bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP217: Prognostic Factors in Craniocervical Artery Dissection: A Latin American Cohort Study.
Authors: Reges Danyelle , Navarro Borba Adissy Erica , Lopes Ronney , Trombin Marques Marina , Gabas Miglioli Fernanda , Lessa Vanessa , Pinheiro Modolo Gabriel , Bazan Rodrigo , Gagliardi Rubens , Miranda Maramelia , Sampaio Gisele
Published: January 2025

Introduction:
Craniocervical arterial dissection (CCAD) accounts for only a small proportion of ischemic stroke, but it represents 20 to 25% of cases among younger adults. The prognosis of CCAD is generally favorable. In Latin American populations, epidemiological and clinical studies are scarce. This study examines prognostic factors in a multiethnic Latin American cohort with CCAD, aiming to identify key predictors of outcomes in this diverse population.

Methods:
We conducted a 6-month follow-up study, assessing clinical outcomes in patients diagnosed with CCAD. Data collection included demographic information, clinical presentation, imaging findings, and treatment approaches. Patients were monitored for functional recovery using the modified Rankin Scale (mRS) at baseline and at the 6-month follow-up between January 2013 and June 2023.

Results:
A total of 192 patients with CCAD were included,with 55.2% men, 42.9% black, median age 45 (SD: ±13.9). At hospital discharge, the median of mRS was 3 (IQR: 2.00, 45.7% with mRS 0-2). After 6 months post-stroke, the median mRS was 1 (IQR: 3.00), with 73.9% patients scoring between 0 and 2. Extracranial and anterior territory dissection patients were more likely to have higher NIHSS at admission (5 vs 2.5, p>0.05. IC95%, 2.39-3.00, 5,5 vs 2, p<0,001 IC95%-4 a -2, respectively). In multivariate analysis, diabetes and the NIHSS score at admission were independent risk factors for unfavorable outcomes at 6 months: diabetes increased the risk of unfavorable outcomes by over 6 times (OR: 8.78, 95% CI: 1.74 – 44.16, p = 0.008), and for each 1-point increase in the NIHSS score, the risk increased by 1.18 times (OR: 1.18, 95% CI: 1.06 – 1.32, p = 0.002). Thrombolysed patients had more severe strokes (median NIHSS score 13 vs. 3; P < 0.001). However, IVT and MT were neither independently associated with unfavourable outcome too.

Conclusions:
Overall, CCAD is associated with favorable clinical outcomes: Extracranial cervical artery dissection, anterior territory, NIHSS at admission and diabetes were factors associated with less favorable outcomes in a multiethnic Brazilian population. More studies in mixed and ethnic diverse populations are needed to confirm our findings.
Abstract TP218: Prevalence, Characteristics, and Recurrent Event Risk of Cerebrovascular Fibromuscular Dysplasia in Patients with Ischemic Stroke or Transient Ischemic Attack– A Population-level Study
Authors: Kathuveetil Arun , Ray Sucharitha , Hewawasan Yovan , Peters Steven , Menon Bijoy , Singh Nishita , Ganesh Aravind
Published: January 2025

Introduction:
Fibromuscular dysplasia (FMD) is a rare, nonatherosclerotic, non-inflammatory vasculopathy for which only limited population-level data are available. We aimed to evaluate the prevalence and characteristics of cerebrovascular fibromuscular dysplasia (cFMD) in a population-level cohort of patients with ischemic stroke(IS) and transient ischemic attack (TIA).

Methods:
We studied a population-level cohort of all patients diagnosed with IS/TIA in an entire Canadian province (Alberta) from April 1, 2016, to March 31, 2017, followed for at least 5 years until March 31,2022 for recurrent IS/TIA using administrative health data. We used overlapping approaches of direct neuroimaging review as well as keyword searches (FMD, tortuosity, string of beads, and medial fibroplasia) of radiologist reports to identify cases of suspected cFMD. Following confirmatory review of neurovascular imaging by at least two readers, relevant data on clinical characteristics, risk factor profile, tortuosity index, and anatomical extent of the vascular disease were ascertained from imaging review and clinical records. The 5-year risk of recurrent events was estimated using logistic regression adjusted for age, sex and vascular risk factors.

Results:
Among 7,745 patients with IS/TIA found 34 cases of cFMD in the cohort, accounting for a population prevalence of 0.44% or 439/100,000 cases of IS/TIA. Patients with cFMD were similar in age to those without (median age: 74 years, IQR:60-84 vs 71, IQR:60-82, p=0.52) and had similar vascular risk factors (
Table 1
) but were significantly more likely to be female (79.4% vs 48.3%, p<0.001). The median NIHSS was 1.5 (IQR:1-4). The most frequent pattern of vascular involvement was extracranial proximal internal carotid artery with involvement of multiple vascular beds. Twenty-seven (81.8%) FMD cases had tortuous vessels on CT angiogram. Concomitant intracranial or extracranial aneurysms were detected in 9.1%
(Table 2
). 5year mortality following the index event was 29.4% and recurrent IS or TIA occurred in 23.5% of the patients by 5 years; this was not significantly higher than patients without FMD (aOR=1.7 95%CI:0.8-3.9).

Conclusions:
cFMD is a rare finding in patients with IS/TIA and mostly affects females and the extracranial proximal ICA. Whereas these patients had substantial rates of recurrent IS/TIA and mortality, this was not significantly higher than patients without FMD. Our findings merit further validation in larger cohorts of FMD.
Abstract TP219: Pathological and Clinical Findings of Calcified Nodules in Carotid Artery Stenosis
Authors: YAMADA Kiyofumi , Hatakeyama Kinta , Amemiya Kisaki , Abe Soichiro , Shirakawa Manabu , Imamura Hirotoshi , Iihara Koji , Yoshimura Shinichi , Kataoka Hiroharu
Published: January 2025

Introduction:
A calcified nodule (CN) is defined as a lesion with fibrous cap disruption and luminal thrombus associated with eruptive, dense, calcific nodules. CNs have been reported as an important cause of acute coronary syndrome, including sudden coronary death. However, few reports have discussed CNs in the context of carotid artery stenosis. This study aimed to evaluate the prevalence and distribution of CNs in carotid arteries using carotid endarterectomy (CEA) specimens in correlation with clinical symptoms.

