bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP181: Are Genetic Variants Associated With the Location of Cerebral Arterial Lesions in Stroke Patients?
Authors: Kim Yeon-Jung , Kim Bum Joon , Lee Ji Sung , Chang Dae-il , Choi-Kwon Smi , Lee Jong-Keuk , Kang Dong-Wha , Kwon Sun U. , Kim Jong S.
Published: June 2021

Introduction:
Genetic variants may play a role in determining the location of cerebral atherosclerosis.

Hypothesis and aim:
We aimed to investigate the association between
RNF213
,
MMP2
, and genetic polymorphisms linked to vascular tortuosity with the location of cerebral arterial atherosclerosis.

Methods:
A prospective case-control study was conducted on patients with ischemic stroke and age- and sex-matched stroke-free controls. The stroke patients were categorized into those with intracranial artery atherosclerosis (ICAS), extracranial artery atherosclerosis (ECAS), and small vessel occlusion (SVO). Six single nucleotide polymorphisms (SNPs) including rs2118181 (
FBN1
), rs2179357 (
SLC2A10
), rs1036095 (
TGFBR2
), rs243865 (
MMP2
), rs1800470 (
TGFB1
), and rs112735431 (
RNF213
) were analyzed with the TaqMan Genotyping Assay, and the distribution of genotypes across groups was compared.

Results:
None of the six SNPs were associated with stroke on comparing the 449 stroke patients (71 with ECAS, 169 with ICAS, and 209 with SVO) to the 447 controls. In the subgroup analysis, the adjusted odds ratios (aORs) for age and sex indicated a significant association between rs112735431 and ICAS in the allele comparison analysis and in the additive and dominant model analyses. rs112735431was associated with anterior circulation involvement and increased burden of cerebral atherosclerosis. rs2179357 was significantly associated with ICAS in the recessive model analysis, and rs1800470 was significantly associated with ECAS in the recessive model analysis when compared to controls.

Conclusion:
rs112735431 was associated with ICAS, and increased atherosclerosis burden in the Korean population. Further studies are needed to elucidate the role of rs112735431, and to confirm the association of rs2179357 and rs1800470 with cerebral atherosclerosis.
Abstract TP182: Stroke Outcome in Mexican American Immigrants and Non-Immigrants
Authors: Morgenstern Lewis B , Lisabeth Lynda , Gibbs River , Kim Sehee , Agyemang Charles
Published: June 2021

Background/Objective:
We studied the association of being born outside of the U.S. (immigrant) or born in the U.S. (non-immigrant) with 90 day post-stroke outcomes in a population-based stroke study in Texas.

Methods:
Stroke cases from 2008-2016 were identified from the Brain Attack Surveillance in Corpus Christi (BASIC) project. Outcomes among survivors included ADL/IADL score (higher scores worse) for functional assessment, 3MSE (cognition, lower scores worse), and NIHSS Score (neurologic, higher scores worse). Weighted linear regression models were used to assess the effect of immigration status on the outcomes. Analysis was completed using multiple imputation and inverse probability weighting to account for differential attrition.

Results:
Of 935 Mexican Americans available for analysis, 83 were immigrants and 852 were non-immigrants. Immigrants had resided in the U.S. on average 47 years. Immigrants were significantly older (69 vs. 66 years), more likely male (60% vs. 49%), more likely to have atrial fibrillation and have less education than non-immigrants (all p<0.05). No differences in hypertension, diabetes, cholesterol, insurance, smoking or other comorbidities existed. The Table provides the data from the fully adjusted models. Immigrants had better functional outcome (mean difference (MD) = -0.22; p=0.02), and no difference for neurologic outcome (MD= -0.15; p=0.15). There was an association of worse cognitive outcome in immigrants (MD= -5.25; p=0.009), however, the association was explained by attenuated after the adjustment for the lower educational attainment in immigrants (MD= -0.79; p=0.64).

Conclusions:
In this community, there was no evidence of worse stroke outcome among Mexican American immigrants, who had lived in the U.S. for decades, compared with non-immigrants. Further studies of more recent immigrant populations are warranted.
Abstract TP184: High-Density Lipoprotein Cholesterol Levels Inversely Associated With First Ischemic Stroke in a Chinese Hypertensive Population
Authors: Zhang Yue , Li Jingyi , Liu Chengzhang , Chen Chen , Bi Chonglei , Fang Chongqian , Ma Hai , Li Aimin , Dong Qing , Wang Binyan , Cheng Xiaoshu , Zalloua Pierre , Huo Yong , Li Gang
Published: June 2021

Background and Purpose:
Lipid levels are established risk factors for ischemic heart disease, but uncertainty persists about the relevance of lipids for first ischemic stroke (IS). The goal of this study was to evaluate whether lipid profiles are risk factors for first IS in a Chinese hypertensive population.

Methods:
Our study population was selected from 300,000 individuals registered from 2016-2018 in the Lianyungang and Rongcheng “H-type hypertension prevention and control public service project”. Hypertensive patients with stroke data from the Chinese centers for disease control and prevention (CDC, 2013-2018) who had complete records (physical exam, questionnaire, and biological samples) were selected as cases. We used a nested case-control study design and matched 3615 ischemic stroke cases with an equal number of controls (hypertensive patients without stroke) for age±1 years, sex, and village. The crude and adjusted risks of first ischemic stroke were estimated by ORs and 95% CIs using conditional logistic regression, with or without adjustment for pertinent covariates.

