Large Vessel Occlusion Stroke Research Articles

Proteomic analysis of jugular venous blood in acute large vessel occlusion stroke with futile recanalization

Futile recanalization (FR) after endovascular treatment (EVT) remains a significant challenge for acute ischemic stroke (AIS) with large vessel occlusion (LVO). The pathogenesis of FR has not been well elucidated. We prospectively enrolled anterior circulation LVO-AIS patients who achieved successful recanalization after EVT. The jugular venous blood ipsilateral to stroke was collected before and immediately after recanalization. Plasma proteomic analysis based on liquid chromatography-mass spectrometry was performed using data-independent acquisition method. Differentially expressed proteins (DEPs) among patients with or without FR in the whole or propensity score matching (PSM) cohorts were screened according to the absolute value of fold change ≥1.5 and P value <0.05. We identified 104 and 34 DEPs between patients with or without FR in the whole cohort and PSM cohort, respectively. Bioinformatic analysis indicated that the identified proteins were primarily related to specific biological processes including immune response, complement activation, oxidative stress, lipid metabolism, protein ubiquitylation as well as autophagy, suggesting that these may be mechanisms in FR pathogenesis. Collectively, we discovered proteins that may be potential research targets for FR. The combination of proteomic and bioinformatic analysis could provide a better understanding of the pathogenesis of FR in a comprehensive manner.

Simulated Patients to Demonstrate Common Stroke Syndromes: Accurate and Convincing

Introduction: Stroke detection in the preclinical setting is challenging, resulting in more than 1/3 of missed strokes by emergency medical services (EMS) personnel. Recently, prehospital identification of anterior large vessel occlusion (LVO) stroke has come into focus. Cortical signs have a high predictive value for the presence of LVO stroke but are often missed. Simulated patients (SPs) could be an excellent tool to train EMS personnel in the evaluation of stroke syndromes with cortical symptoms, but it has not been studied whether they can simulate these important signs convincingly. The main objective of this study was, thus, to examine whether SPs can simulate stroke syndromes and symptoms so that stroke experts can identify them correctly and reliably, applying the NIH stroke scale (NIHSS). Methods: Lay actors were trained to simulate one of 8 stroke syndromes either typical of a lacunary stroke or of an anterior LVO stroke and then videotaped during an examination according to the NIHSS. Stroke experts were asked to rate each item of the NIHSS based on the videos, determine which stroke syndrome was being demonstrated, and rate the quality of simulation. The primary outcome was the correct identification of the target stroke syndrome by the expert raters. Secondary outcomes were the agreement of the rating of the NIHSS score with the target NIHSS score and the expert raters’ assessment of the quality of simulation. Results: Seven of eight syndromes were rated correctly by at least twelve of fifteen raters and the mean rated NIHSS score was within one point of the target score for six of eight syndromes. The mean rating for the quality of simulation was between 3.54 and 3.98 (as rated on a scale from 1 to 4) for each syndrome. Discussion/Conclusion: SPs are capable of simulating acute stroke symptoms and syndromes accurately and convincingly. Thus, they represent a great resource to improve educational interventions that improve stroke recognition.

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.

Effect of Cerebral Small Vessel Disease Burden on Infarct Growth Rate and Stroke Outcomes in Large Vessel Occlusion Stroke Receiving Endovascular Treatment.

This study aimed to investigate the association between cerebral small vessel disease (CSVD) burden and infarct growth rate (IGR) in patients with large vessel occlusion (LVO) stroke who underwent endovascular treatment (EVT). A retrospective analysis was conducted on a cohort of 495 patients with anterior circulation stroke who received EVT. CSVD burden was assessed using a CSVD score based on neuroimaging features. IGR was calculated from diffusion-weighted imaging (DWI) lesion volumes divided by the time from stroke onset to imaging. Clinical outcomes included stroke progression and functional outcomes at 3 months. Multivariate analyses were performed to assess the relationship between CSVD burden, IGR, and clinical outcomes. The fast IGR group had a higher proportion of high CSVD scores than the slow IGR group (24.4% vs. 0.8%, p < 0.001). High CSVD burden was significantly associated with a faster IGR (odds ratio [95% confidence interval], 26.26 [6.26-110.14], p < 0.001) after adjusting for confounding factors. High CSVD burden also independently predicted stroke progression and poor functional outcomes. This study highlights a significant relationship between CSVD burden and IGR in LVO stroke patients undergoing EVT. High CSVD burden was associated with faster infarct growth and worse clinical outcomes.

