bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P241: Why Do We Expect Clinicians to Perform the Work of Computers? Developing an Automated Stroke Registry
Authors: Johnson Brenda J , Butler Jaime , Potu Niteesh , Millar Tony , Dziedzic Peter , Reed Emily , Urrutia Victor C
Published: March 2021

Background:
Stroke registries are established with the primary goal of improving health care quality and performance improvement through increased adherence to evidenced based guideline recommendations. As a Joint Commission certified organization, the Comprehensive Stroke Center uses the American Heart Association’s Get With The Guidelines® (GWTG) stroke patient management tool to collect performance improvement data on patients admitted with a principle diagnosis of stroke. Data abstraction is laborious and time consuming which requires manual entry by multiple clinicians. Therefore, we developed an automated internal stroke database to improve efficiency and augment accuracy.

Methods:
We collaborated with software engineers and EPIC report writers to create an innovative stroke database with the capability to extract data from an Electronic Health Record (EHR) for upload to GWTG. The clinicians identified data elements for automation in the EHR. Based on final ICD-10 coding the report writer retrieved end-user data, which were organized into tables and sent to the software engineer. These variables were processed to match GWTG specifications and then presented to clinicians in the user interface for validation. Next, a CSV file was generated and uploaded to GWTG, where the remaining data was entered.

Results:
The case completion time was reduced from 45 minutes to one hour to an average of 25 minutes (median 23 minutes), thus achieving our primary goal. Due to the variance in the number of required data elements based on diagnosis and patient specific variables, we aggregated the data elements, automated versus required, and calculated an automation rate of 54%. Approximately half of the 414 fields required in GWTG have the potential for automation, and we continue to strive toward this goal. Due to the complexity of GWTG questions and the way data is captured in the EHR, some data elements require manual entry.

Conclusions:
An automated stroke registry has the potential to enhance efficiency and limit the opportunity for human error. By minimizing the clinicians’ data entry tasks to those of higher-level data abstraction, there is more time for performance improvement.
Abstract P252: Discharge Antithrombotic Therapy for Ischemic Stroke Patients With Prior Aspirin Failure
Authors: Xian Ying , Xu Haolin , Bhatt Deepak L , Fonarow Gregg C , Smith Eric E , Matsouaka Roland , Lytle Barbara , Peterson Eric D , Schwamm Lee H
Published: March 2021

Introduction:
Aspirin is one of the most commonly used medications for cardiovascular disease and stroke prevention. Many older patients who present with a first or recurrent stroke are already on aspirin monotherapy, yet little evidence is available to guide antithrombotic strategies for these patients.

Method:
Using data from the American Heart Association Get With The Guidelines-Stroke Registry, we described discharge antithrombotic treatment pattern among Medicare beneficiaries without atrial fibrillation who were discharged alive for acute ischemic stroke from 1734 hospitals in the United States between October 2012 and December 2017.

Results:
Of 261,634 ischemic stroke survivors, 100,016 (38.2%) were on prior aspirin monotherapy (median age 78 years; 53% women; 79.4% initial stroke and 20.6% recurrent stroke). The most common discharge antithrombotics (Figure) were 81 mg aspirin monotherapy (20.9%), 325 mg aspirin monotherapy (18.2%), clopidogrel monotherapy (17.8%), and dual antiplatelet therapy (DAPT) of 81 mg aspirin and clopidogrel (17.1%). Combined, aspirin monotherapy, clopidogrel monotherapy, and DAPT accounted for 86.8% of discharge antithrombotics. The rest of 13.2% were discharged on either aspirin/dipyridamole, warfarin or non-vitamin K antagonist oral anticoagulants with or without antiplatelet, or no antithrombotics at all. Among patients with documented stroke etiology (TOAST criteria), 81 mg aspirin monotherapy (21.2-24.0%) was the most commonly prescribed antithrombotic for secondary stroke prevention. The only exception was those with large-artery atherosclerosis, in which, 25.3% received DAPT of 81 mg aspirin and clopidogrel at discharge.

Conclusion:
Substantial variations exist in discharge antithrombotic therapy for secondary stroke prevention in ischemic stroke with prior aspirin failure. Future research is needed to identify best management strategies to care for this complex but common clinical scenario.
Abstract P258: The COVID-19 Pandemic is Not Associated With Worse 90-Day Functional Outcomes Following Endovascular Thrombectomy Despite Increased Delays to Recanalization
Authors: Neves Briard Joel , Ducroux Celina , Jacquin Grégory , Alesefir Walid , Boisseau William , Cournoyer Roxanne , Daneault Nicole , Deschaintre Yan , Eneling Johanna , Gioia Laura C , Iancu Daniela , Odier Céline , Raymond Jean , Roy Daniel , Stapf Christian , Weill Alain , Poppe Alexandre Y
Published: March 2021

Introduction:
Several comprehensive stroke centers (CSC) have reported increased delays to reperfusion in acute stroke during the COVID-19 pandemic, but it is unknown whether the pandemic is associated with worse functional outcomes in EVT-treated patients.

Methods:
We performed an observational cohort study of consecutive adult patients evaluated for suspected stroke at our CSC (located in Montreal, a Canadian pandemic epicenter) between March 30 and May 15 2020 (prospective pandemic cohort) and 2019 (retrospective non-pandemic cohort). We excluded in-hospital strokes. We compared short-term (in-house door-to-puncture and door-to-recanalization delays, TICI 2b/3, complications during EVT) and long-term (90-day mRS ≤2 and death) outcomes with univariate analyses. We assessed the effect of the pandemic on 90-day mRS while controlling for clinical confounders.

