bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP178: Dual-Phase C-11 PiB PET Images For Detecting Tau Pathology in Cerebral Amyloid Angiopathy
Authors: Yen Ruoh-Fang , Chiang Meng-Ting , LIU CHIAJU , Lee Bo-ching , Tsai Hsin-Hsi
Published: January 2025

Background and Objective:
Cerebral amyloid angiopathy (CAA) is a major cause of lobar intracerebral hemorrhage and cognitive dysfunction in the elderly, and frequently coexists with Alzheimer’s disease (AD) and tau pathology. Dual-phase
11
C-PiB PET can determine amyloid deposition and cerebral perfusion changes, and may have diagnostic value for detecting tau in CAA. This study aimed to assess the diagnostic utility of combining early- and late-phase PiB PET images in predicting tau pathology in CAA.

Methods:
We prospectively enrolled patients with probable CAA for dynamic PiB and AV1451 scans. Tau positivity was defined as a standardized uptake value ratio (SUVR) > 1.26 in the meta-temporal region on static AV1451 PET. We compared early-stage (0-6 minutes after tracer injection) and late-phase (40-70 minutes) PiB PET between the tau(+) and tau(-) groups. Relationships between PiB PET parameters and tau burden were assessed using a linear regression model. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic value of PET parameters.

Results:
No significant differences in age, sex, educational years,
ApoE2
or
ApoE4
carrier status were observed between the CAA/tau(+) vs. CAA/tau(-) groups. As expected, the CAA/tau(+) group had lower MMSE scores (p=0.021) and was associated with a lower hippocampal volume (p=0.036). On PET analysis, CAA/tau(+) was associated with lower early-phase temporal lobe PiB uptake than CAA/tau(-) (SUVR 0.87 [0.81-0.93] vs. 0.92 [0.89-0.98],
p
=0.014) and higher late-phase PiB uptake in the whole cortex and temporal and parietal lobes (all
p
<0.05). Early-phase temporal lobe PiB SUVR significantly correlated with tau burden (r=-0.34,
p
=0.038). Using Youden’s cutoff, early-phase temporal lobe SUVR had a sensitivity of 55% and specificity of 85% and late-phase temporal lobe SUVR had a sensitivity of 80% and specificity of 65% for detecting tau pathology. Together, combining early- and late-phase temporal lobe SUVRs provided a rule-out sensitivity of 90% and rule-in specificity of 100% for tau pathology in CAA.

Conclusions:
AD-signature tau in CAA is associated with a higher amyloid load and reduced perfusion in the temporal lobe, suggestive of neurodegeneration. The combination of early- and late-phase amyloid PET scans may provide a reliable approach to detect concomitant tau in CAA, and could help reduce the radiation exposure and avoid additional scans or the expense of imaging for tau biomarkers.
Abstract WP189: Evaluating Accuracy in Defining Large Core Infarction: A Comparison of Non-Contrast Head CT ASPECTS and CT Perfusion Core Infarct Volume
Authors: Le Ngoc Mai , Ballekere Anjan Nagesh , Azeem Hussain , Iyyangar Ananya , Bajaj Ritesh , Lee Eunyoung , Ebirim Emmanuel , Sheth Sunil
Published: January 2025

Background:
Imaging definitions of large core infarction are highly variable. Here, we assess the performance characteristics of non-contrast head CT versus CT perfusion at predicting final infarct volume (FIV) in patients with large core acute ischemic stroke (AIS) undergoing endovascular therapy (EVT).

Methods:
From our prospectively collected multi-center registry across four comprehensive stroke centers (CSC) in the Greater Houston area, we identified patients from 2017 to 2023 with LVO AIS who received EVT. FIV was defined using MRI DWI at 48 hours. Large infarct core was defined by CTP as exceeding 70 ml or by CT ASPECTS < 6. Kappa statistics assessed agreement between NCHCT ASPECTS, and CTP-RAPID predicted core values (rCBF < 30%). Receiver operating characteristic (ROC) analyses were used to compare the ability of NCHCT ASPECTS and CTP Core to identify large core infarct populations against MRI FIV.

Results:
Among 264 patients with LVO AIS who underwent thrombolysis and met the inclusion criteria, median NIHSS was 16 [IQR, 11-20], MRI FIV was 17.67 [IQR, 6.53-56.45], ASPECTS was 8 [IQR, 6-9], CTP-RAPID predicted core was 6.5 [IQR, 0-29]. 15.2% of patients had an MRI FIV greater than 100 ml. CTP Core measurements and NCHCT ASPECTS agreed 87.5% of the time, with a kappa statistic of 0.3346 (p-value < 0.0001). In 33 cases with discordant results between CTP Core and NCHCT ASPECTS, MRI FIV identified 21 patients as having a large core, aligning with CTP Core but not NCHCT ASPECTS. Conversely, in 12 patients, MRI FIV agreed with NCHCT ASPECTS but not with CTP Core. Both NCHCT ASPECTS and CTP Core showed moderate accuracy in identifying large core infarcts, with similar AUC values of 0.63. Additionally, both methods demonstrated similar discriminatory power (AUC = 0.62) in identifying patients with a modified Rankin Scale (mRS) score of 0-3 after adjusting for age and NIHSS. Sensitivity analysis confirmed similar discriminatory power between NCHCT ASPECTS and CTP Core in identifying large core infarcts (ROC = 0.62) and mRS 0-3 (ROC = 0.59) after adjusting for age and NIHSS, with an 86.58% agreement rate (p-value < 0.001).