Large‐Vessel Occlusion Stroke Knowledge and Training for Stroke Severity Assessment Among Emergency Medical Services Personnel in the United States

BACKGROUND Prehospital identification of large‐vessel occlusion (LVO) stroke facilitates the development of a regional triage protocol that could lead to an improvement in intrahospital and interhospital workflows. This requires stroke education of emergency medical services (EMS) personnel to improve stroke recognition, severity assessment, and prenotification. However, the current state of EMS personnel's knowledge of LVO stroke, their training for stroke severity assessment, and their preferences for educational methods are unknown. We conducted a nationwide EMS survey across the United States to glean insights that can inform and customize future EMS educational efforts. METHODS The Society of Vascular and Interventional Neurology, in collaboration with EMS World , created an online questionnaire for EMS personnel. It included 12 multiple‐choice and free‐response questions designed to test participants’ clinical knowledge of LVO, knowledge of stroke center certification levels, prior LVO educational experiences, preferences for educational content delivery, and perspectives on prehospital hurdles to stroke care. All subscribers of EMS World received a survey link via email. RESULTS Of the 38 486 subscribers of EMS World , the survey email was opened by 1830, of whom 1107 completed the survey across all states in the United States, with a response rate of 2.9%. Most of the respondents identified themselves as paramedics/emergency medical technicians (91%). The number of patients with stroke that survey participants transported in the past year was &lt;10 for 618 (56%). Only 285 (26%) participants answered both LVO knowledge questions correctly, and only 128 (12%) respondents correctly identified all types of stroke centers with thrombectomy capability. A total of 362 EMS personnel (33%) denied receiving training to perform LVO severity assessment. Respondents who received training to perform an LVO scale demonstrated nearly twice the prevalence of LVO knowledge (30.6% versus 15.7%; prevalence ratio, 1.94 [95% CI, 1.50–2.53]) than respondents who did not receive training. The top hurdle to prehospital LVO education was identified as the lack of standardized LVO training by 535 (48%) respondents. CONCLUSIONS EMS providers in the United States reported inadequate LVO training and demonstrated gaps in knowledge of LVO, stroke severity scales, and stroke center levels. Systematic efforts to enhance and standardize the educational content and delivery of LVO education are needed.

Abstract 300: An Opportunity for Awareness: The International Academy of Emergency Medical Dispatch's Stroke Diagnostic Tool is Predictive, but Underutilized, for Hospital Confirmed Large Vessel Occlusion Strokes

Background: Accurate identification of ischemic stroke from large vessel occlusion (LVO) by 9-1-1 professionals can facilitate prompt patient transfer to stroke centers that perform endovascular thrombectomy. We sought to determine the proportion of LVO stroke patients that were evaluated using the Medical Priority Dispatch System's (MPDS) Stroke Diagnostic Tool (SDxT). Methods: Structured, retrospective review of our institution’s stroke registry, EMS Records, and dispatch codes between January 1, 2019 and November 30, 2022. Inclusion: Adult (age &gt;17), accessed the 9-1-1 system and transported by a ground EMS agency for an acute stroke. Exclusion: age &lt;18, pregnant, incarcerated, cases with missing 9-1-1 data, and intracranial hemorrhage. Two trained/monitored abstractors, blinded to the study purpose, used a standardized data collection tool/dictionary to extract data. Data included MPDS codes, SDxT outcome, EMS care, demographics, hospital NIHSS score, advanced imaging, tPA administration, and mechanical thrombectomy. Primary outcome: the proportion of LVO cases that had an acute stroke (28 protocol) dispatch code. Secondary outcome: the proportion of LVO cases that that a SDxT score indicating “strong or clear evidence of a stroke”. We report proportions and 95% CI's as appropriate. Results: 60 patients met inclusion/exclusion criteria. 11/60, 18.3 % (95%CI= 10.4, 30) of the patients had complete data and a LVO. 54% were male, the median (IQR) age was 69.5 (61.3-77.5), and the median (IQR) NIHSS was 16 (5-19.75). Primary outcome: 45.5 % (95% CI= 21.3.72.0) of the LVO’s were coded as an Acute Stroke by the 9-1-1 center. Of those, 3/5 utilized the stroke diagnostic tool, all 3 of these were determined to have "Clear Evidence of Stroke". Limitations: Retrospective, unlinked data, small number of LVO's. Conclusion: When utilized, the SDxT correctly identified all LVO’s. There is an opportunity to increase awareness and utilization of the SDxT by 9-1-1 centers. Future research should focus on identifying barriers to stroke recognition and provide additional tools to address the real-life challenges our 9-1-1 communications specialists face when rapidly assessing for an acute stroke over the phone.