Results:
Overall, 111 and 106 patients were included in the pandemic and non-pandemic cohorts, respectively. The prevalence of COVID-19 in the pandemic cohort was 3% (3/104). Among ischemic stroke patients, 31/77 (40%) and 41/71 (58%) underwent EVT in each respective cohort (p=0.03). Among EVT-treated patients, baseline characteristics and NIHSS scores were similar (median [interquartile range]: 20 [12-25] vs 18 [14-20], p=0.18), but pre-stroke mRS was lower in the exposed cohort (0 [0-1] vs 1 [0-2], p=0.04). Door-to-puncture (87 [65-102] vs 56 [47-74] min, p=0.07) metrics were similar, but door-to-recanalization (122 [99-126] vs 89 [67-97] min, p<0.01) metrics were longer during the pandemic. The proportions of patients with TICI 2b/3 (94 vs 85%, p=0.27) and with complications during EVT (23 vs 22%, p=0.95) were similar, as were those for 90-day mRS ≤2 (42 vs 37%, p=0.64) and death (19 vs 20%, p=0.99). The logistic multivariate regression did not disclose an association between the COVID-19 pandemic and 90-day mRS ≤2 (aOR 0.70, 95% CI 0.06-7.95).

Conclusion:
The COVID-19 pandemic does not appear to have a negative impact on 90-day functional status among EVT-treated patients despite increased delays to recanalization. However, patient selection may have been stricter during the pandemic, as a smaller proportion of evaluated patients underwent EVT and those treated had lower pre-stroke mRS.
Abstract P262: Early Withdrawal of Life Sustaining Treatment After Mechanical Thrombectomy: A Quantitative and Qualitative Analysis
Authors: Singh Amita , Schutz Rachael , Ruiz Amber , Lou William , Creutzfeldt Claire J , Khot Sandeep P
Published: March 2021

Background:
Mechanical thrombectomy (MT) is now standard of care for patients with acute large vessel occlusion (LVO) ischemic stroke, after several trials showed significant functional improvement at 90 days. Despite this expected duration for recovery, withdrawal of life sustaining treatment (WLST) often occurs within less than 5 days after MT. We aimed to identify determinants of early WLST and better understand decisions that led to it.

Methods:
Retrospective chart review at a single academic stroke center from 1/2015 to 8/2020 using mixed methods. We compared patient characteristics and hospital course in those with early WLST (within 5 days) to those without WLST. Six authors conducted in-depth qualitative analysis of family meeting notes among a subgroup of 16 purposively sampled early WLST patients.

Results:
Among 402 patients (mean age 68.0, SD 14.7 years; 53.7% male) who underwent MT, 88 (21.9%) had WLST, of which 52 (12.9%) were early WLST (mean 2.2, SD 1.3 days). Logistic regression adjusted for sex, race, LVO location, time of MT from last known normal, and post-procedural hemorrhage showed early WLST compared to no WLST was significantly associated with older age, inpatient stroke, increased stroke severity, unsuccessful MT, no tPA given, post-procedural need for craniectomy, and palliative care consultation (p<0.05). One key theme that emerged from goals-of-care conversations was clarity among families of patient’s wishes, with a low tolerance for dependence, which led to early WLST if independence was unlikely immediately after MT.

Conclusion:
Early WLST after MT occurs frequently in patients with severe stroke and high medical complexity, especially if progression to cerebral herniation. Clear communication before and after MT regarding expected prognosis and trajectory of recovery could allow for improved decision making and prevent potentially premature WLST by providers or families. Prior knowledge of patient’s goals-of-care may also reduce patient or caregiver suffering and improve resource utilization for the healthcare system in patients with severe stroke.
Abstract P271: Influenza and Herpes Zoster Vaccination in United States Stroke Survivors: A Nationwide Analysis
Authors: Hwang Mu Ji , Salehi Omran Setareh , Mir Saad , Merkler Alexander E , Kamel Hooman , Navi Babak B , Parikh Neal S
Published: March 2021

Introduction:
Patients with stroke face an increased risk of contracting influenza and herpes zoster. We compared vaccination rates in stroke survivors versus the general United States population.

Methods:
We performed a cross-sectional analysis of data from the Centers for Disease Control and Prevention (CDC) Behavioral Risk Factor Surveillance System, which is an annual, nationally representative, health survey. Respondents are asked about medical conditions and care. We used the most recent years with complete data for influenza (2018) and zoster (2017). We utilized survey procedures to estimate CDC-recommended vaccination rates for influenza (annual vaccination for all) and zoster (one-time vaccination for those at least 50 years old). Multiple logistic regression was used to compare the odds of vaccination in those with and without prior stroke, while adjusting for demographics (including income and health insurance) and comorbidities that may influence vaccination rates (obesity, diabetes, heart disease, cancer, pulmonary disease, and smoking).

Results:
In 2018, 8,254,136 (3.4%; 95% CI, 3.3-3.5) Americans were stroke survivors. The influenza vaccination rate was 44.4% (95% CI, 42.8-46.2) in stroke survivors and 32.8% (95% CI, 32.5-33.1) otherwise. In unadjusted models, stroke survivors were more likely to have had an influenza vaccination in the past year than those without stroke (OR, 1.6; 95% CI, 1.5-1.8). In 2017, 5,839,186 (5.7%; 95% CI, 5.5-5.9) Americans over 50 years old (i.e., eligible for zoster vaccination) were stroke survivors. The zoster vaccination rate was 30.3% (95% CI, 28.8-32.0) in stroke survivors and 27.6% (95% CI, 27.3-28.0) in those without prior stroke. Stroke survivors were more likely to have had zoster vaccination than those without stroke (OR, 1.14; 95% CI, 1.06-1.23). However, after accounting for demographics and comorbidities, stroke survivors were not more likely to be vaccinated for influenza (OR, 1.01; 95% CI, 0.93-1.10) or zoster (OR, 1.00; 95% CI, 0.90-1.12).