Results:
Participants with first IS had higher blood pressure, body mass index, fasting glucose, triglycerides, and low-density lipoprotein cholesterol. High-density lipoprotein cholesterol (HDL-C) was significantly and inversely associated with IS risk (OR, 0.71; 95% CI: 0.61-0.82). When HDL was assessed as quartiles, the lowest quartile was used as reference, a significantly lower risk for IS was found in the highest quartile (HDL-C ≥ 1.8mmol/L: OR, 0.70; 95% CI: 0.59-0.82). There was a significant positive association between TG and the risk of IS (per SD increment; OR, 1.13; 95% CI, 1.07-1.20). Consistently, a significantly higher risk of first IS was found in quartile 4 (≥1.8 mmol/L: OR, 1.41; 95% CI, 1.20-1.65) compared with those in quartile 1 (<0.9 mmol/L).

Conclusions:
HDL-C levels inversely associated with first IS. These results differ from existing evidence from western populations, highlighting potential differences in Chinese populations. These differences can be attributed to multiple factors, including genetics, diet and lifestyle and call for further study to investigate potential explanatory mechanisms.
Abstract TP185: CRP as a Predictor for Hemorrhagic vs Ischemic Stroke
Authors: Lyden Stephanie , DeHavenon Adam , Reddy Vivek , Majersik Jennifer
Published: June 2021

Background:
Studies have found an association between elevated serum C reactive protein (CRP) levels and increased ischemic stroke risk
2,4-5
. Other studies have looked at whether CRP levels correlate with outcome and severity after ICH
1,3
. Less research has been done looking at CRP levels and the risk for hemorrhagic stroke. This study aims to confirm the association of baseline elevated serum CRP levels and increased risk for ischemic stroke, thus validating this dataset, and to evaluate whether these levels correlate with an increased risk for hemorrhagic stroke.

Methods:
This is a secondary analysis of the data from the Cardiovascular Health Study (CHS). The primary outcome is ischemic stroke and the secondary outcome is hemorrhagic stroke. The primary predictor is CRP level at baseline, as a continuous value and, after dividing into quintiles, a comparison between the lowest and highest quintiles. We fit Cox proportional hazards models and adjusted for baseline covariates that were associated with the outcomes, which for ischemic stroke included age, race, cholesterol, diabetes, hypertension, atrial fibrillation, and history of TIA or myocardial infarction; and for hemorrhagic stroke included age, cholesterol, diabetes, and hypertension.

Results:
We included 5,681 patients, of whom 918 (16.2%) had ischemic stroke and 150 (2.6%) had hemorrhagic stroke. Mean (SD) days of follow-up was 4,403 (2,504) and mean (SD) CRP was 4.8 (8.3). We found that baseline CRP was associated with ischemic stroke (HR 1.01, 95% CI 1.00-1.02, p=0.005), but not hemorrhagic stroke (HR 1.00, 95% CI 0.97-1.02, p=0.781). When comparing the highest to lowest quintile of CRP, we found a clinically significant increased risk of ischemic stroke (HR 1.37, 95% CI 1.11-1.70, p=0.004) (Figure 1), but again not for hemorrhagic stroke (p=0.852).

Conclusion:
Our analysis found that elevated baseline CRP levels are associated with an increased risk for ischemic stroke, but not hemorrhagic stroke.
Abstract TP186: Incidence and Risk Factors for Stroke and All-Cause Mortality in Korean Adults Congenital Heart Diseases
Authors: Jung Jin-Man , Shin Hong Ju , Kim Jae-Young , Seo Woo-Keun
Published: June 2021

Objective:
To compare incidence of ischemic stroke, hemorrhagic stroke and all-cause mortality in Korean adults congenital heart disease (ACHD) to that of control and scrutinize risk factors for these outcomes.

Methods:
Subjects aged over 20 were collected from the Korea National Health Insurance Service from 2006 through 2017. ACHD group as case was extracted from the diagnosis records related to CHD according to the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD 10). Those without CHD (control group) was selected as 4 controls for each patient through random sampling. We compared incidence rate of ischemic stroke, hemorrhagic stroke and all-cause mortality. Cox proportional hazard models were used to investigate relevant risk factors for each of outcomes.

Results:
Case and control group were 49,445 and 249,649, respectively. Age-adjusted rates of ischemic stroke, hemorrhagic stroke and all-cause mortality in case was by about 4 times more higher than those of control. Cumulative survival plot demonstrated that ACHD was associated with ischemic stroke (HR 1.31 95% CI 1.25-1.36), hemorrhagic stroke (HR 1.49 95% CI 1.36-1.63), and all-cause mortality (HR 1.41 95% CI 1.35-1.46). Case group was associated with younger age, female, hypertension, diabetes mellitus, coronary artery disease, heart failure, atrial fibrillation (all
p
<.001). In Cox proportional hazard model for ischemic stroke, diabetes (HR 2.13 95% CI 1.93-2.35) and coararctation of aorta (HR 1.54 95% CI 1.13 - 2.09) carried highest risk. In multivariable analysis for hemorrhagic stroke, hypertension (HR 2.28 95% CI 1.74-2.98) was highest risk factor. Multivariable analysis for all-cause mortality showed that congestive heart failure (HR 1.78 95% CI 1.65-1.92) and Eisenmenger syndrome (HR 2.91 95% CI 2.53-3.35) was highest risk factor.

Conclusions:
Korean ACHD patients have significantly higher incidence of co-morbidities including hypertension, diabetes mellitus, several heart diseases. They have a higher tendency of ischemic, hemorrhagic stroke and mortality. These findings suggest that medical surveillance and risk factor management is sustainedly needed for ACHD patients to reduce stroke and mortality in the future.
Abstract TP187: Disparities in Secondary Stroke Prevention Among Filipinos in Hawaii
Authors: Young Nicole , Nakagawa Kazuma , Tokumaru Sheri , Taira Deborah
Published: June 2021

Introduction:
In Hawaii, Filipinos have the highest stroke mortality for unclear reasons. The objective of this study is to elucidate racial-ethnic differences in the use of antithrombotics and statins upon discharge home from hospitalization among stroke survivors.

