Circulation Large Vessel Occlusion Stroke Research Articles

Outcomes of Bridging Intravenous Thrombolysis Versus Endovascular Therapy Alone in Late-Window Acute Ischemic Stroke.

Studies comparing bridging intravenous thrombolysis (IVT) with direct endovascular therapy (EVT) in patients with acute ischemic stroke who present late are limited. We aimed to compare the clinical outcomes and safety of bridging IVT in patients with acute ischemic stroke due to anterior circulation large vessel occlusion who underwent EVT 6 to 24 hours after time last known well. We enrolled patients with anterior circulation large vessel occlusion stroke and a National Institutes of Health Stroke Scale score of ≥6 from 20 centers across 10 countries in the multicenter retrospective CLEAR study (CT for Late Endovascular Reperfusion) between January 2014 and May 2022. We used inverse probability of treatment weighting modeling adjusted for clinical and imaging confounders to compare functional outcomes, reperfusion success, symptomatic intracranial hemorrhage, and mortality between EVT patients with and without prior IVT. Of 5098 patients screened for eligibility, we included 2749 patients, of whom 549 received bridging IVT before EVT. The timing of IVT was not recorded. Witnessed stroke onset and transfer rates were higher in the bridging IVT group (25% versus 12% and 77% versus 55%, respectively, P value for both <0.0001), and time intervals between stroke onset and treatment were shorter (time last known well-start of EVT median 560 minutes [interquartile range, 432-791] versus 724 minutes [interquartile range, 544-912]; P<0.0001). After adjustment for confounders, there was no difference in functional outcome at 3 months (adjusted common odds ratio for modified Rankin Scale shift, 1.03 [95% CI, 0.89-1.19]; P=0.72) or successful reperfusion (adjusted odds ratio, 1.19 [95% CI, 0.81-1.75]; P=0.39). There were no safety concerns associated with bridging IVT versus direct EVT (symptomatic intracranial hemorrhage: adjusted odds ratio, 0.75 [95% CI, 0.38-1.48]; P=0.40; mortality: adjusted odds ratio, 1.14 [95% CI, 0.89-1.46]; P=0.31). Results were unchanged when the analysis was limited to patients who received IVT >6 hours after last known well. In patients with an anterior circulation large vessel occlusion stroke who underwent EVT 6 to 24 hours from last known well, bridging IVT was not associated with a difference in outcomes compared with direct EVT. URL: https://www.clinicaltrials.gov; Unique identifier: NCT04096248.

Deep learning-based model for difficult transfemoral access prediction compared with human assessment in stroke thrombectomy

BackgroundIn mechanical thrombectomy (MT), extracranial vascular tortuosity is among the main determinants of procedure duration and success. Currently, no rapid and reliable method exists to identify the anatomical features precluding...

A systematic review of randomized controlled trials of endovascular therapy for stroke on mortality and disability

BackgroundEndovascular treatment (EVT) has become standard of care for patients with anterior circulation large vessel occlusion (LVO) stroke, with indications having recently expanded to late time-window and large ischemic core patients. There is conflicting evidence on whether EVT reduces mortality or only disability. We performed a meta-analysis of randomized controlled trials (RCTs) to assess the effect of EVT on mortality and severe disability. MethodsWe systematically searched PubMed, Web of Science, Scopus, and Embase on November 15, 2023, to identify phase 3 RCTs comparing EVT to best medical treatment (BMT) in patients with anterior circulation LVO stroke in a common effects meta-analysis. The primary outcome was mortality at 3 months. Secondary outcomes were moderately severe or severe disability (modified Rankin Scale (mRS) score 4–5) at 3 months. Results18 studies comparing EVT to BMT were included, with a total of 4309 patients; 2159 that were treated with EVT, and 2150 treated with BMT. Mortality was significantly lower in the EVT group than in the BMT group (odds ratio (OR): 0.81, 95% CI: 0.70–0.94). Proportions of moderately severe or severe disability (OR: 0.55, 95% CI: 0.48–0.62) were also significantly lower in patients treated with EVT. ConclusionsThis meta-analysis suggests that EVT reduces both mortality and moderately severe or severe disability in patients with anterior circulation LVO stroke.

Thrombus Imaging Characteristics to Predict Early Recanalization in Anterior Circulation Large Vessel Occlusion Stroke.

The early management of transferred patients with a large vessel occlusion (LVO) stroke could be improved by identifying patients who are likely to recanalize early. We aim to predict early recanalization based on patient clinical and thrombus imaging characteristics. We included 81 transferred anterior-circulation LVO patients with an early recanalization, defined as the resolution of the LVO or the migration to a distal location not reachable with endovascular treatment upon repeated radiological imaging. We compared their clinical and imaging characteristics with all (322) transferred patients with a persistent LVO in the MR CLEAN Registry. We measured distance from carotid terminus to thrombus (DT), thrombus length, density, and perviousness on baseline CT images. We built logistic regression models to predict early recanalization. We validated the predictive ability by computing the median area-under-the-curve (AUC) of the receiver operating characteristics curve for 100 5-fold cross-validations. The administration of intravenous thrombolysis (IVT), longer transfer times, more distal occlusions, and shorter, pervious, less dense thrombi were characteristic of early recanalization. After backward elimination, IVT administration, DT and thrombus density remained in the multivariable model, with an AUC of 0.77 (IQR 0.72-0.83). Baseline thrombus imaging characteristics are valuable in predicting early recanalization and can potentially be used to optimize repeated imaging workflow.

