bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 15: Stay at Home Orders During the Covid-19 Pandemic Associated With Race Ethnic Disparities in Patient Access to Healthcare for Stroke Like Symptoms
Authors: Dickens Rondalyn , Senetar Alexander , Olasoji Esther , Branstetter Hannah , Vijayaraghavan Niran , Huynh Tri M , Bruzzone Maria , Simpkins Alexis N ,   on behalf of the Univ of Florida CREST Initiative
Published: March 2021

Introduction:
The COVID-19 pandemic has impacted stroke care and highlighted health care disparities. We aimed to determine if stroke alert (SA) volume, stroke alert mimic (SAM) volume, utilization of reperfusion therapies, and socioeconomic and race ethnic determinants of clinical outcome were impacted by the pandemic.

Methods:
Data was obtained from our Institutional Review Board approved SA database from February 2019-June 2019 and February 2020-June 2020 to capture the impact of the stay at home orders enacted at the end of March 2020 and the increase of COVID-19 cases in Florida in June 2020. Regression analysis was used to identify differences in volumes of SA, reperfusion therapy, SAM, and clinical factors (NIHSS, age, sex, race, ethnicity, insurance status, and rural region).

Results:
A total of 1171 SA were included, median age 66 (interquartile range 55-76), 50% woman, 23% Black, 68% Non-Hispanic White, 1% Hispanic, 8% unknown; 52% of the SA were SAM. SA volumes, thrombolysis and endovascular therapy use was unchanged. The volume of SAM did not differ between time intervals, but SAM were more likely to be older (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.02 - 1.04), White (OR 1.80, 95% CI 1.09 -2.99), uninsured (OR 2.19, 95% CI 1.35 - 3.46), arrive by EMS (OR 1.77, 95% CI 1.31- 2.40), and have a higher NIHSS (OR 1.02, 95% CI 1.003 - 1.034). SAM secondary to migraine, intoxication, medication toxicity, or psychiatric disease were less likely to occur in April 2020 (OR 0.37, CI 0.15- 0.96) and in patients from rural regions (OR 0.42, CI 0.19 - 0.95). They were more likely to occur in older patients (OR 1.06, CI 1.05-1.07) and men (OR 2.31, CI 1.62 - 3.31). SAM secondary to seizure were more likely to occur in April 2020 (OR 2.46, CI 1.06- 0.96) and Whites (OR 2.22, CI 1.16 -4.26). SAM from medical or non-cerebrovascular or epileptic neurologic disease were unchanged.

Conclusions:
Significant changes in the frequency of SAM subtypes occurred in close proximity to stay-at-home orders. Our findings suggest that a proportion of Blacks and Hispanics were not accessing healthcare for stroke like symptoms during the stay-at-home orders. Thus, patient education on how to access healthcare in vulnerable populations should be included with implementation of stay at home orders.
Abstract 3: Early Recanalization of Large Vessel Occlusions by tPA on the Mobile Stroke Unit
Authors: Czap Alexandra L , Grotta James C , Wang Mengxi , Parker Stephanie , Bratina Patti , Phan Kenny , Jagolino-Cole Amanda L , Sheth Sunil A , Rajan Suja S , Yamal Jose-Miguel , Bowry Ritvij
Published: March 2021

Introduction:
The benefit of intravenous tPA in acute ischemic stroke patients with large vessel occlusions (LVOs) is limited but time dependent. We evaluated pre-hospital treatment with tPA on the Mobile Stroke Unit (MSU) to explore the recanalization rate in patients with LVOs and its effect on clinical improvement upon ED arrival.

Methods:
Prospectively derived data were analyzed from patients on the Houston MSU who were treated with tPA and had LVOs identified by hyperdense artery on MSU CT or arterial occlusion on MSU CTA. The primary outcome was early recanalization, categorized as resolution of LVO on repeat vascular imaging in the ED or on emergent angiography versus no recanalization. Secondary outcome was change in baseline NIHSS at 24 hours. Differences in NIHSS were evaluated using Wilcoxon rank sum test with continuity correction.

Results:
Seventy-one patients received tPA and had proximal LVOs both in the anterior and posterior circulation. Eleven had recanalization on CTA upon ED arrival (15.5%), while 7 had recanalization on emergent angiography (9.9%). The total early recanalization rate with tPA was 25.4%. Forty-seven patients with persistent LVOs on ED arrival (66.2%) underwent endovascular thrombectomy (EVT). Time from symptom onset (last known normal) to tPA bolus did not differ significantly between the early recanalization vs non-early recanalization groups (64.5 minutes [IQR 43.0-78.5] vs 64.0 minutes [52.5-92.0]; p = 0.41). Early recanalization resulted in greater improvement in baseline to ED arrival NIHSS (median NIHSS change 4.0 [0-11.8] vs 0 [0-3.5]; p = 0.01). There were no differences in ED arrival to 24 hour NIHSS between the early recanalization versus non-early recanalization groups irrespective of EVT.

Conclusions:
Recanalization by ED arrival occurs in 25% of LVO patients with tPA treatment on a MSU and was associated with early clinical improvement. Subsequent EVT did not “make up” for the clinical benefit of early recanalization.
Abstract 47: Delaying Admission to Inpatient Rehabilitation Worsens Outcome for Stroke Patients: Detrimental Impact of Covid-19 on Stroke Survivors
Authors: Parker Dorothea M , Singh Noopur , Gupta Resmi , Taleb Shayandokht , TAHANAN AMIRALI , Yamal Jose-Miguel , Wozny Joseph , Rahbar Mohammad H , Silos Christin , Paladugu Sreelekha , Norris Dominique , Aggarwal Seema , Green Charles , Tariq Muhammad Bilal , Wewior Natalia , Ibrahim Lamya , Hsieh Billie , Verduzco-Gutierrez Monica , Russell Mary E , Savitz Sean I
Published: March 2021

Introduction:
Inpatient rehabilitation (IPR) is crucial to recovery after stroke. COVID-19, however, has led to delays in post-stroke admission to IPR due to transmission concerns.

