bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P212: Admission National Institutes of Health Stroke Scale Associated With Higher Rates of Post Stroke Depression Independent of Imaging Characteristics
Authors: Alvi Muhammad M , Petrone Ashley , Frey Jessica
Published: March 2021

Introduction:
The etiology of post-stroke depression (PSD) is still not fully understood. It is well known that leukoaraiosis is associated with cognitive decline and depression, but currently unclear if lacunar strokes, thought to be caused by small vessel disease, have higher rates of PSD. A better understanding of PSD etiology can lead to improved treatment of PSD and subsequently better stroke recovery.

Methodology:
Out of 159 patients that were successfully contacted via phone within 3 months of discharge, there were 22 identified as having an acute stroke or TIA and scored ≥ 2 on the Patient Health Questionnaire (PHQ) assessment. MRI brain was reviewed for stroke size, location, periventricular and deep white matter fazekas score, number of microbleeds, and chronic lacunar strokes. Admission and discharge National Institutes of Health (NIH) stroke scale and stroke etiology were also recorded.

Results:
There was a significantly positive correlation between NIH score at admission and PHQ2 score (r = 0.184, p =0.044), demonstrating that patients with NIH ≥ 6 are 4.6 times more likely to develop PSD than a patient with NIH < 6 (Odds ratio (OR) = 4.6, CI [1.284-16.591]). There was no significant difference between PSD incidence in stroke size or location. Although not statistically significant, there was a suggestion of more PSD seen in cortical, cardioembolic, and cryptogenic strokes as well as fazekas score ≥ 2 and old lacunar infarcts. The table summarizes characteristics of the 7 TIA and 15 stroke patients suffering from PSD with PHQ ≥ 2:

Conclusion:
Initial NIH significantly predicted PSD irrespective of leukoaraiosis. This study was limited by the small sample size which could be due to under-diagnosis of PSD. In conclusion, admission NIH is associated with higher rates of PSD, but the underlying etiology is likely multifactorial given the suggestion of higher rates of PSD with higher fazekas score, and cortical, cardioembolic, and cryptogenic strokes.
Abstract P214: Social Network Analysis of a Community Aphasia Group Pre- And Post-Covid: Implications for Future Planning
Authors: Sather Tom , Livera Anna
Published: March 2021

Introduction:
Among the many negative consequences of aphasia is an altered social network. Social network analysis supports an objective, quantitative evaluation of social networks among individuals with aphasia along with potential impacts of social programming and interventions on an individual’s social network. Social network analysis may also support better understanding of the impact of Covid on individuals with aphasia.

Aims:
This pilot evaluation utilized social network analysis via
R
to evaluate the social network characteristics of a community-based aphasia network across a 12-month pre-Covid period. Social network aphasia group data for a standard duration of time pre- and post-Covid were also compared to identify potential social implications of Covid in a population already at higher risk for reduced social interactions. This presentation will also provide fundamental concepts relevant to social network analysis for those interested in pursuing such analysis in further depth.

Methods:
Twelve months of pre-Covid aphasia group program attendance data were examined using the visNetwork
R
package. An additional six months of Covid-era time frame data were also analyzed.The primary relationship function of “
a
attended
b”
(where
a =
individual participant and
b
= event/setting) was used in the analysis. Multiple social network characteristics were analyzed and displayed including node, edgeness, directionality, weight, and centrality indices across individuals with aphasia, care partners and community members and settings.

Results and Conclusions:
Network analysis reveals a directed network graph with primarily unidirectional relationships. There is an emergence of several aphasia group participant behavior types, both pre- and post-Covid, relevant for future planning including: communities of individuals who have similar behaviors in terms of type of event attendance; key individuals who are "heavy users" of various services in terms of frequency and breadth of event attendance; and peripheral users who use only one service. Post-Covid social network implications are discussed including supports to mitigate negative impacts of Covid on social network composition.
Abstract P22: Timing of Initiation of Direct Oral Anticoagulants After Acute Cardioembolic Stroke
Authors: Mikami Takahisa , INOUE Norihiko , Harrington Matthew , Machida Akira , Asada Mizuho , Thaler David E , Tuhrim Stanley , Fushimi Kiyohide
Published: March 2021

Objective:
To investigate the timing of DOAC initiation to decrease mortality rate in the acute phase of cardioembolic stroke.

Design:
Retrospective observational study using a national administrative database.

Setting:
Japanese hospitals providing care to patients with cardioembolic stroke between April 1st, 2012 and March 31st, 2019

Participants:
24,179 patients with acute cardioembolic stroke who received a direct oral anticoagulant (DOAC) during hospitalization.

Main Outcome Measures:
The primary outcome was 90-day in-hospital mortality. Secondary outcomes were functional disability at discharge (modified Rankin Scale ≥3) and major bleeding. Patients were divided into four groups based on the interval between admission and DOAC initiation and, according to the “1-3-6-12 day” rule. The generalized estimated equation model adjusted with entropy balance weighting was used to compare the risk of outcomes. Subgroup analyses were performed by stratifying levels of consciousness on hospital admission.

