patient, maximal dimension of aneurysm, orientation of dome of an aneurysm in relation to gravity, Hunt and Hess scale, Fisher scale, modified Rankin scale at discharge, modality of treatment (endovascular coiling or surgical clipping), history of hypertension, history of hyperlipidemia, history of diabetes, history of antiplatelet and anticoagulant medication usage prior to hemorrhage, history of smoking and family history of aneurysm. Results 41 Aneurysms in 38 subjects were divided in to two groups based on the orientation of the dome of the aneurysm in relation to gravity. 20 aneurysms (48.78%) were oriented towards the force gravity with dome of the aneurysm in the direction of the force of gravity. There was no statistical difference in the severity of the subarachnoid hemorrhage (Hunt and Hess scale, Fisher grading scale) and the outcome after subarachnoid hemorrhage (modified Rankin Scale for neurologic disability) between the two groups. Conclusion Of the aneurysms that were oriented towards the force of gravity, 19 aneurysms (95%) were present in the anterior circulation. Application of this concept to a larger prospective database that includes both unruptured and ruptured aneurysms may show a statistical significant difference in the outcome. Such studies could serve to identify the orientation of the dome of an aneurysm in relationship to gravity as an important factor in contributing to the rupture of a saccular aneurysm. References Madrazo l,et al. Effect of position with respect to gravitational force on the hydrodynamics of an experimental model of saccular aneurysm. PMID: 2103697 Chodzynski KJ, et al. Does the gravity orientation of saccular aneurysms influence hemodynamics? An experimental study with and without flow diverter stent. PMID: 27810105 Disclosures G. Ramaiah: None. I. Sheikh: None. R. Burgess: None. S. Zaidi: None.

Background and purpose Recent data suggests that intra-arterial (IA) thrombolytics may be a safe rescue therapy (RT) for acute ischemic stroke (AIS) patients after failed mechanical thrombectomy (MT); however, its safety and efficacy in MCA occlusions remains unclear. Here, we investigate the use of IA tissue plasminogen activator (IA-rtPA) as RT in MCA occlusions in the Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke (STRATIS) Registry. Methods The STRATIS Registry was a prospective, multicenter, non-randomized, observational study of AIS LVO patients treated with the Solitaire stent-retriever as the first choice therapy within 8 hours from symptoms onset. Clinical and angiographic outcomes were compared in patients with MCA occlusions treated with and without IA-rtPA. Results A total of 680/938 (72.5%) patients with IA-tPA use harbored MCA occlusions, of which 585 (86.0%) and 95 (14.0%) were in the no IA-rtPA and IA-rtPA groups, respectively. Baseline demographics were well-balanced between the cohorts. The majority of MCA occlusions were located in the M1 segment, with 76.1% in the no IA-rtPA group and 74.7% in the IA-rtPA group (p=0.80). IV-rtPA was administered in 64.4% and 71.6% of the no IA-rtPA and IA-rtPA patients (p=0.20). Median IA-rtPA dose was 4mg (IQR 2–10) in the IA-rtPA cohort. Onset to puncture time was less than 6 hours in 88.6% (597/674) of patients. Mean onset to arterial puncture time was shorter in the IA-rtPA group (196.7±109.9 versus 228.2±97.9 minutes, p=0.004); however, mean puncture to procedure end time was longer in the IA-rtPA group than the no IA-rtPA group (74.5±41.5 versus 59.5±33.6 minutes). Mean number of passes (2.0±1.2 versus 1.6±1.0, p=0.005) and rate of distal embolization (53.4% versus 72.1%, p=0.001) were significantly higher in the IA-rtPA group. The rate of substantial reperfusion (mTICI≥2b) was similar in the cohorts (89.9% versus 86.0%, p=0.28). Rates of symptomatic intracranial hemorrhage (sICH) (1.7% versus 2.2%, p=0.68), good functional outcome (mRS≥2, 60.5% versus 58.0%, p=0.85), and mortality (13.9% versus 13.6%, p=0.96) at 90days did not differ between the two groups. Conclusion Use of IA-rtPA as rescue therapy after failed mechanical thrombectomy in MCA occlusions was not associated with an increased risk of sICH or mortality in the STRATIS Registry. More studies are needed to understand the safety and efficacy of IA thrombolysis as rescue therapy in this patient population. Disclosures A. Castonguay: None. S. Zaidi: None. M. Jumaa: None. O. Zaidat: None. D. Liebeskind: None. H. Salahuddin: None. N. Mueller-Kronast: None.