Objective:
We evaluated the effect of time from stroke onset to IPR admission on post-stroke recovery

Design:
A retrospective analysis of 680 patients with acute stroke or intracerebral hemorrhage (ICH), admitted to IPR between APR-2017 and AUG-2019. Association between time from stroke onset to IPR and discharge FIM-Motor Total and FIM-Motor Total with transfers scores was studied, after adjusting for sex, age at onset, stroke severity and type. Multiple linear regression models were conducted for outcomes discharge: (FIM-Motor Total)
2
and (FIM-Motor Total with transfers)
2
(
Table 1)
. Square transformations were used to satisfy model assumptions. Ordinal logistic regression models were run for outcomes discharge FIM subset scores categorized as independent (6-7), needs supervision (5), and needs assistance (1-4, reference). The primary variable of interest was days onset to IPR, adjusted for stroke severity (admit FIM subset scores), sex, stroke type and age. (
Table 2).
The proportional odds assumption was verified using Brant test.

Results:
An inverse relationship was observed between days from onset to IPR and discharge FIM-Motor with and without transfers. Time from stroke onset to IPR admission was associated with decreased discharge FIM-Motor and FIM-Motor with transfers, after adjusting for other covariates. Among FIM subset discharges, an additional day also resulted in a 2-5% decrease in the odds of being more independent.

Conclusion:
Delays to IPR admission result in decreased motor function gains and lower chance of independence. In addition to current community education practices, acute care hospitals and IPR facilities must review their processes to remove delays. These processes include requirements for COVID disease testing and IPR acceptance policies.
Abstract 48: An Updated Early Stroke Recognition Tool for the Inclusivity of Spanish-Speakers: RAPIDO
Authors: Ancer Leal Andrea , Castro Alejandra , Casameni Montiel Tahani , Denny Mary C , Sharrief Anjail Z , Beauchamp Jennifer E
Published: March 2021

Background and Issues:
Hispanics have higher stroke incidence and recurrence and are less likely to know the signs and symptoms of stroke compared to non-Hispanic Whites. Stroke awareness education promotes the recognition of the common signs and symptoms of stroke and subsequent treatment-seeking behaviors resulting in improved outcomes. Acronyms have been created to bring awareness to key stroke sign and symptom indicators; however, there are discrepancies when translating existing acronyms for Spanish-speakers.

Purpose:
The purpose of this project was to create and update a stroke awareness acronym for the inclusivity of Spanish-speakers.

Methods:
We searched the literature and were unable to identify translations of the commonly publicized FAST or BE-FAST acronyms into recognizable and relatable Spanish words across various dialects. Led by a Spanish-speaking nurse with experience working with stroke patients, our research team identified Spanish words that are used across various dialects for the translation of the BE-FAST acronym (balance, eyes, face, arm, speed, and time). Diverse Spanish-speaking members of our research team incorporated relatable images and reviewed the translated acronym for content and clarity.

Results:
We created the acronym RAPIDO for Spanish-speakers. Similar to FAST and BE-FAST, RAPIDO illustrates warning signs and symptoms of stroke and the need to seek treatment quickly.

Conclusions:
The creation of the RAPIDO acronym constitutes an important step in providing stroke awareness education to Spanish-speakers. If validated with the broader healthcare professional and lay community, adding the RAPIDO acronym to public stroke educational programs may be warranted.
Abstract 53: Frontal Functional Connectivity Networks and Executive Function Following Perinatal Stroke
Authors: Meghji Suraya , Hilderley Alicia , Kirton Adam , Carlson Helen
Published: March 2021

Perinatal stroke causes most hemiparetic cerebral palsy and a lifetime of disability with no known prevention strategies. Two types of perinatal stroke predominate, arterial ischemic stroke (AIS) and periventricular venous infarction (PVI), dictating lesion-specific differences in outcomes. Executive functioning challenges and attention deficit hyperactivity disorder (ADHD) are more common in children with perinatal stroke (19-35%) than peers (5-7%). Resting state (RS) functional magnetic resonance imaging (fMRI) measures fluctuations in the blood-oxygen level dependent (BOLD) signal that may estimate network functional connectivity (FC). We evaluated relationships between FC in relevant frontal circuits, ADHD and executive function in children with perinatal stroke compared to typically developing controls (TDC). Participant recruitment was from a population-based research cohort (AIS N=32; PVI N=30; TDC N=59). MRI imaging included T1-weighted anatomical and resting state fMRI sequences. Subsequent seed-to-seed analyses quantified FC within frontoparietal (FPN), dorsal attention (DAN) and default mode networks (DMN). Parent questionnaires quantified executive function (Behavior Rating Inventory of Executive Function (BRIEF)) and ADHD symptoms (ADHD Rating Scale-5). Large group FC differences were observed within FPN, DAN and DMN networks where AIS had lower FC compared to both PVI and TDC. For stroke participants, higher FC within the DAN and FPN was associated with poorer cognitive function (BRIEF). By contrast, higher FC within the DMN was associated with better ADHD ratings. Differences within frontal functional networks appear to be related to poorer cognitive function such that increased FC between the lesioned and nonlesioned hemisphere is associated with symptoms of executive dysfunction and ADHD suggesting that developmental plasticity leads to complex network changes following early unilateral brain injury.
Abstract 54: Bilateral Developmental Alterations in Cortical Morphology in Children With Perinatal Stroke
Authors: Shinde Karan , Craig Brandon T , Hassett Jordan , Kirton Adam , Carlson Helen L
Published: March 2021