Results:
The risk of 90-day in-hospital mortality did not vary between groups according to DOAC initiation timing. Initiation at day 3 or later was associated with an increased risk of functional disability at discharge (highest risk group: day 12-21 vs day 1-2, adjusted OR 2.99 [2.48-3.60]), and an increased risk of major bleeding (highest risk group: day 12-21 vs day 1-2, adjusted OR 2.66 [1.77-3.98]). In the subgroup analysis, patients with spontaneous arousal in whom DOAC initiation occurred at day 12 or later had an increased risk of 90-day in-hospital mortality (day 12-21 vs day 1-2, adjusted OR 1.58 [1.07-2.32]). Patients without spontaneous arousal in whom DOAC administration occurred at day 3 or later had a lower risk of 90-day in-hospital mortality (day 12-21 vs day 1-2, adjusted OR 0.57 [0.40-0.81]).

Conclusions:
In patients with acute cardioembolic stroke and spontaneous arousal, it may be safe and effective initiate DOAC within 2 days of hospitalization. Patients without spontaneous arousal may benefit from a delay in DOAC initiation to day 3 or later.
Abstract P221: First-In-Class Anti-Spastic Drug Candidate (MPH-220) Efficiently Relaxes Spastic Muscles and Improves Motor Functions in Gait Disorder in Preclinical Studies
Authors: Gyimesi Mate , Horvath Adam , Turos Demeter , Penzes Mate , Kurdi Csilla , Kovacs Mihaly , Málnási-Csizmadia András
Published: March 2021

Post-stroke muscle spasticity affects 37% of stroke survivors and disables self-supporting life management. There is a high unmet medical need for an efficient antispastic drug because current muscle relaxants are often of limited efficacy and cause severe neurological and cardiovascular side effects due to targeting the central or peripheral nervous system. We developed a new-generation anti-spastic oral drug, MPH-220, which efficiently relaxes spastic skeletal muscles and lacks cardiovascular and neurological adverse effects because it selectively targets skeletal myosin, the contractile protein of muscles. MPH-220 is an efficient skeletal muscle specific actomyosin relaxant demonstrated on human muscle samples. Orally administered MPH-220 reduces muscle force of living rats without cardiovascular side effects. Brain-damage induced spastic animals showed drastic improvement in gait disorders upon oral MPH-220 treatment resulting in significantly straightened body posture, reduced number of spontaneous falling and cramping, and more ordered limb positions. Due to selective accumulation of MPH-220 in skeletal muscle tissues, antispastic effect was maintained for more than 10 hours. Due to its mechanism of action MPH-220 does not cause complete loss of muscle tone even at high doses. Furthermore, MPH-220 has excellent ADMET properties for oral administration: it is highly absorptive, non-mutagenic and has no effects on hERG channels, kinases, nuclear hormone receptors and GPCRs. Considering these results, MPH-220 is a promising anti-spastic oral drug candidate, which provides potential nervous system-independent therapies for spasticity and muscle stiffness without cardiovascular and neuronal side effects. Phase I clinical trials are scheduled for the beginning of 2021. Funded by the Hungarian National Research, Development and Innovation Office (NVKP 16-1-2016-0051 and PIACI-KFI-2019-00488).
Abstract P225: Improving Prehospital Stroke Identification Using Natural Language Processing of Paramedic Reports
Authors: Mayampurath Anoop , Parnianpour Zahra , Meurer William J , Lee Jungwha , Ankenman Bruce , Perry Ohad , Richards Christopher T , Mendelson Scott J , Holl Jane , Prabhakaran Shyam
Published: March 2021

Introduction:
Early identification of stroke by emergency medical services (EMS) providers in the prehospital setting is associated with increased treatment rates, improved functional outcomes, and reduced mortality. We hypothesize that a predictive model utilizing machine learning and natural language processing (NLP) techniques can be developed to analyze EMS run reports to identify stroke patients accurately.

Methods:
We analyzed EMS data from the Chicago Fire Department matched with inpatient data on confirmed and suspected strokes from 17 Chicago hospitals in the Get With The Guidelines-Stroke (GWTG-Stroke) registry from 11/28/2018 to 5/31/2019. Using features derived from paramedic notes, we developed a support vector machine classifier to predict the following categories: any stroke, AIS-LVO, severe stroke (NIHSS>5), and CSC-eligible stroke (AIS-LVO or ICH/SAH). Individuals were randomly assigned into model derivation (70%) and validation cohorts (30%). C-statistics were used to evaluate discrimination of the classifier for stroke categories.

Results:
A total of 965 patients were included for analysis. In a validation cohort of 289 patients, the text-based model predicted stroke better than models trained using the Cincinnati Prehospital Stroke Scale (CPSS, c-statistic: 0.73 vs. 0.67, P=0.165) and the 3-Item Stroke Scale (3I-SS, c-statistic: 0.73 vs. 0.53, P <0.001) scores. The text-based model also demonstrated improved performance over the CPSS and 3I-SS models in discriminating patients with other stroke categories (Table 1).

Conclusion:
We derived a predictive model using clinical text from paramedic reports that has superior performance to existing prehospital clinical screening tools to identify stroke in the prehospital setting. Future studies can evaluate the implementation of an NLP-based decision tool to assist in prehospital stroke evaluation and destination decision-making.
Abstract P237: Stroke Survivors and Suicide: A Systematic Review and Meta-Analysis
Authors: Vyas Manav V , Wang Jeffrey Z , Gao Meah M , Hackam Daniel G
Published: March 2021

Background:
People with neurological conditions are at a higher risk of suicide compared to the general population. Despite the known association of stroke with depression and suicidal ideation, it is unclear if stroke is associated with a higher risk of suicide.