Conclusion:
Stroke survivors were not vaccinated at higher rates than expected based on demographics and comorbidities, and absolute vaccination rates were low, especially for zoster. Efforts to increase vaccination after stroke may be needed.
Abstract P272: Management of Acute Stroke Patients in the Extended Window in a Large Community Cohort
Authors: Nguyen-huynh Mai N , Alexander Janet , Lee Catherine , Meighan Melissa M , Burnett Molly , Flint Alexander C , Rao Vivek A , Klingman Jeffrey
Published: March 2021

Background:
Published data suggest that treating qualified acute strokes within the extended window (EW) or 6-24 hours of last seen normal with endovascular therapy (EST) is associated with better 90-day outcome. In a real-world multi-ethnic practice setting, we assessed our experience in triaging and treating patients in the EW.

Methods:
In 2016, our system of care launched a telestroke program for 19 primary and 2 comprehensive stroke centers to include immediate video evaluation by a stroke neurologist. In 2018, screening in the EW began. If the patient met clinical criteria (baseline independence and initial NIHSS ≥ 6), neuroimaging was performed to assess for a large vessel occlusion (LVO). Referral for EST was made for patients with an LVO and appropriate CT perfusion criteria. Our study included all health plan members presenting within the EW in 2019. Assessment included demographics, NIHSS, neuroimaging data, LVO, discharge outcomes, 90-day mRS and mortality with 95% confidence interval.

Results:
In 2019, there were 5349 suspected strokes (1255 EW) evaluated by teleneurologists; 2130 (39.8%) patients were appropriate for acute stroke imaging workup. Of 2130, final study cohort included 388 (18.2%) EW patients who met clinical criteria and underwent neuroimaging workup, and 117 of these patients (30.2%) had an LVO. There were 57 (14.7%) meeting CT perfusion criteria and referred for EST. Compared to 331 who were not referred for EST, the 57 patients were older and more likely to have atrial fibrillation, higher NIHSS, and to be discharged to a short-term facility than home. The 51 patients who went for EST within our system had 90-day good (mRS 0-2), bad (mRS 5-6), and mortality rates comparable to those from DAWN and DEFUSE-3 trials [Table].

Conclusions:
In our system, only a small proportion of suspected strokes met criteria for EST during the EW. It was possible in a community setting to achieve 90-day outcomes that were comparable to those from clinical trials.
Abstract P273: Hospitalization Costs for United States Stroke Patients Receiving Tracheostomy
Authors: Albert George P , Hwang David Y , George Benjamin P
Published: March 2021

Introduction:
Stroke patients who receive tracheostomy often undergo prolonged ventilation and have long, complicated ICU stays. Little is known about the hospitalization costs for these patients.

Methods:
We used the National Inpatient Sample from 2008-2017 to identify patients with a primary diagnosis of acute ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage. We identified individuals who received tracheostomy based on procedure codes. We used cost-to-charge ratios to calculate hospitalization costs for each patient and adjusted costs to 2017 US dollars using the Medical Consumer Price Index. We examined differences in hospitalization costs based on age, sex, race, Elixhauser score, length of stay, and early tracheostomy placement (≤7 days). We calculated overall average annual hospitalization costs for all patients with stroke and tracheostomy in the US and compared to the total US acute stroke population inpatient costs.

Results:
We identified an estimated 61,322 acute stroke patients in the US receiving tracheostomy from 2008 to 2017, representing 1.1% of all US acute stroke patients. Stroke patients with tracheostomy had a mean age of 61 years (SD=13.8); 46% were female, 29% black, 12% Hispanic, and 13% rural. Among tracheostomy patients, the mean Elixhauser score was 4.7 (SD=2). The mean hospitalization cost for tracheostomy patients was $117,492 (median $97,063; IQR $64,887-$145,419). Costs were greater for younger patients, females, and those from urban locations. There was no difference in costs for white compared to minority patients. Each additional hospital day accounted for $2,023 in hospitalization costs, and those with early tracheostomy (22% of tracheostomy patients) had lower hospitalization costs (mean $89,811 vs. $125,318; p<0.001). Total US hospitalization costs for acute stroke patients receiving tracheostomy are estimated at $720.4 million per year, which represents 8.1% of total acute stroke hospitalization costs in the US.

Conclusion:
Acute stroke patients who receive tracheostomy account for 1% of all stroke patients, but 8% of all hospitalization costs for stroke in the US.
Abstract P283: Palliative and End-Of-Life Care After Left Ventricular Assist Device-Associated Intracranial Hemorrhage
Authors: Ibeh Chinwe , TIRSCHWELL David L , Mahr Claudius , Creutzfeldt Claire J
Published: March 2021

Background:
Intracranial hemorrhage (ICH) has a high mortality rate (up to 40% in some studies) with most deaths occurring after limitation of life-sustaining therapies. ICH is a feared complication of left ventricular assist device (LVADs) and challenges end-of-life decisions for patients, families, and health-care teams. Palliative care (PC) is considered essential for the management of patients who receive an LVAD, yet little is known about the end-of-life course of patients with LVAD-associated ICH. The goal of this single center study was to better understand the impact of PC involvement in post-ICH care in LVAD patients.

Methods:
We retrospectively identified all patients within our institutional LVAD database who experienced ICH between 2012 - 2018. Demographic, clinical, and outcome data were collected and analyzed using descriptive statistics.