Background and Purpose- Mechanical thrombectomy (MT) devices have led to improved reperfusion and clinical outcomes in acute ischemic stroke patients with emergent large vessel occlusions; however, less than one-third of patients achieve complete reperfusion. Use of intraarterial thrombolysis in the context of MT may provide an opportunity to enhance these results. Here, we evaluate the use of intraarterial rtPA (recombinant tissue-type plasminogen activator) as rescue therapy (RT) after failed MT in the North American Solitaire Stent-Retriever Acute Stroke registry. Methods- The North American Solitaire Stent-Retriever Acute Stroke registry recruited sites within North America to submit data on acute ischemic stroke patients treated with the Solitaire device. After restricting the population of 354 patients to use of RT and anterior emergent large vessel occlusions, we compared patients who were treated with and without intraarterial rtPA after failed MT. Results- A total of 37 and 44 patients was in the intraarterial rtPA RT and the no intraarterial rtPA RT groups, respectively. Revascularization success (modified Thrombolysis in Cerebral Infarction ≥2b) was achieved in more intraarterial rtPA RT patients (61.2% versus 46.6%; P=0.13) with faster times to recanalization (100±85 versus 164±235 minutes; P=0.36) but was not statistically significant. The rate of symptomatic intracranial hemorrhage (13.9% versus 6.8%; P=0.29) and mortality (42.9% versus 44.7%; P=0.87) were similar between the groups. Good functional outcome (modified Rankin Scale score of ≤2) was numerically higher in intraarterial rtPA patients (22.9% versus 18.4%; P=0.64). Further restriction of the RT population to M1 occlusions only and time of onset to groin puncture ≤8 hours, resulted in significantly higher successful revascularization rates in the intraarterial rtPA RT cohort (77.8% versus 38.9%; P=0.02). Conclusions- Intraarterial rtPA as RT demonstrated a similar safety and clinical outcome profile, with higher reperfusion rates achieved in patients with M1 occlusions. Prospective studies are needed to delineate the role of intraarterial thrombolysis in MT.

Objective: To assess whether the choice of pretreatment neuroimaging has an impact on clinical outcomes following mechanical thrombectomy (MT). Background: Most MT trials required advanced neuroimaging including either CT or MR based perfusion studies for patient selection prior to randomization. However, in practice, centers may offer MT based on favorable findings (ASPECT score > 6) on non-contrast head CT (HCT) ± CT angiogram (CTA). We compared outcomes between patients who underwent MT based on HCT ± CTA (HCT- group) versus additional including CT or MR perfusion scan (HCT+ group). Design/Methods: Case records of all patients who underwent MT at our center between Jun 2012 - Jun 2017 were reviewed. Patient demographics, risk factors, presentation, pretreatment scan findings, treatment times and clinical outcomes were compared. Favorable outcome is defined as mRS of 2 or less at 90-days. Results: A total of 528 patients were identified, of which 46.4% were male. There were 385 (72.9%) patients who underwent MT based on findings on HCT or CTA (HCT-); while the remaining 143 (27.1%) also underwent additional CTP (121/528; 22.9%) or MRI perfusion (22/528; 4.2%) prior to MT (HCT+). Median age (73 vs 72, p=0.1) and baseline ASPECT scores (8.4 vs. 8.3, p=0.5) were comparable. The HCT- patients had higher NIHSS (17.8 vs. 15.3, p Conclusions: Our findings suggest that HCT ± CTA based MT selection may achieve similar outcomes as compared to more advanced perfusion based neuroimaging protocols. Further prospective studies are warranted.

Background and Purpose: We previously reported on the successful implementation of a EMS-driven bypass protocol using the Rapid Arterial oCclusion Evaluation (RACE) score for triage of acute strokes. Here, we describe the long-term results of our RACE alert protocol. Methods: Patients with a RACE score > 5, who are last seen normal within 12 hours, wakeup with stroke symptoms, or have unknown time of symptoms onset were directly transferred as RACE alerts (RA) to our two stroke centers (one primary with interventional capabilities and one comprehensive) with interventional capacity in Lucas County, Ohio. Data including baseline demographics, RACE score, diagnosis, treatments and procedures, and clinical and angiographic outcomes were captured in a prospective database. Results: From July 2015 to July 2018, 511 RAs were triaged. Median age of RA patients was 73 (IQR 63-82), 55.8% were female, and median RACE score was 7 (IQR 5-8). Median time from 911 dispatch to ER was 31 minutes (IQR 22-38) and onset to arrival was 85 minutes (IQR 47-307). Of the 511 RAs, 52.3% were diagnosed with an ischemic stroke, 13.5% intracerebral hemorrhage, 6.5% transient ischemic attack, 12.9% seizure, and 7.8% encephalopathy. The rate of IV-tPA use was 24.5% and median door to needle time was 33 min (IQR 24-48). The rate of mechanical thrombectomy (MT) was 24.3%, with median door to puncture and door to revascularization times of 64 (IQR 48.5-78.5) and 91 minutes (IQR 79.3-114.8), respectively. The majority of occlusions were MCA (73.2%). Successful revascularization (TICI≥2b) was achieved in 84.7%. Ninety-day favorable outcome (mRS 0-2) and mortality was 47.2% and 25.4% in patients who underwent MT. Conclusions: Our results show the long-term feasibility and efficiency of an EMS-driven early stroke triage protocol using the RACE score.