Perinatal stroke (PS) causes hemiparetic cerebral palsy (CP) and lifelong disability. Compensatory changes in the nonlesioned hemisphere may mediate residual function and represent targets for neuromodulation. Region-based approaches may reveal relationships between cortical thickness of nonlesioned primary motor/sensory cortices and motor function. This study uses surface-based morphometry to explore cortical alterations in the nonlesioned hemisphere in children after perinatal stroke. Children aged 6-19 with MRI-confirmed unilateral perinatal stroke and CP underwent T1-weighted anatomical imaging. Participants were classified as arterial ischemic stroke (AIS; n=36), periventricular venous infarction (PVI; n=38), or typically developing controls (TDC; n=53). Group differences in cortical thickness (distance between grey/white matter boundary and pial surface), grey matter volume, gyrification and sulcal depth and relationships between these morphology metrics and validated measures of motor/executive function were explored. Group comparisons revealed less cortical thickness, greater gyrification, and greater surface area in the nonlesioned hemisphere in both AIS and PVI as compared to TDC. Greater volume and sulcal depth were observed in the nonlesioned hemisphere for AIS. The PVI group showed greater volume in the cingulate cortex and less volume in the precuneus relative to TDC. The AIS group showed more widespread differences than the PVI group in volume and other cortical surface parameters when compared with TDC. Only modest correlations were observed between morphometric changes and clinical function. We suggest that broad differences in structural developmental plasticity occur in the nonlesioned hemisphere after perinatal stroke, particularly the larger lesions seen with AIS, and may represent novel targets for therapeutic neuromodulation.
Abstract 60: National Temporal Patterns in Recurrent Stroke by Demographic Characteristics and Geographic Regions: 2001-2016
Authors: Lichtman Judith H , Leifheit Erica C , Wang Yun , Goldstein Larry B
Published: March 2021

Background:
There have been important advances in secondary stroke prevention and a focus on healthcare delivery in the US over the past two decades. Yet, little is known about temporal patterns of recurrent stroke in the US. We examined temporal trends in recurrent stroke by sociodemographic characteristics and geographic areas using national Medicare data.

Methods:
We included fee-for-service Medicare beneficiaries aged ≥65y with a primary discharge diagnosis of ischemic stroke from 2001 to 2016. We fit a Cox proportional hazards model that censored for change in Medicare enrollment and accounted for death to evaluate the temporal trend in 1-year recurrent stroke, adjusting for demographic and clinical factors. Models were repeated for subgroups defined by age, sex, race, and state. We mapped smoothed rates of 1-year recurrent stroke by county to assess geographic variation over time.

Results:
There were 3,485,618 unique beneficiaries discharged with stroke during the study period. Demographic and clinical characteristics remained relatively stable over time, but the proportions discharged with home health services and inpatient rehabilitation increased. The observed 1-year recurrent stroke rate decreased from 11.2% in 2001-2004 to 9.3% in 2013-2016, with an adjusted annual reduction in recurrence from 2001-2016 of 1.49% (95% CI 1.40%-1.58%). There were significant reductions for all age, sex, and race groups (A). Geographic areas with persistently high rates were identified over time (B). In state-stratified analysis, the annual percentage reduction in recurrence ranged from -1.2% to 2.5% and was significant for all but 12 states.

Conclusions:
Recurrent strokes decreased over time overall and by sociodemographic subgroups; however, we identified geographic areas with persistently high recurrence rates. Such findings can target secondary prevention intervention opportunities for high-risk populations and communities.
Abstract 61: Community Factors Associated With Persistently High 1-Year Recurrent Stroke Rates in the United States
Authors: Leifheit Erica C , Wang Yun , Goldstein Larry B , Lichtman Judith H
Published: March 2021

Background:
There is known geographic variation in recurrent stroke rates in the US; however, the contributions of socioeconomic status (SES), healthcare access/utilization, and community resources to these disparities are uncertain. We assessed community characteristics in counties having persistently higher recurrent stroke rates over a 16-year period.

Methods:
We included 3,485,618 fee-for-service Medicare beneficiaries aged ≥65y discharged with ischemic stroke from 2001-2016, grouped into four 4-year periods. We categorized 3221 US counties or equivalents into 6 groups based on the % of stroke patients with a recurrent stroke within 1 year. Persistently high-recurrence counties were those in the highest sextile for each 4-year period. We integrated county-specific demographic, geographic, SES, general health, care availability, health behavior, and environmental data from the US Census Bureau, USDA Economic Research Service, and Dartmouth Atlas. We calculated mean standardized differences in county characteristics between high-recurrence and other counties and used logistic regression to model high-recurrence counties as a function of 12 potentially modifiable county characteristics.

Results:
There were 133 persistently high-recurrence counties that were concentrated in the South Central US and included 140,144 stroke patients during the study (A; mean age 78.3y, 57% women, 82% White, 11.5% stroke recurrence vs 79.0 y, 55% women, 86% White, 10.5% stroke recurrence in other counties). Compared with the rest of the US, these counties had populations with lower SES, poorer health, more limited access to care providers and recreation/fitness, and reduced rates of preventive testing (B). The model including 12 potentially actionable characteristics had a c statistic of 0.84.