Conclusions:
Both NCHCT ASPECTS and CTP core volumes are similarly effective in distinguishing large core infarcts and predicting good outcomes suggesting that either NCHCT or CTP imaging techniques are equally useful for identifying patients with large core infarcts in clinical practice.
Abstract WP19: Assessing the Ability of ChatGPT to Guide the Decision for Intravenous Thrombolysis in Patients with Acute Ischemic Strokes
Authors: Ibrikji Sidonie , Uchino Ken , Buletko Andrew , Itrat Ahmed , Sundararajan Jayashree , Kharal Abbas , Al Banna Mona , KHAWAJA Zeshaun
Published: January 2025

Introduction:
Artificial intelligence is emerging as an adjunct promising tool in medicine. ChatGPT, an AI chatbot that uses machine learning to create human-like dialogue, has shown strong potential in the medical field, specifically aiding professionals in clinical reasoning and diagnosis. We aim to assess the ability of ChatGPT to guide the decision for intravenous thrombolysis (IVT) in patients with acute ischemic strokes (AIS).

Methods:
The performance of ChatGPT in clinical decision making for IVT was compared with that of a board-certified stroke neurologist using artificially created AIS scenarios, covering a broad range of indications and contraindications. ChatGPT was asked to act like an acute stroke clinical decision tool and to answer with a “yes” or “no” along with a 1-sentence justification for its answer. The accuracy and interpretation skills of ChatGPT and the stroke neurologist were analyzed by a blinded assessor, with more than 10 years of experience in stroke neurology.

Results:
Out of the 20 scenarios, ChatGPT’s decision to pursue or withhold IVT was deemed congruent with that of the stroke neurologist’s in 16 scenarios (80%). Based on the blinded assessor’s judgement, two clinical decisions made by ChatGPT and one clinical decision made by the stroke neurologist were rendered wrong. In one case, chatGPT’s reasoning was deemed to be incorrect but the correct clinical decision was made not to provide IVT. In another case, both the stroke neurologist and ChatGPT gave reasonable explanations despite different clinical decisions, both deemed plausible by the assessor. Overall, both chatGPT’s decision to pursue or withhold IVT and the explanation it provided were deemed accurate by the assessor in 17 scenarios (85%).

Conclusion:
This study shows that ChatGPT performed well in most scenarios, potentially reinforcing its ability to guide clinical decision making for IVT in AIS patients. However, ChatGPT is still prone to errors, as shown by its inability to consistently depict contraindications for IVT, and may still not be ready for independent use.
Abstract WP192: Differentiation between contrast extravasation and hemorrhagic transformation in tomography of acute ischemic stroke after thrombectomy with artificial intelligence
Authors: Goulart Thiago , Nather Junior Julio , Okabayashi Miyaji Renato , Pinheiro Fonseca Danilo , Pontes-Neto Octavio , Camilo Millene
Published: January 2025

Background:
Mechanical Thrombectomy (MT) treats Acute Ischemic Stroke (AIS) removing the thrombus, and improves clinical outcome. However, it uses high quantities of contrast, with risk of Contrast Extravasation (CE), but also Hemorrhagic Transformation (HT), both detected by cranial Computed Tomography (CT). However, to differentiate between them, it is necessary to perform a control CT 72 hours after MT.

Aims:
This study aims to develop a tool capable of differentiating HT from EC in cranial CT.

Methodology:
398 CTs were classified into four classes: TH, CE HT with CE, and without HT nor CE. We selected 111 CT performed until 72 hours after angiotomography+MT and segmented the images with 3DSlicer. Then, we had 2 approaches: 1) Three classification models were developed based on phenotypic characteristics: Support Vector Machines (SVM), Random Forest (RF) and Logistic Regression (LR); 2) The U-Net, a Convolutional Neural Networks (CNN) model for biomedical image segmentation.

Results:
SVM and RF had ROC AUC above 92% for the three classes. Cross-validation demonstrated good accuracy (SVM=0.947±0.064; RF=0.893±0.076; LR=0.956±0.048) and macro-precision (SVM=0.947 ± 0.066. RF=0.901±0.075, LR=0.956±0.049). The U-Net also presented good predictive performance after cross-validation: ROC AUC above 98% for the three classes, accuracy=0.956±0.072 and macro-precision=0.965±0.055.

Conclusion:
In this study, we developed a tool with high performance to distinguish between CE and HT with two different approaches, which could help in clinical decision-making, such as introduction of anticoagulants and antiaggregants.
Abstract WP20: The Effect Of Remote Ischemic Conditioning On The Form And Function Of Red Blood Cells In Patients With Acute Ischemic Stroke
Authors: Blauenfeldt Rolf , Waller Jennifer , Ryun Drasbek Kim , Bech Jesper , Hvas Anne-Mette , Larsen Julie Brogaard , Andersen Morten Nørgaard , Nielsen Marlene , Kjoelhede Maria , Kjeldsen Mathilde Damm , Gude Martin , Khan Mohammad B. , Baban Babak , Andersen Grethe , Hess David
Published: January 2025

Background:
Remote Ischemic Conditioning (RIC) is a simple and low-cost intervention that is thought to increase collateral blood flow through the vasodilatory effects of nitric oxide (NO) produced by the endothelium and red blood cells (RBC). This study aims to investigate whether RIC affects RBC deformability and levels of NO and nitrite in ischemic stroke patients.