Impact of Sex on Thrombectomy Outcomes in Ischemic Stroke: A Propensity Score‐Matched Study, Systematic Review, and Meta‐Analysis

Background Women are underrepresented in stroke thrombectomy trials, and the impact of sex differences in outcomes after stroke thrombectomy is unclear. We performed a multicenter propensity matching study to define sex‐related differences in outcome after endovascular thrombectomy and integrated results in a meta‐analysis. Methods We included patients with anterior circulation large vessel occlusion consecutively treated with thrombectomy at 2 Comprehensive Stroke Centres (2016–2023). Selection criteria reflected international guidelines. Through systematic review we selected all studies reporting endovascular thrombectomy outcomes in anterior circulation large vessel occlusion stroke, applying propensity score matching. MEDLINE, EMBASE, and Cochrane CENTRAL were searched up to August 15, 2023 according to predefined protocol (OSF.io/je3da). Data were extracted by 2 independent raters, pooled estimates calculated according to random‐effect modeling meta‐analysis and reported as odds ratio (OR) and standard 95% CI. Outcomes were good functional outcome, defined as modified Rankin Scale score 0–2 at 90 days after stroke, and symptomatic intracranial hemorrhage, adjudicated according to European Cooperative Acute Stroke Study II criteria. Results After matching, 698 patients (349 women versus 349 men) had similar cardiovascular risk factors, baseline features, and treatment approach. No significant differences were found for good functional outcome (OR = 0.89, 95% CI = 0.66–1.2) and symptomatic intracranial hemorrhage (OR = 1.00, 95% CI = 0.44–2.26) in the cohort study by sex. Systematic review identified 3 studies (n = 3706), all of high quality. No differences emerged in rates of good functional outcome (OR = 1.00, 95% CI = 0.79–1.21) or symptomatic intracranial hemorrhage (OR = 0.85, 95% CI = 0.60–1.19) depending on sex. Conclusion Women receiving endovascular thrombectomy for anterior circulation large vessel occlusion related stroke have similar rates of good functional outcome and symptomatic intracranial hemorrhage compared to men.

Abstract WP248: Developing and Validating Post-Treatment HERMES Score to Predict Outcome From Anterior Circulation Large Vessel Occlusion Stroke: A Meta-Analysis of Individual Data From 7 Randomized Clinical Trials

Introduction: Clinicians need simple and highly predictive prognostic scores to assist practical decision-making and family discussion. We aimed to develop and validate a simple prediction score applied at 24 hours to assist prognostication in patients with anterior circulation ischemic stroke due to large vessel occlusion. Methods: Using the HERMES collaboration dataset (n = 1764), patients in the endovascular therapy (EVT) arm were divided randomly into a derivation cohort (n = 430) and a validation cohort (n = 441). From a set of candidate predictors, forward selection using c-statistics was employed to select a model which was both parsimonious and highly predictive for modified Rankin Scale (mRS) ≤2 at 90 days. The score was validated in both the EVT validation cohort and in the control arm (n = 893) for mRS ≤2 and ≤3. Results: In the derivation cohort, two significant predictors of mRS ≤2 (National Institutes of Health Stroke Scale [NIHSS] score at 24 h and age [β-coefficient 0.34 and 0.06]) were selected. Incorporating other variables did not much improve model performance. Among models with different weights, we derived the HERMES score: age (years)/10 + NIHSS score at 24 h, based on model performance and simplicity. The HERMES score was highly predictive for mRS ≤2 in the derivation cohort, validation cohort-EVT, and control arm (c-statistics 0.907, 0.914, and 0.909, respectively). Evaluation of the score against mRS ≤3 as an alternative outcome yielded similar results (c-statistics 0.911, 0.903, and 0.885). Among 435 subjects (24.7%) with HERMES score ≥25, the observed probability was 3.1-3.4% for mRS ≤2 and 9.4-16.7% for mRS ≤3 in the derivation cohort, validation cohort-EVT, and control arm (Figure). Conclusions: The HERMES score is a simple validated score to predict outcomes in patients with anterior circulation large vessel occlusion ischemic stroke regardless of intervention. HERMES score should be helpful in prognostic discussion with families on day two.

