Large Vessel Occlusion Patients Research Articles

Acute Infarct Core Volume Estimation on Noncontrast Computed Tomography With a Deep Learning Algorithm

Background A simplified patient selection paradigm with noncontrast computed tomography (NCCT) can reduce the time to reperfusion and widen the eligibility of acute ischemic stroke large vessel occlusions (LVOs) for endovascular therapy. The objectives of this article are (1) to develop, train, and internally validate a deep learning algorithm that estimates baseline infarct core volume (ICV) on NCCT in anterior circulation LVO patients, and (2) by using an external set, to ascertain how this algorithm's (aICV‐NCCT) predictive performance compares with Alberta Stroke Program Early Computed Tomography Score‐NCCT and ICV‐CT perfusion in its capacity to estimate the final infarct volume established on diffusion‐weighted magnetic resonance imaging at 24‐ to 48‐hour follow‐up. Methods In the first phase, stroke activations with baseline NCCT and CT angiography were used to train an aICV‐NCCT. The algorithm was then internally validated using intraclass correlations and Intersection over Union. In the external set, patients with LVO treated with endovascular therapy achieving modified Thrombolysis in Cerebral Infarction score ≥2b and available baseline NCCT, CT angiography, and CT perfusion were included. Results A total of 2858 studies of patients with stroke alerts were used for training (80%) and internal validation (20%). We obtained a high correlation (intraclass correlation coefficient, 0.78; CI, 0.73–0.83) and an acceptable Intersection over Union of 0.24 on the internal validation set. The external set consisted on 230 patients with an LVO. When predicting final infarct volume on the external set, our aICV‐NCCT was similar to ICV‐CT perfusion (intraclass correlation coefficient, 0.50 versus 0.54; P = 0.764) and Alberta Stroke Program Early Computed Tomography Score‐NCCT (r s , −0.41; P = 0.436). Conclusion In this study, we developed and validated a deep learning algorithm that demonstrates an at least equivalent performance to CT perfusion in estimating core volume on acute stroke imaging studies in patients with suspected anterior circulation LVO strokes. The algorithm's robust performance holds significant potential in settings with limited access to advanced imaging technologies across diverse healthcare environments.

Endovascular therapy for large ischemic stroke in directly admitted versus transferred patients: A secondary analysis.

Endovascular therapy (EVT) has been proved beneficial in patients with acute large vessel occlusion (LVO) with large infarcts, but it is unknown whether the benefit would be affected by the interhospital-transfer status. We investigated the efficacy of EVT according to the interhospital-transfer status in such patients. This was a secondary analysis of the ANGEL-ASPECT trial. Patients with acute anterior-circulation LVO and large infarcts, defined by Alberta stroke program early CT score (ASPECTS) 3-5 or infarct core volume 70-100 mL, were enrolled from 46 centers across China and randomized (1:1) to receive EVT with medical management (MM) versus MM alone. We dichotomized patients into two subgroups based on whether admitted directly to the EVT-capable center or transferred from a primary center. The primary outcome was the 90-day modified Rankin Scale (mRS). From October 2020 to May 2022, 456 patients were recruited and one withdrew consent. So, 455 patients were included in this analysis, with 210 (46.2%) in the direct subgroup and 245 (53.8%) in the transfer subgroup. The transfer subgroup had longer median onset-to-arrival time than the direct patients (379 vs 279 mins, p < 0.001), while there was no significant difference in the arrival-to-recanalization time (197 vs 205 mins, p = 0.087) between the two subgroups. A significant ordinal shift of 90-day mRS toward a better functional outcome in EVT than MM (generalized odds ratio [gOR] = 1.67; 95% confidence interval (CI) = 1.03-2.70, p = 0.036 versus gOR = 1.60; 95% CI = 1.02-2.50, p = 0.039) was found in the direct and transfer group, respectively. There was no significant interaction of the two subgroups over the treatment effect of EVT versus MM on the primary outcome (p for interaction = 0.706). In acute anterior-circulation LVO patients with large infarcts, the benefit of EVT compared to MM did not vary by the interhospital-transfer status.

Endovascular thrombectomy for large vessel occlusion stroke patients with baseline disability: Long-term outcomes and end-of-life care.

Endovascular thrombectomy for large vessel occlusion stroke patients with baseline disability: Long-term outcomes and end-of-life care.