Methods:
We systematically searched MEDLINE, Embase, PsycINFO, and Google Scholar from their inception to July 26, 2020 using keywords and database-specific subject. We independently adjudicated and selected observational studies that compared the risk of suicide in stroke survivors to a comparison group, consisting either of people without history of stroke or the general population. We evaluated study quality using the Newcastle Ottawa scale. Using random effects meta-analysis, we calculated the pooled adjusted risk ratio (RR) of suicide in stroke survivors, and separately calculated the pooled adjusted RR of death by suicide and suicide attempt. Using prespecified analyses, we explored study-level factors to explain heterogeneity.

Results:
We screened 4023 articles and included 23 studies, of fair quality, totaling over 2 million stroke survivors, of whom 5563 committed suicide. Compared to the non-stroke group, the pooled adjusted RR of suicide in stroke survivors was 1.73 (95% confidence interval, 1.54-1.95,

I
2

= 93%), with a significantly (P=0.03) higher adjusted risk of suicide attempt (RR 2.09, 1.69-2.58) than of death by suicide (RR 1.61, 1.44-1.80). Observed heterogeneity could not be explained by pre-specified meta-regression and subgroup analyses.

Conclusions:
Stroke should be recognized as an independent risk factor for suicide. Comprehensive strategies to screen and treat depression and suicidal ideation in stroke survivors should be developed to reduce the burden of suicide in stroke survivors.
Abstract P239: Trends in Ischemic Stroke Treatments and Mortality in the United States From 2012-2018
Authors: Anand Sharath Kumar , Benjamin William J , Adapa Arjun , Park Jiwon V , Daou Badih , Wilkinson D. Andrew , Pandey Aditya
Published: March 2021

Introduction:
The establishment of mechanical thrombectomy (MT) as a first line treatment for select patients with ischemic stroke (IS) and the resulting expansion of stroke systems of care have been major advancements in the care of IS patients. Our study aims to identify temporal trends in the usage of tPA and MT, as well as mortality for IS patients from 2012-2018.

Hypothesis:
We hypothesize that not only MT but also tPA utilization increased after 2015 compared to years previous, while mortality likely improved, given enhanced public education and optimization of stroke systems of care.

Methods:
Using a nation-wide, private health insurance database, we identified 141,959 patients who presented with a primary IS between 2012 and 2018. We evaluated trends in tPA and MT usage, and mortality stratified by treatment group using chi square and Cochran-Armitage testing.

Results:
Among patients presenting with IS in this population, the average age was 69.00 ± 12.23, and 47.43% were male. Between 2012-2018, the proportional use of tPA and MT increased significantly (tPA: 6.30%% to 11.79%, p<0.0001; MT: 1.57% to 5.69%, p<0.0001). Mortality at 30 days decreased significantly from 2012-2018 in the overall IS population (4.82% to 4.18%, p<0.0001). Mortality following MT saw the greatest improvement (30-day: 16.42% to 9.04%, p=0.0291), followed by tPA (30-day: 8.54% to 4.91%, p<0.0001) and finally by no treatment (30-day: 4.43% to 3.79%, p<0.0001).

Conclusion:
From 2012-18, we found the use of tPA and MT increased significantly while 30-day mortality decreased in the entire IS population. The most dramatic decrease in mortality was seen in the MT population, followed by tPA and no treatment groups.
Abstract P246: Population-Based Rates of Emergency Department Visits for Stroke in the Different Phases of COVID19 Restriction and Reopening
Authors: Yu Amy Ying Xin , Lee Douglas , Vyas Manav , Porter Joan , Rashid Mohammed , Fang Jiming , Austin Peter , Hill Michael D. , Kapral Moira K
Published: March 2021

Introduction:
Reductions in hospital visits for stroke during the COVID19 pandemic have been reported, but few have studied this question on a population-basis and less is understood about the temporal trends after economic and social reopening. We aimed to describe the rate of emergency department visits for acute stroke before and after the declaration of the pandemic, through the different phases of reopening, in the population of Ontario, Canada (14 million people).

Methods:
Using administrative data linkage, we will show the age- and sex-standardized rate of weekly emergency department visits for ischemic or hemorrhagic stroke between January 1 to September 30, 2020. Pandemic declaration was on March 11, 2020 (week 11) and phase 1 re-opening started on May 19, 2020 (week 20) in Ontario. We will use piecewise regression analysis models to evaluate the changes in rates during the pandemic and after reopening.

Results:
We identified 5,617 emergency department visits for stroke (53% male, median age 74 IQR [63,83]) between January 1 to May 19, 2020 (week 20). Data beyond May 19, 2020 are not available yet, but these will be presented at the ISC 2021. The proportion of patients treated at a comprehensive stroke center was similar pre- and post-pandemic (41.7% versus 42.7%, standard difference (SD) 0.02), as was the proportion of people admitted to hospital (87.9% versus 86.7%, SD 0.03), treated with intravenous thrombolysis (11.6% versus 11.8%, SD 0.01), or underwent endovascular thrombectomy (5.1% versus 4.8%, SD 0.02). Weekly rates of stroke visits decreased after the pandemic declaration, but they seem to increase after week 16 (Figure 1). We show rates from 2019 for comparison.