Methods:
The Get With the Guidelines-Stroke (GWTG-Stroke) data from January 2010 to December 2016 at the only Comprehensive Stroke Center in Hawaii was retrospectively reviewed. Subjects with non-ischemic stroke and with disposition other than home were excluded. Multivariable logistic regression models examined differences in appropriate medication use at discharge related to race/ethnicity compared with whites after adjusting for age, sex, insurance status, prior medication use and stroke risk factors.

Results:
Among a total of 2347 patients studied (621 (26%) whites (W), 302 (13%) Filipinos (FI), 838 (36%) other Asians (OA), 538 (23%) Native Hawaiians and other Pacific Islanders (NHOPI), and 48 (2%) other race (O)), FI were prescribed less antithrombotic agents at discharge [OR 0.56; 95% CI 0.380, 0.837] than W, while there were no racial-ethnic differences among OA, NHOPI and O compared to W. Age [OR 1.02; 95% CI 1.006, 1.03], prior antithrombotic use [OR 2.04, 95% CI 1.47, 2.82] and coronary artery disease/prior myocardial infarction [OR 2.04, 95% CI 1.23, 3.39] were also independent predictors of antithrombotic prescription upon discharge.

For statin prescription upon discharge, there was no difference between FI and W. NHOPI race [OR 2.09; 95% CI 1.54, 2.83], age [OR 1.01, 95% CI 1.001, 1.02], female sex [OR 0.68; 95% CI 0.55, 0.84], prior anti-cholesterol medication use [OR 4.12, 95% CI 3.01 5.63], dyslipidemia [OR 1.91, 95% CI 1.47, 2.49] and carotid stenosis [OR 0.49, 95% CI 0.32, 0.74] were predictors of statin prescription upon discharge.

Conclusions:
Filipinos are less likely to be prescribed an antithrombotic for stroke prevention compared with whites after hospitalization for stroke.
Abstract TP190: Elderly Stroke Patients Seen by Telemedicine and Retained at Spoke Community Hospitals Have Lower Early Mortality and Discharge to Hospice Than Those Presenting to a University Hub Hospital
Authors: Chu Kristie , Zhu Liang , Ankrom Christy , Trevino Alyssa , Joseph Michele , Malazarte Rene , Sarraj Amrou , Zha Alicia , Cossey TC , Savitz Sean , Wu Tzu-Ching , Jagolino-Cole Amanda
Published: June 2021

Introduction:
Age remains one of the most important non-modifiable risk factors leading to poor outcomes after acute ischemic stroke (AIS). Telemedicine (TM) increases care access for elderly AIS patients especially in rural areas, yet their outcomes after initial TM consultation in the emergency department (ED) are unknown. We compared discharge disposition between elderly AIS patients who presented to and were retained at spoke community hospitals (SCHs) in our TM network versus those who presented directly to the TM hub (DTH).

Methods:
From both our network’s hub and TM stroke registries, we identified AIS patients ≥80 years old who presented to the ED (9/2015 - 12/2018). We compared incidence of discharge disposition to hospice or expiration (HE) as well as demographic and clinical characteristics between the SCH and DTH patients. Patients transferred after TM evaluation or who did not present directly to the hub ED were excluded.

Results:
Of 716 patients seen by TM, 532 were admitted to SCHs and 64 (12%) went on to HE. Out of 388 patients presenting DTH, 111 (29%) went on to HE. DTH patients were more likely to go on to HE (OR 2.93; 95% CI 2.08 - 4.12) compared to those presenting to and retained at SCHs (Figure 1a). This difference persisted when adjusting for baseline characteristics, stroke severity, and acute treatment (OR 3.01; 95% CI 1.01 - 8.96) (Figure 1b). In both study groups, increased age and severe stroke were highly associated with HE in the multivariate analysis. DTH patients with dementia had a higher odds of HE upon discharge (p=0.009) while those who received endovascular therapy had a lower odds (p=0.014). High premorbid mRS did not confer significantly higher odds of HE in either group.

Conclusions:
Elderly patients seen over TM and admitted to SCHs have lower early mortality and discharge disposition to hospice compared to those who present DTH. Further study is needed to elucidate whether disparities in palliative care utilization account for this difference.
Abstract TP192: Four-Year Incidence of Major Adverse Cardiovascular Events in Patients With Established Cerebrovascular Disease
Authors: Miao Benjamin , Hernandez Adrian , Alberts Mark , Roman Yuani , Coleman Craig
Published: June 2021

Introduction:
Data on the contemporary risk of major adverse cardiovascular events (MACE) in patients with established cerebrovascular disease (CVD) are needed.

Objective:
To evaluate the 4-year incidence of MACE in patients with established CVD.

Methods:
Using US IBM MarketScan claims we identified patients ≥45-years old with billing codes indicating established CVD during the 2013 calendar year (baseline). Starting on January 1, 2014, patients identified as having CVD were followed for the occurrence of MACE (defined as the composite of cardiovascular death, ischemic stroke or myocardial infarction). To be included in this analysis patients had to have a minimum of 4-years (±3-months) of available follow up prior to the end-of-data availability (December 31, 2017). Secondary study outcomes included the incidence of individual MACE components.

Results:
We identified 48,160 patients with CVD with a minimum 4-years (±3-months) of follow up. At baseline, the median (25%, 75% range) age of patients was 71 years (59, 79), 47.6% were women and 27.9% had disease in at least 1 additional vascular bed (16.9% coronary, 14.9% peripheral, 25.7% carotid). Stroke risk factors included hypertension (90.4%), hypercholesterolemia (68.6%), heart failure (21.6%) and atrial fibrillation (21.0%). During 2013, CVD patients were receiving angiotensin-converting enzyme inhibitor/receptor blockers (57.5%), beta-blockers (50.5%), calcium antagonists (34.9%), diuretics (41.0%), oral anticoagulants (19.1%), P2Y12 inhibitors (27.0%) and statins (65.7%). During the 4-years of follow up, 11.5% of established CVD patients experienced MACE. Of these, 8.3% had an ischemic stroke, 4.9% had a myocardial infarction and 1.2% died of cardiovascular causes.

