bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP378: RAcial Disparities in Ich After iv-tpA and Neurointerventional Treatment (RADIANT)
Authors: Chiang Chia-Chun , Meyer Dawn M , Meyer Brett C , Agrawal Kunal , Modir Royya
Published: January 2019

Introduction:
Studies have reported ethnic/racial disparities in intravenous tPA treatment. The outcome of tPA and/or intra-arterial intervention (IA) among different ethnicities/races requires investigation. The purpose of the study was to examine the symptomatic intracranial hemorrhage (SxICH) and major systemic hemorrhage (MSH) after acute stroke treatment among different ethnicities/races.

Methods:
We retrospectively reviewed all stroke code patients from an IRB- approved stroke code registry between June 2004 and June 2018. We identified patients who received either IV tPA, IA, or IV tPA+IA. Demographics, clinical presentation, co-morbidities, stroke treatments, and adverse outcomes were collected. Patients were classified into two ethnic groups - Hispanics or non-Hispanics (H/NH) and four racial groups- Asians, Black, Others (includes Native Americans and Pacific Islanders), and White (A/B/O/W).

Results:
We identified 916 patients that received acute therapy (A/B/O/W: n=50/104/16/746, H/NH: n= 184/730). For those received IV tPA only (n=759), the overall SxICH rate was 4.3% (A/B/O/W: 8.1%/6.6%/8.3%/3.7%, p=0.17; H/NH: 5.7%/4.1%, p=0.42), and the MSH rate was 1.3% (A/B/O/W: 2.7%/1.1%/0%/1.3%, p=0.55; H/NH=1.4%/1.3%, p=1.00). White race was significantly correlated with lower SxICH rate after IV tPA (OR 0.07, p=0.02). There was a significant correlation between age and baseline NIHSS with SxICH (p<0.01, p=0.02, respectively). Age, INR and PTT were independent predictors of SxICH after IV tPA (OR 1.06, 46.52 and 1.18, p= 0.02, 0.04 and 0.04, respectively). For IA only (n=85), the rate of SxICH was 4.7% (A/B/O/W: 0%/0%/25%/4.5%, p=0.31; H/NH: 0%/ 6.1%, p=0.57), and 6.9% for IV tPA+IA (A/B/W: 0%/16.7%/6.6%, p=0.59; H/NH: 4.2%/8.3%, p=0.66). There was no MSH in IA only or IV tPA+IA groups.

Conclusions:
White race correlated with a significantly lower rate of SxICH after IV tPA. There was no significant difference in the rate of SxICH or MSH after IV tPA, IA, or IV tPA+IA among different racial or ethnic groups in this study. Larger studies are needed to elucidate the race specific causes of these SxICH and MSH after acute stroke treatment.
Abstract WP379: Femoral Neuropathy Following Transfemoral Neuroendovascular Procedures. An Analysis of a Prospective Registry
Authors: Qureshi Adnan I , Babar Sehar , Kherani Danish , Saleem Muhammad A , Qi Laura , Wallery Shawn S , Raja Faisal M
Published: January 2019

Background:
Although femoral neuropathy is recognized as an adverse consequence following trans-femoral neuro-endovascular procedures, no reliable estimates are available. We analyzed data from a prospective registry to ascertain the frequency and characteristics of femoral neuropathy following trans-femoral neuro-endovascular procedures.

Methods:
Consecutive patients who underwent neuro-endovascular procedures through the trans-femoral route were included. Detailed assessment was performed if any patient reported occurrence of sensory or motor symptoms in the femoral or lower extremity region including neurological examination (sensory/motor deficits) and femoral region ultrasound.

Results:
Femoral neuropathy was diagnosed following 4 of 270 neurovascular procedures with an occurrence rate of 1.5% (95% confidence intervals 0.4% - 3.7%). The symptoms were exclusively sensory without any motor involvement. The femoral neuropathy appeared to involve anterior femoral cutaneous nerves in all and medial cutaneous branches in 2 patients, and more than one nerve distribution in one patient in whom lateral cutaneous nerve appeared to be involved. All patients reported resolution of symptoms within a period ranging from 1 week to 2 months. No local hematoma or arterial pseudo-aneurysm was identified at femoral region ultrasound.