Conclusions:
Population-based rates of emergency department visits for stroke initially decreased after the pandemic compared to pre-pandemic rates. Changes in rates after reopening and the results of the piecewise regression analysis will be presented at the ISC 2021.
Abstract P247: Geographic Disparities in Access to Outpatient Stroke Rehabilitation Centers
Authors: Doherty Susan V , Parker Dorothea , Sonawane Kalyani , Zhu Yenan , Wozny Joseph , Krause Trudy , Ganduglia-Cazaban Cecilia , Hoang Nicholas , Varghese Susan , Savitz Sean I
Published: March 2021

Outpatient stroke rehabilitation centers (OSRC) play a vital role in providing post-discharge care essential for stroke survivors’ optimum recovery. However, with the ongoing pandemic, reduced access to outpatient stroke rehab has become a serious concern, particularly for stroke survivors residing in rural areas.

Key aim:
Examine access to OSRC across micropolitan and non-core rural counties in southeastern Texas.

Method:
We systematically identified OSRC in rural southeast Texas by performing an internet search. A telephonic survey was administered to collect data on OSRC. Estimated stroke incidence and discharge status were extracted from claims databases. Google maps determined travel distance and time. Descriptive statistics were used to examine and compare the characteristics of rural counties. Analyses were performed using SAS® 9.2.

Results:
We surveyed 65 OSRC from a total of 42 rural (12 micropolitan and 30 non-core) southeast Texas counties
(Fig 1).
Over 50% non-core counties had no access to OSRC; number of centers per 1000 stroke patients was 4.7 (non-core) versus 11.0 (micropolitan) (P=0.01)
(Table 1)
. Compared to micropolitan areas, fewer centers in non-core rural areas offered physical therapy, occupational therapy, speech-language therapy. Telerehabilitation is also far less available in rural non-core counties than micropolitan counties (table 1). Survivors from non-core counties need to travel twice the distance to access OSRC. Stroke incidence, however, remains high in non-core versus micropolitan areas (
Fig 1).

Conclusion:
In conclusion, non-core rural counties in southeast Texas have inferior access to OSRC despite a high need for post-stroke care. During the pandemic, when patients remain at home, urgent efforts such as telerehabilitation are needed to improve access to these critical services to improve rural stroke survivor outcomes.
Abstract P251: Estimates and Temporal Trends for US Nationwide 30-Day Hospital Readmission Among Patients With Ischemic Stroke Treated With Thrombolytic Therapy
Authors: Chaudhry Saqib , Laleka Ibrahim , Bahiru Zelalem , Chaudhry Mohammad Rauf A , Gill Hussan S , Akhtar Iqra , Rahman Haseeb , Tahsili-Fahadan Pouya , Wang Jing , Qureshi Adnan I
Published: March 2021

Background:
Avoidance of readmission is linked to improved quality of care, reduction in cost, and is a desirable patient-centered outcome. Nationally representative readmission metrics for patients with acute ischemic stroke treated with intravenous thrombolytic treatment (IV-tPA) are unavailable to date. Such estimates are necessary for benchmarking performance.

Objectives:
To identify US nationwide estimates and a temporal trend for 30-day hospital readmissions.

Methods:
We identified the cohort by year-wise analysis of the Nationwide Readmissions Database between January 1, 2010, and September 30, 2015. The database represents 50% of all US hospitalizations from 22 geographically dispersed states. Participants were adult (=>18 years) patients with a primary discharge diagnosis of acute ischemic (ICD-9-CM 433.x1 and 434.x1) who were treated with thrombolytic therapy (ICD-9-CM 9910). Readmission was defined as any admission within 30 days of index hospitalization discharge.

Results:
Based on study criteria, 57,676 eligible patients were included (mean [SE] age, 68.7 ± 14.4 years; 48.7% were women). Thirty-day readmission rate for acute ischemic stroke patients treated with IV-tPA was 11.17 % (95%CI, 10.92 %-11.43%). On average, there was a 4.4% annual decline in readmission between 2010 and 2014, which was statistically significant for the period of investigation (odds ratio, 0.95; 95%CI, 0.94-0.97). Age ≥ 65 years (OR 1.16
P
<.0001), medical history of congestive heart failure (OR 1.11
P
= 0.0056), chronic lung disease (OR 1.11
P
= 0.0034) and renal failure (OR 1.35
P
= <.0001) were independent predictors of readmission within 30 days.

Conclusion:
Nationally representative readmission metrics can be used to benchmark hospitals’ performance, and a temporal trend of 4.4 % may be used to evaluate the effectiveness of readmission reduction strategies.
Abstract P253: Readmission in Acute Ischemic Stroke Patients Undergoing Endovascular Treatment
Authors: Chaudhry Saqib , Laleka Ibrahim , Bahiru Zelalem , Gill Hassan S , Chaudhry Mohammad Rauf , Akhtar Iqra , Bashir Sairah , Wang Jing , Fang Yun , Hassan Ameer E , Altaweel Laith , Qureshi Adnan I
Published: March 2021

Background:
Recent trials have demonstrated a reduction in death or disability with endovascular treatment in patients with acute ischemic strokes. However, readmission rates and predictors are not known.

Objective:
To identify rates and factors associated with 30-day readmission after endovascular treatment in ischemic stroke patients.

Methods:
Nationwide Readmissions Data (NRD) between 2010 and 2017 was utilized to identify endovascular treatment in acute ischemic stroke patients using ICD-9 and ICD-10 codes. We used hierarchical logistic regression model to identify factors associated with 30-day readmissions.