Association of Chinese visceral adiposity index with clinical outcome in patients after endovascular thrombectomy

Background and purposeThe Chinese Visceral Adiposity Index (CVAI) is a reliable indicator of visceral adiposity dysfunction in the Chinese population. We aimed to evaluate the association between CVAI and clinical outcome in Chinese ischemic stroke patients who received endovascular thrombectomy (EVT). MethodsThis study retrospectively included patients with large vessel occlusive stroke receiving EVT treatment in 2 China stroke centers. Baseline CVAI was calculated after admission. Patients with a modified Rankin scale score ≥ 3 at 3 months after ischemic stroke were defined as poor outcome. Binary multivariate logistic regression models were utilized to explore the association between CVAI and the risk of 90-day unfavorable outcome. ResultsA total of 453 patients (mean age, 70.4 ± 12.1 years; 280 male) were included. During the 90-day follow-up, 236 (52.1 %) patients experienced poor outcome. After multivariable adjustment for potential confounders, increasing CVAI was associated with an increased risk of 90-day poor outcome (odds ratios, per-standard deviation increase: 1.521; 95 % confidence interval, 1.127−2.052; P = 0.006). Similar significant results were observed when the CVAI was analyzed as a categorical variable. Furthermore, the multiple-adjusted spline regression model showed an inverted J-shape association between CVAI and risk of unfavorable outcome (P = 0.048 for non-linearity). ConclusionsThis study demonstrated that CVAI is positively correlated with 90-day poor outcome in Chinese ischemic stroke patients after EVT.

Thrombus Attenuation Gradient Can Predict Successful First-Pass Recanalization Following Stentriever Thrombectomy

ObjectiveComputed tomographic angiography (CTA) derived thrombus enhancement characteristics can predict the first pass (FP) recanalization. In this study, we analyzed whether dynamic contrast kinetics with in the clot in multiphase CTA can predict first pass (FP) recanalization following stentriever thrombectomy. MethodsAcute large vessel occlusive stroke evaluated with multiphasic CTA and underwent stentriever thrombectomy (MT) were selected. Thrombus perviousness on various phases like arterial, venous and delayed phases were calculated. Additionally, thrombus attenuation gradient (TAG) defined as average attenuation difference between adjacent phases were also evaluated and correlated with successful FP outcome (mTICI>2b). ResultsOf the 69 patients, 32/69 (46 %) had successful FP recanalization (group 1) and 37/69 (53%) required more than one attempts (group 2). The TAG showed significant difference in the arterial-plain and venous-arterial phases. The early increase in TAG was seen in group 1 in the arterial-plain phase compared to group 2 (12.6 vs. 9, P value - 0.01), which plateaued in the venous-arterial phase for group 1, while it showed further increment in the group 2 (2.1 vs 5.1, P value - 0.02). A cut-off value of 9.2 HU for arterial-plain phase (P value 0.001) and 4.2 HU (P value 0.001) for venous-arterial phase was predictive of FP effect. Combining two metrics had odds ratio of 2.8 for FP recanalization (P value 0.035). The accuracy evaluated in a validation cohort yielded 74%. Other features including histology were not significant. ConclusionTAG evaluated from multiphase CT can predict the first pass effect in stentriever thrombectomy.

Abstract 251: Characterizing coma in patients presenting with large vessel occlusion stroke

Introduction 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. Methods 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 NIH Stroke Scale (NIHSS) item 1a. Results A total of 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&lt;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 modified Rankin Scale (mRS) score, basilar artery occlusion location, intravenous thrombolysis, and EVT, coma independently increased the odds of transitioning to comfort care during the admission (aOR 6.75; 95%CI 2.87,15.84; p &lt;0.001) and decreased the odds of 90‐day mRS 0‐2 (aOR 0.12; 95%CI 0.03,0.55; p=0.007). Conclusion 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, given the poor outcomes.

Large vessel occlusion prediction scale thresholds that are sensitive for DAWN Trial patients

Background Large vessel occlusion (LVO) prediction scales are used to triage prehospital suspected stroke patients with a high probability of LVO stroke to endovascular therapy centers. The sensitivities of these scales in the 6-to-24-h time window are unknown. Higher scale score thresholds are typically less sensitive and more specific. Knowing the highest scale score thresholds that remain sensitive could inform threshold selection for clinical use. Sensitivities may also vary between left and right-sided LVOs. Methods LVO prediction scale scores were retrospectively calculated using the National Institutes of Health Stroke Scale (NIHSS) scores of patients enrolled in the DAWN Trial. All patients had last known well times between 6 and 24 h, NIHSS scores ≥ 10, intracranial internal carotid artery or proximal middle cerebral artery occlusions, and mismatches between their clinical severities and infarct core volumes. Scale thresholds with sensitivities ≥ 85% were identified, along with scores ≥ 5% more sensitive for left or right-sided LVOs. Specificities could not be calculated because all patients had LVOs. Results A total of 201 out of 206 patients had the required NIHSS subitem scores. CPSS = 3, C-STAT ≥ 2, FAST-ED ≥ 4, G-FAST ≥ 3, RACE ≥ 5, and SAVE ≥ 3 were the highest thresholds that were still 85% sensitive for DAWN Trial LVO stroke patients. RACE ≥ 5 was the only typically used score threshold more sensitive for right-sided LVOs, though similar small differences were seen for other scales at higher thresholds. Conclusions Our findings likely represent the maximum sensitivities of the LVO prediction scales tested for ideal thrombectomy candidates in the 6-to-24-h time window because NIHSS scores were documented in hospitals during a clinical trial rather than in the prehospital setting. Patients with NIHSS scores &lt; 10 or more distal LVOs would lower sensitivities further. Selecting even higher scale thresholds for LVO triage would lead to many missed LVO strokes.

