Large Vessel Occlusion Stroke Research Articles

Deviation From Personalized Blood Pressure Targets Correlates With Worse Outcome After Successful Recanalization.

Personalized blood pressure (BP) management for patients with acute ischemic stroke after successful endovascular thrombectomy lacks evidence. We aimed to investigate whether the deviation of BP from cerebral autoregulation limits is associated with worse outcomes. We determined autoregulation by measuring mean velocity index and calculated the percentage of time and the burden (defined as the time-BP area) with BP outside the autoregulatory limits of each subject within 48 hours after endovascular thrombectomy. In total, 91 patients with large vessel occlusion stroke who had achieved successful recanalization were prospectively enrolled between May 2020 and February 2022. The burden with BP outside the autoregulatory limits was associated with poor outcome (modified Rankin Scale score 3-6) at 90 days (adjusted odds ratio, 1.28 [95% CI, 1.03-1.59]). The percentage of time with BP out of the autoregulatory limits was correlated with early neurological deterioration (National Institute of Health Stroke Scale scores increased ≥2 at 7 days) (adjusted odds ratio, 1.38 [95% CI, 1.04-1.83]). The burden of BP that decreased below the autoregulatory lower limit was associated with significant infarct growth (volume of infarct growth >11.6 mL) at 7 days (adjusted odds ratio, 1.21 [95% CI, 1.01-1.44]). The percentage of time that BP exceeded the autoregulatory upper limit was associated with symptomatic intracranial hemorrhage within 48 hours (adjusted odds ratio, 1.55 [95% CI, 1.02-2.34]). Both the percentage of time and the burden of BP that deviates from the autoregulation-preserved range are associated with unfavorable clinical outcomes. This study highlights the potential benefits of autoregulation-guided BP management strategy after successful recanalization.

Influence of Infarct Morphology and Patterns on Cognitive Outcomes After Endovascular Thrombectomy.

To assess the association of qualitative and quantitative infarct characteristics and 3 cognitive outcome tests, namely the Montreal Cognitive Assessment (MOCA) for mild cognitive impairment, the Boston Naming Test for visual confrontation naming, and the Sunnybrook Neglect Assessment Procedure for neglect, in large vessel occlusion stroke. Secondary observational cohort study using data from the randomized-controlled ESCAPE-NA1 trial (Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke), in which patients with large vessel occlusion undergoing endovascular treatment were randomized to receive either intravenous Nerinetide or placebo. MOCA, Sunnybrook Neglect Assessment Procedure, and 15-item Boston Naming Test were obtained at 90 days. Total infarct volume, gray matter, and white matter infarct volumes were manually measured on 24-hour follow-up imaging. Infarcts were also visually classified as either involving the gray matter only or both the gray and white matter and scattered versus territorial. Associations of infarct variables and cognitive outcomes were analyzed using multivariable ordinal or binary logistic regression models. Of 1105 patients enrolled in ESCAPE-NA1, 1026 patients with visible infarcts on 24-hour follow-up imaging were included. MOCA and Sunnybrook Neglect Assessment Procedure were available for 706 (68.8%) patients and the 15-item Boston Naming Test was available for 682 (66.5%) patients. Total infarct volume was associated with worse MOCA scores (adjusted common odds ratio per 10 mL increase, 1.05 [95% CI, 1.04-1.06]). After adjusting for baseline variables and total infarct volume, mixed gray and white matter involvement (versus gray matter-only adjusted common odds ratio, 1.92 [95% CI, 1.37-2.69]), white matter infarct volume (adjusted common odds ratio per 10 mL increase 1.36 [95% CI, 1.18-1.58]) and territorial (versus scattered) infarct pattern (adjusted common odds ratio, 1.65 [95% CI, 1.15-2.38]) were associated with worse MOCA scores. Results for Sunnybrook Neglect Assessment Procedure and 15-item Boston Naming Test were similar, except for the territorial infarct pattern, which did not reach statistical significance in multivariable analysis. Besides total infarct volume, infarcts that involve the white matter and that show a territorial distribution were associated with worse cognitive outcomes, even after adjusting for total infarct volume.