Results:
Among 17, 562 acute ischemic stroke patients who survived to discharge after endovascular treatment, 2334 (13.29%) were readmitted within 30-days. Age => 65 years (odds ratio [OR]: 1.23, 95% confidence interval [CI]: 1.09 to 1.39, p =0.0005), chronic kidney disease (OR: 1.28, 95%CI: 1.12 to 1.47, p = 0.0004), congestive heart failure (OR: 1.25, 95%CI: 1.13 to 1.39, p <.0001), post procedure intracranial hemorrhage (OR: 1.09, 95%CI: 0.99 to 1.20, p = 0.04) and diabetes mellitus (OR: 1.09, 95%CI: 0.99 to 1.20, p = .09) during the index hospitalization were associated with readmission within 30 days.

Conclusion:
In this large nationally representative study, nearly one in 10 patients were readmitted within 30 days after discharge in acute ischemic stroke patients undergoing endovascular treatment. Medical comorbidities and post procedure intracranial hemorrhage were associated with 30-day readmission.
Abstract P260: Ischemic Strokes on Direct Oral Anticoagulants
Authors: Navalkele Digvijaya , Polu Ashok , Ginnane Janis , Frankel Michael R , Bhatt Nirav , Nahab Fadi B
Published: March 2021

Introduction:
The objective of our study was to identify the underlying causes of acute ischemic strokes (AIS) in patients prescribed direct oral anticoagulants (DOACs).

Methods:
This is a retrospective study of patients presenting to a large urban comprehensive stroke center from December 1, 2019 to May 31, 2020 who were prescribed DOACs at the index event. Two board-certified vascular neurologists independently reviewed medical charts including patient baseline characteristics, laboratory results, stroke mechanism, and patient-reported adherence. DOAC “failure” was defined as AIS occurring in the setting of self-reported adherence to the FDA-indicated dosing regimen.

Results:
Of 302 AIS patients admitted during the study period, 18 (6.0%) patients had AIS while on DOACs. Median age was 82 (IQR 72, 86) years, 9 (50%) were black and 14 (78%) were female. Eight patients (44%) presented within the IV Alteplase window and 5 (28%) patients presented with large vessel occlusion. At the time of stroke, 13 (72%) patients were on apixaban, 4 (22%) were on rivaroxaban and 1 (6%) on dabigatran. Atrial fibrillation (mean CHADS-VASc score 4.7) was the most common indication for DOAC (72%), followed by deep venous thrombosis (17%), and embolic stroke (11%). The most frequent causes of AIS on DOACs were underdosing in patients ≥ 80 years (n=6), known active malignancy (n=5), and non-adherence (n=4). The remaining cases included procedure-related discontinuation of the DOAC (n=1), symptomatic extracranial internal carotid artery stenosis (n=1), and unknown cause (n=1). Overall, the frequency of DOAC “failure” was 39%. In 6 (33%) patients, the initial anticoagulant was switched to an alternative anticoagulant at discharge.

Conclusion:
In this cohort of patients who had AIS while on DOAC therapy, 39% of cases were attributed to DOAC “failure” and primarily occurred in patients with active malignancy. Underdosing in the elderly and non-adherence remained the leading cause of AIS in patients on DOAC. Our findings highlight the importance of accurate dosing in the elderly and reinforcing adherence to medications. Further studies are needed to understand the role of DOACs in patients with active malignancy.
Abstract P264: Trends in Diagnostic Testing and Mechanism of Stroke Determination
Authors: De Los Rios La Rosa Felipe , Khoury Jane C , Alwell Kathleen S , Haverbusch Mary , Woo Daniel , Mackey Jason , Ferioli Simona , Martini Sharyl R , Mistry Eva , Demel Stacie L , Coleman Elisheva R , Jasne Adam , Slavin Sabreena J , Walsh Kyle B , Star Michael , Madsen Tracy E , Adeoye Opeolu M , Broderick Joseph P , Flaherty Matthew L , Khatri Pooja , Kissela Brett M , Kleindorfer Dawn O
Published: March 2021

Introduction:
A main goal for hospital admission following acute ischemic stroke (AIS) is to establish the mechanism of stroke (MoS) allowing for patient specific secondary prevention of stroke interventions. We previously reported on diagnostic testing trends and MoS determination from 1993 through 2010. We updated this analysis with 2015 data to better understand the effects of trends in diagnostic testing on MoS determination.

Methods:
Patients with AIS aged
>
20 years from all study time periods (Table) of the population based GCNKSS were included. Charts were abstracted in a systematic way for tests performed during the hospital stay. Only first-ever ischemic stroke cases, evaluated in an emergency department were used for this analysis. Stroke experts reviewed these events and adjudicated the mechanism of stroke according to modified TOAST criteria. We looked at and compared trends for testing and MoS.

Results:
Our analysis included 7226 patients. Basic patient demographics, MoS categories and tests across study periods are detailed in the Table. There were significant increases in EKG (7%), TTE (35%), TEE (7%), HCT (4%), brain MRI (65%), MRA (30%) and CTA (28%). Across study periods, cardioembolic (4.1%), small vessel disease (3%), large artery disease (0.9%) and other (1.5%) MoS increased while unknown MoS decreased (-9.5%).

Discussion:
From 1993/1994 to 2015 there has been a significant increase of in-hospital testing in AIS and decreases in undetermined MoS. Cardioembolic and small vessel disease MoS categories increased the most. Despite a significant increase in vessel imaging, large artery disease and “other determined” MoS categories are largely unchanged. Further research is required to elucidate the occult MoS underlying the undetermined category. Based on our analysis it appears unlikely to be significantly associated with our current definition of stroke associated with large artery disease defined as ≥ 50% ipsilateral stenosis.
Abstract P275: Predicting Stroke Mimics in Telestroke Consultations
Authors: Siriwardane Jennifer , Martin Holly , Edwards Brandon , LaPradd Michelle , Daggy Joanne , Myers Laura , Graham Glenn , Martini Sharyl , Anderson Jane A , Williams Linda S
Published: March 2021

Background:
Telestroke consultation is increasingly used to provide stroke care. Much like in-person stroke consults, stroke mimics are common. This study sought to identify patient and hospital characteristics more likely to be associated with a Telestroke diagnosis of stroke mimic.