Results:
Of the 283 patients who underwent LVAD placement, 32 (11%) experienced 34 ICHs: 16 intraparenchymal (IPH, 47%), 4 subdural (SDH, 12%), and 14 subarachnoid (SAH, 41%), a median of 258 (110-526) days post-LVAD. PC was consulted in 23 (68%) cases (69% of IPHs, 75% of SDHs, and 64% of SAHs). The patients who received PC were younger (50.5 [16.5] vs 54.9 [17.1] years) and more neurologically impaired (mean GCS 12.8 [3.6] vs 13.2 [4.0]). Women were referred more frequently than men (80% vs 63%) and White patients more frequently than non-White (74% vs 63%). All patients were full code at the time of their ICH; following PC consult, code status was changed to DNR in 48%. Ten patients (29%) died during their hospitalization. Though most patients in the cohort were referred for PC, only one died on home hospice; the remaining patients died in the hospital setting, 7 (70%) in the intensive care unit (ICU).

Conclusions:
In this single-center study, the vast majority of LVAD patients who died from their ICH died in the hospital setting, and most in the ICU, despite high numbers of PC consultation. As prior studies have associated in-hospital death with worse end-of-life-care and more physical and emotional distress for terminal patients, the use of hospice services has been increasing in the stroke population. Further work is needed to provide better end-of-life options for LVAD patients following serious neurologic injuries.
Abstract P285: Thrombectomy Treatment Times Pre-Post Early Activation of Interventional Radiology Team
Authors: Henderson Susan , Baraban Elizabeth , Rogers Bronwyn S , Provencher Michelle , Ho Joseph T , Loh Yince , Scherman Ashley
Published: March 2021

Background:
Reducing treatment time for ischemic stroke is crucial. In 2017, an urban Comprehensive Stroke Center (CSC) in the Pacific Northwest (PNW) initiated early activation of the interventional radiology team (Early-IR) based on first responder LAMS’ score of 4 or 5 to improve thrombectomy treatment times (door-to-arterial access times [DTAA]) for acute ischemic stroke patients. Policy efficacy has not been evaluated.

Objectives:
1) Compare DTAA times and clinical outcomes pre vs post Early-IR initiation using a multi-state stroke registry. 2) Compare DTAA times and clinical outcomes between the PNW and other CSCs in the same multi-state stroke registry.

Methods:
Included ischemic stroke patients arrived via emergency medical services from 01/01/2015 to 03/30/2020 at PNW CSC and from 05/15/2017 to 03/31/2020 at five other CSCs. Mann-Whitney U test and multiple linear regression were used to compare DTAA among patients arriving Pre-Early IR vs Post-Early IR at PNW and then to compare PNW vs other CSCs during the Post-Early IR phase. Discharge disposition and ambulation were compared using Pearson’s chi-squared tests. Models were adjusted for admission NIHSS, age, gender, race, IV tPA treatment, comorbidities and medications at admission.

Results:
A total of 156 PNW patients were included in the primary analysis, 32.1 % (n=50) in the Pre- and 67.9% (n=106) in the Post-Early IR groups. Bivariate analyses showed DTAA was faster Post-Early IR (131 minutes vs 92 minutes, p<.001) and remained faster after adjusting for covariates (B=-.500,
p
<.001). Early IR did not significantly impact discharge disposition (
p
=.620) or ambulation (
p
=.995) (Table 1). Comparing the PNW to five other CSCs during the Post-Early IR period showed no significant difference in DTAA or secondary outcomes (Table 1).

Conclusion:
Early IR decreased thrombectomy treatment initiation times for ischemic stroke patients at the PNW CSC.
Abstract P292: Characteristics of Asian Americans With Acute Ischemic Stroke Treated at a Tertiary/Quaternary Stroke Center
Authors: Nguyen Claude , Grosvenor David , Spokoyny Ilana , Chen Charlene , Wong Christine S , Ke Michael , Gao Billy S , Choe Jessica S , Liu Zuolu , Jia Judy , Bedenk Ann , Newsom Healy Sarah , Bishop Deborah , Tong David C , Barazangi Nobl
Published: March 2021

Background:
Asian Americans comprise a rapidly increasing segment of the population, but little is known of their outcomes after acute ischemic stroke. We compared Asians and whites presenting to a San Francisco Bay Area tertiary/quaternary stroke center that uniquely serves a high proportion of Asian American patients, and reviewed the treatment rates and outcomes of Asian Americans presenting with acute ischemic stroke compared to whites.

Methods:
We performed a retrospective study of ischemic stroke patients presenting to our center between 1/2014-7/2020, conducting univariate analyses of demographics, comorbidities, and clinical outcomes in those designated as Asian compared with white patients. Odds ratios and chi-square analyses were conducted between groups. Asians were defined as those of Asian Indian, Chinese, Filipino, Japanese, Korean, or Vietnamese descent.

Results:
Between 1/2014 and 7/2020, 3958 patients presented with ischemic stroke; 852 (21.5%) were Asian and 2107 (53.2%) were white. Asians were older and more likely to have hypertension, hyperlipidemia, and diabetes, and less likely to have atrial fibrillation (Table 1). More Asians presented directly to our center, while more whites were transferred in. IV rt-PA rates are described in Table 1. Overall, Asians were less likely to receive endovascular treatment (Table 1). Asians had a higher NIHSS at discharge, although there was no difference in the proportion who expired or who were discharged home.