Abstract 158: Association between thrombus characteristics and endovascular therapy outcome in stroke: a systematic review and meta‐analysis

Introduction Background: Prediction of successful revascularization and achieving a favorable functional outcome may help to determine the optimal recanalization strategy and improve the management of stroke. A growing body of literature has implicated a prognostic value for thrombus imaging characteristics for stroke outcomes [1‐5]. 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 (EVT) or intravenous thrombolysis (IVT) following large vessel occlusion stroke from 2000‐2023 and involved MR‐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 (SVS) was reported in 3531 subjects (51.2%). Nine studies only involved the administration of IVT, while 24 studies intervened by EVT. Seventeen studies found at least an association between a thrombus imaging characteristic and successful recanalization while the others reported no association. On the other hand, only thirteen studies found at least an association between thrombus characteristics and functional outcome, while the rest thrombus characteristics showed no association with functional outcome. Pooled meta‐analysis of studies that involved EVT with or without preceding IVT showed a statistically significant association between the presence of SVS and both successful recanalization (RR: 1.57 [1.09 – 2.27]; P: 0.02) and favorable functional outcome (RR: 1.76 [1.17 – 2.66]; P: 0.007). Conclusion The presence of SVS on MR‐based clot imaging was associated with functional outcome and successful recanalization following thrombectomy.

Abstract 066: Mechanical Thrombectomy Access in Africa: A Mission Thrombectomy (MT‐2020 Plus) MT‐GLASS Study Sub‐Analysis

Introduction Despite the well‐established potent benefit of mechanical thrombectomy (MT) for large vessel occlusion (LVO) stroke, access to MT remains low globally, particularly in Africa. We compared the access to MT in Africa versus access in other regions of the globe. Methods Mission Thrombectomy conducted a survey in 75 countries between November 22, 2020, and February 28, 202 to assess the access to mechanical thrombectomy and its determinants. Mechanical thrombectomy access (MTA) was defined as the estimated proportion of patients with LVO receiving MT annually. The current MT operator availability was defined as ([current MT operators x 50/current annual number of estimated thrombectomy‐eligible LVOs] x 100) and the current MT center availability was defined as ([current MT centers x 150/current annual number of estimated thrombectomy‐eligible LVOs] x 100). Baseline survey responses in Africa versus the rest of the world were summarized using descriptive statistics. Between group differences in baseline characteristics were evaluated using the Wilcoxon rank‐sum test Results Of all 61 countries included in the final analysis, 14.8% (n=9) were from the African continent. Median MT access in Africa (0.4%) was about 10% of that of the rest of the world (4.9%). Country‐level summary characteristics of different determinants of MT access in Africa vs the rest of the world are presented in Table 1. Less than 50% of African countries (44.4%) have prehospital medical services, compared to 84.6% in the rest of the world (p‐value for comparison =0.007). In generalized linear models, LVO stroke patients in Africa had 90% lower odds of MT access when compared to the rest of the world (OR 0.10, 95%CI 0.04‐0.22). Conclusion Access to MT in Africa is extremely low and far below that of other regions of the globe. Public health interventions must be prioritized to increase access to MT in the continent of Africa.

Abstract 010: Technical Approaches for Intracranial Atherosclerotic Disease Large Vessel Occlusion Strokes

Introduction The optimal management strategy for large vessel occlusion strokes (LVOS) from intracranial atherosclerotic disease (ICAD) remains debated. We aimed to evaluate the efficacy and safety of various acute medical and endovascular management options in patients who underwent mechanical thrombectomy of an ICAD‐related occlusion. Methods Retrospective analysis of ICAD‐related LVOS of a prospective mechanical thrombectomy database at a comprehensive stroke center between November 2010‐May 2023. Endovascular intervention was defined as either angioplasty, stenting, or a combination of both. Acute management was divided into 5 groups: Group#1: proactive antiplatelets (patients who received antiplatelets prior to groin puncture without further endovascular intervention after initial reperfusion); Group#2: reactive antiplatelets (patients who received antiplatelets after groin puncture without further angioplasty and/or stenting after initial reperfusion), Group#3: proactive revascularization (patients treated with angioplasty and/or stenting after initial reperfusion), Group#4: reactive revascularization (patients treated with angioplasty and/or stenting after vessel re‐occlusion after initial reperfusion), and Group #5: rescue revascularization (patients with unsuccessful reperfusion and subsequent angioplasty and/or stenting). Results A total of 200 ICAD‐LVOS MT were identified. Baseline characteristics were comparable between the 5 groups. The rate of TICI2b‐3 final reperfusion was lower in Group 4, while the rate of TICI 2c‐3 final reperfusion was comparable among groups. The rates of in‐hospital re‐occlusion were high even in patients loaded with DAPT before puncture; the rates of re‐occlusion were lower in patients managed with intervention in a proactive manner (Group 3) when compared to those managed in a reactive manner (Group 4) (0% vs 27%, p= 0.005). In ordinal analysis, mRS scores were lowest in Groups 2 and 3.Safety outcomes were comparable with similar rates of symptomatic intracranial hemorrhage (sICH). Conclusion While limited by small subgroup sample size, medical management only was associated with relatively high rates of reocclusion, while proactive angioplasty/stenting with performed best. Symptomatic intracranial hemorrhage was low in medically treated patients. Further studies are warranted.