Methods:
This is a predefined sub-study to the RESIST randomized clinical trial. RIC was started in the ambulance and continued at the hospital for seven days. Patients with a prehospital putative stroke and symptom duration <4 hours could be included in this biomarker study. Blood-samples were collected at different time points: Prehospital in the ambulance, in-hospital upon arrival, 2 hours post-admission, 24 hours post-admission. RBC deformability and erythrocyte aggregation rate were assessed using ektacytometry, NO using flowcytometry, and nitrite content using ozone chemiluminescence.

Results:
A total of 486 patients were included in this study, and of these 249 had AIS (51%). RIC treatment was not associated with increased RBC maximal deformability (RIC: 0.549, Sham: 0.548, p=0.31), RBC NO (RIC 35.30 median fluorescence intensity[MFI], Sham: 34.98 MFI, p=0.89) or nitrite (RIC: 0.036 µM, Sham: 0.034 µM, p=0.38), but RIC treatment was associated with a significantly reduced aggregation pressure, and a slower erythrocyte aggregation rate (RIC: 323.76 Pascal, Sham: 352.74 Pascal, p=0.0113)

Conclusion:
Prehospital and in-hospital Remote ischemic conditioning significantly reduced erythrocyte aggregation rate in patients with acute ischemic stroke, while there was no change in red blood cell deformability, NO content or whole-blood nitrite levels.
Abstract WP201: The Performance of Portable Low-field Magnetic resonance imaging in Acute Ischemic Stroke
Authors: Ciaramitaro Cody , Han Alexander , Nimjee Shahid , Forrest Cassandra , Sorby-Adams Annabel , Kimberly W. Taylor , Lee Vivien
Published: January 2025

Introduction:
The use of ultra low-field portable Magnetic Resonance Imaging (pMRI) in acute ischemic stroke (AIS) is gaining interest, as pMRI is FDA approved and has practical advantages over high-field MRI brain (hMRI). The ACTION PMR study is a prospective cohort study enrolling AIS and perform pMRI within 24 hours of last known normal (LKN). We sought to report patients enrolled in the study from our institution to evaluate the performance of pMRI compared to hMRI.

Methods:
Among the 10 patients enrolled in our center, 1 was excluded for technically nondiagnostic imaging and 1 was excluded due to no infarct visible on hMRI, leaving 8 AIS patients in the cohort for analysis. All 8 patients had both pMRI and hMRI during their hospitalization. Our institutional pMRI (Hyperfine Inc. Swoop®) is a 0.064 Tesla MRI machine, and the protocol includes diffusion-weighted imaging, apparent diffusion coefficient, and fluid-attenuated inversion recovery (scan time 18 minutes) sequences. Infarct size was measured based upon maximum longitudinal axis on DWI.

Results:
Among the 8 AIS patients with radiographic infarcts on hMRI, the mean age was 61.0 years (range, 47.2 to 76.2) and 2 were female. Thrombolysis was administered in 7 (87.5%) patients, and the mean NIHSS on presentation was 3.8 (range, 2 to 7). The mean time from LKN to pMRI was 15.9 hours (range, 10.9 to 20.3) and from pMRI to hMRI was 7.3 hours (range 1.2 to 17.6). All 8 AIS patients had infarcts visible on pMRI. On the 8 hMRI scans, 10 infarct lesions were demonstrated. Infarct distribution was as follows: subcortical (6), cerebellar (1), and cortical MCA/PCA (3). Among 10 infarct lesions measured, mean size was 15.2 mm (range 3.6 to 37.6), and 9 (90%) of hMRI infarcts were visible on pMRI, with the smallest infarct visible on pMRI being 4.5 mm. In contrast, the hMRI visible infarct that was not visible on pMRI measured 3.6 mm. Case 1 (Figure 1) demonstrated DWI-FLAIR mismatch of a right subcortical infarct on hMRI and on pMRI as well.

Conclusions:
In our series, pMRI performed reasonably well on AIS patients and was able to detect the majority (90%) of acute infarcts seen on hMRI. pMRI was able to detect infarcts above 4.5 mm and was also able to demonstrate DWI-FLAIR mismatch. Clinicians need to be aware of the strengths and limitations of pMRI to maximize patient selection for use in the AIS population. Future improvements in DWI imaging at low field may improve sensitivity for small infarcts in the future.
Abstract WP211: A Retrospective Analysis of the Association of Rehab Time on Discharge Disposition and Length of Stay in Hospitalized Patients with Ischemic Stroke or Intracerebral Hemorrhage
Authors: Eperjesi Sarah , Yutrzenka Kayla , Marginean Horia , Crawford Erin , Lesko Alexandra , Clark Diane
Published: January 2025

Introduction:
Physical and occupational therapy are a standard of care for in-hospital stroke patients. The Activity Measure for Post-Acute Care (AMPAC) daily activity and basic mobility scores, a measure of functional ability, are used to assess the need for rehab time while hospitalized. Previous studies demonstrate that AMPAC predicts a patients discharge disposition (DD). This study aims to evaluate whether NIHSS, AMPAC or total rehab duration while hospitalized predicts DD or length of stay (LOS).

Methods:
Data from adult patients who discharged from two medical centers in Portland, OR in 2019 or between January 2022 and May 2023 were abstracted from electronic medical records. Inclusion criteria was a diagnosis of ischemic stroke or intracerebral hemorrhage (ICH). Patients were excluded from the analysis if they:

Had a diagnosis of subarachnoid hemorrhage or traumatic ICH.

Died in-hospital or entered hospice within 7 days of arrival.

Had concurrent acute disease at arrival that was determined to impact rehab.

The primary outcomes were DD and LOS. We dichotomized DD as “good” (home, inpatient rehab) or “poor” (hospice, left against medical advice, acute care facility, intermediate care, and skilled nursing facility). Generalized linear models were used to test if cohort year, arrival NIHSS, 1
st
AMPAC score, and rehabilitation time associated with DD and LOS. Two-tailed p value of less than 0.05 was considered statistically significant.