Conclusions:
Patients with established CVD possess a substantial 4-year risk of MACE, notably ischemic stroke.
Abstract TP198: The Impact of Regular Employments on Hyper-Acute Ischemic Stroke
Authors: Sato Takeo , Sakai Kenichiro , Nakada Ryoji , Shiraishi Tomotaka , Komatsu Teppei , Sakuta Kenichi , Terasawa Yuka , Umehara Tadashi , Omoto Shusaku , Murakami Hidetomo , Mitsumura Hidetaka , Iguchi Yasuyuki
Published: June 2021

Background and Purpose:
We aimed to investigate the differences in weekly variations of stroke occurrence between hyper-acute ischemic stroke patients with and without regular employments (RE), and the impact of RE on outcome.

Methods:
Consecutive symptomatic ischemic stroke patients with
<
4.5 h from onset to door between October 2012 and May 2018 were enrolled. All the situations of employment on admission were obtained from interviews with the participant or substitute guardians. First, we divided the patients into with and without RE to evaluate the differences in weekly variations of stroke occurrence. Second, we divided the same patients into with and without favorable outcome (mRS score of 0 to 2 at 3 months from the onset) to evaluate the impact of RE on outcome.

Results:
We screened 1,249 consecutive symptomatic ischemic stroke patients, including 385 patients (292 (76%) male, median age 67 years) with hyper-acute ischemic stroke. Of all, 251 patients (65%) were included in RE group. In the multivariate analysis, patients with RE were more likely to develop strokes on Monday compared to that on Sunday and public holiday (OR 2.841, 95% CI 1.145-7,049,
p
= 0.024, Figure A). In the multivariate analysis, the factors associated with favorable outcome were low NIHSS score on admission (OR 0.909, 95% CI 0.857-0.964,
p
= 0.001), not receiving endovascular therapy (OR 0.175 95% CI 0.069-0.444,
p
<0.001), and having RE (OR 2.506, 95% CI 1.049-5.986,
p
= 0.039, Figure B).

Conclusions:
There were dramatic differences in weekly variations of hyper-acute ischemic stroke occurrence between patients with and without RE. Monday seems to be “a black day” for ischemic stroke patients with RE. RE had a positive impact on outcome in hyper-acute ischemic stroke.
Abstract TP20: Protocol to Isolate Lymphocytes for Flow Cytometry From BACTRAC Samples
Authors: Maglinger Benton , Turchan Jadwiga , Pennypacker Keith , Grupke Stephen , Ujas Thomas , Fraser Justin , Stowe Ann
Published: June 2021

Introduction:
Since 2015, mechanical thrombectomy is the standard treatment for emergent large vessel occlusion stroke. Using standard techniques during mechanical thrombectomy, the Blood and Clot Thrombectomy Registry and Collaboration (BACTRAC) protocol (clinicaltrials.gov NCT03153683) isolates distal blood within the artery immediately downstream from the clot, peripheral blood proximal to the clot, and the thrombus. BACTRAC is the first protocol utilizing the thrombectomy technique to collect local whole blood samples during brain infarction. We aimed to augment the current collection protocol to reproducibly obtain and study local leukocyte populations during human stroke.

Methods:
We started with the established BACTRAC protocol previously published (PMID: 30064997). We modified the tissue collection protocol to isolate lymphocytes for flow cytometry and to bank the clot and plasma. We performed a flow cytometry panel that identifies CD3, 4, 8, 11b, 11c, 14, 19, 31, 45, 66b, 161, 183 markers to investigate populations of B-cells, T-cells, dendritic cells, NK cells, macrophages/monocytes, granulocytes, endothelial cells, and progenitors, respectively.

Results:
The protocol was first established in healthy controls (n=9) by drawing venous blood and simulating a vial of distal blood and a vial of proximal blood. In healthy subjects, we were able to isolate on average 2x10
6
leukocytes/ml with a viability of 97.85%. Banked lymphocytes are also viable upon reconstitution and for flow cytometry. This protocol successfully isolates leukocytes in proximal and distal blood samples in subjects undergoing mechanical thrombectomy, with identification and analysis by flow cytometry currently ongoing.

Conclusions:
This modification to the existing BACTRAC protocol provides the opportunity, for the first time, to study local leukocyte populations in the arteries undergoing ischemic stroke in the human condition. Efficient processing of these samples will provide insight into the neuroinflammatory microenvironment of the occlusion and accelerate translational stroke research towards new methods of diagnosis and treatment.
Abstract TP21: Safety of Cangrelor in Emergency Endovascular Stroke Recanalization, a Single Center Experience
Authors: Vanguru Husitha Reddy , Albright Karen C , Ahmed Rashid , Gould Grahame , Masoud Hesham , Latorre Julius G
Published: June 2021

Introduction:
Optimal antiplatelet regimen post-emergent stenting in acute stroke remains challenging among patients at high-risk for thrombosis and/or hemorrhage, especially after tPA. We describe our preliminary experience with cangrelor, an immediate acting IV P2Y12 receptor inhibitor with rapid onset and clearance.

Methods:
Retrospective cross-sectional study of mechanical thrombectomy (MER) patients requiring urgent stenting(0-48h). Patients treated with cangrelor were compared to those treated with other antiplatelets.

Results:
Nine cangrelor patients were compared to twelve patients treated with other antiplatelets. Pre- and post-treatment measures were similar overall (Table).