Utilizing RNA sequencing to identify gene expression markers of stroke-causing thrombi origin: A pilot study

IntroductionStroke embolic source have an unknown origin in 30-40% of cases. Mechanical thrombectomy for acute large vessel occlusion stroke has provided us with a method to directly retrieve the thrombi from patients for analysis. By collecting stroke-causing thrombi from known sources, we can then use high-throughput RNA sequencing (RNAseq) technology to directly measure the gene expression signatures of these clots. This may allow us to identify genetic markers to predict the cause of cryptogenic embolism. MethodsThis is a prospective study in which RNAseq was used to analyze cerebral thrombi retrieved by mechanical thrombectomy devices in acute ischemic stroke patients. Samples were separated into two groups based on known stroke thrombus etiology, including Carotid group (patients with ipsilateral >70% carotid stenosis) and Atrial fibrillation (AF) group (patients with atrial fibrillation). Gene expression was compared by RNAseq analysis between the groups. ResultsFrom October 2016 to September 2017, 8 thrombi (4 in Carotid group, 4 in Afib group) were included in this study. There were 131 genes that were significantly up- or down-regulated between the two groups defined as a false discovery rate ≤ 0.05 and a fold change ≥ 2. Twenty-six genes were selected as candidate gene biomarkers based on the criteria in the methods section. Candidate genes HSPA1B, which encodes a heatshock protein, and GPRC5B, which encodes a G-protein, showed the greatest fold differences in expression between the two groups. ConclusionThis study has shown that RNA sequencing of acute ischemic stroke thrombi is feasible and indentified potential novel biomarkers for identifying stroke-causing thrombi origin, especially in cryptogenic stroke.

Prolonged venous transit on perfusion imaging is associated with higher odds of mortality in successfully reperfused patients with large vessel occlusion stroke

BackgroundPoor venous outflow (VO) profiles are associated with unfavorable outcomes in patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO), despite achieving successful reperfusion. The objective of this...

Does Ischemic Core Volume Modify the Treatment Effect of Endovascular Thrombectomy?

Imaging-based selection has become integral in guiding endovascular thrombectomy for large vessel occlusive stroke, driven by positive trial outcomes incorporating parenchymal and perfusion imaging criteria. While small-moderate core trials transformed acute reperfusion therapy, uncertainties persisted for large ischemic strokes. This was recently addressed in several treatment trials which demonstrated a benefit of endovascular thrombectomy in patients with large ischemic strokes, defined by parenchymal and/or perfusion imaging. Although individual trials suggest treatment benefits regardless of core size, patient-level meta-analyses are essential to clarify this relationship. Our aim was to summarize the imaging ramifications of the major endovascular thrombectomy trials of the past decade focusing on the interaction between the core and the treatment effect, to assist in the design of future meta-analyses. The core-treatment relationship that will be investigated in these meta-anlalyses will likely have major implications in our systems of care designs and in determining the utility of imaging-based selection.

Time-dependent systolic blood pressure within 72h after endovascular treatment in large vessel occlusion stroke.

The association of systolic blood pressure (SBP) and ischemic stroke outcome has recently been proved to be varied at different time points within 72h after acute ischemic stroke onset; however, the specific status of how SBP affects prognosis at different time points within 72h after endovascular treatment (EVT) among patients with large vessel occlusion (LVO) remains unclear. Consecutive LVO patients treated with EVT were enrolled in our study. BP data were collected at eight time points (1, 2, 4, 8, 16, 24, 48, and 72h post-EVT). Outcome measure of interest was functional dependence, which was defined as mRS >2 at 90 days. A total of 406 LVO patients treated with EVT from 2016 to 2022 were included. At 16h after EVT, the relationship between SBP and functional dependence showed a nonlinear association. At other time points after EVT, SBP had linear relationships with functional dependence. Furthermore, higher SBP, as either a linear or quadratic term, had an adverse effect on functional outcome. In addition, three SBP trajectories were observed, and the high-to-low group was independently associated with functional dependence. Taken together, higher SBP within the first 72h after EVT has a time-dependent association with adverse clinical outcomes. Optimal blood pressure management during the first 72h after EVT may be important to improve clinical outcome.