Methods:
We included 508 consecutive patients with moderate to severe (50–95%) carotid artery stenosis who underwent CEA between April 2008 and March 2023. We performed pathological analysis of plaque characteristics in carotid arteries and compared with patient characteristics.

Results:
Of the 508 specimens, 462 (90.9%) were from male patients and mean degree of stenosis was 73.8±16.4%. Fourteen CNs (2.8%) were identified. Seventy-eight calcified plaques (10.4%) defined as the presence of nodular or sheet calcifications were also identified. The number of women was significantly higher in CN group (9/14: 64.3%) than in non-CN group (37/494: 7.5%;
P
<0.001) for all specimens. CNs were slightly more frequent in the common carotid artery (8/14: 57.1%) than in the internal carotid artery (6/14: 42.9%). In cases of calcified plaque, the number of symptomatic stenosis was significantly higher in CN group (11/14: 78.6%) than in non-CN group (29/64: 45.3%;
P
=0.049).

Conclusion:
This is the first clinical report on the prevalence and distribution of CNs in carotid artery stenosis. CNs were found in 2.8% of patients with moderate to severe carotid artery stenosis who underwent CEA. CNs were significantly more prevalent in women and cases of symptomatic stenosis, suggesting that CNs play an important role in the pathogenesis of ischemic stroke in moderate to severe carotid artery stenosis.
Abstract TP220: Per-segment Evaluation of Atherosclerostic Stenosis of Intracranial Internal Carotid Artery: A hospital-based cross-sectional study
Authors: Luo Anling , Zhang Zhao , Yang Yujia , Ye Jing , Li Xuzi , Deng Yiting , Yang Qin , Zheng Hongbo , Hu Fayun , Chen Lizhang , Wang Jian , He Li , Zhou Muke
Published: January 2025

Background:
The uneven distribution of intracranial atherosclerotic stenosis (ICAS) along the internal carotid artery (ICA) had been described in early clinicopathological studies, yet related, large-scale data is lack despite the widespread utilization of angiography. This study aimed to determine the distribution pattern of atherosclerotic stenosis for each of 6 segments within intracranial ICA.

Methods:
This cross-sectional study utilized prospective data from the secure digital subtraction angiography (DSA) registry at the West China Hospital of Sichuan University from 2011 to 2024. Patients with clinically defined intracranial atherosclerotic vascular diseases or risk factors of atherosclerosis were available. Patients with ICAS having no or only mild stenosis (≤30%) of the ipsilateral extracranial ICA (C1) were included. The degree of stenosis and distribution pattern of atherosclerotic stenosis for each of 6 segments (C2-7) were analyzed. Poisson regression analysis was used to investigate the associated factors with ICAS.

Results:
A total of 8,084 patients were included in the preliminary analysis. The mean (SD) age was 59.88 (12.85) years; 5,493 (67.95%) were men, and 1,475 (18.25%) had ICAS. Identical site-specific distribution patterns were found on both left and right intracranial ICA that C2 segment had the lowest proportion of ICAS (36 (0.45%) on the left side and 30 (0.37%) on the right) while C6 had the highest proportion (365 (4.52%) on the left and 392 (4.85%) on the right). The ICAS probability per unit length was also calculated for each segment and C2 still had the lowest average value with 1.58 per millimeter (mm) on the left followed by C4 (10.63), C3 (12.04), C7 (28.71), C6 (46.38), and C5 (116.04), and 1.31 per mm on the right followed by C3 (10.99), C4 (12.51), C7 (35.09), C6 (49.81), and C5 (133.02), respectively. Poisson regression showed that the C2 segment might be a protective factor for ICAS.

Conclusion:
Compared with other segments of intracranial ICA (C3-7), C2 segment has extremely low proportion of atherosclerotic stenosis among all internal ICA segments. This striking segmental differences of ICAS within intracranial ICA may be attributed to the peculiar external support from bony carotid canal that decreases vessel wall stretching and alleviates circumferential stresses, generating a unique atheroprotective hemodynamic microenvironment for this "well-wrapped" C2 segment.
Abstract TP221: Prevelance of Triggers and Risk Factors in Cervical Artery Dissection
Authors: Yaghi Shadi , Shu Liqi , Mandel Daniel , Ghani Mohammad , Al Kasab Sami , Sarvath Mohammed , Zubair Adeel , Khan Farhan , Heldner Mirjam , Marialuisa Zedde , Khazaal Ossama , Martins Sheila , Choi Richard , Mohammadzeh Nahid , Marto Joao Pedro , Tentolouris Piperas Vasileios , FRIDMAN SEBASTIAN , Mallick Dania , Siegler James , Liebeskind David , Stretz Christoph , Pan Kelly , Yaddanapudi Sridhara , De Marco Giovanna , Aguiar De Sousa Diana , Bakradze Ekaterina , Dantu Vishnu , Traenka Christopher , Cheng Yee Kuang , Carrasco Wall Victor , de Havenon Adam , ELTATAWY ALI , Saleh Velez Faddi , Aruaz Antonio , Indraswari Fransisca , Patel Shivam , Sarwat Zoha , Vishnu Venugopalan , Lodhi Omair ul haq , Liu Shilin , Romoli Michele , Rosa Sara , Qureshi Abid , Nehme Ahmad , Guo Xiaofan , Kaufmann Josefin Emelie , Longoni Marco , Barata Vasco , Henninger Nils , Furie Karen
Published: January 2025

Introduction:
Cervical artery dissection (CAD) accounts for nearly 2% of all ischemic strokes but up to 25% of ischemic strokes in young adults. Dissection is likely precipitated by the interplay between risk factors (migraine, low body mass index), environmental triggers (cervical trauma or infection), and genetic connective tissue abnormalities (e.g. Ehlers-Danlos or Marfan’s disease). In this study, we delineate the prevalence of triggers and risk factors in a multicenter cohort of cervical artery dissection.