First validation of the novel Freiburg Neurointerventional Score purposely designed for use by emergency medical dispatchers for detecting anterior circulation large-vessel occlusion in patients with suspected stroke

BackgroundDetecting an anterior circulation large-vessel occlusion (aLVO) as a cause of stroke during emergency calls could optimise dispatch, particularly in rural areas. Numerous stroke severity scales assessing motor and cortical...

Abstract WP239: Outcomes of adjunct use of intravenous antiplatelets in large vessel occlusion patients secondary to underlying atherosclerosis

Abstract WP239: Outcomes of adjunct use of intravenous antiplatelets in large vessel occlusion patients secondary to underlying atherosclerosis

Abstract TMP58: Impact of DWI-ADC Mismatch on Infarct Progression and Endovascular Thrombectomy Outcomes in Acute Stroke

Introduction: An apparent diffusion coefficient (ADC) threshold of ≤ 620 × 10-6 mm2/s identifies irreversible infarcts and guides endovascular thrombectomy (EVT) decisions. However, in hyperacute ischemic infarcts, diffusion-weighted imaging (DWI) hyperintense lesions can show varying ADC values. This study investigates DWI-ADC mismatch, defined as the significant difference between DWI hyperintense lesion volume and ADC ≤ 620 × 10-6 mm2/s volume. Methods: This retrospective, single-center study included patients with acute large vessel occlusion in the anterior circulation who: (1) underwent MRI within 24 hours of stroke onset, (2) received EVT, and (3) had follow-up MRI within 5 days of EVT from January 2018 to January 2020. Neuroradiologists segmented DWI hyperintense infarcts with ADC hypointensity on pre- and post-EVT MRI, using Fluid-attenuated inversion recovery (FLAIR) sequences to avoid T2 shine-through effects. The DWI/ADC volume ratio was calculated by dividing DWI volume by ADC ≤ 620 × 10-6 mm2/s volume. DWI-ADC mismatch was defined as a DWI/ADC ratio ≥ 2, with no mismatch indicated by a ratio &lt; 2. Final infarct segmentation included hemorrhagic transformation. DWI lesion reversal (DWIR) was defined as the volume of normal-appearing voxels on follow-up DWI but previously hyperintense. DWIR% = (DWIR/baseline DWI volume) × 100 was calculated. We compared demographics, radiological findings, clinical outcomes, and follow-up results between mismatch and no mismatch groups. Results: Among 73 patients, 20 (27.4%) had DWI-ADC mismatch. Baseline demographics and National Institutes of Health Stroke Scale (NIHSS) were similar between groups. The DWI/ADC ratio was higher in the mismatch group (2.9 vs. 1.5, P &lt; 0.0001). Follow-up lesion volumes and functional outcomes were similar; however, the mismatch group showed a slower infarct growth rate (3.8 ml/h vs. 7.5 ml/h, P = 0.04), a higher likelihood of parent artery stenosis (65% vs. 20.8%, P &lt; 0.001), and increased need for angioplasty or stenting (50% vs. 17%, P &lt; 0.001). The mismatch group also had a higher DWIR% (37.7% vs. 21.2%, P = 0.02). Conclusions: DWI-ADC mismatch is associated with slower infarct growth, greater likelihood of parent artery stenosis, increased need for angioplasty or stenting, and more DWI lesion reversal in anterior circulation large vessel occlusion patients undergoing EVT. These findings suggest DWI-ADC mismatch could be important in EVT decision-making and outcome prediction.

Abstract 30: Association between Time and Severe Hypoperfusion with Risk of Hemorrhagic Transformation in Thrombectomy Stroke Patients