Conclusions:
Our findings highlight the value of identifying potentially modifiable community characteristics that, if improved, might reduce recurrent stroke rates.
Abstract 9: Peak Width of Skeletonized Mean Diffusivity and Cognition in Cerebral Amyloid Angiopathy
Authors: Horn Mitchell J , Gokcal Elif , Becker J. A , Das Alvin S , Schwab Kristin , Biffi Alessandro , Goldstein Joshua , Rosand Jonathan , Viswanathan Anand , Polimeni Jonathan , Duering Marco , Greenberg Steven M , Gurol M. E
Published: March 2021

Background:
We hypothesized that Peak Width of Skeletonized Mean Diffusivity (PSMD), an automated marker of cerebral microangiopathy representing microstructural disruption of white matter (WM), would be increased in patients with cerebral amyloid angiopathy (CAA) compared to healthy controls (HCs) and increased PSMD would be associated with lower processing speed scores (PSSs) in patients with CAA.

Methods:
Seventy-two nondemented probable CAA patients and 23 HCs prospectively underwent high-resolution brain MRIs and cognitive tests. PSMD scores were quantified from a probabilistic skeleton of the WM tracts as previously validated (http://www.psmd-marker.com). In subjects with intracerebral hemorrhage (ICH, n=27), ICH regions were masked and removed from the PSMD pipeline. The analyses were repeated in the non-ICH hemisphere. Raw scores of Trail Making Test-B and Symbol Substitution Test were transformed into standardized
z
-scores and averaged to obtain PSSs.

Results:
The mean age (p=0.366) and sex (p=0.811) were similar between CAA patients and HCs. PSMD was higher in the CAA group [(3.95±0.9) х 10
–4
mm
2
/s] compared to HCs [(3.32±0.6) х 10
–4
mm
2
/s] (p=0.003). This association remained significant in a linear regression model corrected for age and sex (β=0.700, 95%CI 0.3-1, p=0.001). Within the CAA cohort, higher PSMD was associated with higher WM hyperintensity volume in a multiple regression model adjusted for all relevant variables (β=0.890, 95%CI 0.7-1, p<0.001). In a regression model corrected for age, sex, years of education and presence of ICH, a lower PSS was independently associated with increased PSMD (β=-0.405, 95%CI {-0.6}-{-0.2}, p<0.001). These results did not change when the non-ICH hemisphere was used for PSMD processing.

Conclusion:
PSMD is increased in CAA and is associated with worse PSSs supporting the view that disruption of white matter has a significant role in cognitive impairment in CAA.
Abstract MP15: Hypoxia and Endothelin-1 in Microglial Cell Activation
Authors: Rodriguez-Matos Francisco J , Castaño-Pesante Sebastian O , Romero Jose R , Inostroza-Nieves Yaritza
Published: March 2021

Oxidative stress and inflammatory responses play critical roles in hypoxic-ischemic brain injury. Microglial cells are rapidly activated in response to injury and stressful stimuli, including hypoxia. Endothelin-1 (ET-1) is a potent vasoconstrictor that has been associated with cerebrovascular diseases. Hypoxia stimulates endothelial ET-1 production. However, the role of ET-1 in microglia under hypoxia is not clear. The aim of this project was to characterize the effect of hypoxia in a human microglial cell line, HMC3. We induced hypoxia using a chamber (1% O2, 5% CO2, and 92 % N2) at 37 °C for 4h, 24h, and 48h. MUSE Oxidative Stress Assay was performed to measure reactive oxygen species (ROS) formation, ELISA to determine TNF, IL-6, and ET-1 levels, qPCR to measure gene expression of ET-1, and immunofluorescence staining to visualize and compare the presence of ET-1 in hypoxic and control group cells. It was observed that, when compared to normoxic HMC3 cells, hypoxic HMC3 exposure significantly increased the ROS by a factor of 2.5 (p<0.001, n=3), the pro-inflammatory cytokine TNF-α increased 3.8 times (p<0.01, n=4), and IL-6 increased by a factor of 1.6 (p<0.01, n=4). In addition, hypoxia stimulates ET-1 gene expression 5.0-fold (p<0.001, n=4) and increased protein production 1.3 times (p<0.01, n=4). Consequently, treatment with ET-1 increased the amount of ROS, TNF-α, and IL-6 in HMC3 cells by a factor of 1.4 (p<0.05, n=4), 1.6 (p<0.001, n=4), and 1.9 (p<0.05, n=4), respectively. All these events were blocked by ET-1 receptor A (ETRA) antagonist, BQ123. Our results suggest that hypoxic conditions create a cycle of microglial cell activation leading to increased ROS and ET-1 production that further stimulate microglial cells. Thus, we posit that the ET-1 receptor blockade represents a promising therapeutic approach to regulate microglial cell responses in hypoxic-ischemic brain injury.
Abstract MP30: Reporting of Sex-Specific Results in Randomized Clinical Trials of Acute Stroke (2010-2020)
Authors: Pudar Julia , Strong Brent , Howard Virginia J , Reeves Mathew J
Published: March 2021

Introduction:
When reporting primary results, it is recommended that RCTs report sex-specific outcomes. We reviewed the reporting of sex-specific outcomes in contemporary acute stroke RCTs.

Methods:
We searched MEDLINE for manuscripts published between 2010 and June 2020 in one of nine major clinical journals reporting the primary results of phase 2 or 3 stroke RCTs. Eligible trials tested a therapeutic intervention initiated within one month of stroke onset. Reporting of sex-specific primary results was the outcome of interest. We also investigated whether the trial formally tested for an interaction between sex and treatment and if that interaction test was statistically significant. We performed bivariate analyses using Fisher’s exact tests to identify study-level factors associated with sex-specific reporting including journal, geographic region, trial phase, sample size, stroke type, trial type (e.g. thrombolytic, EVT, secondary prevention), and industry funding. Temporal trends using two-year time periods were also explored.