Methods:
This is a post-hoc analysis of the Antithrombotic for Stroke Prevention in Cervical Artery Dissection Study (STOP-CAD). We recorded information using the admission data on risk factors (migraine), triggers (upper respiratory infection, COVID-19, and minor cervical injury), and whether the patient had a known connective tissue disorder (CTD). We determined the prevalence of risk factors, triggers, and presence of CTD in patients with cervical artery dissection as well as the interplay between these factors in the pathogenesis of CAD.

Results:
We identified 4023 patients with CAD, the mean age was 47 years and 45% were women. A history of migraines was present in 16.6% (668) patients. At least one environmental trigger was present in 26.3% of patients (1061 patients), with minor cervical injury being the most common (22.2%, 892 patients), then upper respiratory infections (6.2%, 251 patients), and COVID-19 (1.2%, 49 patients). Among cervical injury, the most common was chiropractic manipulation (5.7%, 228 patients). Only 2% (83 patients) were known to have a CTD with Fibromuscular Dysplasia being the most common (0.6%, 23 patients). Among the entire STOP-CAD cohort, only 5 patients (0.1%) had evidence of at least one trigger, risk factor, or a known connection tissue disease. On the other hand, 61% of patients (2441 patients) had none of the three recorded.

Conclusion:
In patients with CAD, the absence of any risk factor, trigger, or known CTD is common and should not lead to dismissing a dissection diagnosis in patients with symptoms concerning for CAD.
Abstract TP222: Impaired Distal Perfusion as a Predictor of Stroke Recurrence in Intracranial Atherosclerosis: A Single-Center Study
Authors: Wu Eileen , Shu Liqi , Antonenko Kateryna , Almiri William , Hakim Arsany , Radojewski Piotr , Mordasini Pasquale , Yaghi Shadi , Heldner Mirjam
Published: January 2025

Background:
Symptomatic intracranial atherosclerotic disease carries a high stroke recurrence rate. Accurate prediction of stroke recurrence is critical for improving patient outcomes through timely and targeted interventions. Prior studies have shown that impaired distal perfusion is a driver of early recurrence. This study aims to validate T max delay and mismatch as predictors of 30-day ischemic stroke recurrence.

Methods:
This is a single-center study from a comprehensive stroke center including hospitalized patients with symptomatic intracranial arterial stenosis (50-99%) of the intracranial ICA and proximal middle cerebral artery (M1 or proximal M2). The study outcome was recurrent ischemic stroke by day 30. We determined associations of baseline demographics, vascular risk factors, clinical, laboratory variables, imaging variables, and in-hospital treatments with study outcome. Optimal threshold values for perfusion delay volume and perfusion mismatch volume were identified using the Stata module cutpt by the Liu method. Variables with p<0.05 on univariate analyses (Wilcoxon rank-sum test and chi-square test) were identified as important outcome predictors.

Results:
We identified 114 patients hospitalized with symptomatic intracranial stenosis who met the inclusion criteria. 28 patients (24.6%) had a recurrent ischemic stroke within 30 days. Optimal threshold values were determined as 149.5 ml for T max of 4 seconds, 61.5 ml for T max of 6 seconds, 129.5 ml for mismatch volume at T max of 4 seconds, and 57.5 ml for mismatch volume at T max of 6 seconds. Predictors of early recurrence were younger age (66.5 vs. 74.6, p=0.038), increased hemoglobin A1c (6.2 vs. 5.7, p=0.035), home aspirin (50.0% vs. 23.3%, p=0.007), mismatch volume at T max of 4 seconds (p=0.017), and mismatch volume at T max of 6 seconds (p=0.015).

Conclusions:
Key predictors of early recurrence in symptomtic ICAS include impaired distal perfusion, specifically mismatch volume at T max of 4 seconds and at T max of 6 seconds, and already being on antiplatelets prior to the event. Further research is required to confirm these findings and evaluate reperfusion strategies for individuals with impaired perfusion.
Abstract TP226: Drug-Eluting Stenting Versus Medical Treatment Alone For Patients With Extracranial Vertebral Artery Stenosis: The VISTA Trial
Authors: Liu Delin , Wang Tao , Xu Wenlong , Wang Haibo , Markus Hugh , Shi Huaizhang , Jiao Liqun
Published: January 2025

Purpose:
Two previous randomized controlled trials focusing on vertebral artery stenting, the Vertebral Artery Stenting Trial (VAST) and the Vertebral Artery Ischaemia Stenting Trial (VIST), were underpowered because they failed to reach expected recruitment, and they found no difference in stroke prevention between stenting and medical treatment alone. Drug-eluting stents have shown better performance than bare metal stents. To further determine the effect of drug-eluting stenting in reducing stroke in patients with extracranial vertebral artery stenosis, we designed this study.

Materials and Methods:
Multicenter, randomized, open-label, outcome assessor-blinded trial will be conducted at 31 centers in China. Patients with extracranial vertebral artery (V1-2) 70% to 99% stenosis and transient ischemic attack or ischemic stroke within the past 3 months will be recruited (first patient enrollment: Sep 15, 2023).

Results:
A total of 472 patients will be enrolled. Patients will be randomized (1:1) to drug-eluting stenting plus medical therapy or medical therapy alone. Medical treatment includes dual antiplatelet (aspirin 100mg per day + clopidogrel 75mg per day or ticagrelor 90mg twice per day) for 6 months. The primary outcome is any fatal or non-fatal stroke within 30 days, or ischemic stroke in the targeted area within 30 days to 1 year. Secondary outcomes include stroke, death, crescendo TIA in the targeted area within 1 year.