Results:
More rehab minutes were documented for the 2019 cohort [178 (105, 320) vs. 115 (78, 195) Table 1]. We found no differences between NIHSS at arrival or 1
st
AMPAC score. Our model showed that NIHSS at admit (OR = 0.94, CL: 0.90-0.99, Table 2) and 1
st
AMPAC score (OR = 1.2, CL: 1.2-1.3, Table 2) were significant predictors of a good DD. 1
st
AMPAC was also a predictor of shorter LOS (β = -3.8, CL: -5.8 to -1.9, Table 2).

Conclusions:
AMPAC was the most predictive measure of a good discharge disposition. These findings highlight the continued importance of AMPAC in predicting discharge outcomes and suggest that variations in rehabilitation minutes and hospital stay do not substantially impact discharge disposition.
Abstract WP213: An experimental and theoretical study on electrical brain stimulation for post Intracerebral Hemorrhagic stroke rehabilitation.
Authors: Muguli Ananya , Luan Lan , Xie Chong , Britz Gavin , Aazhang Behnaam
Published: January 2025

Intracerebral Hemorrhagic (ICH) stroke is the second most common type of stroke and its aftermath is often more severe than ischemia. Recent population data has shown increasing trends of ICH in middle aged people, contributing to the economic burden of society. In order to improve post ICH outcome, immediate therapeutic interventions should be administered. Hence, our research is looking into the effects of electrical stimulation of the perihematomal cortex in the hyperacute/acute phase post ICH. The end goal is to test improvement in outcomes of subjects post the administration of such a stimulation paradigm by using the observations in experimental data to validate the theoretical model and hence design a closed loop stimulation paradigm. The two approaches in the work:

Experimental:
Hemorrhagic stroke is induced in minipigs by injecting 2cc of blood into the ventricular space beneath sensorimotor cortex to simulate an ICH. We insert ultra flexible microelectrodes in this region to record cortical neuronal activity and administer stimulation. Neural activity (Electrophysiological) data is collected pre/post stroke and during stimulation. The data collected is analyzed to understand changes in neural activity at different points in time. Through preliminary data analysis, we could clearly see the changes in the statistics of neural activity (pre/post ICH InterSpike Interval (ISI) histogram and firing frequency histogram). Local connectivity changes were observed in the data. Further removal of stimulation artifacts and analysis of neural data before, during and after stimulation shall be performed to understand the changes that occur during stimulation.

Theoretical:
We have mathematically modeled a neuron-astrocyte-vascular system in the cortical perihematoma by extending Hodgkin-Huxley biophysics to simulate pre/post acute ICH and electrical stimulation paradigms in such conditions. The results obtained help us understand the changes in the system dynamics post ICH with bifurcation analysis giving unique outlook of the complex system. The simulated data shows increase in excitability of perihematomal tissue during acute phase. Further, the model also showcases calcium ion dyshomeostasis and problems in ATP production and consumption. Normal stimulation paradigms are shown to not work in such settings. Further exploration of the intricacies of the system is at focus to better understand electrical stimulation in such cerebrovascular conditions.
Abstract WP215: Reliability and Agreement of Artificial Intelligence and Semi-Autonomous Quantification of Anticoagulant-Related Supratentorial Intraparenchymal Hemorrhage
Authors: Sokola Maria , Hassett Catherine , Shah Chintan , Ahrens Christine , Gomes Joao
Published: January 2025

Background:
FDA clearance of fully automated artificial intelligence (AI)-based software for quantifying intracerebral hemorrhage (ICH) volumes has the potential to meaningfully impact the acute management of hemorrhagic stroke. ICH volume is a critical prognostic factor, with larger hemorrhages associated with oral anticoagulant (OAC) use typically resulting in poorer outcomes. Quantifying ICH volume in OAC-related ICH presents challenges due to variability of morphology and density. Although prior studies suggest AI models may improve the accuracy of ICH volume calculation compared to the ABC/2 method and Semi-Autonomous Segmentation (SAS), there is limited data evaluating their performance in OAC-related ICH.

Methods:
A retrospective analysis was conducted on 161 adults presenting to a comprehensive stroke center from 2016-2021 with acute supratentorial OAC-related ICH. Volumes on initial de-identified CT brain were measured using SAS (Syngo.Via, Siemens) and AI (Viz ICH volume, Viz.ai). Agreement of ICH volumes between SAS and AI was assessed using the Intraclass Correlation Coefficient (ICC) for absolute agreement. A two-way mixed effects model was employed for single measurements. A Bland-Altman (BA) analysis with proportional bias assessment was performed. Data analysis was conducted using R studio.

Results:
Out of 161 adults, 50 met eligibility criteria and 39 (78%) CT scans were analyzed by AI and SAS. AI software failed to correctly process 11 scans due to small ICH volumes (n=8), misclassification of lesions as subdural (n=1), or image retrieval issues (n=2). For the 39 scans that were analyzed, the median ICH volume measured by SAS was 15.89 cm
3
(IQR 5.69 – 41.86 cm
3
) and by AI was 17.0 cm
3
(IQR 5.0 – 44.5 cm
3
). The ICC for absolute agreement between the software platforms was 0.973 (95% CI 0.950 – 0.986), indicating excellent reliability. A BA plot revealed a mean difference (bias) of -0.861 cm
3
(95% CI -3.1 – 1.37 cm
3
) with limits of agreement from -14.84 cm
3
to 13.12 cm
3
, demonstrating good agreement between the two methods with no significant proportional bias.