Results:
Of the 115 studies identified, sex-specific primary outcome data were reported in 37% (n=42). Reporting varied significantly by journal, with NEJM (61%) and Lancet journals (40%) having the highest rates (p=0.03) (Table). Reporting also differed by geographic region (p=0.03), trial phase (p=0.05), and sample size (p<0.01). Reporting did not vary significantly by stroke type, trial type, or industry involvement. While not significant, there was a positive temporal trend in favor of greater reporting in later publications (p=0.09). Of the 29 trials that formally tested for an interaction between sex and treatment, only one significant interaction was found.

Conclusions:
Although reporting of sex-specific outcomes improved from 2010 to 2020, the prevalence of reporting in major journals is still low. Further efforts are required to ensure that journals and authors comply with reporting guidelines.
Abstract MP32: Machine Learning Models Identify Predictors of Poor Outcome in Patients Undergoing Mechanical Thrombectomy for Acute Ischemic Stroke
Authors: Teitcher Michael , Kubicki Konrad , Saini Pravesh , Sharba Lana , Singh Jasmine , Taylor William , Syed Anam , de la Pena Paula , Thomas Shon , Serrone Joseph , Garg Ravi , Gill Rick
Published: March 2021

Introduction:
Predicting outcome after mechanical thrombectomy (MT) for ischemic stroke due to LVO can inform prognosis and guide early management. Prior studies report heterogeneity in risk factors for poor outcome. Machine learning may identify patterns of poor outcome from diverse variables that are difficult to discern with conventional statistical methods.

Methods:
Using a retrospective database of 233 stroke patients (2015-20) who had MT for LVO, we created machine learning predictive models with clinical and imaging variables for the following 4 outcomes: decompressive craniectomy, discharge mRS ≥4, development of post-stroke cerebral edema with mass effect, and in-hospital mortality. We compared 10 learner models: AdaBoost, Tree, Random Forest, Neural Network, CN2 Rule Induction, Logistic Regression, Naïve Bayes, kNN, Stochastic Gradient Descent, and Support Vector Machine. Variables were ranked by 5 scoring methods: information gain, information gain ratio, gini decrease, chi-square, ReliefF, and fast correlation-based filter. A prediction model was created using the top 5 variables to maximize the area under the receiver operating characteristic curve and classification accuracy. Models were 5-fold cross validated. Analyses were conducted via Stata and Orange Data Mining.

Results:
Prediction model sets of 5 variables were generated for the 4 outcomes of interest. Infarction volume was most important for predicting decompressive craniectomy, discharge mRS ≥4, and in-hospital mortality. Cerebral edema was important for decompressive craniectomy, discharge mRS ≥4, and in-hospital mortality. Initial NIHSS was important for decompressive craniectomy, discharge mRS ≥4, and in-hospital mortality. Contrast staining on post-procedural CT was important for cerebral edema (χ
2
11.9) and in-hospital mortality (χ
2
21.8). Patient age was important for discharge mRS ≥4 and decompressive craniectomy.

Conclusion:
We identified prediction models consistent with established prognostic variables. Post-MT contrast staining is a novel and important predictor of poor outcome, which merits further research. In conclusion, machine learning can be used to create accurate prediction models for outcome after MT for ischemic stroke with LVO.
Abstract MP33: Association Between Neurologic Outcomes and Temporal Profile of Systolic Blood Pressure Variability After Endovascular Thrombectomy
Authors: Prasad Ayush , Kobsa Jessica , Kodali Sreeja , Nguyen Cindy Khanh , Quispe Orozco Darko , Farooqui Mudassir , Zevallos Cynthia , Ortega Santiago , Anadani Mohammad , Almallouhi Eyad , Giles James A , Spiotta Alejandro M , Kim Joon-Tae , Maier Ilko , Psychogios Marios , Liman Jan , Riou-Comte Nolwenn , Richard Sébastien , Gory Benjamin , Wolfe Stacey , Brown Patrick A , Fargen Kyle , Mistry Eva , Fakhri Hiba , Mistry Akshitkumar , Wong Ka-ho , De Havenon Adam H , Nascimento Fabio , Kan Peter , Sheth Kevin N , Petersen Nils H
Published: March 2021

Introduction:
Higher systolic blood pressure variability (BPV) after endovascular thrombectomy (EVT) has been associated with an increased risk of hemorrhagic transformation and worse functional outcomes. However, the time-varying behavior of BPV after EVT and its effects on functional outcome have not been well characterized.

Methods:
We analyzed data from an international cohort of patients with acute large-vessel occlusion stroke who underwent EVT at 11 centers across North America, Europe, and Asia. Repeated time-stamped blood pressure data were recorded for the first 72 hours after thrombectomy. Parameters of BPV were calculated in 12-hour epochs using five established methodologies: standard deviation (SD), coefficient of variation (CV), average real variability (ARV), successive variation (SV), and residual SD (rSD). Patients’ overall mean BPV was then used to assign patients into tertiles for regression analysis: low BPV, intermediate BPV, and high BPV. Functional outcome was measured with the modified Rankin Scale (mRS) at 90 days.

Results:
Of the 1,791 patients (age 69 ± 14, NIHSS 15 ± 6) included in our analysis, 1,085 (60.6%) had a poor 90-day outcome (mRS >3). Patients with poor outcome had significantly higher systolic BPV (p<0.05) measured as standard deviation (SBP SD) at each epoch (Figure 1B). Compared to patients with low BPV, those in the highest tertile group had significantly greater odds of a poor functional outcome after adjusting for age, sex, hypertension, NIHSS, ASPECT, tPA, time to reperfusion, and TICI score (OR 1.5; 95% CI 1.2-2; p=0.001). Patients in the highest tertile of BPV demonstrated time-dependent variability with the highest SBP SD during the first 24 hours after thrombectomy (Figure 1A).