Conclusions:
Femoral neuropathy is a rare occurrence following trans-femoral neuro-endovascular procedures and usually occurs with pure sensory manifestations with complete resolution.
Abstract WP38: High Variability in Neuronal Loss: Time is Brain, Re-quantified
Authors: Desai Shashvat , Rocha Marcelo , Jovin Tudor , Jadhav Ashutosh
Published: January 2019

Background and Purpose:
Rapid and progressive loss of brain elements occurs in the setting of acute ischemic stroke (AIS) due to a large-vessel occlusion (LVO). With time, the amount of brain lost increases. This has been previously quantified to be approximately 1.9 million neurons per minute. Clinically observed phenotypes indicate that large heterogeneity exists in ischemic cell death, in this study we aim to quantify the distribution and range of rate of loss of brain elements.

Methods:
After Institutional Review Board approval, we performed a retrospective chart review of consecutive anterior circulation AIS due to LVO. Ischemic core volume was measured using automated software processing and time from last known well to imaging was recorded. Using previously published data on brain volume and element counts from morphometry and neuro-stereology studies, we computed rate of loss of brain elements for our real-world LVO stroke patients.

Results:
Mean ischemic core was 50.4 ml and mean time to imaging from symptoms onset was 8.7 hours. This translated to a mean loss per minute of 2.03 million neurons, 14.8 billion synapses and 12.8 kilometers myelinated fibers. The rate of neuron loss was highly variable, ranging from less than 35,000 to more than 27 million neurons per minute.

Conclusions:
AIS due to LVO has wide ranging phenotypes of infarct growth. Rate of neuron loss per minute ranges from less than 35,000 to more than 27 million, with a mean and median of 2 million and 0.9 million respectively. These data suggest that time to treatment may be even more critical for a subset of patients while a separate population of patients may continue to benefit from reperfusion therapy, even at late time windows.
Abstract WP381: Cryptogenic Stroke: Contemporary Characteristics, Treatments, and Outcomes in the United States
Authors: Prabhakaran Shyam , Messe Steven R , Kleindorfer Dawn , Smith Eric E , Fonarow Gregg C , Zhao Xin , Lytle Barbara , Cigarroa Joaquin , Schwamm Lee H
Published: January 2019

Objective:
Nationwide data on patients with cryptogenic stroke (CS) are lacking. We evaluated patient and hospital characteristics, in-hospital treatments, and discharge outcomes among CS patients compared to other subtypes in the Get With The Guidelines (GWTG)-Stroke registry.

Methods:
We identified patients admitted to GWTG-Stroke participating hospitals between January 1, 2016 and September 30, 2017 with 1) ischemic stroke and 2) documented stroke etiology (cardioembolic [CE], large artery atherosclerosis [LAA], small vessel occlusion [SVO], other determined etiology [OTH], or CS). Using multivariable logistic regression, we compared discharge outcomes by subtype adjusted for patient and hospital characteristics.

Results:
Among 348,715 patients from 1,725 hospitals with documented stroke subtype, there were 69,857 (20.0%) patients with CS. Compared to CE subtype, patients with CS were younger, less likely to arrive by ambulance, less often white, more privately insured, and milder by NIHSS score. In multivariable analysis (Table), patients with CS had lower mortality than CE, LAA, and OTH subtypes but higher mortality than SVO. Patients with CS were more likely to be discharged home than all subtypes and be independent at discharge than patients with LAA or OTH subtypes.

Conclusions:
In a large nationwide registry, CS accounted for 20% of ischemic stroke subtypes. Patients with CS had lower stroke severity than CE stroke subtype and had intermediate outcomes at discharge being better than CE and LAA subtypes, but worse than SVO subtype.
Abstract WP382: Using Natural Language Processing Algorithms to Identify Stroke Cases and Stroke Subtypes From Neuroimaging Reports
Authors: Northuis Carin , Michalowski Martin , Lakshminarayan Kamakshi
Published: January 2019

Background/Objective:
The long-term goal of our research is to develop automated, accurate methods for conducting stroke outcome surveillance across large populations. To facilitate this, we developed natural language processing (NLP) based machine learning algorithms to classify stroke cases and sub-type strokes using neuroimaging reports. We report on the performance of our algorithms.