Abstract TP175: Older Age is Associated With Smaller Ischemic Core Volume and Slower Infarct Progression Despite High Clinical Severity in Anterior Circulation Large Vessel Occlusion Stroke

Background: Older patients with acute stroke due to anterior circulation large vessel occlusion (ACLVO) experience worse clinical outcomes. Fast progressors typically present early with high stroke severity and larger ischemic core volumes. However, the relationship between aging and early infarct growth rate is unknown. We examined the association between older age, baseline ischemic core volumes and fast or slow infarct growth during ACLVO. Methods: Retrospective study of patients with acute ICA or MCA occlusion across two academic centers in 2014-2019. Patients were included if they had baseline CTP or MRI within 24 hours after estimated stroke onset. Infarct growth rate (IGR) was calculated as ischemic core volume (ml) / stroke onset to imaging time (h). Fast or Slow progressor status was defined by IGR ≥ or &lt; 10 ml/h. Univariate comparisons were made across age tertiles. Multivariable linear and logistic regression analysis examined the association of age tertile with ischemic core volume and slow progressor status adjusting for sex, vascular co-morbidities and NIHSS. Results: We included 312 patients (57% female; age tertiles [T1-T3]: 33—66, 67—81, and 82—102). Older age was associated with decreasing ischemic core volume (median [range] ml: T1, 29 [0-253]; T2, 12 [0-406]; T3, 6 [0-244]; p&lt;0.001) and lower IGR (median [range] ml/h: T1, 5.8 [0-153]; T2, 2.6 [0-122.5]; T3, 0.6 [0-248]; p&lt;0.001). The frequency of slow progressors increased with age (N (%): T1, 65/107 (61); T2, 76/105 (72); T3, 78/100 (78); p=0.02). However, baseline NIHSS was numerically higher with older age (median [range]: T1, 16 [1-30]; T2, 17 [2-38]; T3, 18 [1-33]; p=0.22). In multivariable models, age tertile (T3 vs T1) and NIHSS were associated with: 1. ischemic core volume (age coefficient [95% CI], -18.9 [-36.1, -1.7], p=0.03; NIHSS coefficient [95% CI], 3.2[2.3, 4.1], p&lt;0.001); and 2. slow progressor status (age OR 2.63 [1.27, 5.43], p=0.009); NIHSS OR 0.91 [0.87, 0.95], p&lt;0.001). Conclusions: Older age was paradoxically associated with lower baseline core volumes and slow progressor status, despite high stroke severity during acute ACLVO, suggesting older patients may be more vulnerable to even slow infarct growth. Future studies are needed to confirm and extend the findings.

Abstract WP190: Comparison of Collateral Score to ASPECTS to Exclude "Very Large" Infarct Core Volumes in Anterior Circulation Large Vessel Occlusion Strokes at 0-24 Hours

Purpose: ASPECTS&lt;3 was an explicit exclusion criterion in the SELECT2 trial to exclude "very large" infarcts (&gt;100mL) for reperfusion using endovascular thrombectomy (EVT). While specific, ASPECTS&lt;3 may be too insensitive of a threshold on noncontrast CT at 0-24 hours (especially 0-6 hours). We aim to determine if CTA based Collateral Score (CS) can be a more sensitive surrogate marker for infarct core volume (ICV)&gt;100mL while maintaining similar specificity to ASPECTS. Methods: Retrospective analysis included consecutive stroke patients arriving within 24 hours of onset, with intracranial ICA and/or M1 occlusion on CTA, and had concurrent CT perfusion. RAPID AI software estimated ICV using the rCBF&lt;30% threshold. CS was scored on CTA using the method of Tan et al on a 4-point scale for % collaterals compared to contralateral side: 0 none, 1 &gt;0 but &lt;50%, 2 &gt;=50 but &lt;100%, and 3 100%. ROC curve analysis was used to find the optimal CS cutpoint with high specificity for ICV&gt;100mL. Sensitivity and specificity of that CS threshold vs ASPECTS&lt;3 were compared using the N-1 chi square test. Results: 164 patients were included with median (IQR) age of 74 (66-84), NIHSS of 20 (12-25), and time of onset-to-CT of 4 hours (2-7.5). The LVOs were 17 ICA (10.4%), 108 M1 (65.9%), and 39 both (23.8%), with median ICV of 12mL (0-45). 16 patients had ICV&gt;100mL (9.8%) with median of 136mL (105-172). Using ASPECTS&lt;3 identified only 1 of these (ICV of 118mL at 18.5 hours), sensitivity of 6.3% (95% CI: 0.16-30.2%), with no false positives, specificity of 100% (95% CI: 97.6-100%). ROC analysis for CS showed AUC=0.818 (p&lt;0.001), with maximal specificity at CS=0 (no visible collaterals). Using CS=0 identified 6 of these infarcts, sensitivity of 37.5% [95% CI: 15.2-64.6%], with 2 false positives, specificity of 98.7% [95% CI: 95.2-99.8%]. The 2 false positives were ICV of 97mL at 2 hours and 96mL at 3 hours. The improved sensitivity of CS=0 over ASPECTS&lt;3 was significant (p=0.036) while the difference in specificity was not (p=0.144). Conclusion: In our cohort of LVOs, CS=0 was a more sensitive surrogate marker for ICV&gt;100mL compared to ASPECTS&lt;3 while maintaining near 100% specificity. If confirmed in future prospective studies, CS=0 has the potential to further streamline patient selection for EVT.