Conclusions:
Asians with ischemic stroke tended to have more comorbid conditions than whites. Though there was a trend towards similar IV rt-PA rates between Asians and whites presenting to the ED, Asians were less likely to receive endovascular treatment, and had worse NIHSS on discharge with similar proportion going home. This may have to do with local geographic/socioeconomic distribution, or differences in stroke etiology. Further analyses are needed to better elucidate these disparities.
Abstract P305: Post-Stroke Aphasia as a Predictor of 30-Day Readmission Associated With Infection: A Retrospective Chart Review
Authors: Loebel Emma M , Rojas Mary , Mensching Connor , Wheelwright Danielle , Stein Laura K
Published: March 2021

Introduction:
Studies have demonstrated that aphasia may negatively impact morbidity and mortality among ischemic stroke (IS) patients. However, the association between post-stroke aphasia and readmission with infection (RI) is poorly understood. We sought to assess the impact of aphasia on post-stroke RI. We hypothesized that aphasic patients are at increased risk of infection in the 30-day post-stroke period.

Methods:
We performed retrospective chart review of the Mount Sinai Hospital IS patients with 30-day all cause readmission from January 2016 - December 2019. All variables were abstracted from the index admission (IA) electronic medical records except for aspects related to the readmission (RA). Aphasia was present if a neurologist diagnosed the patient with acquired language dysfunction during IA. We performed chi square and logistic regression analyses to compare readmitted patients with and without aphasia at IA. Our fully adjusted model controlled for age, sex, medical comorbidities, NIHSS ≥ 8, IA LOS > 7, IA infection, discharge to facility. We completed all analyses with SPSS.

Results:
During IA, 36% (n=42) were diagnosed with aphasia. At IA, there were no significant differences in age (dichotomized at 65), sex, or medical comorbidities between aphasic and non-aphasic cohorts. However, more aphasic patients had admission NIHSS ≥ 8 (89% vs 35%, p<0.0001), LOS > 7 (76% vs 42%, p=0.0004), discharge to facility (79% vs 49%, p=0.0016), and RI (52% vs 19%, p=0.002). The presence of aphasia predicted RI in both unadjusted (OR=4.6, p<0.001) and adjusted (OR= 3.3, p=0.014) multivariate analyses. The Kappa inter-reliability ranged from 0.7-1.0 for the key variables included in our adjusted model.

Conclusions:
The adjusted odds of 30-day readmission with infection were significantly greater in those with diagnosis of aphasia at the time of index admission compared to those without. Our study provides preliminary evidence that the presence of aphasia may have negative consequences on a patient’s health beyond the language disturbance. Further study is needed to better understand the reasons and risk reduction strategies in this vulnerable population.
Abstract P306: The Association of Discharge Disposition With 30-Day Readmission After Ischemic Stroke
Authors: Man Shumei , Bruckman David , Tang Anne S , Schold Jesse D , Uchino Ken
Published: March 2021

Objective:
Readmission after ischemic stroke presents immense social and financial burden on patients, families and society at large. Post-stroke follow-up, a way to prevent readmission, has generally been focused on patients discharged to home with limited attention to those discharged to other facilities. This study aimed to examine 30-day readmission likelihood among patients of different discharge disposition.

Methods:
We studied patients who were hospitalized for ischemic stroke in states of Wisconsin, Iowa, Arkansas, and New York in 2016-2017 using the Healthcare Cost and Utilization Project State Inpatient Database. Generalized estimating equation was used to study the association of discharge disposition with 30-day all-cause readmission, after adjusting for patient sociodemographics, 23 comorbidities, hospital characteristics, in-hospital complications, and proxies for stroke severity, accounting for in-hospital clustering.

Results:
Among 52,301 patients hospitalized for ischemic stroke, 45% were discharged to home without home-health-care, 19% to home with home-health-care, 33.5% to rehabilitation and skilled nursing facilities, 1.5% to short-term hospital, and 0.93% left against medical advice. Patients discharged to home accounted for 34.7% of total 30-day readmissions while discharged to rehabilitation and skilled nursing facilities accounted for 40.6% of total 30-day readmissions. Compared to the patients discharged to home without home-health-care which had the lowest 30-day all-cause readmission rate (8.4%), patients with other dispositions were at higher likelihood of readmission: home with home-health-care (11.3%, adjusted odds ratio [OR], 1.18; 95% confidence interval [CI], 1.08-1.28); rehabilitation and skilled nursing facilities (13.2%; adjusted OR, 1.33; 95% CI, 1.22-1.46); short-term hospitals (23.7%; adjusted OR, 3.09; 95% CI, 2.44-3.93); and left against medical advice (18.6%; adjusted OR, 2.2; 95% CI, 1.75-2.83).

Conclusion:
Patients who are discharged to rehabilitation and skilled nursing facilities after ischemic stroke are at high likelihood of 30-day readmission and should be a focus of discharge planning to prevent events that lead to readmission.
Abstract P309: Provider Specific Quality Metrics: A Qualitative Approach to Quantitative Data
Authors: Van Vliet Rebecca , Fanale Chris
Published: March 2021

Introduction:
Quality measures and benchmarks are well known constants in the stroke world, but there are no established metrics for provider-specific quality related to the practice of stroke care via telemedicine technologies. We propose quality measures uniquely attributable to the practice of stroke telemedicine, regardless of the site where the telemedicine is provided.

Methods:
By analyzing client feedback obtained through surveys and reviewing historical opportunities, we identified four common themes essential to an excellent telemedicine provider. We then defined and refined each category into reportable measures. Data for the measures are obtained from data entry fields in our internal electronic medical record and reported using Tableau analytics software. Additional data is obtained from client reports and converted into a numerical score.