Conclusions:
There is strong agreement and reliability in OAC-related ICH volume measurements between SAS and AI. Such local validation is imperative for safe and responsible integration of AI tools into clinical workflows. Further research into limitations of AI, including failure modes and biases is necessary to inform human oversight.
Abstract WP224: Hematoma location and symptom onset to sampling time are predictors of GFAP release into plasma in acute intracerebral hemorrhage
Authors: Zylyftari Sabina , Kalra Love-Preet , Luger Sebastian , Blums Kristaps , Barthelmes Stephan , Foerch Christian
Published: January 2025

Background:
The astroglial protein GFAP (glial fibrillary acidic protein) is a promising biomarker candidate for prehospital differentiation between intracerebral hemorrhage (ICH) and ischemic stroke. GFAP is rapidly released into plasma from disrupted astrocytes in expanding ICH, but increases more slowly following ischemic cell necrosis. Besides hematoma volume, factors associated with GFAP release in acute ICH have not been explored. It has been noted in previous studies that a certain proportion of ICH patients did not show elevated GFAP levels, leading to a reduced sensitivity of the test. The aim of this study was to analyze GFAP release kinetics according to ICH location and the time span between symptom onset and blood sampling.

Methods:
Consecutive ICH patients admitted within 6 hours of symptom onset were derived from a prospective biomarker study in acute stroke. All blood samples were collected in the prehospital phase. Plasma GFAP measurements were performed on the i-STAT Alinity® (Abbott) point of care device. We determined both ICH volume and hematoma location from the first available brain scan after admission in a standardized way.

Results:
We analyzed 74 ICH patients (mean age 73.5 ± 12.4 years). The median [IQR] time span from symptom onset to blood sampling was 144.0 minutes [113.3] and the mean ICH volume was 35.7 ± 38.8 mL. A strong correlation between hematoma volume and GFAP plasma levels was observed (Spearman rho 0.697; p<0.001). After adjustment for hematoma volume, ICH located in the striatum showed lowest GFAP release rates (44.2 ± 99.8 ng/mL per mL hematoma volume), whereas for cerebellar and brainstem this value was significantly higher (262.5 ± 177.0 and 192.5 ± 212.1). Our findings well match the histopathological distribution of GFAP in the brain. In order to validate this finding, we analyzed datasets of two previous GFAP studies which showed an identical pattern of GFAP release depending on location. We found a positive correlation between time span from symptom onset to blood sampling and GFAP release rate (Spearman rho 0.378; p<0.001).

Conclusion:
Besides hematoma volume, ICH location and time between symptom onset and blood sampling are predictors of GFAP release in acute ICH. Thus, particularly small striatal bleedings in an early time window may be difficult to detect. This shortcoming has to be considered when biomarker-based identification strategies for acute ICH patients are applied in the prehospital phase.
Abstract WP239: Outcomes of adjunct use of intravenous antiplatelets in large vessel occlusion patients secondary to underlying atherosclerosis
Authors: Ali Hamid , Al Kasab Sami , Jumaa Mouhammad , Inoa Violiza , Capasso Francesco , Nahhas Michael , Starke Robert , Fragata Isabel , Bender Matthew , Moldovan Krisztina , Yaghi Shadi , Maier Ilko , Grossberg Jonathan , Jabbour Pascal , Psychogios Marios , Samaniego Edgar , Burkhardt Jan-Karl , Jankowitz Brian , Abdalkader Mohamad , Hassan Ameer , Altschul David , Mascitelli Justin , Regenhardt Robert , Quintero Stacey , Ezzeldin Mohamad , Limaye Kaustubh , Grandhi Ramesh , Al Jehani Hosam , Niazi Hafeez , Goyal Nitin , Zaidat Osama , Derdeyn Colin , Nguyen Thanh , de Havenon Adam , Almallouhi Eyad
Published: January 2025

Introduction:
Preliminary results demonstrated positive outcomes with the adjunct use of IV antiplatelets in patients presenting with large vessel occlusion secondary to underlying intracranial atherosclerosis (ICAS-LVO) undergoing mechanical thrombectomy (MT). We aimed to assess the outcomes of this approach in a prospective registry.

Methods:
This is a pre-specified secondary analysis of the RESCUE-ICAS registry, a prospective cohort study including patients with 50-99% residual intracranial stenosis or re-occlusion following MT. Patients were divided into three groups: MT alone, MT with adjunct IV antiplatelets, or MT with adjunct stenting. Periprocedural IV antiplatelets used in this study included tirofiban, eptifibatide, and cangrelor. Primary endpoint was modified Rankin scale (mRS) of 0-2 at 90 days. Statistical analysis included logistic regression model to assess the factors associated with good 90-day outcomes.

Results:
A total of 57 patients received periprocedural IV antiplatelets without stenting (group 1) compared to 182 patients who underwent MT alone (group 2) and 198 who underwent MT with adjunct stenting (group 3). Median age was 69 and 40.4% of patients were females. There was no significant difference in baseline demographic and clinical characteristics of patients in the IV antiplatelets group compared to groups 2 and 3. There was no significant difference in mRS 0-2 at 90 days between patients in the IV antiplatelets group compared to the MT alone group (19.3% vs 30.2% P=0.108). However, patients in the MT with adjunct stenting group had higher rate of 90-day mRS of 0-2 (42.4% vs 19.3%, P=0.001) compared to the IV antiplatelets group. On multivariable analysis, MT with adjunct stenting was independently associated with good 90-day outcome (AOR 3.946, 95% CI 1.845-8.439, P<0.001) (Table 1).