Background and Purpose: To determine recent treatment and outcome trends in patients undergoing elective surgical clipping (SC) or endovascular therapy (EVT) for unruptured intracranial aneurysms (UIAs) in the United States. Methods: Data were extracted and analyzed from the National Inpatient Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality for all patients admitted for elective EVT or SC of UIAs between 2011 and 2014. Treatment trends, in-hospital mortality, complication rates, length of stay (LOS) and total hospital costs were evaluated and analyzed. Results: A total of 31,070 patients with UIAs were included in our analysis, of which 14,411 and 16,659 underwent elective SC and EVT, respectively. There was no significant difference in in-hospital mortality rates between the 2 groups. EVT was associated with lower in-hospital complication rates, decreased median LOS (.8 days versus 3.3 days, P ≤ .0001), and an increased likelihood of discharge to home (92.9% versus 72.9%, P = .0001). Median total hospital charges were similar in both treatment cohorts. Independent predictors of mortality in the elective population were age over 40 years ( P ≤ .0001), weekend treatment ( P ≤ .0001), and high co-morbidity status ( P ≤ .0001). Conclusions: In-hospital mortality rates were similar in elective EVT and SC UIA patients; however, EVT was associated with lower in-hospital complication rates and shorter LOS.

Intra-arterial (IA) thrombolytic drugs were used as a primary therapy for recanalization of large vessel occlusions (LVO) with limited success. In recent years, endovascular interventions for the treatment of acute ischemic stroke (AIS) have rapidly evolved to include newer stentriever devices, which are now considered the standard of care for the treatment of AIS secondary to LVO. Although MT with stentriever technology has led to superior reperfusion rates, less than one third of patients achieve complete reperfusion. The role of thrombolytics in modern AIS endovascular therapy is undefined. However, new research suggests that IA thrombolytic use with MT may be beneficial in improving revascularization rates in AIS patients. Large series have shown that IA thrombolysis can be used as an adjunct/rescue therapy to MT, without increasing the risk of symptomatic intracerebral hemorrhage. In this chapter, we provide a brief history of IA thrombolytics, current approaches, and their potential role in modern endovascular therapy.

Introduction: Our objective was to determine trends in treatment preference and in-hospital complications of patients undergoing elective and non-elective treatment for unruptured intracranial aneurysms (UIA) in the United States over a 12-year period. Methods: We identified patients from the National Inpatient Sample database who were electively or non-electively admitted to the hospital with a primary ICD 9 diagnosis of unruptured intracranial aneurysm (437.3) from 2002 to 2014. We identified the method of treatment (surgical clipping or endovascular coiling) and studied in-hospital complications. Results: We identified 111,811 patients with UIAs between 2002 to 2014. Of these patients, 89,599 (80.1%) of patients were electively admitted. Approximately 47% (42,112) of patients underwent surgical clipping, while 53% (47,487) of patients underwent endovascular coiling. Of 22,212 patients who were admitted non-electively, 38.6% (8570) patients underwent surgical clipping and 61.4% (13,642) underwent endovascular coiling. There was a significantly higher proportion of patients treated with endovascular coiling for non-electively admitted patients as compared to elective admissions. For electively treated UIAs there were no significant differences in in-hospital mortality between the two treatment groups. Iatrogenic cerebrovascular accidents and intracranial hemorrhage were significantly less common in the endovascular coiling group throughout the study period. For non-electively treated UIAs, there was no significant difference in hospital mortality over the 12-year period. The rate of iatrogenic cerebrovascular accidents was generally lower for endovascular coiling with the exception of 2003. Endovascular coiling resulted in a significantly lower rate of iatrogenic cerebrovascular accidents in 2004 and 2008-2012. Intracranial hemorrhage was significantly less common in the endovascular group in 2004 and 2008-2014. Conclusions: Endovascular therapy has lower rates of in-hospital iatrogenic cerebrovascular accidents, and similar rates of mortality. The rate of endovascular and surgical therapies has plateaued since approximately 2005.