Background and objective: Perfusion imaging studies consistently show a substantially increased risk of hemorrhagic transformation (HT) in severely hypoperfused tissue. Pathophysiological evidence indicates that ischemic damage is influenced not only by the degree of hypoperfusion but also by the duration of exposure to that hypoperfused state. We aim to investigate the association of time and severe hypoperfusion with parenchymal hematoma (PH) in ischemic stroke and explore whether there is a combined effect of the two variables on PH. Methods: Data are from the ESCAPE-NA1 trial, which evaluated the effect of nerinetide in large vessel occlusion patients treated with thrombectomy. For this study, we included patients with some degree of recanalization (expanded Thrombolysis in Cerebral Infarct [eTICI] &gt;0) and available baseline CT perfusion. Severe hypoperfusion was defined as at least 1mL volume of relative cerebral blood flow (rCBF)&lt;20%. The primary and secondary outcomes were the presence of PH and of any HT, respectively, assessed on 24-hour imaging, according to Heidelberg criteria. The effect of time and severe hypoperfusion on outcomes was assessed with univariable and multivariable logistic regression analyses, including interaction terms to assess treatment effect modification. Results: Out of 1105 patients from ESCAPE-NA1, 396 (35.8%) were included. The median age was 70 years (IQR=59.8-79.2), 202 (51%) were females, and 50 (12.6%) experienced PH. Onset-to-imaging time (adjusted OR 1.04 [95%CI=1.01-1.06] per 15-minute increase) and the presence of severe hypoperfusion (adjusted OR 2.63 [95%CI=1.21-5.72]) were the only variables associated with PH in multivariable analysis. No significant interaction effect of time and severe hypoperfusion on PH was found. The presence of severe hypoperfusion has a negative predictive value of 98% and a positive predictive value of 39.4% for predicting PH in patients presenting within three hours and after six hours from symptom onset, respectively. Conclusion: Both severe hypoperfusion and time affect the risk of hemorrhagic transformation in ischemic cerebral tissue. Analyzing these variables may help identify patients with a leaky, severely compromised blood-brain barrier in the ischemic core—a “leaky core.”

Prehospital scale to differentiate intracerebral hemorrhage from large-vessel occlusion patients: a prospective cohort study

Evaluating scales to detect large vessel occlusion (LVO) could aid in considering early referrals to a thrombectomy-capable center in the prehospital stroke code setting. Nevertheless, they entail a significant number of false positives, corresponding to intracranial hemorrhages (ICH). Our study aims to identify easily collectible variables for the development of a scale to differentiate patients with ICH from LVO. We conducted a prospective cohort study of stroke code patients between May 2021 and January 2023. Patients were evaluated with CT/CT-Angiography at arrival. We compared clinical variables and vascular risk factors between ICH and LVO patients. Out of 989 stroke code patients, we included 190 (66.7%) LVO cases and 95 (33.3) ICH cases. In the multivariate analysis, headache (odds ratio [OR] 3.56; 1.50–8.43), GCS < 8 (OR 8.19; 3.17–21.13), SBP > 160mmHg (OR 6.43; 3.37–12.26) and male sex (OR 2.07; 1.13–3.80) were associated with ICH, while previous hypercholesterolemia (OR 0.35; 0.19–0.65) with LVO. The scale design was conducted, assigning a score to each significant variable based on its specific weight: +2 points for SBP > 160, + 1 points for headache, + 1 points for male sex, + 2 points for GCS < 8, and − 1 points for HCL. The area under the curve was 0.82 (0.77–0.87). A score ≥ 4 exhibited a sensitivity of 0.10, a specificity of 0.99, a positive predictive value of 0.21, and a negative predictive value of 0.98. We present the development of a prehospital scale to discriminate between ICH and LVO patients, utilizing easily detectable variables in the prehospital setting.

Clot signature in patients with large vessel occlusion stroke and concomitant active cancer.

Patients with active cancer face an increased risk of ischemic stroke. Also, stroke may be an initial indicator of cancer. In patients with large vessel occlusion (LVO) stroke treated with thrombectomy, analysis of the clot composition may contribute new insights into the pathological connections between these two conditions. We compared the content of 64 consecutively retrieved clots from LVO stroke patients with concomitant active cancer and 64 clots from matched-control LVO stroke patients without a history of cancer. Clots were analyzed with respect to histological composition by Martius Scarlet Blue, von Willebrand factor (vWF), citrullinated histone H3 (H3Cit, a biomarker of NETS), CD42b, and CD3 expression by immunohistochemistry. Orbit Image Analysis was used for quantification. Differences between groups were tested using the Mann-Whitney U-test and Chi-square Test. Clots from patients with concomitant cancer had a significantly higher content of vWF (median 26 [IQR13-38]% vs. 10 [4-18]%, p < 0.0001) and H3Cit (median 0.11 [IQR0.02-0.46]% vs. 0.05 [0.00-0.28]% p = 0.027) than controls. The presence of collagen >1% within the retrieved clots was highly indicative of cancer, occurring in 16/64 with active cancer and in 3/64 controls, p = 0.002. After correction for multiple comparisons, the statistical significance for H3Cit was lost. Red and white blood cells, platelets, fibrin, and expression of CD3 and CD42b did not differ between the groups. Clots from LVO patients with concomitant active cancer possess distinct characteristics, indicating an influence of cancer on the innate immune system, fibroblasts, and the vascular endothelium in the formation of LVO clots.