Discussion:
In patients presenting with ICAS-LVO, IV antiplatelets as an adjunct to MT was not associated with higher odds of favorable functional outcome compared to MT alone. Patients undergoing MT with adjunct intracranial stenting had better functional outcomes when compared to MT with IV antiplatelets group. Further studies are necessary to validate our findings in this unique stroke subgroup.
Abstract WP245: Even minimal-dose intravenous heparin injection around mechanical thrombectomy would be related to higher incidence of early hemorrhagic conversion and distal migration without any clinical benefical effect.
Authors: Park Heekwon , Kim Jong-Uk , Jeong Sang , Rha Joung-Ho
Published: January 2025

Background and Aims:
Previous studies indicated the usual dose heparin(5000 IU bolus followed by 500~1250 IU/h) during mechanical thrombectomy(MT) is associated with an increased risk of hemorrhagic conversion without beneficial effect. East Asians are known to have a higher risk of bleeding compared to other races, and they often take lower doses of antithrombotics. However, role of minimal-dose heparin as an adjuvant treatment during MT in East Asians remains unclear.

Methods:
We enrolled the patients who underwent MT from the Inha University Hospital Stroke Prospective Registry and compared clinical findings between patients who received heparin during MT and those who did not.

Results:
From January 2016 to March 2024, 460 patients (68.8 years, 270 men) were included, and 70(15.2%) subjects received intravenous heparin, dose 500-1000 IU bolus, followed by 500 IU per hour. There were no differences in baseline characteristics or procedural parameter including procedural time, device, and TICI grade between two groups. However, intravenous thrombolysis was performed more frequently in the non-user group than in the heparin group, and the apTT value after the procedure was higher in the heparin group than in the other groups(75.9±12.5 vs 40.8±10.1 sec). The risk of hemorrhagic conversion on image was significantly higher in heparin group than non user group(31.4% vs 21.3%, p=0.04). This trend also seemed to be seen in patients who did not undergo intravenous thrombolysis group. This Early distal migration of embolus, defined as difference location of embolus between initial CT angiography and initial conventional angiographym was observed more frequently in heparin group, compared with non-user group. However, there was no difference in mRS at 90 days and early neurological deficit between the two groups.

Conclusions:
Even minimal dose of intravenous heparin injection around MT was associated with an increased risk of hemorrhagic conversion and distal migration without significant change in functional outcome or recanalization status.
Abstract WP261: Tortuosity and Navigation in Mechanical Thrombectomy: A Computational Study of Anatomical Challenges
Authors: Kareddy Abhinav , Ullah Tahmid , Rifkin Jared , Kellogg Ryan
Published: January 2025

Mechanical thrombectomy (MT) is an established treatment for anterior circulation stroke due to large vessel occlusion. Multiple endovascular approaches exist to reach the same target, yet determining the best route remains unclear. Operators often rely on subjective and qualitative factors in their decision-making due to a lack of quantitative data. The primary navigation challenge stems from the interaction between devices (catheters, guidewires) and arterial anatomy. This study uses computational modeling to simulate these interactions, aiming to identify anatomical features that contribute most to procedural difficulty. We evaluated navigation tortuosity in anterior MT cases by comparing vessel centerlines derived from imaging (TI-tortuosity index) with computationally simulated device navigation in 107 patient anatomies. Twelve pathways were analyzed by considering femoral and radial approaches targeting the right or left carotid terminus (RCA, LCA) and the right or left vertebral arteries (RVert, LVert). Finite element modeling was employed to simulate device navigation with two primary metrics: local bending energy (LBE—representing the acuteness of a 2 cm segment of the path highlighting local curvature) and device tortuosity index (dTI) to measure overall tortuosity of the simulated device. Cases included surgical notes detailing procedure duration like time to first pass (FP) and Likert scores of operator-reported navigation difficulty. The relationship between case difficulty and computed metrics was assessed using Kendall’s tau. Vessel centerline metrics varied based on approach and target vessel. Time to FP showed the strongest associations with case difficulty, followed by LBE. These associations improved when utilizing the simulated device TI. Device simulation metrics outperformed vessel centerline metrics in predicting case difficulty. However, no metric—whether from imaging or simulation—outperformed time to FP in predicting case difficulty. Our findings underscore the variability in centerline metrics based on anatomy and choice of arterial access. While time to FP remains strongly correlated with procedural difficulty, centerline metrics can be obtained preoperatively to predict navigation challenges. Notably, simulated device metrics demonstrate superior predictive performance compared to traditional vessel centerlines, suggesting that endovascular simulations could be crucial for preoperative planning to assess navigation difficulty.
Abstract WP263: Successful Endovascular Thrombectomy Accelerates Recovery of Multiple Post-Stroke Domains
Authors: Llinas Edward , Aldridge Chad , Metu Jeet , Southerland Andrew
Published: January 2025

Introduction:
Despite evidence showing overall improvement of post-stroke outcomes following endovascular therapy (EVT), existing literature on comparative recovery rates of different stroke deficits is limited. We hypothesized that the rate of change in aphasia may vary compared to other neurological deficits in stroke patients post successful EVT.