Conclusion:
The study has been registered on ClinicalTrials.gov (Identifier: NCT05885932) and enrollment is ongoing. This trial aims to reveal whether drug-eluting stenting is safe and effective in vertebral artery stenosis.
Abstract TP228: CYP2C19 GENETIC VARIANTS AND THROMBOTIC RISK IN CLOPIDOGREL THERAPY: A PATH TO PERSONALIZED ANTI-PLATELET THERAPY
Authors: A Vishnu , Ratan Chameli , PT Karthika , S Midhun , Chandran Divyasree , RAO Deshmukh Anirudh , Komakula Snigdha , r Dr. Uday , David Sachin , Jeengar Manish , Ahamed Hisham , NAMBIAR VIVEK
Published: January 2025

Introduction:
Cerebrovascular and cardiovascular diseases are major causes of global mortality, with significant impact in India. Clopidogrel, an antiplatelet prodrug, requires activation by CYP enzymes to inhibit platelet activation. Clopidogrel resistance, affecting 4-30% of patients, is often due to CYP2C19 gene variations, among other factors. This study explores genetic variants associated with clopidogrel resistance to improve personalized therapy for thrombotic conditions.

Objective:
To evaluate the relationship between CYP2C19 polymorphisms and recurrent thrombotic events in patients treated with clopidogrel for coronary artery disease and stroke.

Methods:
An ambispective observational study at a tertiary hospital over six months included 114 adults on clopidogrel for various ischemic conditions. Exclusion criteria were pregnancy, lactation, intracerebral hemorrhage, atrial fibrillation, left ventricular clot, and cardioembolic stroke. Data were collected from medical records. CYP2C19
2 and CYP2C19
3 polymorphisms were analyzed using PCR and gel electrophoresis. Statistical analysis was conducted with chi-square tests in IBM SPSS version 20.0 (p<0.05).

Results:
The study included 114 participants (71.9% males, mean age 64.7 ± 10.9 years). Significant associations were found between recurrent ischemic events and hypertension (p=0.001), diabetes (p=0.033), and smoking (p=0.001). Of the 114 patients, 72 (63.2%) were positive for CYP2C19*
2, with 61 (84.7%) experiencing recurrent events (p=0.005). CYP2C19*
3 positivity was observed in 20 (17.5%) patients, with 9 (45%) having recurrent events (p=0.401). All 12 patients who underwent PCI had recurrent thrombotic events (p=0.000), with 7 (58.3%) having CYP2C19 polymorphisms—5 with CYP2C19*
2 and 2 with CYP2C19*
3. Medication adherence was not significantly linked to recurrence (p=0.063). The findings suggest a potential association between CYP2C19*2 and recurrent thrombotic events.

Conclusion:
This study highlights a significant association between CYP2C192 polymorphism and recurrent thrombotic events in clopidogrel-treated patients, indicating that genetic screening may help identify clopidogrel resistance. No significant association was found with CYP2C193. Smoking, hypertension, and diabetes were significant risk factors for recurrent ischemic events. The high prevalence of CYP2C19 polymorphisms among PCI patients with recurrent thrombotic events suggests the potential benefit of genetic screening in clinical practice.
Abstract TP23: Efficacy and Safety of Apixaban for Stroke Prevention in Atrial Fibrillation: A Study-Level Meta-Analysis of Randomized Controlled Trials
Authors: Sebastian Sneha Annie , Varghese Varna , Padda Inderbir
Published: January 2025

Background:
Stroke is the second leading cause of death worldwide, with atrial fibrillation being a significant risk factor that substantially increases the likelihood of stroke. Although many observational studies have assessed the effectiveness of apixaban, a widely used direct oral anticoagulant (DOAC), in preventing stroke in atrial fibrillation, there is limited evidence from randomized controlled trials (RCTs).

Objectives:
We aimed to integrate findings from RCTs to compare the efficacy and safety of apixaban with the standard of care (SOC)—antiplatelet therapy (aspirin) or vitamin K antagonists (warfarin)—for stroke prevention in atrial fibrillation.

Methods:
We analyzed the data using RevMan 5.4 with a random effects model, pooling outcomes as hazard ratios (HR) with 95% confidence intervals (CI). The primary efficacy outcome of the study was the composite endpoint of either stroke or systemic embolism. The primary safety outcome was major bleeding. Our study protocol is registered in PROSPERO (CRD42024572983).

Results:
Our analysis included 6 RCTs involving 33,000 participants, an average age of 71.3 years, and follow-up periods ranging from 6 months to 3.5 years. The pooled analysis revealed a statistically significant reduction in the composite outcome of stroke or systemic embolism for patients on apixaban compared to SOC, with an HR of 0.62 (95% CI: 0.44 to 0.87, p = 0.005). No significant difference was observed in major bleeding events between apixaban and SOC, with an HR of 0.93 (95% CI: 0.63 to 1.38, p = 0.72). For secondary outcomes, apixaban did not show a significant impact on all-cause mortality (HR: 0.92; 95% CI: 0.83 to 1.03, p = 0.13) or cardiovascular mortality (HR: 0.92; 95% CI: 0.81 to 1.05, p = 0.22).

Conclusion:
In patients with atrial fibrillation, apixaban was superior to aspirin or warfarin in preventing stroke or systemic embolism. However, no significant differences were found in major bleeding, all-cause mortality, or cardiovascular mortality when comparing apixaban to standard of care. Further randomized controlled trials with longer follow-ups are needed to assess the potential long-term effects and benefits of apixaban.
Abstract TP230: Global Survey on the Management of Cervical Artery Dissection: Assessing Consensus and Variability in Practice
Authors: Akpokiere Favour , Shu Liqi , Engelter Stefan , Yaghi Shadi , Leker Ronen
Published: January 2025

Background:
Cervical artery dissection (CAD) is a leading cause of stroke in young adults, accounting for up to 25% of strokes in this population. Despite its prevalence, there is considerable variability in the management of CAD due to the lack of large-scale randomized trials and inconsistent findings in existing literature. This study aims to assess global treatment practices for CAD and evaluate the consistency of clinical decision-making among stroke physicians using a structured survey.