Outcome after Endovascular Treatment of Patients with Acute Ischemic Stroke with Large Vessel Occlusion over 90 Years of Age.

The effectiveness of endovascular therapy for patients aged 90 years and over (≥90 years) is still not well understood. We compared the patients aged ≥90 years with those aged 85-89 years, 80-84 years, and <80 years using data from the Japanese Registry of NeuroEndovascular Therapy that enrolled acute large vessel occlusion patients from January 2015 to December 2019. The primary outcome was the rate of return of the modified Rankin Scale to at least the premorbid modified Rankin Scale after 30 days. Secondary outcomes were the incidences of intracranial hemorrhage and mortality.Among 13,540 patients, patients aged ≥90 years, 85-89 years, 80-84 years, and <80 years were 1,104, 1,925, 2,477, and 8,034. The prevalence of female gender, the premorbid Rankin Scale, and the National Institutes of Health Stroke Scale score before endovascular therapy were highest in the patients aged ≥90 years (n [%], 819 [74.2]; median [interquartile range]; 2 [0-3], and 21 [15-26]). The primary outcome of the adjusted odds ratio (95% confidence intervals) for the patients aged 85-89 years, 80-84 years, and <80 years for ≥90 years was 0.89 (0.72-1.10), 0.95 (0.77-1.16) and 1.07 (0.89-1.28). However, the incidence of symptomatic intracranial hemorrhage was lower in patients aged ≥90 years compared with patients aged 85-89 years and <80 years (adjusted odds ratio [95% confidence intervals]; 1.86 [1.16-2.98] and 1.71 [1.11-2.64]). The return of the modified Rankin Scale to at least the premorbid modified Rankin Scale after 30 days in patients aged ≥90 years with large vessel occlusion was not significantly different in other groups but symptomatic intracranial hemorrhage was less observed than in younger patients.

Extending the time window for tenecteplase by effective reperfusion of penumbral tissue in patients with large vessel occlusion: Rationale and design of a multicenter, prospective, randomized, open-label, blinded-endpoint, controlled phase 3 trial.

The benefit of tenecteplase in the treatment of large vessel occlusion (LVO) patients presenting within 24 h of symptom onset remains unclear. This study aimed to assess the effectiveness and safety of tenecteplase, compared to standard of care, in patients presenting within the first 24 h of symptom onset with an LVO and target mismatch on perfusion computed tomography (CT). The "Extending the time window for Tenecteplase by Effective Reperfusion of peNumbrAL tissue in patients with Large Vessel Occlusion" (ETERNAL-LVO) trial is a prospective, randomized, open-label, blinded-endpoint, phase 3, parallel-group, superiority trial with covariate-adjusted 1:1 randomization, and adaptive sample size re-estimation. Patients with an anterior circulation LVO stroke, who present within 24 h of stroke onset or last known well with a target mismatch on computed tomography perfusion (CTP) or magnetic resonance imaging (MRI), will be randomized to tenecteplase (0.25 mg/kg) or standard of care (alteplase 0.90 mg/kg or conservative management at clinician discretion) prior to undergoing endovascular therapy. The primary outcome is the proportion of patients with a modified Rankin Scale (mRS) of 0-1 (no disability) or return to baseline mRS at 3 months. Secondary and safety outcomes include the proportion of patients with an mRS of 0-2 at 3 months, an ordinal analysis of the mRS at 3 months, the proportion of patients with symptomatic intracerebral hemorrhage (sICH), the proportion of patients with death due to any cause, and the proportion of patients with mRS 5-6 at 3 months (severe disability or death). The ETERNAL-LVO trial will build on the current evidence for tenecteplase in the > 4.5-h window. Specifically, this trial will evaluate tenecteplase in a patient population who have access to endovascular therapy but may incur delays to endovascular therapy commencement or require transfer from a primary to a comprehensive stroke center. ClincialTrials.gov: NCT04454788.

Optimal Cerebral Blood Flow Thresholds for Ischemic Core Estimation Using Computed Tomography Perfusion and Diffusion-Weighted Imaging.