Effect of concomitant usage of alteplase and mechanical thrombectomy for M1 middle cerebral artery occlusion on clinical outcome: a retrospective analysis of 457 patients from two centers.

Endovascular thrombectomy (EVT) and concomitant usage of intravenous alteplase (alteplase) in large vessel occlusion stroke may produce unwanted excess intracerebral hemorrhage (ICH). Whether this applies specifically to isolated occlusion of the M1 segment of the middle cerebral artery (MCA) is unknown. A retrospective study from two tertiary thrombectomy centers. ICH was determined according to Heidelberg Bleeding Classification (HBC). Factors associated with the occurrence of ICH in EVT alone vs. EVT with alteplase were evaluated using logistic regression analysis. Factors related to the clinical outcome as determined with a modified Rankin scale (mRS) were investigated with univariate and adjusted multivariate logistic regression analysis. The interaction between clinical variables and the usage of alteplase on the occurrence of ICH was evaluated. Any ICH occurred in 156/457 (34.1%) patients Class 1a bleeding in 37 (8.1%), type 2 in 45 (9.8%) Class 1c in 22 (4.8%), Class 2 in 25 (5.5%), and Class 3 (extraparenchymal) in 27 (5.9%). ICH occurred in similar frequency between alteplase-treated patients vs. EVT alone (85/262 [32%] vs. 71/195 [36%]; OR 1.19 (95% CI 0.81-1.76). After adjustment, odds for clinical outcome were lower in ICH patients (OR 0.44 [95% CI 0.25-0.74]), p = 0.002). Higher ICH rate was associated with more EVT steps (p for interaction -0.005), and usage of only stent-retriever (p for interaction =0.005). Utilization of alteplase alongside EVT for MCA M1 occlusion did not result in excessive ICH occurrences or clinical deterioration.

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.

Radiomics-Based Prediction of Collateral Status from CT Angiography of Patients Following a Large Vessel Occlusion Stroke.

A major driver of individual variation in long-term outcomes following a large vessel occlusion (LVO) stroke is the degree of collateral arterial circulation. We aimed to develop and evaluate machine-learning models that quantify LVO collateral status using admission computed tomography angiography (CTA) radiomics. We extracted 1116 radiomic features from the anterior circulation territories from admission CTAs of 600 patients experiencing an acute LVO stroke. We trained and validated multiple machine-learning models for the prediction of collateral status based on consensus from two neuroradiologists as ground truth. Models were first trained to predict (1) good vs. intermediate or poor, or (2) good vs. intermediate or poor collateral status. Then, model predictions were combined to determine a three-tier collateral score (good, intermediate, or poor). We used the receiver operating characteristics area under the curve (AUC) to evaluate prediction accuracy. We included 499 patients in training and 101 in an independent test cohort. The best-performing models achieved an averaged cross-validation AUC of 0.80 ± 0.05 for poor vs. intermediate/good collateral and 0.69 ± 0.05 for good vs. intermediate/poor, and AUC = 0.77 (0.67-0.87) and AUC = 0.78 (0.70-0.90) in the independent test cohort, respectively. The collateral scores predicted by the radiomics model were correlated with (rho = 0.45, p = 0.002) and were independent predictors of 3-month clinical outcome (p = 0.018) in the independent test cohort. Automated tools for the assessment of collateral status from admission CTA-such as the radiomics models described here-can generate clinically relevant and reproducible collateral scores to facilitate a timely treatment triage in patients experiencing an acute LVO stroke.

Characterizing coma in large vessel occlusion stroke.