Methods:
An international survey was distributed to stroke physicians and trainees, including those from the STOP-CAD and TREAT-CAD studies. The survey explored multiple aspects of CAD management, including patient characteristics influencing treatment choices, preferred antithrombotics, treatment duration, and criteria for stopping therapy. Six case-based scenarios were also included to evaluate initial treatment decisions, follow-up imaging practices, and medication duration. Responses were analyzed using Krippendorff’s alpha to quantify inter-rater reliability and assess the degree of consensus among respondents. The data was further analyzed in order to evaluate inter-rater reliability for the case scenarios.

Results:
The survey was completed by 102 stroke neurologists, revealing a moderate overall agreement with a Krippendorff’s alpha of 0.481. Detailed analysis indicated significant variability in responses across different aspects of CAD management, particularly regarding the choice of anticoagulants and treatment duration. While some areas showed higher levels of consensus, the overall variability highlights the lack of standardized practices. Table 1 presents Krippendorff’s alpha values for each of the six case scenarios, assessing overall agreement among respondents within each case. Table 2 provides Krippendorff’s alpha values for each of the five questions within each scenario, examining response consistency for each question across all scenarios.

Conclusions:
The observed variability in CAD management underscores the critical need for further research to establish optimal treatment strategies. While variability itself is not inherently problematic, it suggests that some clinicians may unknowingly provide suboptimal care due to inconsistent practices. This study highlights the importance of developing evidence-based guidelines to reduce uncertainty, ensure optimal care, and improve patient outcomes in CAD treatment.
Abstract TP231: Circle of Willis Arterial Size is Associated with Symptomatic Status in Chronic Carotid Occlusions
Authors: Galecio-Castillo Milagros , Bajrami Arsida , Krug Randall , Cruz-Criollo Leonardo , Kalakoti Piyush , geyik serdar , Ortega-Gutierrez Santiago
Published: January 2025

Introduction:
Patients with chronic carotid occlusion (CCO) may present as either symptomatic or asymptomatic, with significant differences in prognosis and treatment strategies between these groups. Anterograde collateral circulation, particularly through the Circle of Willis (CoW), is essential for sustaining adequate cerebral blood flow in CCO patients. This study aimed to evaluate the association between collateral pathways within the CoW and the symptomatic status of patients with CCO.

Methods:
This retrospective cohort study was conducted across two large comprehensive stroke centers in Turkey and the US, and included patients with CCO treated between January 2018 and December 2023. The Circle of Willis (CoW) was assessed using a combination of CTA, MRA, and DSA, focusing on the visualization and diameter of the following arteries: the anterior communicating artery (AcoA), the first segment of the anterior cerebral artery (A1), the posterior communicating artery (PcoA), the first segment of the posterior cerebral artery (P1), the ophthalmic artery (OA), and the fetal posterior cerebral artery (FPCA). Symptomatic status was defined as any TIA/stroke ipsilateral to the occluded ICA. Multivariable logistic regression was employed to evaluate the independent association between the visualization/presence and size of these arteries and symptomatic status.

Results:
205 patients were included in the study, of whom 153 were symptomatic and 52 asymptomatic. The median age was 67 yrs. [IQR 59–76], and 26.8% were women. Patients in the symptomatic group were younger (median age 64 yrs. [58-72] vs. 75 [68-80],
p
<0.001), and had lower rates of prior treatment with antiplatelets (63.4% vs. 84.6%,
p
=0.04) and contralateral ICA severe stenosis (16.5% vs. 30%,

p
=0.010

). Patients with symptomatic status had significantly smaller diameters of the AcoA (median diameter 1.64 vs. 1.91 mm, aOR 0.09,

p
=0.003

), A1 (median diameter 1.81 vs. 1.91 mm, aOR 0.20,

p
=0.017

), and PcoA (median diameter 1.28 vs. 1.49 mm, aOR 0.21,

p
=0.029

), compared to patients in the asymptomatic group
(Figure 1)
.

Conclusion:
The size of the arteries within the Circle of Willis, serving as a surrogate for anterograde flow, may represent an important parameter to consider in identifying high-risk patients who may not respond adequately to medical therapy.
Abstract TP236: Pretreatment Predictors Of 30-Day Very Poor Outcome After Thrombectomy In Large Ischemic Core Stroke: A Multicenter Prospective Cohort Study
Authors: Nguyen Trung , Nguyen Vinh Khang , Tran Hang , Le Thien , Nguyen Lanh , Bach Dung , Nguyen Nhi , Huynh Quoc Huy , Le Tra , Tran Vu , Pham Binh , Truong Anh , Dang Hung , Phan Bang , Nguyen Thang , Nguyen Huy Thang
Published: January 2025

Introduction:
Despite the efficacy and safety of endovascular treatment (EVT) demonstrated in many large-core randomized controlled trials, up to half of the patients experience very poor outcomes, suggesting a significant number of futile treatments. We aimed to identify predictors of very poor 30-day outcomes (mRS 5-6) after endovascular thrombectomy in patients with large infarct.

Methods:
We conducted a prospective, multicenter, observational study in Vietnam involving four comprehensive stroke centers, screening all consecutive patients who underwent EVT within 24 hours of symptom onset from August 2023 to August 2024. Large cores were defined by an Alberta Stroke Program Early CT Score (ASPECTS) of 3-5 on non-contrast CT or DWI-MRI and were assessed by two ASPECTS-certified stroke neurologists, with disagreements resolved by a senior reader. Risk factors were analyzed using multivariable logistic regression models. Prognosis was evaluated using the modified Rankin Scale (mRS), with very poor outcomes defined as a mRS score of 5-6 at 30-day follow-up. The study adheres to STROBE criteria and is registered as NCT06016348.