Methods:
Our population of interest included patients with stroke symptoms presenting to the emergency room of our large academic healthcare system. We randomly sampled 332 probable stroke cases. A trained neurologist validated stroke diagnoses using neuroimaging reports. Data preprocessing included cleaning and normalizing the reports into a standardized format. We trained and tested machine learning algorithms using the formatted reports. The NLP-based algorithms predicted a stroke diagnosis (binary classification) and a stroke type diagnosis (multiclass classification) using n-grams of length 1 (i.e., ‘stroke’, ‘hemorrhage’) through 3 (i.e., ‘no mass effect’), term-frequency weighting, and feature dimensionality reduction via truncated singular value decomposition (SVD). We report algorithm performance using the area under the receiver operating characteristic curve (AUC-ROC). Classification methods we tested included Multinomial Naïve Bayes, Logistic Regression, Random Forest Classifier, and Support Vector Machine (SVM).

Results:
The highest performing algorithm for both stroke and stroke sub-type classification contained 1 to 2 n-grams, no term-frequency, and 200 SVD components. For the stroke case detection, SVM achieved the best AUC-ROC of 95.6%. For stroke sub-type detection, SVM also yielded the highest AUC-ROC of 93.5% for no stroke, 92.3% for ischemic stroke, 91.9% for intraparenchymal hemorrhage, and 94.8% for subarachnoid hemorrhage.

Conclusions:
We report very promising results in our pilot study using machine learning algorithms to classify stroke cases from neuroimaging reports. Feature selection on this pilot data revealed a subset of words that are highly effective in categorizing stroke. Future work will focus on algorithm improvement, finer grained stroke sub-type stratification, and multi-label phenotyping.
Abstract WP384: Impact of Comorbidities on All-cause Mortality among Patients Hospitalized with Acute Ischemic Stroke - a Medicare Cohort Study
Authors: Tong Xin , Yang Quanhe , George Mary G , Chang Anping , Coleman King Sallyann , Odom Erika C , Merritt Robert
Published: January 2019

Introduction:
Limited studies examined the prevalence and impact of comorbidities on all-cause mortality longitudinally among older patients with acute ischemic stroke (AIS).

Methods:
We included Medicare fee-for-service beneficiaries diagnosed with AIS from 2007 to 2010 and followed up to 2015. We calculated prevalence of 12 comorbidities, including atrial fibrillation (AF), congestive heart failure (CHF), chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), diabetes, hypertension, hyperlipidemia, ischemic heart disease (IHD), obesity, peripheral vascular disease (PVD), cancer, and depression at baseline. We used Cox proportional hazard models to examine the associations with all-cause mortality, and calculated population attributable fraction (PAF) contributing to mortality.

Results:
Among 306,142 Medicare beneficiaries 65-74 years of age hospitalized with AIS, we documented 139,228 deaths (45.5%) during a median 5.8 years of follow-up. Six comorbidities had a prevalence ≥15% and were associated with ≥20% increased risk of death. Prevalence and adjusted hazard ratio (AHR) were 28.5% and 1.75 for CKD, 30.9% and 1.67 for CHF, 26.9% and AHR 1.52 for COPD, 47.7% and 1.33 for diabetes, 22.1% and 1.29 for depression, and 16.1% and 1.23.for AF. Beneficiaries with ≥4 of 6 prevalent comorbidities had a 5.8 fold increased risk of death as compared to those without any comorbidities. The all-cause mortality among AIS beneficiaries would be reduced by about 50% (PAF) if all six comorbidities could be prevented. Beneficiaries with cancer, IHD, and PVD were also more likely to die as compared to those without. However, beneficiaries with hyperlipidemia (AHR 0.54), hypertension (AHR 0.81), and obesity (AHR 0.85) had a significantly lower risk of death than those without.