Conclusions:
Cangrelor may be a safe alternative to current antiplatelets used in immediate perioperative period post-MER and urgent stenting, including tPA patients and those at high-risk for malignant cerebral edema or hemorrhagic transformation. Additional studies are required to confirm or refute our observations.
Abstract TP215: Machine Learning Analysis of Gene Expression Data and Predictive Stroke Outcomes in Acute Ischemic Stroke
Authors: Martha Sarah R , Cheng Qiang , Gong Liyu , Collier Lisa , Davis Stephanie , Lukins Doug , Alhajeri Abdulnasser , Grupke Stephen , Fraser Justin F , Pennypacker Keith R
Published: June 2021

Background and Purpose:
The ability to predict ischemic stroke outcomes in the first day of admission could be vital for patient counseling, rehabilitation, and care planning. The Blood and Clot Thrombectomy Registry and Collaboration (BACTRAC; clinicaltrials.gov NCT03153683) collects blood samples distal and proximal to the intracranial thrombus during mechanical thrombectomy. These samples are a novel resource in evaluating acute gene expression changes at the time of ischemic stroke. The purpose of this study was to identify inflammatory genes and patient demographics that are predictive of stroke outcomes (infarct and/or edema volume) in acute ischemic stroke patients.

Methods:
The BACTRAC study is a non-probability, convenience sampling of subjects (≥ 18 year olds) treated with mechanical thrombectomy for emergent large vessel occlusion. We evaluated relative concentrations of mRNA for gene expression in 84 inflammatory molecules in static blood distal and proximal to the intracranial thrombus from adults who underwent thrombectomy. We employed a machine learning method, Random Forest, utilizing the first set of enrolled subjects, to predict which inflammatory genes and patient demographics were important features for infarct and edema volumes.

Results:
We analyzed the first 28 subjects (age = 66 ± 15.48, 11 males) in the BACTRAC registry. Results from machine learning analyses demonstrate that the genes CCR4, IFNA2, IL9, CXCL3, Age, DM, IL7, CCL4, BMI, IL5, CCR3, TNF, and IL27 predict infarct volume. The genes IFNA2, IL5, CCL11, IL17C, CCR4, IL9, IL7, CCR3, IL27, DM, and CSF2 predict edema volume. There is an intersection of genes CCR4, IFNA2, IL9, IL7, IL5, CCR3 to both infarct and edema volumes. Overall, these genes depicts a microenvironment for chemoattraction and proliferation of autoimmune cells, particularly Th2 cells and neutrophils.

Conclusions:
Machine learning algorithms can be employed to develop predictive biomarker signatures for stroke outcomes in ischemic stroke patients, particularly in regard to identifying acute gene expression changes that occur during stroke.
Abstract TP217: Association Between Thrombophilia and Chronic Cerebrovascular Disease in Young Adults With Acute Ischemic Stroke
Authors: Simonetto Marialaura , Shams Sara , Wu Xian , Diaz Ivan , Salehi Omran Setareh , Buchman Stephanie , Huq Tashfin , Santillan Alejandro , Lerario Mackenzie P , Merkler Alexander E , Kamel Hooman , Gupta Ajay , Navi Babak B
Published: June 2021

Introduction:
Thrombophilias are a known cause of acute ischemic stroke (AIS) in the young. We hypothesized that thrombophilias would be associated with an increased burden of chronic cerebrovascular disease in these patients.

Methods:
We included patients enrolled in the prospective Cornell AcutE Stroke Academic Registry (CAESAR) who were 18-65 years of age, diagnosed with AIS by brain MRI between 2011-2015, and had thrombophilia testing within 6 months of their stroke. The exposure variable was thrombophilia, defined as at least one positive thrombophilia test according to standard criteria. The primary outcome was the total Age-Related White Matter Changes (ARWMC) score (0-15). Secondary outcomes were the Fazekas score (0-3) and the number of chronic small vessel (subcortical) cerebral infarcts. Outcomes were determined by a single radiologist blinded to thrombophilia status using clinically-performed brain MRIs at the time of index stroke. Doubly robust estimator analyses were used to test the association between an underlying thrombophilia and outcomes. Models were adjusted for age, gender, race, and vascular risk factors.

Results:
Among 177 patients meeting eligibility criteria, mean age was 47 (SD, 10) years and 50% were women. Thrombophilia was detected in 77 patients (44%). The mean total ARWMC score, Fazekas score, and number of chronic small vessel infarcts were 1.90 (SD, 1.74), 0.91 (SD, 0.69), and 0.16 (SD, 0.63) in patients with thrombophilia and 2.16 (SD, 1.64), 1.07 (SD, 0.69) and 0.35 (SD, 0.81) in patients without thrombophilia. In multivariable analyses, there was no difference in the total ARWMC score (mean difference -0.05, 95% CI -0.43 to 0.33, p=0.80) or Fazekas score (mean difference -0.05, 95% CI -0.21 to 0.11, p=0.52) between patients with thrombophilia and those without. However, in multivariable analyses, the number of chronic infarcts (mean difference -0.22, 95% CI -0.42 to -0.01, p=0.01) was lower in patients with thrombophilia than in those without.

Conclusions:
In a single-center study of young adults with AIS, underlying thrombophilia was not associated with white matter disease burden. However, contrary to our hypothesis, it was inversely associated with the number of chronic small vessel infarcts.
Abstract TP220: Differential Risk Factors and Outcomes of Ischemic Stroke Due to Cervical Artery
Authors: Garg Aayushi , Molian Vaelan , Limaye Kaustubh , Hasan David , Leira Enrique C , Derdeyn Colin P , Adams Harold P , Shaban Amir
Published: June 2021

Introduction:
Cervical artery dissection (CeAD) is a major cause of acute ischemic stroke (AIS) in young adults. Its pathophysiology is distinct from the other etiologies of AIS and is determined by both genetic and environmental factors. In this study, we sought to determine the risk factors for and outcomes of AIS due to CeAD in young adults, in the era of increasing utilization of neuroimaging and neuro-intervention procedures.