Results:
The four thematic areas we identified are responsiveness, documentation compliance, clinical metrics, and citizenship. Responsiveness is measured by callback time and on-camera time. Documentation compliance is measured by percent compliance with documentation of NIHSS score, IV thrombolytic contraindication, and intra-arterial (IA) intervention contraindication. Clinical metrics are defined as alteplase decision making time and alteplase recommendation rate. Although not a purely objective measure, citizenship is a critical component of telemedicine, and thus included for all providers. We investigate and inventory both compliments and complaints received, which are then converted into a score based on all telemedicine encounters.

Conclusion:
There is a lack of definition in what constitutes clinical excellence for telemedicine, apart from benchmarks that exist for hospitals. Our approach is a novel perspective on categorizing and quantifying telemedicine performance, which can be used as a constructive feedback tool for providers, as well as a mechanism to evaluate and define clinical excellence. We can track performance over time and recognize providers for excellence. Future study is required to correlate these measures with patient outcomes.
Abstract P316: Non-Stenotic Carotid Plaques in Ischemic Stroke - Analysis of the STRATIS Registry
Authors: Singh Nishita , Ospel Johanna , Mayank Arnuv , Marko Martha , Zaidat Osama , Liebeskind David S , GOYAL MAYANK
Published: March 2021

Objective:
To determine the prevalence of non-stenotic carotid plaques (<50%) and their association with ipsilateral strokes.

Methods:
Data was analyzed from the STRATIS registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke)—a prospective, nonrandomized study of patients undergoing thrombectomy with the Solitaire device. Prevalence of non-stenotic carotid plaques, ipsilateral and contralateral to the stroke was compared in patients with ESUS and cardioembolic strokes. Plaque features were further compared within both subgroups between patients with and without ipsilateral stroke. Uni- and multivariable logistic regression was performed to determine associations between non-stenotic carotid plaque, plaque characteristics, and ipsilateral stroke in both subgroups.

Results:
Of the 946 patients in the database, 226 patients with cardioembolic stroke (median age, 72 years) and 141 patients with ESUS (median age, 69 years) were included in the analysis.The prevalence of non-stenotic carotid plaque in the cardioembolic and ESUS subgroups was 33/226 (14.6%) and 32/141(22.7%) respectively. Bilateral non-stenotic carotid plaques were seen in 10/226(4.4%) cardioembolic and 13/141(9.2%) ESUS patients. Non-stenotic carotid plaques were significantly associated with ipsilateral strokes in cardioembolic stroke (aOR,1.91 [95% CI,1.15-3.18]) and in ESUS (aOR,1.69 [95% CI, 1.05-2.73]). Plaque irregularity, plaque hypodensity and increasing plaque thickness were significantly associated with ipsilateral stroke, only in the ESUS subgroup.

Conclusion:
Non-stenotic carotid plaques were significantly associated with ipsilateral stroke in cardioembolic and ESUS subgroups and there was increased association of hypodense plaque, increasing plaque thickness and plaque irregularity with ipsilateral stroke in the ESUS subgroup, suggesting these plaques could be a potential cause of stroke in these patient subgroups.
Abstract P341: Cerebral Microbleeds Load and Long-Term Outcomes in Minor Ischemic Stroke
Authors: Sakuta Kenichi , Yaguchi Hiroshi , Nakada Ryoji , Sato Takeo , Kitagawa Tomomichi , Takatsu Hiroki , Miyagawa Shinji , Komatsu Teppei , Sakai Kenichiro , Mitsumura Hidetaka , Iguchi Yasuyuki
Published: March 2021

Background and Purpose:
The association between the cerebral microbleed (CMB) count and outcomes in ischemic stroke has not been fully clarified. The aim of this study was to investigate the relationship between the CMB count and functional outcomes in patients with a minor ischemic stroke treated with antiplatelet therapy.

Methods:
Non-cardiogenic minor ischemic stroke (NIHSS score <4 on admission) patients who were treated with antiplatelet therapy were enrolled. The patients were divided into four groups based on the number of CMBs (absent, 1, 2-4, and >4), and their clinical outcomes were compared. Deep white matter hyperintensities (DWMHs) were assessed using the Fazekas scale, and the relationship between DWMH burden and the CMB count was evaluated. A poor outcome was defined as a modified Rankin scale (mRS) score of 3-6 90 days after symptom onset. Logistic regression analysis was performed to evaluate whether the CMB count contributes to poor outcomes.

Results:
A total of 240 patients were enrolled, and their pre mRS scores were matched based on CMB presence. The median CMB count increased linearly with the Fazekas scale grade (P<0.001). A higher burden of CMBs was linearly correlated with the rate of poor outcomes (4% in the absent group, 8% in the 1 CMB group, 13% in the 2-4 CMB group, and 20% in the >4 CMB group, P=0.002). Multivariate logistic regression analysis performed with well-known risk factors including DWMH showed that CMB burden (subgroups) was the independent factor associated with poor outcomes (odds ratio 1.75, 95% confidence interval 1.13-2.72, P=0.012), whereas the DWMH burden was not.

Conclusion:
The CMB count contributes independently to poor outcomes in minor ischemic stroke patients treated with antiplatelet therapy.
Abstract P343: Relationship of Infarct Volume to Inflammation and Prognostic Significance in Patients With Acute Ischemic Stroke
Authors: Ding Lingling , Li Zixiao , Wang Yongjun
Published: March 2021

Background and Purpose:
The diffusion weighted imaging (DWI) lesion volumes in acute ischemic stroke (AIS) can be automatically measured using deep learning-based segmentation algorithms. We aim to explore the prognostic significance of artificial intelligence-predicted infarct volume, and the association of markers of acute inflammation with the infarct volume.