Methods:
We performed a retrospective analysis of acute stroke patients at a single comprehensive stroke center who presented with aphasia and underwent EVT from 2022 to 2023 (n=122). Total and itemized NIHSS scores were documented at three separate timepoints: admission, immediately post-EVT, and at discharge; NIHSS scores were normalized by dividing each score by its maximum possible value. We also investigated the NIH Cog-4 and Motor-6 as summative scores representing domain specific cognitive and motor deficits, respectively. We analyzed the effects of TNK and successful reperfusion (TICI 2B to 3 vs 0 to 2A) on the normalized stroke deficit scores with a linear mixed-effect regression model adjusted for measurement timepoint with subjects as a random effect. We extracted each variable’s beta coefficient, representing the variable’s average effect on NIH score (e.g. average change in score from admission to post-EVT). Recovery was represented by percent changes in beta coefficient by successful vs unsuccessful reperfusion. We also evaluated the percent change in beta coefficients with a stratified analysis of ≥ TICI 2B using permutation testing (500 permutations) to test the null hypothesis that there are no change in beta coefficients between subgroups (p<0.05).

Results:
Successful reperfusion (≥ TICI 2b) was associated with a decline in aphasia impairment post-EVT (Beta -7.5%; SE 0.038; p 0.049) and at discharge (Beta -22.6%; SE 0.038; p< 0.01) versus unsuccessful reperfusion (< TICI 2b) post-EVT (Beta -2.6%; SE 0.112; p 0.821) and discharge (Beta -7.7%; SE 0.112; p 0.499). A similar decline in impairment with successful reperfusion was also observed for Cognition (p<0.01), Motor (p 0.027), and Global (p 0.001) scores (Figure 1).

Conclusions:
Successful reperfusion was associated with a significant decline in impairment in aphasia as well other itemized domains for stroke patients post-EVT and at time of discharge. Future research in larger, multicenter datasets and incorporating longitudinal outcomes may help further differentiate long term recovery of individualized stroke deficits post treatment.
Abstract WP266: The Association Between Sleep Apnea Symptoms and Depression in Stroke Survivors: Insights from the Stroke Transitions Education and Prevention (STEP) Clinic
Authors: Almohamad Maha , Mofleh Dania , Sharrief Anjail
Published: January 2025

Background:
Sleep apnea symptoms, such as snoring and breathing pauses, often co-occur with depression in stroke survivors, adversely affecting recovery and quality of life. This study examines the relationship between the frequency of these symptoms and depression in stroke survivors.

Methods:
Data were analyzed from 737 stroke survivors enrolled in the Stroke Transitions Education and Prevention (STEP) clinic from January 2021 to August 2023. Sleep apnea symptoms were assessed using a modified questionnaire that emphasized frequent symptoms such as snoring, breathing pauses, being severely overweight, morning headaches, dry mouth, and gasping arousals. The presence of these symptoms contributed to coding participants as "Yes" for sleep apnea. Data were collected from patients seen over telemedicine or through electronic form submissions. Patients who opted out of participation in the registry were excluded from the analysis. Depression was measured using the Patient Health Questionnaire-9 (PHQ-9) and coded as binary: "Yes" for a PHQ-9 score ≥5 (mild to severe depression) and "No" for a score <5. Logistic regression was used to evaluate the association between sleep apnea symptoms and depression, adjusting for race, gender, tobacco use, heavy alcohol use, and respiratory symptoms.

Results:
The study population was 46.64% male, 54.52% White/Caucasian, and 30.88% Black/African American, with 62.4% Non-Hispanic. In terms of lifestyle factors, 51.16% had no history of tobacco use, while 38.18% reported past tobacco use. Additionally, 32.04% reported heavy alcohol use. Clinically, 74.16% had hypertension, and 29.90% had diabetes. Stroke survivors who reported frequent sleep apnea symptoms had significantly higher odds of depression compared to those without significant symptoms (OR: 4.40; 95% CI: 1.85-10.47; p=0.001). Tobacco use was marginally associated with depression (OR: 1.77; 95% CI: 0.97-3.23; p=0.065). Other variables, such as race, gender, heavy alcohol use, and respiratory symptoms, were not significantly associated with depression.

Conclusion:
Assessing sleep apnea symptoms in routine stroke clinic evaluations can help identify patients at risk for depression. Although the questionnaire used is not a diagnostic tool for sleep apnea, understanding the frequency of these symptoms can lead to improved mental health management and post-stroke recovery. Personalized care that addresses both physical and mental health is essential for stroke survivors.
Abstract WP267: Paradoxical Stroke-Related Mortality Risk Among Asian Americans
Authors: Ding Xueting , Albala Bruce , Boden Bernadette
Published: January 2025

Introduction:
While stroke-related health disparities among certain racial/ethnic groups in the US are well-documented, less is known about outcomes for Asian Americans. Despite lower overall mortality rates, Asians globally may face a high stroke burden, particularly in East and Southeast Asia. This study investigates whether Asian Americans exhibit elevated risks for stroke-related mortality compared to other racial/ethnic groups in the US.

Methods:
We analyzed 2011-2014 National Health and Nutrition Examination Survey (NHANES) data linked to mortality records through December 2019. Outcomes included all-cause and stroke-specific mortality (ICD-10 codes I60-I69). Race/ethnicity was self-reported as Non-Hispanic White, Black, Asian, Hispanic, and Other. Cox proportional hazard models examined mortality risks by race/ethnicity, adjusting for age and sex.

Results:
Among 9,860 participants, the demographic breakdown revealed a consistent distribution of sex and age across racial/ethnic groups, with females comprising about half of each group. The mean age ranged from 21.0 years (Other) to 37.5 years (Non-Hispanic White), and non-Hispanic Asians were at about 32 years. For all-cause mortality, non-Hispanic Asians (HR=0.40, 95% CI: 0.30-0.53) and Hispanics (HR=0.62, 95% CI: 0.51-0.75) showed significantly lower hazard ratios compared to non-Hispanic Whites. However, for stroke-related mortality, non-Hispanic Asians showed a higher risk (HR=2.60, 95% CI: 1.15-5.92) relative to the reference group.