Methods:
We retrospectively reviewed all cases of AIS between 15-45 years of age admitted to our comprehensive stroke center between January 2010 - November 2016. Risk factors and outcomes were compared between patients with and without CeAD using univariate analysis. Multivariable generalized linear and logistic regression models were used to adjust for confounding variables.

Results:
Of the total 333 patients with AIS included in the study (mean±SD age: 36.4±7.1 years; females 50.8%), CeAD was identified in 84 (25.2%) patients. When compared to the non-CeAD group, patients with CeAD were younger in age and more likely to have a history of migraine and recent chiropractic neck manipulation (p<0.05). Risk factors including hypertension, diabetes, hyperlipidemia and obesity were more prevalent in the non-CeAD group (p<0.05). Patients with CeAD had shorter hospital stay by an average of 1.8 days (95% CI=0.3-3.4, p<0.05), however, this difference was not statistically significant after adjustment for initial NIHSS score, age, gender, and comorbidities. Patients with CeAD were more likely to have worse functional outcome at discharge, defined as modified Rankin scale score (mRS) ≥3, independent of the above confounding variables (adjusted odds ratio 3.6, 95% CI=1.6-8.1). The in-hospital mortality rate, discharge disposition, mRS score and recurrence rates at follow-up (mean time 4.2 months) were similar between the two groups.

Conclusions:
While history of migraine and recent chiropractic neck manipulation are significantly associated with CeAD; most of the traditional vascular risk factors are less prevalent in this group. In comparison with AIS due to other etiologies, patients with CeAD have worse functional outcomes at the time of discharge but similar outcomes at follow up, which suggests a propensity for better recovery.
Abstract TP222: Prevalence of Carotid Web in Patients With Cryptogenic Stroke
Authors: Boyanpally Anusha , El Jamal Sleiman , Reznik Michael , Burton Tina , Cutting Shawna , Stretz Christoph , Stretz Christoph , Sacchetti Daniel , Sarafin Jo-Ann , Harmon Melissa , Mahta Ali , Wendell Linda , Thompson Bradford , Rao Shyam , Jayaraman Mahesh , McTaggart Ryan , Madsen Tracy , Schrag Matthew , Yaghi Shadi , Furie Karen , Mac Grory Brian C
Published: June 2021

Introduction:
Carotid web is a putative mechanism of cryptogenic ischemic stroke. We aimed to determine the prevalence of carotid web based on assigned stroke mechanism, and hypothesized that carotid webs would be found more frequently in younger cryptogenic stroke patients.

Methods:
We performed a single-center retrospective cohort study using institutional registry data from consecutive patients with confirmed anterior circulation ischemic stroke between July 2015-September 2017. We reviewed all available computed tomography angiogram (CTA) studies of the neck, and excluded patients who did not have a high-quality CTA of the neck performed. Carotid web was defined as a thin shelf of non-calcified tissue protruding into the lumen of the internal carotid artery immediately distal to the bifurcation, best visualized on sagittal oblique imaging and evident as a small septum on axial imaging. Stroke subtype was adjudicated a priori using validated methods, and we compared relevant risk factors in patients with cryptogenic stroke with and without carotid web.

Results:
We identified 882 patients with anterior circulation stroke who had a CTA neck available for review (49.3% male, 30% cryptogenic). A total of 7 patients (0.8%) were found to have carotid webs, of which 4 were ipsilateral to a patient’s stroke; all patients with ipsilateral carotid webs were adjudicated to have cryptogenic stroke. Patients with carotid web were younger than other patients in our cohort (age 49.0±14.6 vs. 72.2±14.9 years, p=0.003), and none of them had a history of hypertension (0% vs. 72%, p=0.04). In patients with cryptogenic stroke, overall prevalence of carotid webs was 1.5%, but the prevalence was significantly higher in younger cryptogenic stroke patients (age <60: 4.8%; age ≥60: 0.5%; p=0.01). Imaging findings that mimicked carotid webs, including non-calcified atherosclerosis and small protruding lesions, were prevalent in 8.3% of all patients.

Discussion:
Carotid web may represent an under-recognized occult mechanism of cryptogenic stroke, particularly amongst younger patients.
Abstract TP224: A Deep Learning Based-Algorithm to Automatically Measure Carotid Stenosis Using Cine-Images of Carotid Duplex Ultrasonography
Authors: Jeon Kiwan , Chang Hee Jin , Yook Gyeongmi , Hyon Yun Kyong , Ha Tae Young , Kim Jei
Published: June 2021

Background and Objective:
The present study was performed to develop an automated algorithm to measure the carotid stenosis by considering both deep learning and mathematical model using carotid duplex ultrasonography (CDU) images.

Methods:
We first obtained cine images of CDU from right and left carotid arteries of 18 ischemic stroke patients by continuous moving from supraclavicular to submandibular area. Then, we collected raw axial-CDU images from the cine-CDU images, and then, labelled segmentation of the stenosis caused by atherosclerotic plaque from the vessel wall in the individual axial image by two experts. To develop segmentation algorithm from the axial-CDU images, we first applied a deep learning algorithm to segment vessel lumen from vessel wall. Next, a mathematical algorithm using Gaussian mixture was used to segment atherosclerotic stenosis from the vessel lumen. Dice coefficient was obtained to evaluate whether the segmentation algorithms could accurately segment lumen of carotid artery and predict the stenosis severity measured by the experts using python packages including TensorFlow and scikit-learn on a workstation (Intel i9-7900X CPU, Nvidia Titan Xp GPU and 128G 2400GHz memory).

Results:
We finally collected total 13,586 raw axial-CDU images from the cine-CDU images of the 18 patients. After application of two steps of segmentation algorithms to the axial-CDU images, accuracy of the algorithm to segment lumen from the carotid vessel wall was mean 0.92 (±standard deviation 0.46) of dice coefficient. And, accuracy to estimate the stenotic area was mean 0.201 (±standard deviation 0.137) of dice coefficient.