Abstract 223: Pre‐Thrombectomy Diagnosis of Large Vessel Occlusion with Underlying Intracranial Atherosclerotic Disease

Introduction Intracranial atherosclerotic disease (ICAD) is one of the leading causes of ischemic stroke. We sought to identify variables associated with ICAD underlying large vessel occlusion strokes (LVOS) to facilitate pre‐procedural diagnosis. Methods Retrospective analysis of a prospectively collected thrombectomy single comprehensive stroke center database. Inclusion criteria: anterior circulation occlusion involving the intracranial ICA, MCA‐M1/M2/M3 or ACA(A1‐A2‐A3). ICAD cases were matched for age and sex in a 1:1 ratio to non‐ICAD controls. Results A total of 348 patients were included in the analysis. Patients with ICAD more frequently presented with vascular risk factors. ICAD LVOS showed less frequent atrial fibrillation(AF)(4%vs31%,P=0.001), and lower baseline NIHSS(14vs17,P=0.002) compared to the non‐ICAD group. The ICAD group less frequently showed hyperdense vessel sign and territorial cortical infarcts, but presented more frequently borderzone, deep subcortical and bilateral infarcts on CT compared to the non‐ICAD group. ICAD strokes had higher ASPECTS, and more frequently had calcifications at the carotid siphon as well as multifocal intracranial stenosis on CTA. CTA collaterals scores were comparable between groups. The ICAD group had lower median infarct core volume (1vs12 ml;P&gt;0.001), Tmax&gt;4s (249vs276 ml;P&gt;0.003), and Tmax&gt;6s (97vs140 ml;P&lt;0.003) and higher Tmax&gt;4:6 s ratio (2vs1;P=0.007) on CTP compared to non‐ICAD group. On multivariable analysis, absence of AF, absence of cortical infarcts, presence calcium at ipsilateral carotid siphon, cerebrovascular stroke risk factors burden (DM‐HTN‐Hyperlipidemia‐smoking), borderzone infarcts either (superficial cortical or Internal deep border zone), and multifocal intracranial stenosis were independent factors associated with ICAD. The model (table 1) by AUC for the whole model had sensitivity of 88% [P=&lt;0.001,95%CI(0.84‐0.91)]. Conclusion In patients with anterior circulation LVO strokes, our study suggests that presence of CVS risk factors burden, calcium at carotid siphon, borderzone infract pattern, absence of territorial cortical infarct pattern, multifocal intracranial stenosis, and absence of AF were predictors for ICAD. Additional validation is warranted

Abstract 233: First‐line Techniques for Endovascular Therapy of Primary Distal medium Vessel Occlusion Stroke: A Matched Analysis