Computed tomography perfusion (CTP) imaging is crucial in quantifying cerebral blood flow (CBF) and thereby making an endovascular treatment (EVT) after large vessel occlusion. However, CTP is prone to overestimating the ischemic core. We sought to delineate the optimal regional CBF (rCBF) thresholds of pre-EVT CTP. We collected acute ischemic stroke patients due to large vessel occlusion who achieved successful recanalization with baseline CTP, immediate post-EVT diffusion-weighted image (DWI) within 3 hours, and delayed post-EVT DWI between 24 and 196 hours. Core volumes estimated by CTP at various rCBF thresholds were validated against immediate and delayed DWI lesion volumes. A total of 175 acute large vessel occlusion patients were included. Baseline CTP was taken in a median of 24 minutes (interquartile range [IQR] 21-31 minutes) after arrival; after the CTP, groin puncture in a median of 37 minutes (IQR 28-52 minutes), immediate post-EVT DWI scans in a median of 1.6 hours (IQR 0.8-2.1 hours), and delayed DWI scans in a median of 89 hours (IQR 69-106 hours). The correlations between the rCBF thresholds were the best at rCBF <22% for immediate DWI (0.64; 95% CI 0.55-0.73) and at rCBF <30% for delayed DWI (0.69; 95% CI 0.61-0.76). The interval between CTP and recanalization was inversely correlated with the overestimation of ischemic core volume compared with the subsequent DWI. Optimal rCBF thresholds for estimating ischemic core using CTP depend significantly on the timing of DWI post-EVT and CTP to recanalization delay. The optimal rCBF thresholds for ischemic core estimation may vary depending on the clinical setting. ANN NEUROL 2024.

Microembolic signal detection in acute ischemic stroke: Clinical relevance and impact on treatment individualization-A narrative review.

Microembolic signals (MES) can be detected using transcranial Doppler (TCD) ultrasound in several clinical scenarios, including acute ischemic stroke (AIS). This narrative review aims to provide insights into their role in AIS patient management and outcomes. The present narrative review consolidates current observational and randomized evidence on the prevalence and clinical relevance of MES in different AIS subtypes and settings. MES prevalence is higher in AIS patients with large artery atherosclerosis, indicating unstable or vulnerable plaques, and lower in those with small vessel disease. Detecting MES can significantly aid in managing AIS patients, particularly when the cause is unclear, as MES detected in different cerebral arteries can indicate conditions like covert cardioembolism, aortic arch atherosclerosis, or coagulation disorders, including cancer-related stroke. MES are associated with higher risk of stroke recurrence, independently of the underlying stroke mechanism. The detection of MES during and after acute systemic or endovascular reperfusion procedures in large-vessel occlusion patients appears to be predictive of adverse clinical outcomes and recurrent stroke. Finally, a reduction in MES detection may serve as surrogate marker and intermediate endpoint evaluating secondary stroke prevention treatments in the settings of randomized-controlled clinical trials. MES detection on TCD in AIS remains a useful diagnostic tool as it helps the clinicians to approach the stroke underlying mechanism by detecting and quantifying ongoing cerebral embolization and localizing an embolic source in real time. In addition, it allows monitoring and treatment individualization in stroke patients, while further determining recurrent stroke risk.

Characteristics of peripheral immune response induced by large-vessel occlusion in patients with acute ischemic stroke

IntroductionDespite improvements in the treatment of acute ischemic stroke (AIS), some patients still suffer from functional impairments, indicating the poor understanding of pathophysiologic process of AIS. Inflammation plays an important role in the pathophysiology of AIS. The purpose of the study was to investigate the peripheral inflammation in different subtypes of AIS.MethodsHere, retrospective data from AIS with large vessel occlusion (LVO) and small vessel occlusion (SVO), and healthy controls, were initially analyzed. Then, flow cytometry was performed to evaluate the levels of peripheral naïve and memory T-cells. Finally, we characterized the T cell receptors (TCR) repertoire using high-throughput sequencing.ResultsElevated levels of leukocytes, neutrophils, and neutrophil-to-lymphocyte ratio (NLR), and decreased levels of lymphocytes were found in LVO group than that in SVO group, which were correlated with the severity of LVO. In addition, higher percentages of both effector memory (Tem) and central memory (Tcm) T cells, and lower percentage of naïve T cells in CD4+ and CD8+ T cells, were found in LVO group than that in SVO and healthy groups. Moreover, impaired TCR diversity, and different abundances of V-J gene combinations and amino acid sequences, were found in LVO as compared with healthy group, which would be potential biomarkers for LVO diagnosis.DiscussionIn conclusion, AIS with LVO can rapidly induce peripheral immune response, which provides new insight into the understanding of pathophysiology of AIS.

Intra-arterial cocktail therapy for patients with anterior circulation large vessel occlusion who achieved endovascular reperfusion.