Conclusions:
We proposed an algorithm to automatically quantify the carotid stenosis using two steps of approach. First, a deep learning based-algorithm to segment lumen of carotid artery; second, a mathematical model based-algorithm using Gaussian mixture to segment carotid stenosis from the lumen. Even though we need more studies to increase the accuracy to predict the stenosis, the present prediction algorithms provide a possible tool to automatically measure the severity and regional characteristics of carotid stenosis using cine-CDU images.
Abstract TP225: Coated-Platelet Levels Are Associated With Chronic Hyperglycemia and Systemic Inflammation in Acute Ischemic Stroke
Authors: Ray Debarti , Matthews Eleanor A , Dale George L , Ray Bappaditya , Prodan Calin I
Published: June 2021

Introduction:
Elevated levels of coated-platelets (a subset of procoagulant platelets) are often associated with acute ischemic stroke (AIS). Diabetes mellitus (DM) and chronic inflammation are both known risks factor for AIS. Elevated neutrophil-lymphocyte-ratio (NLR) and platelet-lymphocyte-ratio (PLR) are also often seen in the setting of acute myocardial infarction and AIS. However, the relationship between prothrombotic, dysglycemic and proinflammatory states in AIS is incompletely characterized.

Hypothesis:
To investigate whether elevated coated-platelet levels in AIS patients with chronic hyperglycemia is associated with proinflammatory states.

Methods:
The present cohort consists of patients with AIS or transient ischemic attack (TIA) due to large-artery disease over the period of one year. Coated-platelet levels were assayed upon admission. Glycated hemoglobin (HbA1c) and leukocyte count with differential were obtained through retrospective chart review. Study population was subcategorized into DM (HbA1c >6.4 and/or history of DM), prediabetic (PD, HbA1c 5.7-6.4) and non-diabetic (ND, HbA1c <5.7). Inter-relationship was assessed using linear regression models.

Results:
We recruited 47 AIS/TIA patients, with an average age of 67.3±8.1 years and 17/47 (36.2%) being current smokers. Thirty of 47 patients (63.8%) were diabetic with 23 patients having HbA1c levels >6.4. Higher coated-platelet levels were associated with higher lymphocyte count for the entire group (r=+0.375; p=0.0094) and also for the patients with HbA1c >6.4 (r=+0.516; p=0.012; n=23). Although PLR and HbA1c >6.4 showed a positive correlation (r=+0.42; p=0.046; n=23) in DM patients, this was not observed among DM patients with HbA1c <6.4.

Conclusion:
Our study demonstrates positive correlations between elevated coated-platelets and lymphocyte count and between PLR and HbA1c in AIS/TIA patients with HbA1c >6.4. This alludes to a synergistic role for procoagulant and proinflammatory states in chronically dysglycemic AIS/TIA patients.
Abstract TP227: Vascular Calcification, Atherosclerosis Burden, and Stroke Mechanism in Ischemic Stroke
Authors: Shimoyama Takashi , Nakamura Kunio , Gaj Sibaji , Kovi Shivakrishna , Uchino Ken
Published: June 2021

Background and Purpose:
Calcification of the intracranial carotid artery is recognized as a risk factor for stroke in the general population. The significance of vascular calcifications in its relationship stroke mechanisms is incompletely understood. We hypothesized that vascular calcium quantification using CT angiography (CTA) can differ by stroke mechanism among ischemic stroke patients.

Methods:
From a prospective single-hospital stroke registry from 2018, we identified ischemic stroke patients who underwent CTA. Automatic artery and calcification segmentation method measured calcification volumes in the intracranial, extracranial, and aortic arteries using deep-learning U-net model and region-grow algorithms. Stroke subtypes were diagnosed based on the TOAST classification: large artery atherosclerosis (LAA), small vessel occlusion (SVO), cardioembolism (CE), others/undetermined. We evaluated the relationship between CTA calcification volume and stroke subtypes on one-way ANOVA and Tukey’s post-hoc test.

Results:
Of the 558 consecutive acute ischemic stroke patients, we enrolled 388 patients (212 males; mean age 66.6 years) in the study. Others/undetermined (34.8%) was the most frequent stroke subtype, followed by CE (29.4%), LAA (25.5%), and SVO (10.3%). The overall prevalence of atherosclerotic calcification was 95.9% in stroke patients. LAA had significantly higher calcification volume with 809 mm
3
compared to SVO (390 mm
3
, P=0.040), others/undetermined (300 mm
3
, P=0.001), but not CE (860 mm
3
, P=0.958). In age < 65 years subset, LAA showed higher calcification volume with 567 mm
3
than SVO (176 mm
3
, P=0.014), CE (213 mm
3
, P=0.021) and others/undetermined (180 mm
3
, P<0.001). There were no significant differences in calcification volume among stroke subtypes in age ≥65 years.

Conclusion:
Atherosclerotic calcium burden with a quantitative analysis of CTA images may be useful to differentiate stroke mechanism in younger patients.
Abstract TP232: Initial Experience With a Fully Autonomous Robotic Transcranial Doppler System for Patent Foramen Ovlae Detection in Cryptogenic Stroke
Authors: Shah Ruchir A , Devlin Thomas
Published: June 2021

Background:
Right to Left shunting (RLS) through a PFO is a known risk factor for ischemic stroke and commonly screened in cases of ESUS. With emerging evidence linking the significance of PFO closure for reduction of recurrent stroke, there is a need for broader access to accurate, easily repeatable tools to identify high-risk patients considered for transcatheter PFO closure. The use of a Transcranial Doppler (TCD) bubble study has proven to be a valuable, non-invasive tool due to its high sensitivity and specificity in detecting and grading a PFO. In this case series, we evaluate a fully autonomous rTCD to perform bubble studies in ESUS population to assess the presence of PFOs.