Introduction Previous studies did not show a difference in terms of safety and efficacy among first‐line stent retriever (SR), contact aspiration (CA), or combined techniques for proximal large vessel occlusion strokes. However, the optimal reperfusion therapy in patients with primary distal medium vessel occlusion (DMVO) strokes is uncertain. We aimed to compare the clinical and procedural outcomes among first‐line SR, CA and combined techniques in patients with primary DMVO. Methods This is a retrospective analysis of a prospectively maintained database from 14 comprehensive stroke centers in the US and Europe. Patients were included if they had a primary DMVO stroke due to MCA‐M3/M4, ACA‐A1/A2‐3, or PCA‐P1/P2‐3 and underwent mechanical thrombectomy with first‐line SR, CA, or combined technique. The primary outcome was FPE defined as eTICI 2c/3 on the first pass. Secondary outcomes included mFPE defined as eTICI 2b/3 on the first pass, successful reperfusion defined as eTICI 2b/3 at the end of the procedure. Clinical outcomes included 90‐day mRS0‐1 and 90‐day mRS0‐2. Safety measures included procedural complications, symptomatic intracranial hemorrhage (sICH), and 90‐day mortality. The secondary analysis aimed to identify the procedural and clinical outcomes in 3 matched cohorts: (SR vs. CA), (SR vs. combined technique), and (CA vs. combined technique). Results A total of 365 patients were eligible for analysis; 38.1% were female, with a mean age of 69.3 years and a median NIHSS score of 11 [7‐18]. The first‐line SR group consisted of n=74 (20.3%), CA group n=142 (38.9%), and combined technique group n=149 (40.8%). Patients with first‐line SR or combined technique had a lower median NIHSS score, less frequent MCA‐M3 segment occlusion, and less usage of the rescue strategy compared to those with first‐line CA, P&lt;0.05. Patients with first‐line CA had less frequent BGC usage and lower rates of FPE and procedural complications compared to first‐line SR or combined technique, P&lt;0.05. Successful reperfusion at the end of the procedure was similar among the 3 groups (Figure). On multivariable analysis, there was no difference in terms of primary, secondary outcomes, or safety measures among the 3 first‐line techniques, except for higher procedural complications in patients who underwent the first‐line combined technique compared to those with first‐line CA (aOR 3.66, 95% CI [1.25‐10.75], P=0.02). The matched analyses did not show any difference in the primary outcome: (1) (SR, n=54 vs. CA, n=54) FPE; 31.5% vs. 26.9%, P=0.61, aOR 1.33, 95% CI [0.57‐3.11], P=0.52), (2) (SR, n=72 vs. combined technique, n=54) FPE; 37.5% vs. 31.9%, P=0.48, aOR 1.48, 95% CI [0.73‐3.03], P=0.28), and (3) (CA, n=109 vs. combined technique, n=109) FPE; 24.1% vs. 25.7%, P=0.78, aOR 0.94, 95% CI [0.50‐1.74], P=0.84). Similarly, there was no difference in terms of secondary outcomes and safety measures. Conclusion Our study suggests that in patients with primary DMVO, first‐line SR, CA, and combined techniques have a similar rate of FPE with no differences in final reperfusion or clinical outcomes. Randomized clinical trials are warranted

Abstract 057: Recent Trends and Outcomes of Hospital Transfer for Endovascular Stroke Treatment in U.S.

Introduction Optimal triage strategies for patients suspected of acute ischemic stroke due to large vessel occlusion remains debated. Whereas secondary analyses from randomized trials have demonstrated no differences in thrombectomy outcomes in transferred vs direct presentation strokes (1‐2), several registry based cohorts reported worse functional outcomes in those with transferred presentation mode (3‐4). We explored the US national claims database to explore trends in presentation (transferred vs direct presentation) and their outcomes for EVT hospitalizations using a nationally representative sample. Methods National Inpatient Sample database was retrospectively explored from 2016 to 2020 for stroke hospitalizations with EVT. Outcomes were compared for EVT hospitalizations with direct vs transferred presentation at discharge. Outcomes included favorable discharge disposition (home without assistance); in‐hospital mortality; and radiographic intracranial hemorrhage (ICH). Results Among 100,865 admissions with EVT, 32,685 (32.4%) presented following hospital transfer for thrombectomy. The utilization of EVT in US nearly doubled during between 2017 to 2020, and the proportion of in‐hospital transfer for EVT remained unchanged during this period. White race, higher baseline NIHSS, hospital size and status (urban teaching vs rural), and hospital location were independent predictors of transferred status for EVT. Transferred status was significantly associated with a lower likelihood of achieving favorable outcome (OR: 0.80, CI: [0.72, 0.89], P&lt;0.001) and a higher likelihood of ICH (1.18 [1.07, 1.31], P=0.001), whereas no differences were observed in early mortality following transferred vs direct presentation mode (1.07 [0.93, 1.23], P=0.33). Conclusion Nearly one in 3 EVTs in US is performed in patients presenting following transfer from another acute care hospital. Transferred presentation status was associated with worse clinical outcomes following EVT in a real‐world setting. Future studies are needed to determine the optimal triage strategies for patients suspected of harboring large vessel occlusion strokes.

Abstract 278: Patterns of Mechanical Thrombectomy for Stroke Before and After the 2015 Pivotal Trials:5 Years Follow‐up