Methods:
We analyzed 2 years of video consults by the VA National Telestroke Program (NTSP). Stroke mimic was defined as a Telestroke consult coded as a diagnosis of “other.” Text responses for “other” diagnoses were grouped into clinical categories. We used Chi-squared and t-tests analysis to compare characteristics of patients with a stroke mimic diagnosis and those without. Co-variates studied included age, gender, co-morbid conditions (history of dementia, cancer, or alcohol abuse), NIHSS, time of consult (night/weekend vs day), location of consult (emergency department vs inpatient), hospital rurality; hospital consult volume, and duration of institutional participation in NTSP at time of consult. Variables with a p-value < 0.25 in the bivariate analysis were included in the multivariate model.

Results:
There were 561 stroke mimics. The most common mimics were toxic metabolic encephalopathy (19%) and seizure (12%). Variables significantly associated with stroke mimic in bivariate analyses were age, gender, history of alcohol abuse, history of atrial fibrillation, history of dementia, NIHSS, nights/weekend consults, and hospital rurality. In multivariate analyses, female sex [OR=1.63, p=0.001], inpatient consultations [OR=1.55, p= 0.019], history of dementia [OR=1.85, p=0.0002], and alcohol abuse [OR=1.42, p=0.002] were associated with a stroke mimic. Consults during nights/weekends [OR=0.76, p=0.001], and patients with atrial fibrillation [OR=0.81, p=0.031], increasing age [OR=0.90, p=0.019], and increasing NIHSS [OR=0.97, p=0.0042] were less likely to be a mimic.

Conclusion:
Patient and consult characteristics influenced the likelihood of a stroke mimic diagnosis. Medical history may reflect conditions likely to cause neurologic symptoms, and patients hospitalized who have new symptoms represent a challenging subset to accurately distinguish stroke from mimics. Awareness of these factors may alert providers to diagnoses other than stroke.
Abstract P276: The Perception/ Misperception of Treatability of 7AM vs 7PM Stroke Codes
Authors: Meyer Brett C , Shifflett Ben , Meyer Dawn M
Published: March 2021

Background:
Prior studies have assessed the effect of time of day and day of week on stroke code frequency. Observations that early evening times might result in more treatable stroke cases have been noted. Experiential data raise the question as to whether 7pm codes are often “real” and “intervenable”. Understanding treatment patterns can help allocate resources. We assessed whether 7am early morning stroke code activation resulted in higher yield of acute treatment compared to 7pm evening stroke codes.

Methods:
A retrospective analysis of prospectively collected data from an IRB approved stroke registry, from 7/2004-7/2020, was performed. All patients presenting as a stroke code to our comprehensive stroke center (CSC) or covered hospitals were included. Subjects were divided into 2 groups: (7ASC): Stroke code called 06:00-08:00 and (7PSC) Stroke code called 18:00-20:00. Treatment was defined as receiving any thrombolytic or endovascular intervention. Chi-squared was used for categorical and 2-proportion Z-Test was used for proportional data.

Results:
A total of 988 subjects were identified with stroke codes in these time epochs. Total number of code activations (including mimics) was higher in 7PSC group [277(28.0%) 7ASC, 711(72.0%) 7PSC; p<0.0001] compared to 7ASC group. For patient with final diagnosis of stroke, number of code activations remained higher in 7PSC group [134(28.3%) 7ASC, 340(71.7%) 7PSC; p<0.0001]. Acute treatment rates did not differ between groups [22.7% 7ASC, 22.5% 7PSC; p=0.62].

Conclusions:
We noted more 7PSC stroke codes even when not adjusting for the extended stroke code time windows in later years of the database. We hypothesize that this may be due to more witnesses being available in the early evening. In spite of this finding, acute treatment rates did not differ between times. This data does not support provider perception that early morning codes are unlikely to be “true or treatable” and early evening codes are often “true and treatable”. Irrespective of perception, stroke providers in a CSC must be immediately and equally available in both early morning and evening. This also has ramifications for interventional procedure staffing and clinical trial enrollments. Further analyses in a larger dataset are warranted.
Abstract P28: Stroke Treatment With Tenecteplase Improves Door-To-Needle Time
Authors: McKinney James S , Treible Laura , Vinodh Doss , Kalp Matthew , Beecher Jeff , Nakajima Steven , Curley Tom
Published: March 2021

Introduction:
Intravenous tenecteplase (TNK) may be as effective as alteplase (TPA) in treatment of stroke. Due to ease of administration, we hypothesized that TNK would reduce treatment times when compared to TPA.

Methods:
All emergency department (ED) patients arriving as a Code Stroke between July 1, 2019 and June 30, 2020 were included. Data was analyzed retrospectively. The primary outcome was time from ED presentation to thrombolytic administration, “door to needle” (DTN). The times from presentation to groin/radial puncture and final recanalization mechanical thrombectomy cases was also studied. The primary independent variable was treatment with TNK versus TPA. Differences in baseline characteristics between groups were examined. Chi-squared and nonparametric Mann-Whitney U tests were performed for categorical and continuous variables, respectively. Statistical significance was defined as a p-value ≤ 0.05.