Methods:
A total of 34 patients were diagnosed with ESUS. All patients received rTCD bubble study using the Lucid Robotic System to autonomously search, insonate and monitor bilateral Middle Cerebral Artery signals. A Transthoracic Echocardiogram (TTE) with a bubble was completed in 29 of 34 patients. A Transesophageal Echocardiogram (TEE) with a bubble was completed in 5 of 34 patients. All studies were performed at rest and with a Valsalva maneuver. Some patients were selected for an rTCD bubble after a positive TTE bubble study.

Results:
A PFO was detected in 65% (22 of 34) of the patient population. Both rTCD and TTE were performed in 19 of 22 patients. We identified 9 patients (47%) that had a positive rTCD bubble study which went undetected by a TTE bubble study. In these 9 patients, 56% had an ICC grade 3, 33% had grade 2, and 11% had grade 1 shunt.

Conclusion:
The high sensitivity and specificity of a TCD bubble study for the detection of a PFO provide a valuable, underutilized tool to accurately screen for high-risk patients benefiting from a PFO closure. This is highlighted by the 9 patients where a PFO went undetected by a TTE. The implementation of a fully autonomous rTCD allowed for broader access to perform TCD bubble studies, resulting in greater patient management and workflow efficiency. With the small number of patients in this case series, further research is recommended.
Abstract TP237: Can We Improve Clinical Detection of Right Hemisphere Large Vessel Occlusion?
Authors: Somani Sana , Gazi Melissa , Minor Michael , Acker Joe , Fadairo Abimbola , Lazar Ron , Gropen Toby I
Published: June 2021

Introduction:
The Emergency Medical Stroke Assessment (EMSA) is a six point stroke severity scale with one point each for gaze preference, facial droop, arm drift, leg drift, abnormal naming, and abnormal repetition that was developed to help emergency medical services (EMS) providers identify acute ischemic stroke (AIS) patients with large vessel occlusion (LVO). We hypothesized that the EMSA would detect left hemisphere LVO with a higher sensitivity than right hemisphere LVO.

Methods:
We trained 24 trauma system-based emergency communication center (ECC) paramedics in the EMSA. ECC-guided EMS in performance of the EMSA on patients with suspected stroke. We compared the sensitivity, specificity, area under the curve (AUC), and 95% confidence interval (CI) of ECC-guided prehospital EMSA for right versus left hemisphere ICA or M1 occlusion.

Results:
We enrolled 569 patients from September 2016 through February 2018, out of which 236 had a discharge diagnosis of stroke and 173 had a diagnosis of AIS. We excluded patients with bilateral (n=21) and brainstem (n=21) AIS. There were 64 patients with left hemisphere AIS including 19 with LVO. There were 67 patients with right hemisphere AIS including 22 with LVO. A score of ≥ 4 points yielded a sensitivity of 84.2 (95% CI = 60.4-96.6) and specificity of 66.7 (51.1-80.0) for left hemisphere LVO compared to a sensitivity of 68.2 (45.1-86.1) and specificity of 73.9 (58.9-85.7) for right hemisphere LVO. For predicting a left hemisphere LVO, the AUC was 0.77 (0.65-0.90) compared to 0.66 (0.50-0.82) for right-sided LVO. Assigning 2 points for abnormal gaze yielded an AUC of 0.78 (0.66-0.91) versus 0.67 (0.52-0.83) for left and right hemisphere LVO, respectively.

Conclusions:
The EMSA, like the National Institutes of Health Stroke Scale (NIHSS) upon which it is based, is more sensitive to left compared to right hemisphere LVO. More heavily weighting abnormal gaze did not improve the sensitivity of the EMSA for right hemisphere LVO. There is no comparable data on the right versus left hemisphere performance of other prehospital scales. There is a need to develop sensitive tests of right hemisphere dysfunction that are suitable for use in the field.
Abstract TP241: Neurologists' Role in Telestroke; How Essential Are We?
Authors: Adcock Amelia , Choi Justin , Petrone Ashley
Published: June 2021

Background:
Telestroke networks have effectively increased the number of ischemic stroke patients who have access to acute stroke therapy. However, the availability of a dedicated group of stroke subspecialists is not always feasible.

Hypothesis:
Rates of tPA recommendation, accuracy of final diagnosis and post-tPA hemorrhagic complications do not differ significantly between neurologists and an emergency-medicine physician during telestroke consultations.

Methods:
Retrospective review of all telestroke consults performed at a comprehensive stroke center during one year. Statistical analysis: Chi squared test.

Results:
303 consults were performed among 6 spoke sites. 16% (48/303) were completed by the emergency medicine physician; 25% (76/303) were performed by non stroke-trained neurologists, and 60% (179/303) were completed by a board-certified Vascular Neurologist. Overall rate of tPA recommendation was 40% (104/255), 38% (18/48), 41% (73/179), and 41% (31/76) among the all neurology-trained, emergency medicine- trained, stroke neurology-trained and other neurology- trained provider groups respectively (p = .427). Accuracy of final stroke diagnosis was 77% (14/18) and 72% (75/104) in the emergency-medicine trained and neurology-trained provider groups (p = 0.777) No symptomatic hemorrhagic complications following the administration of tPA via telestroke consultation occurred in any group over this time period. One asymptomatic intracerebral hemorrhage was observed (0.96% or 1/104) in the neurology-trained provider group.

Conclusion:
Our results did not illustrate any statistically significant difference between care provided by an Emergency Medicine-trained physician and neurologists during telestroke consultation. While our study is limited by its relatively low numbers, it suggests that identifying a non-neurologist provider who has requisite clinical experience with acute stroke patients can safely and appropriately provide telestroke consultation. The lack of formerly trained neurologists, therefore may not need to serve as an impediment to building an effective telestroke network. Future efforts should be focused on illuminating all strategies that facilitate sustainable telestroke implementation.