Conclusions:
Higher BPV measured by SBP SD appears to be associated with poor 90-day outcome in EVT-treated stroke patients. Early treatment strategies targeting early high BPV warrant further prospective investigation.
Abstract MP43: Paradoxical Response to Antibodies in Periodontal Microbes in Subjects With Intracranial Atherosclerotic Stenosis
Authors: Kodumuri Nishanth , Sen Souvik , La Valley Elizabeth A , Suri Fareed , Wasserman Bruce A , Gottesman Rebecca F , Rosamond Wayne D , Moss Kevin , Beck James D
Published: March 2021

Introduction:
Previously we have shown that periodontal disease and systemic inflammation are related to intracranial atherosclerosis (ICAS) in Atherosclerosis Risk In Communities study (ARIC). In this study we evaluated the relationship between serum antibodies against periodontal pathogens and ICAS.

Methods:
In this ongoing, prospective, longitudinal community-based cohort study, participants were assessed for antibodies to periodontal organisms including Porphyrmonas
gingivalis
(PG), Prevotella
intermedia
(PI), Prevotella
nigrescens
(PN), Bacteriodes
forsythensis
(BF), Treponema
denticola
(TD), Actinobacillus
actinomycetemcomitans
(AA), Campylobacter
rectus
(CR), Eikenella
corrodens
(EC), Fusobacterium
nucleatum
(FN), Peptostreptococcus
micros
(PM), Selenomonas
noxia
(SN), Capnocytophaga
ochracea
(CO), Veillonella
parvula
(VP), Streptococcus
sanguinis
(SS), Streptococcus
intermedius
(SI), Streptococcus
oralis
(SO), Actinomycosis
viscosis
(AV) and Helicobacter
pylori
(HP). These participants underwent 3D time-of-flight magnetic resonance angiography (MRA) to evaluate ICAS. Log mean antibody (IgG), CRP and IL-6 levels were compared using t-test between groups with and without ≥50% ICAS.

Results:
In this ARIC cohort, 1066 participants were assessed by MRA for ICAS. Serum CRP and IL-6 data were available for all and IgG levels were available for 772 participants. The log mean IgG level was significantly lower for patients with ≥50% ICAS versus patients with <50% ICAS in four organisms: PN (1.69 vs 1.80,
p= 0.03
), BF (1.30 vs 1.38,
p=0.05
), CO (1.23 vs 1.33,
p= 0.04
), FN (0.87 vs 1.01,
p=0.02
). The log mean IgG was also lower for CR, EC, SN, VP, SI, SO and AV though not significant. Log mean CRP was higher in the ≥50% ICAS group versus the <50% ICAS group (0.58 vs. 0.47,
p < 0.001
). Log mean IL-6 levels were also higher but not significant (0. 17 vs. 0.11,
p= 0.07
).

Conclusion:
Higher levels of systemic inflammatory markers (CRP, IL-6) are associated with significant ICAS, but we report a significantly lower level of IgG antibodies to specific periodontal pathogens (PN, BF, CO and FN) in patients with ≥50% ICAS. This paradoxical finding may represent the effect of systemic inflammation and oxidative stress on IgG levels to periodontal bacteria.
Abstract MP5: Intravenous Thrombolysis With Tenecteplase in Patients With Large Vessel Occlusions: Systematic Review and Meta-Analysis
Authors: Katsanos Aristeidis H , Safouris Apostolos , Sarraj Amrou , Magoufis Georgios , Leker Ronen R , Khatri Pooja , Cordonnier Charlotte , Leys Didier , Shoamanesh Ashkan , Ahmed Niaz , Alexandrov Andrei V , Tsivgoulis Georgios
Published: March 2021

Background:
Accumulating evidence from randomized-controlled clinical trials (RCTs) suggest that tenecteplase may represent an effective treatment alternative to alteplase for acute ischemic stroke (AIS). In the present systematic review and meta-analysis we sought to compare the efficacy and safety outcomes of intravenous tenecteplase to intravenous alteplase administration for AIS patients with large vessel occlusions (LVO).

Methods:
We searched MEDLINE and Scopus for published RCTs providing outcomes of AIS with confirmed LVO receiving intravenous thrombolysis with either tenecteplase at different doses or alteplase at standard dose 0.9mg/kg. The primary outcome was the odds of modified Rankin Scale (mRS) score of 0-2 at 3 months.

Results:
We included 4 RCTs including a total of 433 patients. Patients with confirmed LVO receiving tenecteplase had higher odds of successful recanalization (OR=3.05, 95%CI: 1.73-5.40; Figure A), mRS scores of 0-2 [odds ratio (OR)=2.06, 95%CI: 1.15-3.69; Figure B], and functional improvement defined as 1-point decrease across all mRS grades (common OR=1.84, 95%CI: 1.18-2.87; Figure C) at 3 months compared to patients with confirmed LVO receiving alteplase. There was little or no heterogeneity between the results provided from included studies regarding the aforementioned outcomes (I
2
≤20%). No difference in the outcomes of early neurological improvement, symptomatic intracranial hemorrhage (ICH), any ICH and the rates of mRS 0-1 or all-cause mortality at 3 months were detected between patients with LVO receiving intravenous thrombolysis with either tenecteplase or alteplase.