Results:
167 acute ischemic stroke patients (25 TNK, 142 TPA) were treated in the study period. There were no differences in baseline characteristics between groups (age, gender, race, NIHSS, or RACE score). TNK was associated with significantly shorter treatment times when compared to TPA (p=0.024). (Table 1). No difference was observed in the door to puncture (p=0.486) or final recanalization (p=0.478) between treatment groups. No differences in clinical outcomes were observed.

Conclusions:
TNK treatment is associated with lower DTN when compared to TPA. No differences were observed in treatment times of mechanical thrombectomy cases or in overall clinical outcomes. However, shorter treatment times may ultimately lead to better neurological outcomes and deserves further research.
Abstract P290: Predicting Readmission and Mortality After Ischemic Stroke
Authors: Nguyen-huynh Mai N , Alexander Janet , Zhu Zheng , Meighan Melissa M , Escobar Gabriel J
Published: March 2021

Background:
Stroke patients have high rates of all-cause rehospitalization at 30 days (7-24%) and within one year (30-62%). Limited information is available on how to predict these outcomes. We assessed two existing predictive models and whether adding NIHSS or modified Rankin scale (mRS) score improved their predictive ability for 30-day non-elective rehospitalization and/or mortality post-stroke.

Methods:
Using a cohort of ischemic stroke patients in a large multi-ethnic integrated healthcare system from June 2010 to December 2017, we tested 2 existing predictive models for a composite outcome (30-day non-elective hospitalization or death). The models were based on administrative data (LACE) as well as a comprehensive model (Transition Support Level, TSL) that included multiple clinical data elements from the electronic health record, including admission acute physiology and discharge care directives. LACE score included information on length of stay, acuity, comorbidities, and emergency department visits. The models, NIHSS and mRS scores were tested independently, and in combination and combined with age and sex. We assessed model performance using the area under the receiver operator characteristic (c statistic), Nagelkerke pseudo-R
2
, and Brier score.

Results:
The study cohort included 4843 patients with 5,014 stroke hospitalizations. Average age was 71.9 ± 14 years with 50.6% female and 52.1% White. Median initial NIHSS was 4. Median length of stay was 4 days, and 55.6% were discharged home. There were 527 non-elective readmissions within 30 days. The logistic models revealed that the best performing models were TSL (c-statistic = 0.685) and TSL plus mRS score at discharge (c-statistic = 0.694) [Table].

Conclusions:
We found that neither the initial NIHSS nor the mRS score at discharge enhanced the predictive ability of the LACE or TSL models. Future efforts at prediction of short-term stroke outcomes will need to incorporate new data elements.
Abstract P295: The Effect of Endovascular Procedure and Tissue Plasminogen Activator Treatments on 90 Days Episode Payments Among Ischemic Stroke Patients
Authors: Hailat Raed , Yost Monica , Thompson Michael , Burke James , Reeves Mathew J
Published: March 2021

Introduction:
Endovascular therapy (EVT) and tissue plasminogen activator (tPA) are highly effective treatments but little is published on their impact on health care utilization and payments. We analyzed of data from the Michigan Value Collaborative (MVC) registry to compare 90-day episode payments for EVT and tPA treatments acute ischemic stroke patients.

Methods:
The MVC registry uses claims data from Michigan residents insured by Medicare fee-for-service and Blue Cross Blue Shield, to construct risk-adjusted and price-standardized payments for 90-day episodes of care. Total payments are categorized into index hospitalization, professional services, readmissions, and post-acute care. All ischemic stroke admissions between January 2014 and June 2019 were identified and then categorized using a combination of diagnosis and procedure codes into 3 mutually exclusive treatment groups: EVT (with and without tPA), IV or IA tPA only, and all other ischemic strokes (non EVT-tPA). We compared 90-day episode payments between the 3 groups using analysis of variance and Tukey’s pairwise comparisons.

Results:
We identified 47,235 acute ischemic stroke patients admitted to 83 Michigan hospitals, 1,775 (3.8%), 4,889 (10.3%), and 40,571 (85.9%) received EVT, tPA only, or neither, respectively. Statistically significant differences were observed across the 3 treatment groups in all payment categories. EVT treated patients had the highest 90-day mean payments in all categories, but particularly for readmissions and post-acute care (Table). tPA treated patients had significantly higher costs than the non EVT-tPA group for total payments, professional and hospitalization fees.

Conclusions:
EVT and tPA treatments significantly affect 90-day episode payments - primarily due to higher hospitalization and professional payments. Higher readmission and post-acute cost in EVT treated patients reflect higher readmission rates and use of in-patient rehabilitation.
Abstract P296: Utility of Routine Transfer for Patients Administered Intravenous Alteplase for Ischemic Stroke
Authors: Okematti Emmanuel , Ukatu Hope , Shakur Zahrah , Okematti Mary , Streib Christopher
Published: March 2021

Introduction:
Intravenous Alteplase is currently the only approved medical therapy for treatment of acute ischemic stroke (AIS). Although complications are uncommon, AIS patients receiving IV Alteplase are routinely transferred to higher level stroke centers for monitoring. This resource intensive treatment paradigm is of unclear medical benefit.