Clinically ineffective reperfusion (CIR) refers to the discrepancy between successful reperfusion and a favorable functional outcome in patients with large vessel occlusion (LVO) stroke after endovascular treatment (EVT). The Improving Neuroprotective Strategy for Ischemic Stroke with Sufficient Recanalization after Thrombectomy by Intra-arterial Cocktail Therapy (INSIST-CT) trial aimed to explore the safety, feasibility, and efficacy of intra-arterial cocktail therapy using argatroban, dexamethasone, and edaravone in patients who achieved sufficient reperfusion after EVT. In this prospective, single-arm, pilot study, eligible patients with anterior circulation LVO who achieved sufficient reperfusion after EVT were enrolled in the INSIST-CT trial. Consecutive patients who met the inclusion/exclusion criteria were included in the control group retrospectively. In the INSIST-CT group, argatroban, dexamethasone, and edaravone were continuously administered for 30 min into the culprit artery after sufficient recanalization. The primary endpoint was the proportion of favorable functional outcome, defined as a modified Rankin Scale (mRS) score of 0-2 at 90 days. The primary safety outcome was symptomatic intracranial hemorrhage (sICH). Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) analyses were performed to account for multiple confounders. A total of 30 patients were included in the INSIST-CT group, and 261 patients were included in the control group. The proportion of the patients with the primary endpoint was 60% in the INSIST-CT group and 55.9% in the control group (unadjusted odds ratio [OR] 1.18, 95% CI 0.55-2.61, p = 0.67; adjusted OR 1.42, 95% CI 0.62-3.26, p = 0.41). No significant difference in sICH at 48 h after treatment was observed between the two groups (unadjusted OR 0.96, 95% CI 0.15-3.56, p = 0.96; adjusted OR 0.82 95% CI 0.17-3.97, p = 0.809). Similar results were observed after the PSM and IPTW analyses. In anterior circulation, LVO patients who achieved sufficient reperfusion after EVT, bridging intra-arterial cocktail therapy with argatroban, dexamethasone, and edaravone may be safe and feasible. However, it did not improve the 90-day functional outcomes. A numerically higher probability of a favorable outcome in the INSIST-CT group suggests the potential promise of this cocktail therapy in reducing clinically ineffective reperfusion. ClinicalTrials.gov, NCT04202549.

Thrombectomy Failure and Associated Factors for Large-Vessel Occlusion Stroke.

Ischemic stroke due to Large Vessel Occlusion (LVO) represents a critical and time-sensitive neurological emergency. Advancements in imaging technology and endovascular therapies have transformed the management of LVO. Nonetheless, thrombectomy failure diminishes the chances of patients achieving a favorable clinical outcome. We aimed to determine the factors influencing recanalization failure in order to optimize thrombectomy therapy along with enhancing patient outcomes. A retrospective analysis was performed employing consecutive LVO patients who underwent Endovascular Thrombectomy (EVT) in a tertiary comprehensive stroke center between January 2020 and June 2024. Recanalization failure (mTICI 0-2a) following thrombectomy was assessed using the Kolmogorov-Smirnov test, χ2 test, Fisher's exact test, and multivariable logistic regression to identify the related factors. A total of 82 EVT patients were analyzed. The mean age was 58.20 years and 70.73% of the patients were male. The rate of recanalization failure was 61%. Multivariable logistic regression analysis with age-sex adjusted factors has revealed hypertension [aOR: 5.31 (95% CI: 1.23-22.77); p =0.025] and no IVT [aOR: 2.75 (95% CI: 1.06-7.14); p =0.037] to be independent predictors of recanalization failure in this study. Hypertension and the absence of prior intravenous thrombolysis have been found to be significant contributing factors to the high rate of thrombectomy failure in large-vessel occlusion.

The Los Angeles Motor Scale is independently associated with cerebral blood flow < 30% volume in large vessel occlusions.