Conclusion:
AIS patients with LVO receiving intravenous thrombolysis with tenecteplase have significantly better recanalization and clinical outcomes compared to patients receiving intravenous alteplase.
Abstract MP52: International Variations in Age-Standardized Stroke-Related Mortality in Men and Women
Authors: Ouellet Suzie , AlTurki Ahmed , Marafi Mariam , Wein Theodore , Vieira Lucy , Huynh Thao
Published: March 2021

Background:
Stroke is one of the leading causes of mortality worldwide. We aimed to evaluate the international variations in stroke-related mortality in men and women.

Methods:
We completed a systematic review of all population-based cohort studies published during the decade 2010-2020. We retained only studies which reported age-adjusted and sex-specific stroke-related all-cause mortality (per 100 000 population). We computed the median sex-specific stroke-related mortality for each of the following group of countries: developed countries (as defined by the International Monetary Fund) with predominantly white population (Canada, United States of America, Western Europe, Australia, New Zealand), Eastern Europe, Latin America, Asia and Africa. We compared stroke-related mortality between women and men and between regions.

Results:
Of the 210 articles screened, there were seven studies which reported population-based age-standardized and sex-specific stroke-related mortality in 57 countries. We presented the most recent age-adjusted and sex-specific stroke-related mortality medians (and 25
th
and 75
th
percentiles) in Figure 1. Globally, we observed a significantly lower stroke-related mortality rate in women compared to men (23.6 and 30.8, respectively) (p-value = 0.007). Age-adjusted stroke-related mortality was the highest for both sexes in Eastern Europe, followed by the African rates. Age-adjusted stroke-related mortality was the lowest for both men and women (p<0.0001) in developed countries with predominantly white population compared to the other regions.

Conclusions:
There were marked international variations in the age-adjusted stroke-related mortality for both men and women. The high stroke-related mortality in Eastern Europe and Africa should motivate further improvement in stroke care in these regions. Finally, future research is needed to understand and decrease the sex-related difference in stroke-related mortality.
Abstract MP55: Endothelial Sirtuin-1 Deficiency Promotes the Rupture of Intracranial Aneurysm
Authors: Purcell James , Sato Hiroki , Ikedo Taichi , Seta Francesca , Ai Jinglu , Lawton Michael , Hashimoto Tomoki
Published: March 2021

Background:
Sirtuin-1 is highly expressed in vascular tissues and plays an important role in numerous metabolic and inflammatory processes. Age-related reduction in Sirtuin-1 expression has been linked to chronic vascular inflammation and senescence, and may explain the increased risk of aneurysm rupture seen in the elderly population. Our previous study showed that pharmacological inhibition of Sirtuin-1 increases the rate of aneurysm rupture. This suggests that Sirtuin-1 protects against the rupture of intracranial aneurysm. However, the cell type responsible for this effect has not been determined.

Hypothesis:
We hypothesize that reduced expression of Sirtuin-1 in endothelial cells promotes the rupture of intracranial aneurysm.

Methods:
We induced intracranial aneurysms in mice by combining systemic hypertension and a single injection of elastase into the cerebrospinal fluid. We induced aneurysms in tamoxifen-inducible vascular smooth muscle cell-specific Sirtuin-1 knockout mice (SIRT1
f/f
MYH11
ER-Cre+
) and in endothelial cell-specific Sirtuin-1 knockout mice and their littermates (SIRT1
f/f
Tie2
Cre+
, SIRT1
f/f
Tie2
Cre-
). We used the rate of aneurysm rupture as the primary endpoint.

Results:
Smooth muscle cell-specific Sirtuin-1 knockout had no effect on rate of aneurysm rupture. In contrast, SIRT1
f/f
Tie2
Cre+
mice experienced a significantly increased rate of aneurysm rupture (SIRT1
f/f
Tie2
Cre+
vs. SIRT1
f/f
Tie2
Cre-
: 86% vs. 42%,
P
< 0.05).

Conclusions:
Our findings suggest that Sirtuin-1 expressed in the endothelium, but not in smooth muscle cells, protects against the rupture of intracranial aneurysm. As Tie2 is also expressed in hematopoietic cells, we are conducting experiments using SIRT1
f/f
LysM
Cre+
mice to exclude potential contributions of hematopoietic Sirtuin-1 to the observed effects. Endothelial Sirtuin-1 may be used as a therapeutic target for preventing the rupture of intracranial aneurysm.
Abstract P1: Antiplatelet Therapy for Secondary Prevention After Ischemic Stroke: Systematic Review and a Network Meta-Analysis From Randomized Trials
Authors: Mikami Takahisa , Sakamoto Michika , Kuno Toshiki , Machida Akira , Siau Evan , Al-Dulaimi Mohammed , Green-laroche Deborah , Kornbluth Joshua , Helenius Johanna , Thaler David E , Leung Lester , Harrington Matthew , Steinberg Daniel
Published: March 2021

Introduction:
While various antiplatelet regimens are currently available for secondary prevention after ischemic stroke, data comparing their efficacy and safety are scarce. We conducted a network meta-analysis investigating the efficacy and risk profile of each antiplatelet regimen including combination therapies for secondary prevention of recurrent stroke.

Methods:
PubMed and EMBASE were searched for reports on randomized controlled trials published between January 1, 1985, and July 21, 2020. Random-effects model was used for meta-analysis. Primary outcome was recurrent stroke after ischemic stroke and secondary outcomes was major bleeding.