Conclusion:
We identified several common comorbidities associated with a significantly increased risk of all-cause mortality. Our findings provide useful information to better target prevention and treatment strategies to enhance overall survival.
Abstract WP385: Burden of Rehospitalizations for Venous Thromboembolism Among Patients With Ischemic Stroke
Authors: Amin Alpesh , Deitelzweig Steven , Lin Jay , Lingohr-Smith Melissa , Menges Brandy , Neuman W. Richey
Published: January 2019

Introduction:
Patients hospitalized for ischemic stroke are at risk for venous thromboembolism (VTE) that remains high after discharge. Without adequate VTE prophylaxis covering the entire risk period, including after discharge, patients are at risk of VTE-related rehospitalization. The goal of this study was to analyze the frequency and associated cost of VTE-related readmissions among patients with ischemic stroke in the US.

Methods:
Patients hospitalized for ischemic stroke, based on the primary hospital discharge diagnosis codes, were identified from the MarketScan databases (7/1/2011 to 3/31/2015). Eligible patients were ≥40 y and had continuous insurance enrollment ≤6 mo prior to initial (index) hospitalizations (baseline period) and >6 mo after discharge (follow-up period). The study endpoints were: the proportion of patients readmitted for the primary VTE or any position VTE (VTE-related) during the follow-up period, and the associated resources and costs of readmissions.

Results:
For this retrospective analysis, data from 1,030 patients hospitalized for ischemic stroke were available; mean age: 71.6 y (66.2% were ≥65 y), 52.1% female, mean Charlson Comorbidity Index score: 3.3. For index hospitalization, 55.3% of patients were hospitalized for 1-3 d, and 33.3% for 4-7 d. During index hospitalization, 1.3% of patients had a VTE. In the 6 months following discharge, 1.4% had a VTE-related hospital readmission, of which 50% were for a primary diagnosis of VTE. Over one-third (35.7%) of the VTE-related readmissions occurred ≤30 d of discharge. For VTE-related readmissions, mean length of hospital stay (LOS) was 14.9 d and the mean total cost for a hospital readmission was $39,692. For primary VTE readmissions, the mean LOS was 4.9 d and the mean total cost of a readmission was $12,384.

Conclusions:
In this real-world study, 1.4% of patients hospitalized for ischemic stroke had a VTE-related hospital readmission, and of these, one-third were readmitted ≤30 d of discharge. The economic burden of VTE-related or primary VTE hospital readmissions was substantial. Improvement in VTE prophylaxis across the inpatient/outpatient care continuum may reduce the clinical and economic burden of VTE and associated rehospitalizations in these patients.
Abstract WP386: tPA Treatment for Patients Found to Have Stroke Mimic is Similar Among Neurovascular Fellows and Attendings
Authors: Kerro Ali , Cai Chunyan , Ankrom Christy , Bambhroliya Arvind , Malazarte Rene , Trevino Alyssa , Astudillo Cesar , Soomro Jazba , Cossey TC D , Wu Tzu-Ching , Savitz Sean , Jagolino-Cole Amanda
Published: January 2019

Introduction:
Neurovascular fellows (NVFs) may need formalized telemedicine (TM) training to prepare for increasing acute ischemic stroke (AIS) coverage needs. TM assessment of stroke mimics (SM) can be challenging given physical barriers. We evaluated for differences between NVF and neurovascular attending (NVA) AIS management for patients who receive tPA but are found to have SM.

Methods:
We identified patients in our TM stroke registry (9/2015-12/2017) who received tPA for suspected AIS. We compared frequency of tPA treatment for SM patients between NVFs and NVAs. We also compared baseline patient characteristics and outcomes post-tPA.

Results:
Of 693 patients who received tPA for suspected AIS over TM, 16.6% had a final diagnosis of SM. NVFs evaluated 12.2% of tPA treated patients. 16.5% of the 85 tPA-treated patients seen by NVFs were found to have SM, compared to 16.6% of the 608 tPA-treated patients seen by NVAs. There were no differences in characteristics among SM patients including age, gender, race/ethnicity, comorbidity and stroke severity (Table 1). Adverse effects after tPA for all SM patients were minimal. More patients had good mRS at 90 days after NVF assessment, however this may be limited by the small number of patients treated by NVFs. Time to treatment was similar among NVFs and NVAs (Table 2).