Methods:
12,598 AIS/TIA patients were included in this analysis. Intarct volume was automatically measured using a U-Net model for acute ischemic stroke lesion segmentation on DWI. Participants were divided into 5 subgroups according to infarct volume. Spearman’s correlations were employed to study the association between infarct volume and markers of acute inflammation. Multivariable logistic regression and Cox proportional hazards model were performed to explore the relationship between infarct volume and the incidence of poor functional outcome (modified Rankin scale score 3-6), stroke recurrence or combined vascular events at 3 months.

Results:
The U-Net model prediction correlated and agreed well with manual annotation ground truth for infarct volume (r=0.96; P<0.001). There were positive correlations between the infarct volume and markers of acute inflammation (neutrophil [r=0.175; P<0.001], hs-CRP [r=0.180; P<0.001], and IL-6 [r=0.225; P<0.001]). Compared with those without DWI lesions, patients with the largest infarct volume (4th Quartile) were nearly five times more likely to have poor functional outcome (mRS 3-6) (adjusted odds ratio, 4.70; 95% confidence intervals [CI], 3.29-6.72; P for trend<0.001) after adjustment for confounding factors and markers of acute inflammation. The infarct volume category was significantly associated with stroke recurrence (adjusted hazard ratios [HRs], 1.0, 1.43[0.95,2.17], 2.22[1.49,3.29], 2.06[1.40,3.05], 2.26[1.52,3.36]; P for trend<0.001) and combined vascular events(adjusted HRs, 1.0, 1.38[0.92,2.09], 2.25[1.53,3.32], 2.03[1.38,2.98], 2.28[1.54,3.36]; P for trend<0.001).

Conclusions:
Infarct volume measured automatically by deep learning-based tool was a strong predictor of poor functional outcome as well as stroke recurrence, with the potential for widespread adoption in both research and clinical settings.
Abstract P344: Validation of Computational Fluid Dynamics Against PC-MRI Measurements of Blood Flow in Healthy Intracranial Arteries: On the Threshold to Clinical Utility for Stroke Prediction
Authors: Yeo Leonard L , Boopathy Sethu raman , Nemes Andras , Engin Melih , Lange Robin , Mohammadzadeh Milad , Monajemi Sadaf , Pavlin-Premrl Davor , Lim Ruth
Published: March 2021

Aim:
Computational Fluid Dynamics (CFD) modeling of blood flow is a promising technique to obtain hemodynamic biomarkers and predict recurrent strokes. Few studies, however, have validated CFD against other methods for measuring hemodynamics, e.g. phase contrast MRI (PC-MRI). To resolve the uncertainties about the accuracy of CFD, this study validates the results of an automated software that combines deep learning and CFD for simulating blood flow given an MR angiogram against PC-MRI.

Methods:
Intracranial arteries in 10 healthy volunteers (60% male, mean age 38 ± 16 years) were automatically segmented from TOF MRA obtained at 3T using deep learning. Subject-specific CFD modelling was undertaken. PC-MRI flow rate for each subject was used at the inlet boundary condition, but not at the outlets. Outlet boundary condition was set to lumped parameter Windkessel model, with the resistance programmatically determined using allometric scaling laws based on the dimension and branching of vasculature. For comparison, two commonly used outlet conditions (exponent 2 & 3 in Murray’s Law) were also considered. CFD results for flow rate and wall shear stress were compared against PC-MRI using Pearson’s correlation coefficient.

Results:
The flow rate across major intracranial arteries from CFD was in excellent agreement with the PC-MRI (MCA: r = 0.83, ACA: r = 0.81 & PCA: r = 0.82). In addition, there was good correlation for both wall shear stress (WSS) and WSS Ratio (WSSR, i.e. the ratio of WSS between a branch and its parent vessel) (MCA (WSS/WSSR): r = 0.6/0.77, ACA (WSS/WSSR): r = 0.86/0.93 & PCA (WSS/WSSR): r = 0.72/0.85). The inter-subject variability of the flow rate (i.e. standard deviation) obtained from CFD matched closely the variation range observed from PC-MRI and the literature. The two alternative outlet models behaved similarly but suffered from vessel truncation and high errors in some cases.

Conclusion:
CFD modelling of blood flow in intracranial arteries from static images has good agreement with PC-MRI measurements when allometric scaling laws are applied for setting Windkessel outflow conditions. This lays the foundation for using CFD to predict recurrent strokes as the technique uses standard MRA images already commonly acquired for stroke evaluation.
Abstract P345: Perfusion-Guided Bridging Therapy in Strokes With Unknown Time of Onset and Large Vessel Occlusion
Authors: Escribano Paredes Jose Bernardo , Klug Julian , Dirren Elisabeth , Sanda Nicolae , Vargas Maria , Machi Paolo , Carrera Emmanuel
Published: March 2021

Introduction:
Endovascular treatment (EVT) is the therapy of choice, in patients with unknown stroke onset (unwitnessed and wake-up strokes) and large vessel occlusion (LVO) with a favorable perfusion pattern. Whether bridging therapy (intravenous thrombolysis (IVT) and EVT) is superior to EVT alone remains unknown.

Material and Methods:
We retrospectively included all patients admitted to the Geneva University Hospital from 01.2016 to 06.2020 with i) stroke of unknown onset, due to ii) anterior circulation occlusion, with iii) favorable CT perfusion pattern based on the DEFUSE criteria (ischemic core volume< 70ml; mismatch ratio >= 1.8 and mismatch volume >= 15ml), and iv) treated < 4.5 hours after symptom recognition. As a standard of care, the patients fulfilling these inclusion criteria were treated with EVT and IVT or EVT alone when IVT was contraindicated. Outcome measures were any intracerebral bleeding (symptomatic or asymptomatic), mortality and favorable outcome (mRS 0-1) at three months.