Mechanical thrombectomy (MT) is the treatment standard for large vessel occlusion (LVO) stroke. Under current guidelines, only patients with smaller ischemic core volumes (ICV) are eligible for MT. Thus, it is of interest to quickly estimate ICV in stroke patients. The Los Angeles Motor Scale (LAMS) is a validated tool used to assess stroke severity directly in the field. This study aims to determine whether LAMS score is also associated with ICV, as defined by the CBF <30% volume on CT perfusion imaging. We performed a retrospective, multicenter cohort study of consecutive patients presenting with LVO stroke from 9/1/2017 to 10/1/2023. The inclusion criteria were patients with (1) stroke caused by large vessel occlusion confirmed on CTA and (2) diagnostically adequate, multimodal pretreatment CT imaging. Demographic, clinical, and imaging data was collected through manual chart review. Both univariate and multivariate analyses were applied to assess associations. A p-value <.05 was considered significant. A total of 283 patients (median age: 69, IQR: 61-78) were included in the study. On multivariate logistic regression analysis, we found that lower admission LAMS score (adjusted OR: 0.511, 95% CI: 0.313-0.834, p = .007) was independently associated with a CBF <30% volume of less than 50cc. Admission LAMS is an independent predictor of a CBF <30% volume of less than 50cc. This demonstrates that LAMS can be used to estimate ICV, which will aid in the early triaging of LVO patients to thrombectomy-capable centers.

Prevalence of ipsilateral “vulnerable carotid plaques with

BackgroundCarotid plaques may be an important etiology in ischemic stroke. We aimed to assess carotid plaque characteristics ipsilateral and contralateral to the ischemic stroke and assessed the prevalence of “vulnerable carotid plaques with <50% stenosis” based on different imaging-based definitions in patients with large vessel occlusion and source of embolic stroke of undetermined source (ESUS) on CT Angiography (CTA). MethodsData are from the ESCAPE-NA1 trial (Efficacy and safety of nerinetide for the treatment of acute ischemic stroke), a multicenter, randomized study that included anterior circulation large vessel occlusion patients undergoing thrombectomy. Various CTA features of plaque vulnerability were combined to define “vulnerable carotid plaques” in different ways. Within ESUS patients, prevalence of vulnerable plaques ipsilateral vs. contralateral to the intracranial occlusion was compared. ResultsWe analyzed 132 patients whose ischemic stroke mechanism was determined to be ESUS. Plaques causing 30–50 % stenosis (as compared to no stenosis) and plaque surface irregularity were significantly more common in ipsilateral carotid arteries (37[28.0 %] vs. 18[13.6 %]; p < 0.001 and 102[77.3 %] vs. 78[59.1 %]; p = 0.002). The prevalence of ipsilateral “vulnerable carotid plaques” varied depending on imaging definition used for such plaques between 55 and 74 %, but irrespective of the definition used, the prevalence of “vulnerable carotid plaques” was consistently higher in ipsilateral carotid arteries compared to contralateral carotid arteries. ConclusionsIn ESUS patients undergoing thrombectomy for anterior circulation large vessel occlusion, vulnerable carotid plaques are more prevalent ipsilateral to the intracranial occlusion. Irregular plaque surface, and a higher degree of stenosis were the most common vulnerable plaque features.

Abstract 228: Comparative Analysis of Mobile Stroke Treatment Unit (MSTU) and Emergency Department (ED) Patients with Large Vessel Occlusion (LVO) in Need of Endovascular Thrombectomy

Introduction Large vessel occlusion (LVO) strokes represent a critical medical emergency requiring prompt intervention to minimize neurological damage and improve patient outcomes. Traditionally, patients with LVO are taken to the Emergency Department (ED) via standard Emergency Medical Services (EMS) before undergoing endovascular mechanical thrombectomy (MT). However, some Mobile Stroke Treatment Units (MSTUs) are introducing an alternative pathway for rapid, pre‐hospital care by taking the LVO patient directly to the Operating Room (OR), bypassing the ED all together. This study compares the outcomes of patients with LVOs admitted directly to the OR from the MSTU versus those arrived by EMS and admitted through the ED. The findings from this project will aim to inform best practice for managing LVO cases, improve patient care protocols, as well as further investigate the value of a MSTU. Methods This quality improvement project is a retrospective cohort analysis comparing LVO patients directly admitted to the OR from the MSTU versus the standard process of EMS‐to‐ED, excluding hospital‐to‐hospital transfers and arrival by personal vehicle. “Door” for MSTU patients is measured as the time the patient crosses the threshold of the unit. Time measurements for MSTU LVO patients include transport time to the hospital. We reviewed the records of patients with LVO treated with mechanical thrombectomy at the University of Florida between 7/25/23 and 6/30/24. Demographics, endovascular thrombectomy stroke metrics, functional outcomes, and mortality data were compared using univariate and multivariate logistic regression analyses. Results A total of 71 patients (mean age 72.2, 47.8% female) were included in the final analyses. 20 patients in the MSTU cohort and 51 patients in the ED cohort were evaluated. The MSTU patient cohort had a faster mean door‐to‐puncture time of 40.9 minutes compared to 65.2 minutes for the ED cohort (OR 1.10 (95%CI 1.04‐1.17), p=0.001). Similarly, the MSTU cohort also had a faster mean door‐to‐recanalization time of 62.9 minutes versus 86.4 minutes in the ED cohort (OR 1.06 (96%CI 1.02‐1.11), p=0.003). These findings remained statistically significant despite adjusting for age and sex. Patients treated on the MSTU with direct to OR also had higher odds of being discharged with favorable functional outcomes defined as mRS of 0‐2 compared to patient arriving via EMS‐to‐ED (OR 9.61 (95%C.I. 1.64‐56.4), p=0.012, adjusted for age and sex). While not statistically significant, we also found a trend towards decreased mortality with patients treated on the MSTU (p=0.09). Conclusion Our study demonstrates improved quality measures and outcomes for LVO stroke patients treated on a MSTU. The MSTU brings expert stroke care to the patient and allows for improved early diagnosis and intervention. With direct admission to the OR, door‐to‐puncture and door‐to‐recanalization times were significantly decreased and functional outcomes were improved as compared to those admitted through the ED via traditional EMS arrival. MSTUs are well‐positioned to enhance the efficiency and effectiveness of LVO stroke pathways by providing more timely treatment, and improving stroke systems of care and patient outcomes.