Abstract 87: Predictive Scoring System for Pre-Thrombectomy Diagnosis of Intracranial Atherosclerotic Disease LVOS

Introduction: Early identification of intracranial atherosclerotic disease (ICAD) underlying large vessel occlusion strokes (LVOS) may allow for mechanical thrombectomy (MT) optimization. We sought to create a pre-procedural scoring system to predict ICAD. Methods: Retrospective analysis of prospectively collected MT databases from 2 comprehensive stroke centers (derivation and validation) including patients with anterior circulation LVOS. ICAD cases were matched for age / sex (1:1) to non-ICAD controls and stepwise logistic regression utilized for various clinical and radiological (NCCT, CTA and CTP) variables. Calibration slope / intercept as well as the area under curve (auROC) were assessed. Results: Of 2870 MTs within the study period, 174 anterior circulation ICAD (6.6%) were matched with 174 controls (n=348) in the derivation cohort. Multivariable analysis β coefficients lead to a 20 point-scale: absence of AF (5), vascular risk factor burden (1 for each: hypertension, diabetes, smoking, hyperlipidemia), CTA multifocal ICAD (3), absence of cortical infarcts (3), presence of borderzone infarct (3), calcium at the siphon (2). The validation cohort comprised 75 ICAD patients (6.9% of 1359 MTs) and 75 controls. AuROC for the derivation cohort was 0.88(0.84-0.91) while for the validation cohort 0.82(0.73-0.89). Calibration slope and intercept showed a good fit for the development cohort although with overestimated risk for the validation cohort. After intercept adjustment, the overestimation was corrected (intercept 0; 95%CI -0.5-0.5 / slope 0.8 95%CI 0.5-1.1). In the full cohort (n=498), ≥ 11 points showed the best performance for distinguishing ICAD from non-ICAD patients, with a sensitivity 0.71 (0.65-0.78) and specificity 0.82 (0.77-0.87), a positive likelihood ratio of 3.92 (2.92, 5.28) and a negative LR of 0.35 (0.28, 0.44). Scores ≥ 12 showed 90% specificity, although sensitivity of 63% (55%-69%). Conclusion: We developed a predictive scoring system for pre-procedural diagnosis of ICAD LVOS with satisfactory discrimination and calibration based on clinical and non-invasive radiological data.

Subhairline Electroencephalography for the Detection of Large Vessel Occlusion Stroke.

Endovascular thrombectomy is standard treatment for patients with anterior circulation large vessel occlusion stroke (LVO-a). Prehospital identification of these patients would enable direct routing to an endovascular thrombectomy-capable hospital and consequently reduce time-to-endovascular thrombectomy. Electroencephalography (EEG)has previously proven to bepromising for LVO-a stroke detection. Fast and reliable electrode application, however, can remain a challenge. A potential alternative is subhairline EEG. We evaluated the diagnostic accuracy of subhairline EEG for LVO-a stroke detection. We included adult patients with a suspected stroke or known LVO-a stroke and symptom onset time <24 hours. A single 3-minute EEG recording was performed at the emergency department, before endovascular thrombectomy, using 9 self-adhesive electrodes placed on the forehead and behind the ears. We evaluated the diagnostic accuracies of EEG features quantifying frequency band power and brain symmetry (pairwise derived Brain Symmetry Index) for LVO-a stroke detection using receiver operating characteristic analysis. EEG data were of sufficient quality for analysis in 51/52 (98%) included patients. Of these patients, 16 (31%) had an LVO-a stroke, 16 (31%) a non-LVO-a ischemic stroke, 5 (10%) a transient ischemic attack, and 14 (27%) a stroke mimic. Median symptom-onset-to-EEG-time was 266 (interquartile range 130-709) minutes. The highest diagnostic accuracy for LVO-a stroke detection was reached by the pairwise derived Brain Symmetry Index in the theta frequency band (area under the receiver operating characteristic curve 0.90; sensitivity 86%; specificity 83%). Subhairline EEG could detect LVO-a stroke with high diagnostic accuracy and had high data reliability. These data suggest that subhairline EEG is potentially suitable as a prehospital stroke triage instrument.

Effects of edaravone dexborneol on neurological function and serum inflammatory factor levels in patients with acute anterior circulation large vessel occlusion stroke.