Results:
39 trials enrolling a total of 158,507 patients were eligible for our network meta-analysis. Patients were randomly allocated to receive aspirin, cilostazol, clopidogrel, dipyridamole, ticagrelor, ticlopidine, or combination of these antiplatelet agents in each study. In comparison to those who received aspirin monotherapy, the risk of recurrent stroke was significantly lower in patients who received cilostazol (odds ratio (OR), 0.65; 95% confidence interval (CI), 0.51-0.83), aspirin + ticagrelor (OR, 0.72; 95% CI, 0.62-0.83), aspirin + clopidogrel (OR, 0.73; 95% CI, 0.54-0.98) without significant heterogeneity (I2=45.1). Ticagrelor monotherapy did not demonstrate a significant difference in risk of recurrent stroke compared to clopidogrel monotherapy (OR, 1.02; 95% CI, 0.70-1.48). Aspirin and ticagrelor combination therapy did not demonstrate a significant difference in risk of recurrent stroke compared to aspirin and clopidogrel combination therapy (OR, 1.01; 95% CI, 0.74-1.39). Combination therapy of aspirin with clopidogrel or ticagrelor showed a higher risk of major bleeding compared to aspirin monotherapy (OR, 1.54; 95% CI, 1.30-1.84; OR, 2.93; 95% CI, 1.53-5.41, respectively).

Conclusions:
Ticagrelor and clopidogrel demonstrated similar efficacy and risk of major bleeding—as monotherapy and in combination with aspirin—when used for secondary prevention of recurrent stroke. Ticagrelor or clopidogrel in combination with aspirin showed lower risk of recurrent stroke but higher risk of major bleeding than aspirin monotherapy.
Abstract P105: Identification of Cardioembolic Sources and Myocardial Injury in Acute Ischemic Stroke With Delayed-Phase, Low-Dose Chest Ct by Means of a Dual-Layer Spectral Ct Scanner
Authors: Rodriguez Granillo Gaston , Cirio Juan José , Lylyk Ivan , Perez Nicolas , Caballero Maria L , Ciardi Celina , Ceron Marcos , Castrillon Ricardo A , Diluca Pablo , Lylyk Pedro
Published: March 2021

Background:
The COVID-19 pandemic has promoted adaptations in diagnostic algorithms. We explored the feasibility and accuracy of delayed phase (DP) chest computed tomography (CT) performed immediately after brain CT perfusion (CTP) for the identification of thrombotic complications and myocardial fibrosis among patients admitted with acute ischemic stroke (AIS).

Methods:
Since July, we have incorporated the use of low dose chest CT scans using a spectral CT scanner in all patients admitted with AIS, encouraging acquisitions, five min after brain CTP. All scans were non gated and comprised low dose chest CT scans, without additional contrast. Using virtual monochromatic imaging and iodine maps, we evaluated the presence of thrombotic complications, myocardial late enhancement, and myocardial extracellular volume (ECV), as a surrogate of edema and interstitial fibrosis.

Results:
We included 22 patients. The mean age was 66.2±19.6 years. In 5 patients, a cardioembolic (CE) source was later identified by transesophageal echocardiogram (TEE), [left atrial appendage (LAA) thrombus, n=1], transthoracic echocardiogram with agitated saline injection (patent foramen ovale n=2), or by EKG (atrial fibrillation). Seven patients further underwent either TEE or cardiac CT to identify CE sources. DP non gated chest CT had a sensitivity and specificity of 100% to identify CE sources, 1 LAA thrombus correctly detected. Chest CT identified pulmonary thromboembolism (PE), later confirmed with CT angiography. Chest CT identified myocardial late enhancement in 16 patients (80% in CE vs. 71% in non CE, p=0.68), myocardial fat in 1, and coronary calcification in 77% [with 2.6±2.2 vs 3.8±3.6 coronary calcified segments in CE vs. non CE strokes, p=0.36). The mean ECV was 35±4% in CE vs 32±6% in non CE strokes (p=0.17). The 2 patients with a positive PCR test for COVID-19 showed evidence of myocardial late iodine enhancement, and incremented ECV of the septal wall (38% and 40%, respectively).

Conclusions:
In this pilot study, DP, non ECG gated, low dose chest CT scan performed 5 min after brain CTP with a spectral scanner; enabled straightforward identification of CE sources among patients with AIS. This approach allowed detection of PE and myocardial injury.
Abstract P120: The Covid Effect on Stroke Response
Authors: Keigher Kiffon M , Lopes Demetrius , Mikesell Tim , Klassman Lynn , Masor Minna B , Murczek Katherine L , Vilar Paul S , Wolfe Thomas
Published: March 2021

Background & Significance:
The Covid-19 pandemic has created a host of challenges for healthcare systems and hospital teams that have put unprecedented stress on staff and leaders to re-design care and management of not only the Covid positive patient but also the hospitalized non-Covid patient. As this large healthcare system began to prepare for a Covid surge of patients, stroke program leaders recognized the need for alternative placement and management plans. With the re-designation of units and beds and deployment of staff into non-primary units, program leaders were concerned with not only placement of stroke patients outside of regular stroke and Neurocritical Care Units but also with non-trained stroke nursing staff caring for the patient. In response, this stroke program convened a working group to create alternative guidelines for care of the stroke patient during Covid surge and critical bed shortages.

Design & Methods:
The need for established criteria to guide all sites in the care of patients post IV thrombolytic or mechanical thrombectomy was the key objective. The alternative guideline was drafted and submitted to the system Covid clinical command center for emergent approval. Once approval given, education was provided to all stroke coordinators and key leaders at each site. To provide full access, guidelines were posted and available on the system SharePoint site for access to all team members.

Results:
The drafting of alternative stroke guidelines allowed for improved patient safety during our 27-hospital healthcare systems Covid surge. Care of multiple patients occurred outside normal critical care and stroke units with a decreased number of assessments for patients from the standard, pre-Covid and without increase safety events or adverse outcomes. The success of the alternative guidelines and this Covid effect on stroke care management not only helped our staff and patients during a time of need in safe care but also provided a new model of care for our stroke program leaders to consider and implement across our organizations.