Results:
Of the 1,910 patients screened, a total of 361 (18.9%) were included, with a median age of 64.0 years (55.0-70.0) and a median ASPECTS of 4.0 (4.0-5.0). Of these, 145 patients (40.2%) had a mRS of 5-6 at 30-day follow-up. In multivariable analysis, pretreatment predictors included age (aOR 1.06, 95% CI: 1.04-1.08, p <0.0001), a history of atrial fibrillation (aOR 2.65, 95% CI: 1.31-5.47, p=0.007), higher baseline NIHSS (aOR 1.06, 95% CI: 1.01-1.11, p=0.02), anterior cerebral artery (ACA) lesion (aOR 2.72, 95% CI: 1.12-6.82, p=0.03), and higher glucose levels (mmol/dL) (aOR 1.03, 95% CI: 1.01-1.08, p=0.02) and lower ASPECTS (aOR 1.36, 95% CI: 1.008-1.85, p=0.04). The multivariable model demonstrated strong predictive accuracy, with an area under the receiver operating characteristic (ROC) curve of 0.789.

Conclusions:
This study demonstrates that advanced age, higher NIHSS scores, a history of atrial fibrillation, pre-operative glucose levels, ACA lesions, and lower ASPECTS are predictors of very poor outcomes in patients with large ischemic core thrombectomy, which may inform treatment decisions of EVT.
Abstract TP24: The Classification of Stroke Ambulance Dispatches in a Mixed Rural Urban Stroke Ambulance Program
Authors: Sarmiento Robert Joseph , Gilbertson Kimberley , Shuaib Ashfaq , Khan Khurshid , Kate Mahesh , Buck Brian , Jeerakathil Tom
Published: January 2025

Introduction:
Mobile Stroke Units (MSUs) are proven to shorten the time between stroke recognition and thrombolysis resulting to better patient outcomes and are deemed safe and cost-effective. Recent trials demonstrated that a dispatch of a mobile stroke unit in addition to conventional ambulances is associated with lower patient disability at 90 days. Despite these proven advantages, there are few studies describing the nature of the calls that MSUs receive to aid in resource planning. This study aims to describe the types of calls that a mixed rural/urban Stroke Ambulance (SA), in Edmonton, Alberta, Canada received in a year.

Methods:
Stroke Ambulance activations from April 1, 2023 to March 31, 2024 were reviewed to determine the composition of calls and further classify them as to the following criteria: origin of call (metro, suburban, rural), decision of SA (stood down en-route, arrived on scene, SA transport) and thrombolysis decision.

Results:
Of 1030 dispatches 791 were stood down en route. There were 59 patients who received consultation and transport by the Stroke Ambulance of which 51 patients received thrombolysis. There were another 180 patients who received consultation without transport or thrombolysis. Urban patients made up 80% of dispatches with rural and suburban 20%.

Conclusions:
Stroke ambulances in a mixed rural/urban program require a high deployment rate due to a high rate of stand downs. The program provides potentially valuable consultation in the field to three times the number of patients that receive thrombolysis.
Abstract TP240: Efficacy of Platelet Function Testing for Extracranial Carotid Artery Stenting: A Single Center Analysis of 280 Patients
Authors: Roy Joanna , Musmar Basel , Patel Pious , Koduri Sravanthi , Mouchtouris Nikolaos , Ahmed Meah , Fuleihan Antony , Koorie Morena , Mendoza Ayus Santiago , Pedapati Vinay , Hunt Adam , Gooch M. Reid , Jabbour Pascal , Rosenwasser Robert , Tjoumakaris Stavropoula
Published: January 2025

Introduction:
Patients undergoing carotid artery stenting (CAS) are placed on dual antiplatelet therapy (DAPT) to minimize the risk of thromboembolic complications. DAPT carries a risk of thromboembolic events in hypo-responders or hemorrhagic events in hyper-responders to clopidogrel. Despite platelet function testing (PFT) being routinely performed, recent literature has reported varying efficacy in its utility in preventing complications after neurointerventional procedures. Our study evaluates the efficacy of PFT after extracranial CAS.

Methods:
This was a retrospective study of patients who underwent extracranial CAS at our institution from July 2019- March 2023. Patients were dichotomized based on whether they underwent PFT and their subsequent P2Y12- guided antiplatelet regimen of either aspirin (ASA)/ clopidogrel or ASA/ ticagrelor. Outcomes of interest were peri-procedural hemorrhagic complications and follow-up ischemic complications.

Results:
Of 280 patients who underwent extracranial CAS, 47.1% (n= 132) underwent PFT. Among patients who developed a peri-procedural hemorrhagic complication (2.1%, n= 6), 83.3% (n= 5) had their P2Y12 levels drawn (P= 0.073) (Table 1). Among 215 patients who had follow up data, 27.4% (n= 59) developed an ischemic complication and 52.5% (n= 31) had their P2Y12 levels drawn (P= .178). There was no significant difference in rates of peri-procedural hemorrhagic complications (2.9% vs. 0%) or follow-up ischemic complications (23.4% vs. 25.0) across cohorts based on P2Y12 testing.

On multivariate regression, peripheral vascular disease was associated with a 2.36-fold higher odds (95% CI: 1.04- 5.36, P<0.05) of developing a follow-up ischemic complication (Table 2). ASA/ ticagrelor regimen on discharge had a 2.16-fold higher odds (95% CI: 1.04- 4.49, P<0.05) of developing ischemic complications compared to ASA/ clopidogrel.

Conclusion:
Our study revealed significantly higher rates of follow up ischemic complications after the use of ASA/ticagrelor compared to ASA/ clopidogrel. This association was independent of having P2Y12 levels checked.
Abstract TP246: Transcranial Doppler (TCD) Parameters in Predicting Outcomes Following Successful Mechanical Thrombectomy of Large Vessel Occlusions in Anterior Circulation: A Systematic Review and Meta-Analysis
Authors: Ravi Vikas , Pirahanchi Yasaman , Jazayeri Seyed Behnam , Sabayan Behnam , Penagos Julian , Bowers Jeffrey , Hailey Lovella , Mortin Melissa , Modir Royya , Agrawal Kunal , Hemmen Thomas , Meyer Brett , Meyer Dawn , Bavarsad Shahripour Reza
Published: January 2025

Introduction:
Mechanical thrombectomy (MT) is a primary treatment for acute ischemic stroke due to large vessel occlusions. While effective, 20-40% of patients experience hemorrhagic transformation (HT), and around 50% fail to achieve favorable functional outcomes. Transcranial Doppler (TCD) is a non-invasive and cost-effective method for real-time monitoring of hemodynamic status following MT. However, the prognostic value of TCD parameters in predicting HT and poor functional outcome is unclear. We performed a systematic review and meta-analysis of 4 TCD parameters (mean flow velocity (MFV), MFV index, peak systolic velocity (PSV), and pulsatility index (PI) in patients with and without HT and favorable vs poor functional recovery (modified Rankin Scale (mRS) 0-2 vs 3-6).