Abstract 393: Rescue Intra‐arterial Therapy for Emergent Large Vessel Occlusion Secondary to Intracerebral Atherosclerotic Disease In the Philippines: A Single Center Study

Introduction Large vessel occlusions (LVO) secondary to intracranial atherosclerotic disease (ICAD) has an estimated prevalence of 10‐30% of all LVO cases, and the usual risk factors associated with it are hypertension, diabetes, ethnicity, and age. To date, the gold standard of treatment for strokes from LVO are intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT). ICAD‐LVO results in increased morbidity and mortality, as well as early re‐occlusion after revascularization therapy. ICAD‐LVO results in re‐occlusion at 30‐50% compared to 5% rate in cardioembolic strokes. Rescue therapy (RT) for re‐stenosis or re‐occlusion includes intra‐arterial (IA) administration of antiplatelets, angioplasty, and emergency stenting. Despite advancements in endovascular therapy and medical management, the optimal approach for rescuing patients who fail initial reperfusion attempts remains a challenging and underexplored area. By documenting RT strategies, we can identify which are effective in such scenarios and ultimately its impact on clinical outcomes. Of note, this is the first study on RT in ICAD‐LVO in the Philippines. Methods A retrospective chart review of all emergent LVO who underwent cerebral angiogram for the purpose of endovascular thrombectomy from September 2018 to July 2024 was performed. Those included were patients who underwent rescue therapy for ICAD‐LVO. The following were collected, demographic data (age and sex), admitting MRS, NIHSS score upon admission, underlying co‐morbidities (hypertension, diabetes, history of previous stroke), use of anti‐thrombotics/anti‐coagulants as maintenance medications, ASPECTS or MR ASPECTS, history of IV thrombolysis administration, rescue therapy instituted (IA thrombolytics, stenting, or angioplasty), in‐hospital mortality, and discharge MRS. Results Among the 101 LVO patients reviewed, 10 of which were due to ICAD‐LVO and underwent rescue therapy. The mean age was 65 where 80% are male. The demographic data showed that all patients included were hypertensive and half are diabetic and dyslipidemic. 80% (n=8) of patients received IA tirofiban as RT with a mean dose of 960mcg, 1 underwent emergency stenting using a drug eluting coronary stent, and 1 received IA alteplase. No early neurological improvement was seen in those who received RT. For the immediate outcomes, 80% (n=8) of patients had an MRS of 3‐5 upon discharge. Regarding its safety, only 20% (n=2) had hemorrhagic transformation but were asymptomatic. Only 1 patient (10%) with a basilar ICAD‐LVO who received IA tirofiban died, but not as a direct result of the RT, but due to withdrawal of care. CONCLUSIONS ICAD‐LVO remains to be a challenging feat to overcome in revascularization therapy and results in worse outcomes. Rescue therapy with IA tirofiban seems to be safe but does not offer added benefit in terms of acute clinical outcomes. A study on long‐term outcomes of patients who received RT for ICAD‐LVO is recommended to better determine its safety and efficacy.