The goal of this study is to evaluate and analyze the effects of edaravone (EDV) dexborneol on neurological function and serum inflammatory factor levels among patients with acute anterior circulation big artery blockage stroke. A total of 142 patients with acute anterior circulation large vessel occlusion (LVO) were randomly allocated to the study group (69 patients) or the control group (73 patients). In the study group, patients were treated with 37.5 mg EDV dexborneol twice a day for 10-14 days, based on the control group. The primary efficacy outcome was the National Institutes of Health Stroke Scale score change from baseline to 90 days and the proportion of modified Rankin Scale (mRS)score ≤1 at 90 days after randomization. The secondary outcome included the decrease in inflammatory factors at 14 days. The primary safety outcome was the incidence of hemorrhagic transformation assessed according to Heidelberg bleeding classification within 7 days. A higher percentage of patients with HIHSS score ≤5 at 90 days in the EDV dexcamphorol group was observed than in the control group (75.36% vs 64.38%; P = 0.015). A higher percentage of patients with mRS score ≤1 at 90 days in the EDV dexcamphorol group was observed than in the control group (63.77% vs 50.68%; P = 0.012). After treatment, the levels of IL-6 and hs-CRP were significantly lower following treatment and compared to the control group (P < 0.05). In patients receiving the EDV dexborneol group, a significantly decreased risk of radiographic intracranial hemorrhage was found compared with the control group (20.29% vs 39.73%; P = 0.0006). In conclusion, EDV dexborneol can improve the clinical outcomes of patients with acute anterior circulation LVO stroke, which can be used as an effective supplement to thrombectomy therapy.

Predictive value of net water uptake with respect to early neurological improvement after endovascular treatment in patients with acute anterior circulation large vessel occlusion stroke

Objective: To investigate the value of net water uptake (NWU) for predicting early neurological improvement (ENI) after endovascular treatment in patients with acute anterior circulation large vessel occlusion stroke. Methods: A case-control study. A total of 132 patients (80 men, 52 women, median age 68 years) with acute anterior circulation large vessel occlusive stroke receiving endovascular treatment were retrospectively analyzed at Jinling Hospital from October 2014 to September 2019. Patients were divided into two groups based on the occurrence of ENI, which was defined as either an improvement of NIHSS score of ≥4 points, or an NIHSS score of 0 or 1 at 24 hours after endovascular treatment. The rank sum test, Chi square test, and other methods were used to compare differences in baseline characteristics between the two groups. Logistic regression analysis was used to investigate independent predictors of postoperative ENI. Receiver operating characteristic curve analysis used to assess the capacity of NWU to predict ENI. Results: Of the 132 patients in the study, ENI occurred in 47 and did not occur in 85. In multivariate logistic regression analysis age [odds ratio (OR)=0.940, 95% confidence interval (CI) 0.903-0.979, P=0.003], time from stroke onset to puncture (OR=0.995, 95%CI 0.991-0.999, P=0.025), time from puncture to recanalization/end of operation (OR=0.985, 95%CI 0.974-0.996, P=0.007), NWU (OR=0.762, 95%CI 0.620-0.937, P=0.010), and mTICI (OR=1.644, 95%CI 1.043-2.590, P=0.032) were predictive factors for ENI. Receiver operating characteristic curve analysis indicated that NWU could effectively predict ENI (area under the curve=0.642, 95%CI 0.543-0.741, P=0.007), and prediction accuracy was improved when it was combined with other clinical parameters. Conclusion: NWU is an independent predictor of ENI in patients with acute anterior circulation large vessel occlusive stroke undergoing endovascular treatment.

Comparison of CT Perfusion Software Packages for Thrombectomy Eligibility.

Computed tomography perfusion (CTP) has played an important role in patient selection for mechanical thrombectomy (MT) in acute ischemic stroke. We aimed to investigate the agreement between perfusion parametric maps of 3 software packages - RAPID (RapidAI-IschemaView), Viz CTP(Viz.ai), and e-CTP(Brainomix) - in estimating baseline ischemic core volumes of near completely/completely reperfused patients. We retrospectively reviewed a prospectively maintained MT database to identify patients with anterior circulation large vessel occlusion strokes (LVOS) involving the internal carotid artery or middle cerebral artery M1-segment and interpretable CTP maps treated during September 2018 to November 2019. A subset of patients with near-complete/complete reperfusion (expanded thrombolysis in cerebral infarction [eTICI] 2c-3) was used to compare the pre-procedural prediction of final infarct volumes. In this analysis of 242 patients with LVOS, RAPID and Viz CTP relative cerebral blood flow (rCBF) < 30% values had substantial agreement (ρ = 0.767 [95% confidence interval [CI] = 0.71-0.81]) as well as for RAPID and e-CTP (ρ = 0.668 [95% CI = 0.61-0.71]). Excellent agreement was seen for time to maximum of the residue function (Tmax ) > 6 seconds between RAPID and Viz CTP (ρ = 0.811 [95% CI = 0.76-0.84]) and substantial for RAPID and e-CTP (ρ = 0.749 [95% CI = 0.69-0.79]). Final infarct volume (FIV) prediction (n = 136) was substantial in all 3 packages (RAPID ρ = 0.744; Viz CTP ρ = 0.711; and e-CTP ρ = 0.600). Perfusion parametric maps of the RAPID, Viz CTP, and e-CTP software have substantial agreement in predicting final infarct volume in near-completely/completely reperfused patients. ANN NEUROL 2023;94:848-855.