Conclusion:
While differences have been demonstrated in TM management of AIS between NVFs and NVAs, they appear to evaluate SM vs AIS similarly. Our findings support the safety of integrating TM training during fellowship, and provide direction for educational efforts.
Abstract WP387: Language Barrier Impacts Outcome From Acute Ischemic Stroke Without Effect on Receiving Intravenous Thrombolysis
Authors: Janarious Afra U , Anderson Noriko , Liu Shimeng , Stradling Dana , Yu Wengui
Published: January 2019

Objectives:
Early treatment is crucial for patients with acute ischemic stroke (AIS). Language barrier may delay evaluation and therapy. This study aimed to evaluate the impact of primary language on outcome in patients with AIS.

Methods:
This is a retrospective study of consecutive patients with AIS at our institution from January 1, 2013 to December 31, 2016. Data were collected from the electronic medical record and the
Get With the Guidelines
database. Patients were divided into three groups by primary language. Outcome measures include rate of intravenous thrombolysis (IVT), length of stay (LOS), functional outcome per modified Rankin scale (mRS), and mortality at hospital discharge. Statistical analysis was done by non-parametric testing with Kruskal-Wallis for multiple comparisons between groups and Chi-square analysis for comparison of proportions.

Results:
Among the 1,117 patients included within the study period, 189 received IVT. In this cohort, 759 patients spoke English, 194 spoke Spanish, and 164 spoke Other languages including Vietnamese, Arabic, and Mandarin. The severity of stroke per mean NIHSS on arrival was highest at 12 (95% CI, 10-13) in Other-language group, 9.1 (95% CI, 8.5-9.7,
P
<0.001) in English group and 8.6 (95% CI, 7.5-9.7,
P
=0.002) in Spanish group. There was no significant difference in the rate of receiving IVT among the 3 groups, with 16% in English and Spanish groups and 19.5% in Other-language group (
P
=0.62). The Other language group has significantly longer LOS (6.7, 95% CI 5.6-7.8) than the Spanish (6.0, 95% CI 5.0-6.9) and English (5.2, 95% CI, 4.8-5.6,
P
<0.001) groups and worse outcomes with mean mRS 3.5 (95% CI, 3.2-3.7) at hospital discharge compared to English (2.9, 95% CI, 2.8-3.1,
P
=0.008) and Spanish (2.9, 95% CI, 2.7-3.2,
P
=0.02) groups, and lower rate of favorable outcome with mRS 0-2 (26.8%) compared to English (41.5%) and Spanish groups (38.7%) (
P
=0.0022). Mortality was not significantly different between English (7.9%), Spanish (3.2%), and Other groups (7.9%,
P
=0.06).

Conclusions:
At our multiethnic cohort, primary language has no effect on acute stroke therapy with IVT. However, the non-English and non-Spanish speaking patients tended to have longer LOS and worse functional outcome.
Abstract WP389: A Critical Analysis of Stent Retriever and Suction Catheter Thrombectomy Device Cost-Effectiveness Studies
Authors: Pai Akila , Dangayach Neha , Costa Anthony , Yaeger Kurt
Published: January 2019

Background:
Although comprehensive economic evaluation reporting standards exist for medical devices (MDs), the quality of reporting in cost analysis studies remains unknown for neurosurgical devices. The emergence of novel mechanical thrombectomy devices, such as stent-retrievers and suction catheters may reduce the economic burden of acute ischemic stroke by improving patient outcomes in the long term. The objective of this study was to assess the methodological quality of reporting in economic evaluations of stent-retrievers and suction catheters.

Methods:
A systematic review of the literature was performed to identify all available economic evaluations on stent-retrievers and suction catheters published up to June 2018. Articles were excluded if they did not specifically perform cost analyses. The methodological quality of reporting was assessed using the Comprehensive Health Economic Evaluation Reporting Standards (CHEERS) statement with specific criterion employed for MDs.