Methods:
PubMed, Embase, and Scopus were searched on July 25, 2024 to identify observational studies in which TCD parameters were measured within 48 hours from successful MT (Thrombolysis in Cerebral Infarction 2b–3) of anterior circulation. Risk of bias assessment was performed using a standardized tool tailored for TCD studies. The standardized mean difference (Hedges’ g) with 95% CI and risk ratios (RRs) with 95% CI were calculated using random-effects models. The review was prospectively registered on PROSPERO (registration number CRD42024575381).

Results:
Eleven studies met inclusion criteria. No study had high risk of bias. MFV and MFV index were higher in patients with HT+ compared with HT- (Hedges' g = 0.42 and 0.54, p = 0.015 and 0.005, respectively). Patients with MFV index ≥1.3 showed a higher risk of all HT (RR = 2.01, 95% CI = 1.27–3.17, p = 0.003), symptomatic HT (RR, 4.68; 95% CI,1.49–14.65, p=0.008), and poor functional recovery at 90 days (RR, 1.66; 95% CI,1.32–2.08, p<0.001), respectively. There was no difference in mean PSV (p=0.1) and PI (p=0.3) among groups with and without HT.

Conclusion:
Our study highlights the prognostic value of TCD parameters, particularly MFV index, in predicting HT, symptomatic HT, and poor functional recovery after successful MT in the anterior circulation. Our findings were limited by low number of studies. Large-scale and multi-center studies are needed to confirm these findings and validate the MFV index as a reliable predictor to improve post-thrombectomy care.
Abstract TP252: Modulation of Piezo1 Channels Improves Cerebral Blood Flow in a Mouse Model of Alzheimer's Disease.
Authors: Tabrizi Zeynab , Rui Lim Xin , Harraz Osama , Bracko Oliver
Published: January 2025

Alzheimer’s Disease (AD) is the most common form of dementia and is characterized by progressive neurodegeneration and cognitive decline. Cardiovascular risk factors in AD lead to decreased cerebral blood flow (CBF), particularly in capillaries, which play a crucial role in the exchange of oxygen and nutrients in response to neuronal activity. Deficits in capillary-level cerebral blood flow are likely to induce vascular inflammation and disrupt the shear forces associated with blood flow, both of which are hallmarks of Alzheimer's disease and aging. The Piezo1 channel has been shown to be a crucial mechanosensor in brain capillaries that mediates mechanically induced endothelial cell Ca
2+
transients, suggesting a possible role for Piezo1 in CBF regulation. Here, we investigated the contribution of mechanosensitive Piezo1 ion channels to capillary stalling and CBF reductions in the 5xFAD mouse model of AD. We performed cranial window implantation on twelve 4-month-old 5xFAD mice and twelve age-matched wild-type controls. Using
in vivo
multiphoton imaging, we measured cerebral blood flow and capillary stalling in 5xFAD mice following injection with Yoda1, a Piezo1 agonist, before, 24 hrs and one week after Piezo1 activation. Our findings demonstrated that modulating Piezo1 activity reduced capillary stalling and improved CBF in response to Piezo1 activation. Further, Yoda1 injection for one week improved functional hyperemia, measured using laser speckle contrast imaging, in 7-month-old 5xFAD mice. These results suggest the crucial implication of Piezo1 in vascular dysfunction during AD. Importantly, this work highlights the potential therapeutic targeting of Piezo1 to mitigate the effects of impaired cerebral perfusion in AD.
Abstract TP255: Development of an Outcome Prediction Model for Mechanical Thrombectomy in Large Vessel Occlusion and Analysis of the Impact of Age: A Subanalysis of the K-NET Registry
Authors: Tatsuno Kentaro , Ueda Toshihiro , Kaga Yasuyuki , TAKEUCHI MASATAKA , MORIMOTO MASAFUMI , Yamamoto Ryoo , Tsuboi Yoshifumi , SHOGO KAKU , Ito Hidemichi , Onodera Hidetaka , usuki noriko , Takaishi Satoshi , Yoshie Tomohide , Hasegawa Yasuhiro , Yamano Yoshihisa
Published: January 2025

Objective:
Mechanical thrombectomy (MT) for large vessel occlusion (LVO) has become a standard treatment, but outcomes vary depending on patient characteristics and treatment approaches. This study aims to develop a scoring model to quantify the likelihood of good outcomes using data from the K-NET Registry, a prospective study on MT. Additionally, we analyzed the impact of age on these scores and the factors contributing to good outcomes.

Methods:
Among 3,187 patients in the K-NET Registry who underwent MT, 2,381 met the following criteria: 1) pre-mRS 0-2, and 2) occlusion of the internal carotid artery or middle cerebral artery (M1, M2). Patients were randomly divided into 80% training data (n=1921) and 20% test data (n=460). Predictive factors for good outcomes (mRS 0-2 at 90 days) were selected from the training data using a stepwise method, and these factors were utilized as predictor variables. Logistic regression analysis was performed using 10-fold cross-validation, and the K-value minimizing log-loss was applied to the test data. Exponential weights were determined using the model's odds ratio, and discriminative performance was assessed via ROC analysis to estimate the area under the curve (AUC).