Association Between Thrombectomy and Functional Outcomes in Pediatric Patients With Acute Ischemic Stroke From Large Vessel Occlusion

Pediatric large vessel occlusion (LVO) stroke has a poor natural history. However, uptake of mechanical thrombectomy is hindered by a lack of clinical trial data in children. A randomized clinical trial is not feasible due to small sample sizes and absence of equipoise. To evaluate whether pediatric patients with acute LVO stroke who undergo thrombectomy have better clinical outcomes than matched patients managed conservatively. This matched case-control study used pooled stroke registry data from 5 tertiary referral hospitals in Australia and Canada from January 2011 to April 2022. Patients were aged 1 month to younger than 18 years with acute LVO stroke. Pooled data identified 31 thrombectomy patients and 46 control patients. Five patients undergoing thrombectomy with basilar artery occlusion were excluded due to insufficient controls. Using a hierarchal matching system (site of occlusion, age group, side of occlusion, and sex), deidentified consensus matching of patients and controls was undertaken while blinded to clinical outcome. Data were analyzed from July to November 2022. In the case cohort, mechanical thrombectomy was undertaken for management of acute LVO stroke. The control cohort received medical treatment only. The primary outcome was the functional clinical status 3 months following stroke, measured by the pediatric modified Rankin Scale (mRS). Clinical outcomes were compared between groups using ordinal regression analysis. Of 52 included patients, 31 (60%) were male, and the mean (SD) age was 10.3 (4.4) years. Matching was achieved for 26 children undergoing thrombectomy with 26 controls. There was no significant difference between groups for site or side of occlusion, age, sex, etiology, thrombolysis status, baseline Alberta Stroke Programme Early CT Score, or time since last seen well to presentation. Patients undergoing thrombectomy had superior clinical outcomes than control patients at 3 months on the pediatric mRS (odds ratio, 3.76; 95% CI, 1.32-10.67; P = .01). These superior outcomes were maintained at final follow-up (odds ratio, 3.65; 95% CI, 1.25-10.68; P = .02). In the absence of a randomized clinical trial, this case-control study demonstrates better clinical outcomes with thrombectomy than medical management alone for pediatric patients aged 2 to 18 years with anterior circulation LVO stroke.

Area Deprivation Index Predicts Early Severity and Infarct Growth Rate in Anterior Circulation Large Vessel Occlusion Stroke (S3.010)

<h3>Objective:</h3> We aimed to measure the social determinants of early stroke severity (NIHSS) and infarct growth rate (IGR) in anterior circulation large vessel occlusion (ACLVO) stroke using the Area Deprivation Index (ADI). <h3>Background:</h3> Socioeconomic status has been shown to affect the clinical outcome of neurological disease and stroke. Early NIHSS and IGR are highly variable across patients with ACLVO stroke but their determinants remain poorly understood. ADI data incorporates housing, education, income, and employment status at the census block groups level. <h3>Design/Methods:</h3> Single-center retrospective study of all patients with acute intracranial ICA or MCA occlusion and baseline CTP or MRI within 24 hours of stroke onset, from 2014–2017. IGR was calculated as the ischemic core volume/stroke onset to imaging time (ml/h). ADI was obtained from the University of Wisconsin dataset based on US Census data (v 3.2). Demographics, co-morbidities, admission NIHSS, and median income data were collected. Multivariable linear regression models tested the independent association between ADI and NIHSS (model 1) or IGR (model 2, including NIHSS). <h3>Results:</h3> 165 patients were included in the analysis, with mean age 71 (SD, 15), 40% male, median NIHSS 17 (IQR, 12–21), and mean ADI 62 (SD, 23.3). In model 1, ADI (coefficient 0.07, 95% CI 0.025–0.13, P=0.004) and age (coefficient 0.11, 95% CI 0.4—0.19, P=0.003) were independently associated with NIHSS. In model 2, ADI (coefficient 0.11, 95% CI 0.004–0.21, P=0.04) and NIHSS (coefficient 0.46, 95% CI 0.16–0.76, P=0.003) were independently associated with IGR. Median income, sex, diabetes or hypertension status were not associated with NIHSS or IGR in these models. <h3>Conclusions:</h3> ADI is independently associated with worse stroke severity and faster infarct progression of ACLVO stroke. These findings have potential implications for public health planning of stroke systems of care and enrollment in clinical trials of reperfusion therapies. <b>Disclosure:</b> The institution of Dr. Sari has received research support from NIH/NINDS. Dr. Dwairi has nothing to disclose. Mr. Thoma has nothing to disclose. Dr. Magnani has nothing to disclose. The institution of Dr. Rocha has received research support from NIH.