Coma is an unresponsive state of disordered consciousness characterized by impaired arousal and awareness. The epidemiology and pathophysiology of coma in ischemic stroke has been underexplored. We sought to characterize the incidence and clinical features of coma as a presentation of large vessel occlusion (LVO) stroke. Individuals who presented with LVO were retrospectively identified from July 2018 to December 2020. Coma was defined as an unresponsive state of impaired arousal and awareness, operationalized as a score of 3 on NIHSS item 1a. 28/637 (4.4%) patients with LVO stroke were identified as presenting with coma. The median NIHSS was 32 (IQR 29-34) for those with coma versus 11 (5-18) for those without (p < 0.0001). In coma, occlusion locations included basilar (13), vertebral (2), internal carotid (5), and middle cerebral (9) arteries. 8/28 were treated with endovascular thrombectomy (EVT), and 20/28 died during the admission. 65% of patients not treated with EVT had delayed presentations or large established infarcts. In models accounting for pre-stroke mRS, basilar occlusion location, intravenous thrombolysis, and EVT, coma independently increased the odds of transitioning to comfort care during admission (aOR 6.75; 95% CI 2.87,15.84; p < 0.001) and decreased the odds of 90-day mRS 0-2 (aOR 0.12; 95% CI 0.03,0.55; p = 0.007). It is not uncommon for patients with LVO to present with coma, and delayed recognition of LVO can lead to poor outcomes, emphasizing the need for maintaining a high index of suspicion. While more commonly thought to result from posterior LVO, coma in our cohort was similarly likely to result from anterior LVO. Efforts to improve early diagnosis and care of patients with LVO presenting with coma are crucial.

Identification of Anterior Large Vessel Occlusion Stroke During the Emergency Call: Protocol for a Controlled, Nonrandomized Trial.

Endovascular thrombectomy (ET), combined with intravenous thrombolysis if possible, is an effective treatment option for patients with stroke who have confirmed anterior large vessel occlusion (aLVO). However, ET is mainly limited to comprehensive stroke centers (CSCs), resulting in a lack of ET capacity in remote, sparsely populated areas. Most stroke networks use the "Drip and Ship" or "Mothership" strategy, resulting in either delayed ET or intravenous thrombolysis, respectively. This study protocol introduces the Leitstellen-Basierte Erkennung von Schlaganfall-Patienten für eine Thrombektomie und daraufhin abgestimmte Optimierung der Rettungskette (LESTOR) strategy, developed to optimize the preclinical part of the stroke chain of survival to improve the clinical outcome of patients with suspected aLVO stroke. This involves refining the dispatch strategy for identifying patients with acute aLVO stroke using a phone-based aLVO query. This includes dispatching emergency physicians and emergency medical services (EMS) to urban emergency sites, as well as dispatching helicopter EMS to remote areas. If a highly suspected aLVO is identified after a standardized aLVO score evaluation during a structured examination at the emergency scene, prompt transport to a CSC should be prioritized. The LESTOR study is a controlled, nonrandomized study implementing the LESTOR strategy, with a stepped-wedge, cluster trial design in 6 districts in southwest Germany. In an interprofessional, iterative approach, an aLVO query or dispatch protocol intended for use by dispatchers, followed by a coordinated aLVO examination score for use by EMS, is being developed, evaluated, and pretested in a simulation study. After the training of all participating health care professionals with the corresponding final aLVO query, the LESTOR strategy is being implemented stepwise. Patients otherwise receive usual stroke care in both the control and intervention groups. The primary outcome is the modified Rankin Scale at 90 days in patients with stroke receiving endovascular treatment. We will use a generalized linear mixed model for data analysis. This study is accompanied by a cost-effectiveness analysis and a qualitative process evaluation. This paper describes and discusses the protocol for this controlled, nonrandomized LESTOR study. Enrollment was completed in June 2023. Data analysis is ongoing and the first results are expected to be submitted for publication in 2024. The project started in April 2020 and will end in February 2024. We expect that the intervention will improve the clinical outcome of patients with aLVO stroke, especially outside the catchment areas of CSCs. The results of the accompanying process evaluation and the cost-effectiveness analysis will provide further insights into the implementation process and allow for a better interpretation of the results. German Clinical Trials Register DRKS00022152; https://drks.de/search/de/trial/DRKS00022152. DERR1-10.2196/51683.