Methods:
We reviewed the stroke thrombolysis database of a single comprehensive stroke center. All presumed AIS patients who received IV Alteplase without thrombectomy from 01/01/2015 to 12/31/2019 were included. Baseline demographics including age, sex, race, ethnicity, comorbidities, and NIHSS were abstracted. Complication rates including angioedema, intracranial and extracranial hemorrhage were recorded. To determine the utility of routine transfer, medical and surgical/neurosurgical interventions to treat complications of Alteplase administration were studied. Complication rates in the transfer and non-transfer cohorts were compared via Fischer’s exact test.

Results:
Three hundred eighteen patients were reviewed and 222 consecutive AIS patients (median age 67 [IQR 55.5-77], female 48.6%, median NIHSS 5 [IQR 2-10], transfers 54.5%) were eligible for our analysis. Complication rates were not statistically different between transfer and non-transfer patients. Four (1.8%) patients suffered symptomatic intracranial hemorrhage (sICH). All sICH patients received cryoprecipitate and aggressive blood pressure management; none underwent emergent neurosurgical intervention.

Conclusion:
The overall rate of complications post-Alteplase administration for AIS patients was similarly low between transfer and non-transfer patients. These findings call into question the utility of routine transfer of AIS patients treated with Alteplase. Further study of alternative post-Alteplase monitoring strategies, including remote specialist management via telemedicine, should be considered.
Abstract P304: A Novel Method for Modeling Flow in Cerebral Vasculature Diagnostics
Authors: Dinh Huy
Published: March 2021

Introduction:
We examined the viability of pairing wire-obtained flow pressure data with computational fluid dynamic (CFD) analysis for accurate patient-specific 3D reconstruction of flow through cerebral vessels—an approach that provides comprehensive velocity data and other flow parameters to assist the preventative diagnosis of cerebral stenosis.

Methods:
Two physical phantom models of a cerebral stenosis—differing in regard to vascular morphology at and around the stenosis—were prepared, filled with physiological saline and connected individually to a flow pump (Vascular Simulations LLC Left Heart Replicator) applying pulsatile flow. Pressure measurements were taken upstream of the stenosis by microcatheter-guided wires to define an inlet boundary condition for CFD analysis. Pressure and velocity at 2 cm proximal to stenosis, the stenosis inlet, the stenosis outlet, and 2 cm distal to stenosis were measured to validate the CFD simulated flow.

Results:
Excellent agreement was observed between CFD and wire-measured time-dependent flow pressure, with the expected pulsatile behavior observed at each location. Between the two methods, differences in maximum systolic pressures ranged between |0.73±0.72|% and |3.90±0.74|%. Differences in minimum diastolic pressures ranged between |1.79±1.33|% and |9.08±1.42|%. Velocity data from wire measurements lacked pulsatile behavior and showed differences ranging between |2.93±5.20|% and |120.10±2.91|% from CFD-obtained measurements, which did show correct pulsatile behavior. Larger discrepancies were strongly associated with areas of higher CFD predicted velocities (r=0.86).

Conclusion:
Guidewire flow measurements provided CFD analysis with accurate inlet boundary conditions and validated CFD simulation results. CFD analysis allowed for detailed visualization of key flow parameters that may be difficult to physically measure—such as velocity—that are relevant for understanding risk factors associated with cerebral stenosis on a case-by-case basis.
Abstract P317: White Matter Hyperintensity Lesion Burden Modulates Functional Outcome After Acute Ischemic Stroke
Authors: Bonkhoff Anna K , Hong Sungmin , Schirmer Markus , Bretzner Martin , Giese Anne-Katrin , Donahue Katy , Nardin Marco , Dalca Adrian , Etherton Mark , Golland Polina , Wu Ona , Jern Christina , Lindgren Arne , Maguire Jane , Rost Natalia S ,   on behalf of the MRI-GENIE and GISCOME Investigators and International Stroke Genetics Consortium.
Published: March 2021

Introduction:
As a radiographic signature of end-stage small vessel disease, white matter hyperintensity (WMH) burden impacts recovery and outcomes after acute ischemic stroke (AIS). In this study, we sought to investigate the effect of WMH volume (WMHv) on stroke severity and functional outcomes independent of the infarct size and topography.

Methods:
We analyzed 503 AIS patients with MRI data obtained on admission for index stroke enrolled in the multi-center MRI-GENIE study (cohort 1), followed by validation of the findings in an independent single-site study of 555 AIS patients (cohort 2). Stroke severity (NIHSS score) at index stroke and the long-term outcome (3-6 months mRS score) were modeled via Bayesian linear regression. Models included WMHv, age, sex, a 10-dimensional spatial ischemic lesion representation, acute infarct (DWI) volume, and common vascular risk factors (hypertension, diabetes mellitus, atrial fibrillation, coronary artery disease).

Results:
Cohorts did not differ significantly in major clinical characteristics [cohort 1: age: 65.0±14.6, 41% female, NIHSS: 5.5±5.4, mRS: 1(iqr 2); cohort 2: age: 65.0±14.8, 38% female, NIHSS: 5.0±6.0, mRS: 1(iqr 3),
p
>0.05 for all comparisons]. WMHv did not substantially affect AIS severity (
Fig A
); in contrast, it emerged as an independent predictor of functional outcome in both datasets (
Fig B
).

Conclusions:
When accounted for AIS lesion topography and stroke volume, total WMH lesion burden did not appear to modulate initial stroke severity but was associated with worse functional post-stroke outcomes. Future studies are needed to explore potential origins of these detrimental effects of pre-existing WMH burden on recovery after AIS.