Results:
32 patients were included (17 treated with EVT alone and 15 with EVT and IVT). Mean age was 69±18 yo. Median NIHSS was 16 (IQR 12-20) and median time from symptom recognition to treatment was 184 (146-226) minutes. Median hypoperfused tissue volume (Tmax > 6s) was 119 ml (80-151) and infarcted core (CBF ratio <30%) 8 ml (0-27). After propensity score weighting, bridging therapy was not associated with an increased risk of intracerebral bleeding (p=0.72) or mortality (p=0.55). The proportion of favorable outcomes at three months was similar between treatment groups (p=0.78).

Conclusion:
These results suggest that IVT before EVT is a safe therapeutic option in patients with unknown stroke onset selected on perfusion imaging and treated <4.5 hours after symptom recognition. Early administration of IVT may be particularly relevant before interhospital transfer to a comprehensive stroke center for EVT.
Abstract P351: Grayscale Texture Feature Angular Second Moment Correlates With Collagen Alignment in Carotid Artery Plaques
Authors: Mitchell Carol , Wilbrand Stephanie M , Salamat M.Shahriar , Eickhoff Jens , Meshram Nirvedh H , Steffel Catherine , Varghese Tomy , Liu Yuming , Eliceiri Kevin , Dempsey Robert J
Published: March 2021

Introduction:
Grayscale (GS) texture features that examine homogeneity and echogenicity have been used to identify vulnerable plaques with
in vivo
ultrasound imaging have been shown to correlate with plaque tissue composition. However, the relationship of collagen fiber organization to GS texture features extracted from
in vivo
images is a novel idea to provide additional information about plaque structure. We hypothesize that collagen fiber alignment is clinically relevant to identify vulnerable plaques. The objective of this feasibility study was to use multiscale imaging (in vivo ultrasound and high resolution optical microscopy) to determine how GS texture features are related to plaque collagen structure.

Methods:
Participants (n=6) scheduled for clinically indicated carotid endarterectomy underwent
in vivo
carotid ultrasound imaging with texture feature extraction (spatial gray level dependence matrices method for calculating angular second moment [SGLDM-ASM] and grayscale median value [GSM]). Plaque specimens were sent to histopathology and stained with H&E. The collagen fibers in the fibrous cap of the plaque histopathology slides were imaged with liquid crystal based polarization microscopy and quantified using an established software tool (CurveAlign). Correlations between collagen alignment coefficient (range 0-1, 1 represents perfectly aligned fibers) and the texture feature SGLDM-ASM (a measure of homogeneity, higher values are more homogenous) and GSM (a measure of echogenicity higher values are more echogenic) were examined.

Results:
Participants were mean (SD) 72.5 (6.1) years of age, had 71.67 (8.16) percent stenosis. The mean SGLDM-ASM was 0.0017 (0.0023), the mean SD GSM was 73.13 (30.98). SGLDM-ASM was significantly correlated to collagen alignment (r=0.83; p=0.028). There was no significant correlation detected between GSM and collagen alignment (r=-0.43;p=0.38).

Conclusion:
Results of this study indicate the potential role for using high resolution optical microscopy with ultrasound to characterize collagen fiber alignment in plaques with measures of homogeneity. Future studies are needed to see how multiscale imaging can be used to inform
in vivo
imaging for identification of vulnerable plaque features.
Abstract P357: Deep Learning Building on Prior Ischemic Core Segmentation Improves Prediction of Infarction After Stroke
Authors: Klug Julian , Leclerc Guillaume , Dirren Elisabeth , Maria Gulia Preti , Van De Ville Dimitri , Carrera Emmanuel
Published: March 2021

Introduction:
Imaging studies are used to guide patient selection for acute stroke treatment. Perfusion CT (pCT) is widely used to identify the acute ischemic core and penumbra, but the prediction of the final infarct remains challenging. With the advent of machine learning, algorithms learning the prediction of the final lesion from imaging data collected in the acute phase have been proposed. We aimed to investigate whether machine learning methods that integrate prior ischemic core segmentation improve the prediction of the final infarct after stroke.

Methodology:
We retrospectively included all stroke patients admitted to the Geneva University Hospital for intravenous and/or endovascular treatment from 01.2016 to 12.2017. All patients had acute pCT and follow-up MRI. An Attention-Gated 3D Unet was used as the baseline model on which the effect of access to a threshold-based ischemic core segmentation was tested. To ensure the efficient integration of information contained in voxels from the ischemic core, we extended the baseline model with a bayesian skip connection allowing only the prior to bypass most of the network. This modifies the model’s task to predict divergence from the prior representation. All models were evaluated for the prediction of the final infarct on follow-up MRI, given acute pCT maps as input. The output of each model was compared to finals lesions manually delineated by expert neurologists. Dice score was used to assess performance.

Results:
A total of 144 patients were included. Median hypoperfused tissue volume (Tmax > 6s) was 60 ml [17-134], median ischemic core (relative CBF < 38%) volume was 23 ml [17-33] and median final infarct volume was 13 ml [3-38]. Dice score for the threshold based ischemic core segmentation was 0.1. The baseline model with and without prior segmentation as input achieved a Dice score of 0.19. Adding the proposed bayesian skip connection lead to a more efficient integration of the prior segmentation ensuring faster convergence and better performance with a final Dice score of 0.21.

Conclusion:
The evaluated deep learning model can effectively leverage the information contained in a prior segmentation of the ischemic core to enhance the learning process and improve the prediction of the final infarct after stroke.