Renal function association with infarct growth rate in anterior circulation large vessel occlusion strokes (P6-5.017)

Renal function association with infarct growth rate in anterior circulation large vessel occlusion strokes (P6-5.017)

Vascular risk factors, cerebral collateral efficiency and burden of small vessel disease in anterior circulation large vessel occlusion stroke (P11-5.025)

<h3>Objective:</h3> To determine the association between cerebral collateral circulation status and cerebral small vessel disease (CSVD) burden. <h3>Background:</h3> Subclinical ischemia is thought to play a central role in CSVD pathogenesis. In patients with large vessel occlusion, good collaterals on initial presentation are associated with improved outcomes. The relationship between an increased burden of CSVD and collateral network has not been explored in the setting of thrombectomy. <h3>Design/Methods:</h3> This was a retrospective single-center cohort of consecutive patients with anterior circulation large vessel occlusions with available brain MRI and CT-Angiogram. We identified the burden of individual CSVD markers[white matter hyperintensities (WMH), cerebral microbleeds(CMB), lacunes, and enlarged perivascular spaces (EPVS)] and computed the global CSVD burden on MRI obtained in the acute stroke. We used the Tan Collateral score (CS) in CT-Angiogram to grade collaterals (0–3; 0=absent supply, 3=100% collateral supply). We performed univariable and multivariable adjusted analyses to explore the association between collaterals and CSVD. <h3>Results:</h3> 237 patients (66.1±16.8 years), 123(52%) female were included. Mean CS was 2(IQR 1–3). WMH (89%), basal ganglia EPVS (77%) and centrum semiovale EPVS (77%) were the most prevalent markers. Older age(beta=0.15, p&lt;0.0001) had the most potent association with individual CSVD markers and higher global CSVD burden. Older age(beta=−0.01, p=0.002) was associated with lower CS. Although a trend was detected between lower CS score and higher WMH burden, it did not reach statistical significance after adjusting for confounders (beta=−0.21, p=0.15). <h3>Conclusions:</h3> In this cohort of large vessel occlusion patients, we found that older age is associated with higher individual CSVD marker and global CSVD burden and poor collateral status. We did not find an overt association between CS and WMH or global CSVD burden. <b>Disclosure:</b> Dr. McMillan has nothing to disclose. Ms. Carvalho has nothing to disclose. Sarah Marchina has nothing to disclose. Dr. Cole has nothing to disclose. Dr. Selim has received personal compensation in the range of $500-$4,999 for serving as a Consultant for MedRhythms Inc.. Dr. Lioutas has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Qmetis. Dr. Lioutas has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for American Heart Association.

The BAND score: a simple upfront predictive model for futile recanalization to guide patient selection for endovascular thrombectomy during acute ischemic stroke triage (P8-5.004)

<h3>Objective:</h3> To develop a clinical scoring system for upfront prediction of poor post-endovascular thrombectomy (EVT) outcomes during the acute stroke triage process. <h3>Background:</h3> Futile recanalization (FR) is an unfavorable outcome following successful EVT for acute ischemic stroke patients. There is currently no clinical scoring system that can accurately predict FR. <h3>Design/Methods:</h3> Consecutive EVT patients for anterior circulation large vessel occlusion strokes were identified from 2016 to 2021 at a Comprehensive Stroke Center, and clinical information was recorded. FR was defined as a 90-day modified Rankin Scale (mRS) of 4 or greater despite achieving modified thrombolysis in cerebral infarction (mTICI) score 2b or greater. Multivariable regression analyses were used to identify independent risk factors for FR, and a scoring system was constructed. <h3>Results:</h3> 619 patients were identified, and 483 patients with successful recanalization and available 90-day follow-up data were analyzed. Overall, FR was observed in 46.5% of patients. From a randomly selected training cohort (n=357), individual risk factors for FR were identified and used to construct the 10-point BAND score: baseline disability (1 point: baseline mRS ≥ 2), age (1 point: 60–69 years, 2 points: 70–79 years, 3 points: 80–84 years, 4 points: 85 years or older), NIHSS (2 points: 13–17, 3 points: 18–22, and 4 points: 23 or higher), and delay from last known normal (1 point: ≥6 hours). The BAND score achieved good predictability of FR with an area under the receiver-operating characteristic curve of 0.80 in our training cohort and 0.78 in our validation cohort. 88.2% of the total and 90.2% of patients 80 years or older with BAND ≥7 had a 90-day mRS of 4 or greater despite successful EVT recanalization. <h3>Conclusions:</h3> The BAND score is a simple clinical scoring system for prediction of FR, and it has potential to serve as a valuable triage tool for physicians in a real-world setting. <b>Disclosure:</b> Mr. Chen has received research support from National Institues of Health. Dr. Colasurdo has nothing to disclose. Dr. Phipps has nothing to disclose. The institution of Dr. Miller has received research support from Medtronic. The institution of Dr. Miller has received research support from Cerenovus, DePuy Synthes Products, Inc.. The institution of Dr. Miller has received research support from InSightec. The institution of Dr. Miller has received research support from Microvention. The institution of Dr. Miller has received research support from Microvention. The institution of Dr. Miller has received research support from InSightec. The institution of Dr. Miller has received research support from MicroVention. The institution of Dr. Miller has received research support from InSightec. The institution of Dr. Miller has received research support from Vesalio. Jacob Cherian has nothing to disclose. Dr. Marino Granados has nothing to disclose. Dr. Cronin has nothing to disclose. Dr. Wozniak has nothing to disclose. Dheeraj Gandhi has nothing to disclose. Dr. Chaturvedi has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Astra Zeneca. Dr. Chaturvedi has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for University of Calgary. Dr. Chaturvedi has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for American Heart Association. Dr. Chaturvedi has received personal compensation in the range of $10,000-$49,999 for serving as an Expert Witness for Ramar &amp; Paradiso. Dr. Chaturvedi has received personal compensation in the range of $10,000-$49,999 for serving as an Expert Witness for Cole, Scott, Kissane. The institution of Dr. Chaturvedi has received research support from NINDS. Gaurav Jindal has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Penumbra.