Association Between MR‐Based Thrombus Imaging Characteristics and Endovascular Therapy Outcome in Acute Ischemic Stroke: A Systematic Review and Meta‐Analysis

Background Prediction of successful revascularization and achieving a favorable functional outcome may help determine the optimal treatment strategy and improve the management of stroke. A growing body of literature has implicated a predictive value for thrombus imaging characteristics for stroke outcomes. Methods We conducted an electronic search using PubMed, Ovid MEDLINE, and EMBASE, previously published meta‐analyses, and systematic review studies that intervened by endovascular thrombectomy or intravenous thrombolysis following large vessel occlusion stroke from 2000 to 2023 and involved magnetic resonance‐based thrombus imaging, then screened 2007 studies against our eligibility criteria. We extracted the enrollees’ characteristics and the association between clot features and radiological and functional outcome measures. Results Thirty‐three studies were found eligible, with a total number of 6902 enrollees. Susceptibility vessel sign was found in 3531 subjects (51.2%). Nine studies involved only the administration of intravenous thrombolysis, whereas 24 studies intervened by endovascular thrombectomy. Seventeen studies found at least an association between thrombus imaging characteristics and successful revascularization, whereas the others reported no association. only 13 studies found at least one thrombus characteristic associated with functional outcome, while the others showed no association between the thrombus characteristics and functional outcome after stroke. Pooled meta‐analysis of studies that involved endovascular thrombectomy with or without intravenous thrombolysis showed a statistically significant association between the presence of susceptibility vessel sign and both successful reperfusion (odds ratio [OR]: 1.57 [1.09–2.27]; P = 0.02) and favorable functional outcome (OR: 1.76 [1.17–2.66]; P = 0.007). Conclusion The presence of susceptibility vessel sign on magnetic resonance‐based clot imaging was associated with functional outcome and successful reperfusion following thrombectomy.

Methylprednisolone as Adjunct to Endovascular Thrombectomy for Large-Vessel Occlusion Stroke

It is uncertain whether intravenous methylprednisolone improves outcomes for patients with acute ischemic stroke due to large-vessel occlusion (LVO) undergoing endovascular thrombectomy. To assess the efficacy and adverse events of adjunctive intravenous low-dose methylprednisolone to endovascular thrombectomy for acute ischemic stroke secondary to LVO. This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 82 hospitals in China, enrolling 1680 patients with stroke and proximal intracranial LVO presenting within 24 hours of time last known to be well. Recruitment took place between February 9, 2022, and June 30, 2023, with a final follow-up on September 30, 2023. Eligible patients were randomly assigned to intravenous methylprednisolone (n = 839) at 2 mg/kg/d or placebo (n = 841) for 3 days adjunctive to endovascular thrombectomy. The primary efficacy outcome was disability level at 90 days as measured by the overall distribution of the modified Rankin Scale scores (range, 0 [no symptoms] to 6 [death]). The primary safety outcomes included mortality at 90 days and the incidence of symptomatic intracranial hemorrhage within 48 hours. Among 1680 patients randomized (median age, 69 years; 727 female [43.3%]), 1673 (99.6%) completed the trial. The median 90-day modified Rankin Scale score was 3 (IQR, 1-5) in the methylprednisolone group vs 3 (IQR, 1-6) in the placebo group (adjusted generalized odds ratio for a lower level of disability, 1.10 [95% CI, 0.96-1.25]; P = .17). In the methylprednisolone group, there was a lower mortality rate (23.2% vs 28.5%; adjusted risk ratio, 0.84 [95% CI, 0.71-0.98]; P = .03) and a lower rate of symptomatic intracranial hemorrhage (8.6% vs 11.7%; adjusted risk ratio, 0.74 [95% CI, 0.55-0.99]; P = .04) compared with placebo. Among patients with acute ischemic stroke due to LVO undergoing endovascular thrombectomy, adjunctive methylprednisolone added to endovascular thrombectomy did not significantly improve the degree of overall disability. ChiCTR.org.cn Identifier: ChiCTR2100051729.