Results:
The search yielded 93 publications, of which 10 studies met inclusion criteria for cost analyses. Eight of ten (80%) studies were self-reported as cost-effectiveness studies. Only three studies (30%) reported incremental cost-effectiveness ratios and only one study (10%) reported net monetary benefit values. Two of the ten (20%) studies were completed with a lifetime horizon and the remaining were five years or less. No study had a substantial review of device-associated learning curves, incremental innovations in technology, dynamic prices, or institutional impacts of device pricing, all of which influence cost analyses.

Conclusion:
While stent-retrievers and suction catheters have been described to be cost-effective in the literature, the quality of published economic evaluations is highly varied. Since economic assessments can provide essential guidance for clinical decision-making, ensuring high-quality reporting by integrating the CHEERS checklist is critical. Further, as these results indicate, there is a need to create uniform reporting standards for thrombectomy device cost analyses in order to ensure generalizability and comparability amongst studies.
Abstract WP39: Radiographic Classification of ICA Occlusions Predicts Clinical Fluctuation and Post-Stenting Hemorrhage Risk
Authors: Hawkes Christine , Desai Shashvat , Son Ji , Panczykowski David , Tememe Danoushka , Shah Kavit , Gross Bradley , Jankowitz Brian , Jovin Tudor , Jadhav Ashutosh P
Published: January 2019

Introduction:
The optimal treatment strategy for symptomatic extra-cranial internal carotid artery (ICA) occlusion remains unknown. A radiographic classification of ICA occlusions has been proposed to help predict technical feasibility and the risk of complications with revascularization. The classification includes 4 main types (A-D) based on the morphology of the ICA stump (A having a tapered stump, B having a non-tapered stump, C and D having no stump) as well as the presence of reconstitution of flow in the intracranial ICA (C having reconstitution of the ICA within the cavernous and/or petrous segment and D having no reconstitution). In this study, we assess the predictive value of this classification scheme in understanding clinical phenotype and post-stenting complications.

Methods:
A retrospective review of a prospectively maintained database was conducted of clinical and radiological data from patients undergoing attempted angioplasty and stenting of complete symptomatic cervical ICA occlusion without tandem intracranial occlusion.

Results:
Seventy-two patients were included in the study, with a mean age of 63 years and 36% female gender. Classification type was as follows: 36% (type A), 25% (type B), 32% (type C) and 7% (type D). Revascularization was successful in 66/72 (92%) of patients. Clinical fluctuation prior to revascularization was most frequent in type A occlusions (p=0.02) and least frequent in type B occlusion (p=0.02). Only 8% of patients had peri-procedural intracerebral hemorrhage and the highest frequency occurred in group D (p=0.05). In a multivariate analysis, lower age, lower pre-treatment NIH Stroke Scale and favorable Alberta Stroke Program Early CT Score were predictors of higher modified Rankin Scale at 3 months (p=0.025, 0.004, 0.049, respectively).

Conclusions:
Radiographic classification of ICA occlusions can help classify patient phenotypes and potentially predict the technical safety of angioplasty and stenting. Prospective studies are warranted to confirm these findings.
Abstract WP390: Misdiagnosis of Cervicocephalic Artery Dissection in the Emergency Department
Authors: Liberman Ava L , Esenwa Charles , Navi Babak , Murthy Satosh , Kamel Hooman , Merkler Alexander
Published: January 2019

Introduction:
Cervicocephalic artery dissection is an important cause of stroke, particularly in the young. The initial presentation of cervicocephalic artery dissection can resemble benign neurological conditions resulting in delayed or incorrect diagnosis. We therefore sought to quantify the rate of possible cervicocephalic artery dissection misdiagnosis and to assess the impact of misdiagnosis on patient outcomes in a large heterogeneous cohort.

Methods:
We performed a retrospective cohort study using administrative claims data from all ED visits and nonfederal hospitalizations in New York, California, and Florida from 2005-2015. Using previously validated
ICD-9-CM
codes, we identified patients hospitalized with a diagnosis of cervicocephalic artery dissection and no prior stroke diagnosis. Possible misdiagnosis of cervicocephalic artery dissection was defined as having a treat-and-release ED visit for headache, facial pain, neck pain, or Horner syndrome in the 14 days prior to a hospitalization for cervicocephalic artery dissection. Multivariable logistic regression was used to compare adverse clinical outcomes (stroke or death at the time of cervicocephalic artery dissection diagnosis) in patients with and without a possible misdiagnosis.