Results:
In 2,381 cases, the median values were: age 77 years, NIHSS 18, ASPECTS 8, and 142 minutes (min) from onset to puncture. Predictive factors and their coefficients were as follows: Age (<60: 8, 60-79: 3, ≥80: 0), recanalization (TICI 3: 8, 2b: 5, 0-2a: 0), NIHSS (≤10: 4, 11-20: 2, ≥21: 0), ASPECTS (≥9: 4, 6-8: 2, ≤5: 0), number of passes (1 pass: 2, 2 passes: 1, ≥3 passes: 0), time from onset to puncture (≤140 min: 1, ≥141 min: 0), diabetes (no: 1, yes: 0), intravenous tPA (yes: 1, no: 0). The model, validated with the test data, achieved an AUC of 0.768. Scores ranged from 0 to 29, with higher scores indicating better outcomes. A score of 17 or more was necessary to achieve a likelihood of good outcomes exceeding 50%. The age-specific thresholds were 9 for those under 60, 14 for those aged 60-79, and 17 for those aged 80 or older. Among elderly patients, a low NIHSS (≤10), high ASPECTS (≥9), and complete recanalization were crucial for achieving good outcomes.

Conclusion:
A predictive model for MT in LVO patients was developed, demonstrating good discriminative ability. The cutoff points for predicting good outcomes varied by age, with lower NIHSS, higher ASPECTS, and complete recanalization being particularly important for elderly patients.
Abstract TP260:

Utilization of Computed Tomography Perfusion in the Pediatric and Young Adult Population – A Nationwide Cohort Study
Authors: Lun Ronda , Sreekrishnan Anirudh , Lee Sarah , Albers Gregory
Published: January 2025

Introduction:
Computer Tomography Perfusion (CTP) has become widely implemented into workflow models for adults presenting with acute stroke. However, its utilization in the pediatric/young adult population is not well characterized.

Methods:
We queried the RAPID Insights database from 10/05/2018-09/29/2023 for unique patients between 2-25 years with a CTP. Our inclusion criteria required a minimum ischemic core volume (defined as relative cerebral blood flow (rCBF) reduction of 30% less than normal) of >0 cc and a minimum mismatch volume of >/=0 cc. We analyzed age by pre-defined strata: 2-5, 6-11, 12-18, and 19-25 years. Utilization patterns were analyzed using descriptive statistics according to geographic region: Midwest, Northeast, Southeast, Southwest, and West, and by time epochs, defined as Day: 07:00h-14:59h, Evening: 15:00h-22:59h, and Night: 23:00h-06:59h.

Results:
There were 2492 unique CTP scans. There was a positive correlation between CTP usage with increasing age, with only 23/2492 (0.9%) of scans performed in the 2-5 year age group, and 1825/2492 (73.2%) scans performed in the 19-25 year age group. 307 (12.3%) cases had large vessel occlusions (LVOs) detected, and 77 (3.1%) had intracerebral hemorrhage (ICH). The ICH group was significantly younger than the total cohort: 18.8+/-5.1 vs 20.0+/-3.9 years (p=0.0085). There was a significantly higher proportion of ICHs detected on weekend days compared to LVOs: 59/77 (76.6%) vs 85/307 (27.7%), p<0.0001. Similar proportions of scans were done during the Day (37.5%) and Evening (43.1%), with only 19.4% of scans performed during the Night. The Northeast and Southeast had the highest number of scans performed per hospital (599/168 and 577/129, respectively) compared to the Southwest which had the lowest (156/49).

Conclusion:
This is the largest cohort of CTP studies done in the pediatric/ young adult population for suspected acute cerebral ischemia. Future studies should incorporate clinical indications and perfusion thresholds to advance our limited understanding of CTP use in the pediatric and young adult population.
Abstract TP269: Prognostic Value of Elevated D-Dimer in Cancer-Associated Ischemic Stroke – a Systemic Review and Meta-Analysis
Authors: Roy Danielle , Hao Yu , Wells Claire , Khan Faizan , Poon Candice , Hill Michael , Demchuk Andrew , Wells Philip , Lun Ronda
Published: January 2025

Background:
Patients with active cancer and ischemic stroke have significantly higher morbidity and mortality compared to stroke patients without cancer. Elevated d-dimer levels are a key finding for determining cancer coagulopathy as the likely etiology for stroke. Studies that examined d-dimer as a surrogate marker of outcomes in cancer-associated stroke are limited by small sample sizes. Our objective was to conduct a systematic review&meta-analysis for the prognostic value of serum d-dimer measured at the time of ischemic stroke in cancer patients. We hypothesize that high d-dimer is associated with high rates of recurrent stroke, death,&poor functional outcomes.

Methods:
MEDLINE, Embase, and the Web of Science were searched (until July 2024) for cohort studies of patients with cancer-associated ischemic stroke that assessed the prognostic value of elevated d-dimer levels (measured at the time of stroke onset) for recurrent stroke, mortality, and poor functional outcome (modified Rankin Scale [mRS] score of 3-6). For the primary analysis, we conducted meta-analyses of median differences in d-dimer levels between patients with vs. without the outcomes of interest, using the random-effects method. Meta-analyses of studies reporting odds ratios or hazard ratios could not be performed due to the variable d-dimer cutoffs used across the studies; associations from these studies are summarized narratively.

Results:
From 4522 titles, there were 19 eligible studies. Elevated serum d-dimer was significantly associated with an increased risk of recurrent stroke (pooled median difference 14.54 [95% CI, 2.09 to 26.99], p=0.022), and mortality (pooled median difference, 11.18 [95% CI, 9.67 to 12.70], p<0.001)
.
There was no association between d-dimer level and poor functional outcome (pooled median difference, 0.76 [95% CI, -1.71 to 3.24], p=0.55;
Figure 1).
The forest plot for individual studies studying mortality is shown in Figure 2; visual inspection suggests that those with higher d-dimer levels have higher risks of mortality.

Conclusion:
Elevated serum d-dimer measured at the time of ischemic stroke onset in patients with active cancer may identify those at high risk of recurrent stroke and mortality, though our study is limited by the small number of pooled studies and low individual study sample sizes. Nevertheless, they could support routine clinical use of d-dimer to identify high-risk patients for enrolment in secondary prevention trials.