Neurological Improvement by One-Thirds Is Associated With Early Recanalization in Stroke With Large Vessel Occlusion.

A proportion of large vessel occlusion strokes demonstrate early recanalization, obviating the initial intention to proceed to endovascular thrombectomy. Neurological improvement is a possible surrogate marker for reperfusion. We aimed to determine the optimal threshold of neurological improvement, as defined by the National Institutes of Health Stroke Scale (NIHSS), which best associates with early recanalization. We retrospectively analyzed consecutive patients with large vessel occlusion transferred from primary stroke centers to a tertiary comprehensive stroke center in Melbourne, Australia, for possible endovascular thrombectomy from January 2018 to December 2022. Absolute and percentage changes in NIHSS between transfer, as well as other definitions of neurological improvement, were compared using receiver operating characteristic curve analysis for association with recanalization as defined by the absence of occlusion in the internal carotid artery, middle cerebral artery (M1 or M2 segments), or basilar artery on repeat vascular imaging. Six hundred and fifty-four transferred patients with large vessel occlusion were included in the analysis: mean age was 68.8±14.0 years, 301 (46.0%) were women, and 338 (52%) received intravenous thrombolytics. The proportion of extracranial internal carotid artery, intracranial internal carotid artery, M1, proximal M2, and basilar artery occlusion was 18.8%, 13.6%, 48.3%, 15.0%, and 4.3%, respectively, on initial computed tomography angiogram. Median NIHSSprimary stroke center and NIHSScomprehensive stroke center scores were 15 (interquartile range, 9-18) and 13 (interquartile range, 8-19), respectively. Early recanalization occurred in 82 (13%) patients. NIHSS reduction of ≥33% was the best tradeoff between sensitivity (64%) and specificity (83%) for identifying recanalization. NIHSS reduction of ≥33% had the highest discriminative ability to predict recanalization (area under the curve, 0.735) in comparison with other definitions of neurological improvement. One-third neurological improvement between the primary hospital and tertiary center was the best predictor of early recanalization.

Abstract WP170: Patients With Cerebral Microbleeds Are More Likely to Have Poor Collaterals at the Time of Mechanical Thrombectomy

Introduction: Collateral cerebrovasculature is important for the survival of penumbral tissue in patients with large vessel occlusive (LVO) stroke, and adequate collateralization is associated with favorable outcomes. The presence of cerebral microbleeds (CMB) have been implicated in vessel wall remodeling and impaired vasoreactivity. We investigated whether the presence of deep and/or lobar CMB predicts poor collateral recruitment in patients with LVO stroke who underwent thrombectomy (MT). Methods: We performed a retrospective, single-center study of adults who presented with LVO stroke and had MT between January 2012-June 2020. CT angiography of head prior to MT was used to assess collateral status with poor status defined as ≤50% filling and good status as &gt;50% filling. CMBs were assessed using T2*-weighted gradient echo or susceptibility weighted magnetic resonance images. Location of CMB was further characterized as deep vs. lobar using consensus definitions. Poor stroke outcome was defined as modified Rankin Scale (mRS) ≥3 at 90 days. Multivariable logistic regressions were performed to evaluate the associations between CMB, CMB types (lobar, deep, lobar+deep) and poor collaterals after adjusting for vascular risk factors. Results: Consecutive 151 subjects were included (mean age 68±15 years, 47% women), with a median NIHSS of 18. CMB were identified in 57 subjects (37.4%). Of these, 20.5% had lobar CMB, 5.3% had deep CMB and 11.9% had combined lobar &amp; deep CMB. Patients with CMB had higher odds of having poor collaterals compared to those without CMB (OR 1.56, 95% CI 1.09-2.23, P=0.015). The association of CMB with poor collaterals was strongest in patients with combined lobar &amp; deep CMB (OR 4.78, 95% CI 1.43-15.93, P=0.011), compared with those with exclusively deep CMB (OR 2.78, 95% CI 0.44-17.62, P=0.278) or lobar CMB (OR 0.52, 95% CI 0.19-1.38, P=0.188). Patients with poor collaterals were more likely to have poor outcome compared with those with good collaterals (48.4% vs. 31.0%, P=0.03). Conclusion: Cerebral microbleeds are independently associated with poor collateral recruitment when adjusted for traditional vascular risk factors. Further study is warranted to elucidate the differential effects of CMB types on collateral recruitment.