Objective: Computed Tomography Angiography ( CTA) is the standard of care test for ischemic stroke patients with suspected large vessel occlusion. When establishing emergency room stroke pathways, concerns for contrast induced nephropathy (CIN), which occurs in 11% of the general population could influence the time efficiency for CTA. Our aim is to report the incidence of CIN in our suspected severe stroke population. Method: With Institutional Review board approval, we maintained a prospective database on patients who were identified to have a high pre-hospital Rapid Arterial occlusion Evaluation ( RACE) between July 2015 and June of 2016. Per protocol, RACE alert patients go directly to the CT scanner to obtain a CT head and a CTA unless the test is cancelled by the stroke team. Labs are typically not available when CTA is performed. Our data included patient demographics, pre-morbid risk factors, baseline serum Creatinine level (Cr), peak Cr level during admission and at discharge. Incidence of renal consults and need for Hemodialysis was also monitored. Results: A total of 150 RACE alert patients were included in the analysis. Median age of patients was 73 and 12 patients had pre-morbid chronic renal failure. CTA was not performed in 21 of patients, due to low probabability of stroke determined by stroke team onsite.. Transient CIN occurred in 9(6%) of patients, renal consult was obtained in 4(3%) patients and 2(1) patients had a diagnosis of acute kidney injury on discharge. Conclusion: Emergent CTA resulted in a low number of transient CIN in our RACE alert patients. No cases of chronic renal Failure or need for HD were reported in our prospective cohort. A larger prospective registry may be needed to confirm the safety of this approach.

Background: There is concern regarding hospital bypass stroke protocols potentially compromising IVtPA treatment due to transit time delay. We compared our IV thrombolysis time efficiencies before and after Rapid Arterial oCclusion Evaluation Alert (RACE) bypass protocol (RA) implementation in Lucas County (LC) Ohio. Methods: RA protocol whereby RACE score ≥5 patients are transferred directly to comprehensive stroke center (CSC) for potential mechanical thrombectomy (MT) was implemented in Jul 2015. All stroke alerts (SA) that required MT from July 2013 through June 2015 were compared to MT cases performed following RA protocol implementation. Transfers from other counties, private transport and in-hospital cases were excluded and only patients brought via LC-EMS were included in the analysis. Basic demographics, risk factors, 911 activation to treatment time, and outcomes were compared. Results: Between Jul 2015-Jun 2016, 37 RA patients underwent MT of which 21 (56.8%) were given IV tPA at the CSC. Whereas in the preceding 2 years from Jul 2013-Jun 2015, 56 SA patients underwent MT, of which 22 (39%) received IVtPA. Of these SA cases, 11 (50%) were drip and transfer from other LC ERs and the remaining 11 (50%) presented directly to CSC. The 911 activation to 1 st ER arrival remained unchanged (34 vs. 32 mins, p 0.4), whereas tPA administration was significantly faster (64 vs. 88 mins, p Conclusions: Within LC, the RA bypass protocol did not result in a significant delay to ER arrival and it significantly expedited IV tPA delivery to patients undergoing MT. Further prospective studies are warranted.

Background: Early stroke identification and treatment with mechanical thrombectomy (MT) increases likelihood of favorable outcome. We compared our MT time efficiencies before and after Rapid Arterial oCclusion Evaluation Alert (RACE) bypass protocol (RA) implementation in Lucas County (LC) Ohio. Methods: Our RA protocol mandates emergent comprehensive stroke center transfer for patients with RACE score ≥ 5. We compared MT cases for RA patients (N=37) from Jul 2015-Jun 2016 with procedures performed on Stroke Alerts [(SA) N=56] from preceding 2 years. Transfers from outside LC, private transport and inhospital cases were excluded and only patients brought via LC-EMS were included in the analysis. Basic demographics, risk factors, 911 call to treatment, and outcomes were compared. Results: Treatment times including 911 call to IV tPA treatment, groin puncture, and recanalization were all significantly faster in the RA cohort (see graphic). Overall RA patients achieved recanalization and favorable outcomes at higher rate, although the latter was not statistically significant. Conclusion: Our experience indicates that RA protocol is highly effective in enhancing overall time efficiency for MT and may contribute to improved clinical outcomes. Further prospective studies are warranted.