Introduction The 2015 American Heart Association Guidelines recommended mechanical thrombectomy with stent‐retriever devices. A prior published analysis of national trends after one year in mechanical thrombectomy use and outcomes for stroke before and after publication of the 2015 US guideline update showed improved functional outcomes and lower peri‐procedural mortality. We analyze the national trends in mechanical thrombectomy use and outcomes for stroke five years after publication of the US guideline update. Methods We analyzed the National Inpatient Sample from 2012‐2019. ICD‐9 and ICD‐10 codes identified Ischemic stroke and mechanical thrombectomy patients. Similar to the previous study, discharge to home was the primary efficacy outcome measure in this study since it strongly correlates with mild degree of disability at discharge and 3 months post‐stroke. Safety outcomes include in‐hospital medical complications and mortality. We utilized multivariate logistic regression to assess outcomes. Results From 2012‐2019, 4,003,405 individuals with a diagnosis of ischemic stroke were recorded, 103,605 (2.6%) of which were treated with mechanical thrombectomy, proportionally increased from 4,910/452,905 (1.1%) in 2012 to 26,365/552,780 (4.8%) in 2019. The proportion of endovascular thrombectomy performing hospitals nearly doubled during the study period from 2012 (295/4,378; 6.7%) to 2019 (582/4,568; 12.7%). Odds of a mild disability outcome increased from 16% to 20%, OR 0.65 (0.57, 0.74), while mortality decreased from 15% to 12%, OR 0.69 (0.61, 0.78). Compared with 2012‐2014, the 2015‐2019 cohort showed increased odds of ICH and shock while the odds of DVT, pulmonary embolism, pneumonia, and UTI were significantly lower. The presence of septicemia, shock, and cardiac arrest were unchanged. Conclusion The number of large vessel occlusion stroke patients receiving mechanical thrombectomy treatment in the United States is increasing rapidly each year after the 2015 US guideline update. As the use of mechanical thrombectomy expands, included patients have more medical complications at baseline, but experience fewer complications, peri‐procedural mortality and overall improved outcomes.

Abstract 218: Evaluating Thrombectomy Candidacy in Large Core Strokes: Lessons from the SELECT2 Trial at Our Institution

Introduction Reperfusion therapy for patients with large vessel occlusion stroke includes thrombolytics and mechanical thrombectomy. Candidacy for thrombectomy depends on patient factors under active investigation. Historically, patients with large strokes have been excluded from major trials evaluating thrombectomy due to concern that thrombectomy would pose considerable risk with limited benefit. However, new evidence from the Select‐2 Trial found improved modified Rankin scale scores and higher rates of functional independence at 90 days following large stroke in patients who underwent thrombectomy versus medical therapy alone. We explored if patients presenting with large stroke at our institution resemble those in the Select‐2 Trial and, how many previously excluded patients could have possibly benefitted from thrombectomy. Methods Patients presenting as a code stroke at our institution from 1/2022 to 7/2022 were retrospectively analyzed. Large strokes, defined as CTP volume greater than 50mL, were identified. Background information included age, sex, race, and prior stroke. Regarding patient stroke presentation, the following data were gathered: NIHSS, LVO status, CTA results, CTP, tPA, thrombectomy status, TICI score, and discharge status. Our patients included in this study were compared to the patients included the Select‐2 Trial. Mortality rates and NIHSS at discharge were compared between thrombectomized and non‐thrombectomized patients at our institution. Results Of the 365 code strokes activated at our institution during the study period, 26 met criteria for a large stroke. Of those 26, 13 met all criteria for inclusion in SELECT‐2. Only 9 of the 26 patients received thrombectomy, including 7 of 13 patients otherwise meeting SELECT‐2 criteria. 6 patients were excluded from thrombectomy who would have met criteria for SELECT‐2. Of the 9 who underwent thrombectomy, one expired, and the average NIHSS calculated from physical exam at discharge of surviving patients was 13. Of the 17 who did not undergo thrombectomy, seven expired and the average NIHSS at discharge was 19.4. Of large stroke patients, average age was 69.5 years (SD 11.0), similar to Select‐2 (median age 66). Average NIHSS at presentation was 19 (SD 6.55), similar to Select 2. Compared to SELECT2 enrollment, our patients were more likely to be female (50% vs 41%), Black (50% vs 25%), have a history of prior stroke (38% vs. 9%). LVO was identified on 23 of 26 patients. Of these 23, 17 MCA, 3 ACA, 6 ICA, and 2 carotid terminus occlusions were identified (6 had tandem occlusions). The average rCBF volume was 102.3 mL (SD 64.3) compared to median estimated ischemic core volume of 80mL in Select 2. Conclusion The patients presenting to our institution with large stroke resemble those included in the Select 2 trial, which demonstrates positive outcomes following mechanical thrombectomy for this special population. Patients with large strokes are frequently excluded from receiving treatment with mechanical thrombectomy. Analysis of a larger data set, including large stroke patients from 2018 to 2022, is currently pending. In light of the Select 2 trial, patients in our community and in our referral basis stand to benefit from an institutional practice of offering thrombectomy to those presenting with large stroke.