Abstract WMP9: Comparative Analysis of Endovascular Treatment Outcomes in Acute Large Vessel Occlusion Strokes: Intracranial Atherosclerotic vs. Non- Intracranial Atherosclerotic Occlusions

Introduction: Intracranial atherosclerotic disease (ICAD) is a common cause of ischemic stroke worldwide. We assessed the clinical outcomes of endovascular treatment in acute large vessel occlusion (LVO) strokes caused by ICAD and compared them with large vessel occlusion strokes not associated with intracranial atherosclerosis (non-ICAD LVO). Methods: Our study comprised 1390 adult patients diagnosed with LVO stroke that underwent endovascular therapy at Rhode Island Hospital from July 2015 to March 2023 and data collected retrospectively. Among these, 68 patients exhibited Intracranial Atherosclerotic Disease Large Vessel Occlusion (ICADLVO), while 1322 individuals were categorized as non-ICADLVO. In the ICADLVO group, 23 out of 68 patients underwent angioplasty, whereas 38 patients received stenting. We aim to compare treatment outcomes, including recurrent in-hospital large vessel occlusion, disability, and mortality between these two distinct groups, while also assessing demographic characteristics and medical risk factors. T-Test, Chi square and fisher’s exact tests were used for the comparison of groups. Results: The study findings highlight significant differences between the ICADLVO group and the non-ICADLVO group. The ICADLVO group had younger age (mean 66.6 ± 12.64 vs. 71.92 ± 14.56, p &lt; 0.001) , higher proportion of individuals with Asian ethnicity (5.2% vs. 0.8%, p = 0.019), higher incidence of prior strokes (43.3% vs. 23.9%, p=0.000), higher prevalence of smokers (35.6% vs. 22.7%, p = 0.022), and a lower association with known atrial fibrillation (23.9% vs. 42.3%, p=0.003) compared to the non-ICADLVO group. Additionally, the ICADLVO group had a higher occurrence of recurrent large vessel occlusion during hospitalization (11.8% vs. 4%, p = 0.008). This analysis finds no significant difference in good 90-dayfunctional outcome (mRS &lt;= 2) between the ICADLVO and NON-ICADLVO groups (OR = 0.62, 95% CI 0.34-1.13, p=0.118). Conclusion: Our study showed a higher incidence of recurrent large vessel occlusion during hospitalization in the ICADLVO group following endovascular therapy. However, we did not observe any statistically significant differences in long-term outcomes, including measures of disability and mortality.

Abstract TMP36: Anatomical Predictors of Gastrostomy Tube Placement After Large Vessel Occlusion Ischemic Stroke

Dysphagia is a common neurologic deficit after ischemic stroke; as a result, patients often require percutaneous endoscopic gastrostomy (PEG) tube placement for safe maintenance of sufficient caloric intake. Right hemispheric strokes have previously been associated with post-stroke dysphagia. We examined whether topographic locations of post-stroke diffusion-weighted MRI (DWI) lesions associated with the need for placement of PEG tube. A registry of 898 patients evaluated for acute treatment of suspected large vessel occlusion (LVO) stroke was used. 65 patients underwent post-stroke PEG placement, and 65 additional patients were selected as propensity matches based on age, baseline NIH Stroke Scale score, and recanalization status. Binary masks of 24-to-72-hour post-stroke DWI lesions were co-registered to standard template space. Voxel-based lesion symptom mapping (V2.6), rewritten to perform logistic regression at each voxel, was used to generate statistical maps of lesion contribution to PEG placement. Uncorrected t-statistic maps demonstrated voxels in the right frontal, parietal, and temporal regions were associated with post-stroke PEG placement. Upon controlling for age and/or recanalization status, lesions in the right parietal lobe were associated with need for PEG. After controlling for lesion volume, this association weakened; once all variables were controlled for, there were no topographical regions associated with PEG placement. In this limited series, there is not a topographic region on post-stroke diffusion MRI that is significantly associated with need for PEG placement in patients with LVO stroke after controlling for appropriate covariates. PEG tube requirement may be a composite outcome, dependent on various inputs notably including lesion volume.