Conclusions:
Our findings reveal a potential paradox that while Asian Americans have lower all-cause mortality, they may face higher stroke-related mortality risks compared to non-Hispanic Whites. This aligns with global patterns of high stroke burden in Asian populations. These results highlight the need for further investigation around vascular risk factor profiles in Asian populations and the need for targeted stroke prevention and management strategies for Asian Americans, despite their overall health advantages in other areas.
Abstract WP268: The COVID-19 Pandemic Significantly Affected Acute Ischemic Stroke Subtype, Patient Characteristics, and Outcomes
Authors: Belits Anna , Pirahanchi Yasaman , Wang Frank , Higgins Katie , Kim Diana , Rankine Ian , Salottolo Kristin , Bar-Or David , Burrell Christian
Published: January 2025

Introduction:
The overall composition of stroke subtype is typically stable within biogeographical groups. Whether the COVID-19 pandemic impacted stroke etiology is still being investigated, but most studies have been performed outside the United States. This study sought to determine the composition of acute ischemic strokes (AIS) before and during the pandemic.

Methods:
This retrospective cohort study was conducted at a comprehensive stroke center in Colorado (USA). Adults (≥18) with AIS were compared based on admission date: Pre-COVID period (1/1/2019 – 12/31/2019) vs. COVID period (3/1/2020 – 3/1/2021). Stroke subtype was examined using TOAST classification: 1) large artery atherosclerosis; 2) cardioembolic; 3) small vessel occlusion; 4) other known etiology (e.g., hematologic disorders or arterial dissection); 5) cryptogenic stroke. Comparisons were made with Pearson chi-square tests.

Results:
There were 2,130 patients with AIS during the study period: Pre-COVID (n=1,034) and COVID (n=1,096). There were significant differences in stroke subtype by time period (Table 1). Compared to the pre-COVID period, the COVID period had a lower proportion of strokes from large artery atherosclerosis (17.6% vs. 12.1%, p<0.001) and small vessel occlusion (10.1% vs. 7.7%, p=0.05), and significantly more cryptogenic strokes (25.6% vs. 31.8%, p=0.002); rates of cardioembolic stroke and other known etiology were similar between time periods. There were no differences in age, race, and most comorbidities by time period. Compared to the pre-COVID period, there were fewer males (56.1% vs. 49.0%, p=0.001) and more patients with atrial fibrillation (17.2% vs. 21.2%, p=0.02) during the COVID period. Stroke severity and outcomes also differed between time periods. Patients admitted during the COVID period were more likely to be endovascularly treated (17.8% vs. 22.2%, p=0.01), to have more severe strokes (NIHSS ≥21, 9.8% vs. 12.7%, p=0.01), and to have worse discharge mRS compared to patients admitted pre-COVID (Table 1).

Conclusion:
In the setting of a widespread pandemic such as COVID-19, stroke etiology, demographics, and clinical outcomes can shift dramatically. These changes included a higher rate of cryptogenic strokes, fewer strokes from large artery atherosclerosis and small vessel occlusion, more strokes among females, a higher number of patients with atrial fibrillation, more patients requiring endovascular treatment, more severe strokes, and worse clinical outcomes.
Abstract WP281: Optimizing Transthoracic Echocardiography Utilization for Hospitalized Ischemic Stroke Patients
Authors: Jani Neel , Basinger Haley , Jones Ann , Sattin Justin , Struck Aaron
Published: January 2025

Introduction:
Determining ischemic stroke etiology using transthoracic echocardiography (TTE) is often considered to be a standard part of routine stroke care and secondary prevention of stroke. However, TTE’s are not always readily available, can delay hospital discharge, and increase the cost of each hospitalization. Identifying which patients specifically benefit from TTE’s could optimize resource allocation. The aim of the study is to develop a model using machine learning methods to confidently identify patients unlikely to have an actionable finding with enough statistical certainty to defer an inpatient TTE.

Methods:
The model was developed using 874 patients admitted for stroke/TIA from 2017-2018 and was validated on another data set of 200 patients randomly selected from 2017-2018 from a different institution. 23 variables were considered as potential inputs for the model, which was developed using logistic regression. All variables except six were truncated from the model based on coefficient magnitude and adjusted to be the same low-term improper fraction for simplicity. This model was internally validated using a 5-fold cross-validation and was then tested on an external validation data set with performance being compared to other standard machine learning models.

Results:
The training/test data consisted of 874 patients (52.9% male; median age 64 years). Validation data set consisted of 200 patients (53.5% male; median age, 63 years). For the final model, termed ALO
2
HA, mean AUC on the training/test data across five-fold cross validation was 0.79 (95% CI, 0.74 - 0.84). The model consisted of six variables, and one point was awarded for each: atrial fibrillation, large artery atherosclerosis, large vessel occlusion, obesity, prior anti-hypertensive medication usage and if patient’s age was 18-39 or > 69. Risk of positive findings was 6.2% for score of 0, 26.1% for score of 1, 65.0% for score of 2, 90.7% for score of 3, 98% for score of 4, and 99.7% for score of 5 or greater. When tested on the external validation data set, AUC was determined to not be significantly different than the AUC for the training/test data.

Conclusion:
The ALO
2
HA model is a clinical tool which can stratify which patients admitted for acute ischemic stroke/TIA are more likely to benefit from inpatient TTE's.