Abstract 044: Single‐Step Intracranial Angioplasty followed by Atlas Stent Deployment Through Mini Trek Rx Balloon

Introduction The current FDA approved intracranial stent delivery system requires a multi‐step deployment involving the use of exchange length microwire (ELW), typically 0.014‐inch 300 cm wire, to navigate the balloon catheter, which is then exchanged, after performing the angioplasty, over the ELW to a 0.017’ microcatheter that is used to deploy the intracranial stent. Herein, we describe a single‐step approach to deploy Neuroform Atlas stent (Stryker Neurovascular, Fremont, CA) which is a hybrid laser‐cut, nitinol self‐expanding stent without the need for ELW or lesion re‐access using MINI TREK RX (Abbott Vascular, Inc., Santa Clara, CA, USA) semi compliant balloon adapted from cardiovascular literature which showed a pre‐dilation angioplasty capability in coronary stenotic lesions. Methods We performed a retrospective review of prospectively maintained mechanical thrombectomy (MT) databases of 2 comprehensive stroke centers between November 2020, and May 2023. The inclusion criteria were consecutive large vessel occlusion stroke patients in whom single step MINI TREK RX balloon angioplasty followed by Neuroform Atlas intracranial stent deployment was performed without using ELW (Figure‐1). There was no restriction on time from last known well (TLKW) to MT. During the standard mechanical thrombectomy procedure, intracranial atherosclerotic disease/ significant stenotic lesion was suspected by immediate re‐occlusion/ persistent occlusion following at least 1 thrombectomy pass. This is followed by pursuing intracranial angioplasty and stent placement as a rescue recanalization measure. The primary outcome was successful reperfusion defined as a Modified Treatment in Cerebral Ischemia (mTICI) score of 2b or greater at the end of the procedure. Secondary outcomes included NIH Stroke Scale (NIHSS) at 24 hours, NIHSS at discharge, median modified Rankin Scale (mRS) score at discharge and at 90‐day follow‐up. Safety measures included rates of symptomatic intracranial hemorrhage (sICH) and mortality at 90 days. Results Among 9 patients who met our criteria, the median age was 63 (51‐69.5) years and 55.6% were females. Most patients had left middle cerebral artery‐ M1 occlusion (66.7%) and one third received thrombolytics (33.3%). All patients underwent the single‐step approach and achieved successful reperfusion (m TICI 2b‐3) with 2 median number of passes. The median NIHSS was reduced from 13.5 (8.5‐17.5) at baseline to 4 (1‐16.5) at discharge. In addition, median mRS was 1 (1‐3.5) at discharge and 3 (3‐4) at 90 days. None of the patients included in this series had sICH while only one patient with basilar artery occlusion underwent ventriculostomy during hospital stay and was sedated/intubated and died. Conclusion This preliminary experience showed technical feasibility and success of using single‐ step to deploy Neuroform Atlas stent after performing angioplasty using MINI TREK RX without the need for ELW or lesion re‐access. Prospective studies with larger sample size and long‐term clinical follow‐up are warranted to confirm these results.

Abstract 244: Effect of Actuation Frequency on Clot Integration with the Tigertriever Device: An In Vitro Study

Introduction Mechanical thrombectomy has been widely recognized as the preferred treatment for large vessel occlusion strokes. The Tigertriever stent‐retriever (Rapid Medical, Yokneam, Israel) is a novel operator‐adjustable device that can be actively expanded and contracted by the operator [1], which allows for several actuation‐related parameters to be optimized to potentially improve device efficacy. These parameters – such as amplitude and frequency of the actuation cycle, and rate of expansion and contraction – have not yet been evaluated in correlation with device success. We conducted a benchtop study to evaluate the effect of actuation frequency on clot integration within the stent. Methods A Tigertriever 17 device was deployed within a biological thrombus analog (2.5 cm length) placed in a straight silicone tube (2.4 mm diameter). The device was actuated between the maximally contracted and maximally expanded states with three different frequencies: Passive (one‐time opening, n=6), Slow (20 seconds/cycle, n=6), and Fast (5 seconds/cycle, n=7). A flat‐detector CT scan was acquired, the clot and stent wires were segmented, and the boundaries of the clot and stent wires were calculated on each axial slice (Figure 1A). The intersection between the stent and clot boundaries throughout the volume was defined as the volume of clot integrated within the stent. The clot integration factor (CIF, ratio of integrated clot volume to total clot volume) was then statistically compared between the three frequencies as an estimate of clot capture efficiency. Results The CIF was significantly higher (23% increase, p=0.01) with the Fast actuation as compared to the Passive and Slow actuations, with a post‐hoc test showing no difference (p&gt;0.05) between the Passive and Slow actuation frequency (Figure 1B). Conclusion The unique malleability of the Tigertriever stent‐retriever (Rapid Medical) presents an opportunity to better understand actuation parameters that can maximize thrombus capture. Results indicate that faster actuation frequencies may result in improved clot integration with the Tigertriever device. These results are concordant with a previous clinical study [1] that found repetitive‐expansion‐contraction was more successful than single unsheathing (which corresponds to our Passive group). It is possible that the greater acceleration of the stent mesh wires in the Fast actuation frequency resulted in increased radial forces that improved clot integration. This effect must be further validated in an in vitro setting more representative of physiological conditions, as well as eventual clinical evaluation.