Abstract 54: Investigating the Relationship Between Reperfusion and Cerebral Edema Using Novel Cerebrospinal Fluid and Net Water Uptake Biomarkers

Introduction: Studies show that successful reperfusion after large-vessel occlusion (LVO) stroke can lead to reduced mass effect and midline shift (MLS). However, MLS typically occurs late in the edema cascade and only develops in approximately half of patients treated with endovascular thrombectomy (EVT). This study aimed to explore the connection between reperfusion and cerebral edema in more detail, utilizing CSF volumetrics and tissue water concentration. Methods: Using a deep-learning algorithm, we measured cerebrospinal fluid (CSF) volumes and their interhemispheric ratio on CT images at baseline, 24 hours, and 72 hours following a stroke. Automated segmentation of infarct regions on follow-up scans was used to measure net water uptake (NWU), the ratio of density within infarcted tissue relative to the mirrored contralateral region. The change in edema markers from baseline to 24 hours, as well as 72-hour NWU, were dichotomized at the median into significant edema growth and low/moderate edema growth. Reperfusion status was assessed by the modified thrombolysis in cerebral infarction score. Results: This study included 137 patients (mean age 69 ± 15, mean NIHSS 14) with LVO stroke who underwent EVT. There was a gradual decrease in the CSF ratio change at 24 and 72 hours with lower (worse) TICI scores (p=0.023 and p&lt;0.001, respectively, Figure 1A). After adjusting for age, admission NIHSS, and ASPECT score, successful reperfusion was associated with lower odds of significant edema by CSF ratio change at 24 hours (aOR 0.25, 95% CI 0.1-0.6, p=0.002) and NWU at 72 hours (aOR 0.26, 95% CI 0.1-0.7, p=0.01) when compared with unsuccessful reperfusion. Lower CSF ratio growth and NWU at 24 hours were significantly associated with lower global disability measured by the modified Rankin Scale at 90 days (p&lt;0.001 and p=.008, respectively, Figure 1B). Conclusions: Successful reperfusion is associated with reduced edema and better functional outcomes following thrombectomy.

Functional long-term outcome following endovascular thrombectomy in patients with acute ischemic stroke

Endovascular thrombectomy (EVT) is the most effective treatment for acute ischemic stroke caused by large vessel occlusion (LVO). Yet, long-term outcome (LTO) and health-related quality of life (HRQoL) in these patients have rarely been addressed, as opposed to modified Rankin scale (mRS) recordings. We analysed demographic data, treatment and neuroimaging parameters in 694 consecutive stroke patients in a maximum care hospital. In 138 of these patients with respect on receipt of written informed consent, LTO and HRQoL were collected over a period of 48 months after EVT using a standardised telephone survey (median 2.1 years after EVT). Age < 70 years (OR 4.82), lower NIHSS on admission (OR 1.11), NIHSS ≤ 10 after 24 h (OR 11.23) and complete recanalisation (mTICI3) (OR 7.79) were identified as independent predictors of favourable LTO. Occurrence of an infection requiring treatment within the first 72 h was recognised as a negative predictor for good long-term outcome (OR 0.22). Patients with mRS > 2 according to the telephone survey more often had complaints regarding mobility, self‐care, and usual activity domains of the HRQoL. Our results underline a sustainable positive effect of effective EVT on the quality of life in LVO stroke. Additionally, predictive parameters of outcome were identified, that may support clinical decision making in LVO stroke.

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.