Lack of Pre-treatment Thrombolysis and Low ASPECTS are Associated with Poor Rates of Recanalization After Mechanical Thrombectomy (P8-5.025)

<h3>Objective:</h3> To identify factors associated with poor rates of recanalization in patients with large vessel occlusion ischemic stroke undergoing mechanical thrombectomy. <h3>Background:</h3> Mechanical thrombectomy (MT) has been effective in treating ischemic strokes due to large vessel occlusion (LVO). However, all patients with LVO who are deemed candidates for MT do not have successful rates of recanalization and a favorable outcome. Hence, we studied factors associated with an unfavorable outcome in patients undergoing MT. <h3>Design/Methods:</h3> We retrospectively analyzed forty patients with LVO ischemic stroke undergoing MT. We included patients with anterior circulation LVO strokes who were deemed candidates for MT. Patient underwent CTA imaging upon arrival in the emergency room. We collected important variables including initial NIHSS, pre-morbid modified Rankin Scale (mRS), administration of thrombolysis, location of LVO, ASPECTS, TICI (thrombolysis in cerebral infarction) score. Functional outcome was measured with NIHSS and mRS at discharge. <h3>Results:</h3> 40 patients with LVO who underwent MT (age 68 ±15); 62.4 % female; NIHSS 16). Patients were divided into four groups based on TICI scores into those with 0/1, 2b, 2c and 3. Variables including initial NIHSS, pre-morbid mRS, administration of thrombolysis, location of LVO, ASPECTS and TICI score were compared between these groups. In the TICI 0/1 group, patients had low ASPECTS on arrival and were not treated with thrombolysis prior to thrombectomy. They also had a higher NIHSS and mRS at discharge. <h3>Conclusions:</h3> Lack of pre-treatment thrombolysis and low ASPECTS on presentation were associated with poor rates of recanalization after mechanical thrombectomy. <b>Disclosure:</b> Dr. Peshwe has nothing to disclose. Dr. Alvi has nothing to disclose.

A canine thromboembolic model of anterior circulation large vessel occlusion stroke

PurposeTo develop a large animal preclinical model of thromboembolic stroke with stable, protracted large vessel occlusion (LVO) utilizing an autologous clot. Materials and methodsA reproducible canine model of large vessel occlusion stroke was established by endovascular placement of an autologous clot into the middle cerebral artery (MCA) of six adult hounds and confirmed using digital subtraction angiography (DSA). Infarct volume and evidence of hemorrhage were determined by magnetic resonance imaging (MRI) 7 h after occlusion and Thrombolysis in Cerebral Infarction scale (TICI) was assessed before and after clot placement and at 1, 6, 7, and 9 h after middle cerebral artery occlusion (MCAO). Heart rate (HR) and blood pressure (BP) were monitored continuously and invasively through an arterial sheath throughout the procedures and complete blood count and blood gas analysis completed at time of sacrifice. Histopathological findings at time of sacrifice were used to confirm stroke volume and hemorrhage. ResultsMCAO with resulting TICI 0 flow was observed in all six animals, verified by serial DSA, and lack of collateral flow persisted for 9 h after clot placement until time of sacrifice. The mean infarct volume was 47.0 ± 6.7% of the ipsilateral hemisphere and no events of spontaneous recanalization or clot autolysis were observed. ConclusionWe demonstrate a thromboembolic canine model of MCAO that is both feasible and results in consistent infarct volumes to generate a clinically relevant LVO. This model is important to evaluate treatment of LVO in acute ischemic stroke (AIS) outside the established 4.5 h recombinant tissue plasminogen activator (rTPA) therapeutic window utilizing a prolonged occlusive thrombus.