Results:
Among 8,874 patients diagnosed with cervicocephalic artery dissection (mean age 52.7 years, 44.1% women), 300 (3.4%; 95% CI, 3.0-3.8%) had a possible ED misdiagnosis. Patients with a possible misdiagnosis of cervicocephalic artery dissection were younger and more often women than those not misdiagnosed. Stroke occurred in 128 (42.7%; 95% CI, 37.0-48.5%) patients with a possible misdiagnosis of dissection and in 3,908 (44.0%; 95% CI, 43.0-45.1%,
P
=0.63) patients without a possible misdiagnosis of cervicocephalic artery dissection. After adjustment for demographics and vascular risk factors, there were no differences in rates of hospital death (OR 0.48; 95% CI, 0.20-1.9) or stroke (OR 0.94; 95% CI, 0.74-1.2).

Conclusion:
We found a low rate of possible misdiagnosis of cervicocephalic artery dissection in the ED. Possible misdiagnosis was not associated with stroke or death at the time of subsequent hospitalization for cervicocephalic artery dissection.
Abstract WP391: Survey of Neurology Post-Graduate Trainees' Exposure to Interventional Neurology: Report From the Society of Vascular and Interventional Neurology Education Committee
Authors: Liang Conrad W , Ortega Santiago , Liebeskind David S , Grotta James C , Jovin Tudor G , Nguyen Thanh N , Nogueira Raul G , Masoud Hesham , Elijovich Lucas , Zaidat Osama O , Hassan Ameer , Linfante Italo , Sheth Sunil A
Published: January 2019

Introduction:
Exposure to Interventional Neurology (IN) for Neurology trainees varies from site to site and from year to year, depending on training program needs, political climate, and trainee interest. With new stroke trials expanding the indications and manpower needs for endovascular stroke therapy (EST), we sought to determine the current exposure of Neurology residents and fellows to the burgeoning field.

Methods:
Neurology residency and Vascular Neurology (VN) fellowship programs were identified from the ACGME database available online. Electronic surveys were distributed to Neurology residency program directors and Vascular Neurology fellowship directors for further distribution to their trainees.

Results:
A total of 250 programs were invited to participate, from which 76 trainees completed the survey. A range of training levels was captured (22% PGY2, 40% PGY3/4, 30% VN fellows). 72% of respondents had >4 months of exposure to VN in their residency training, though exposure to NeuroICU was less (majority <3 mo). Over 68% of respondents had no exposure to IN, and none had >2 months. Respondents overall felt comfortable with acute stroke treatment decisions, with 60% comfortable or very comfortable with IV tPA decisions and 86% for EST in both early and late windows. While 65% of respondents felt welcomed in the angiography suite and 72% felt a background in Neurology is a good preparation for the field, only 41% agreed that pursuing training and a career in IN is straightforward.

Conclusion:
Neurology trainees and VN fellows have limited residency exposure to IN, and while most feel well prepared for the field, less than half feel that access to a career in IN is readily available. Efforts to expand exposure to IN and creating consistent pathways for training will be paramount to address the current and urgent patient care needs for EST.
Abstract WP393: Usage of Emergency Medical Services Among Ischemic Stroke Patients: Data From China Stroke Center Alliance
Authors: Gu Hongqiu , Li Zixiao , Rao Zhenzhen , Wang Chunjuan , Yang Xin , Wang Yongjun
Published: January 2019

Background and Purpose:
Emergency medical services (EMSs) is critical for the early treatment of ischemic stroke patients, yet data regarding EMSs utilization and its association with timely treatment are still limited in China.

Methods:
We examined the data from Chinese Stroke Center Alliance (CSCA) recording consecutive ischemic stroke patients from 2015 June to 2017 November. The absolute standardized difference was used for covariates balance assessments. We used multivariable logistic models to identify factors associated with EMSs usage and to evaluate the effect of EMSs on timely treatment.

Results:
Of the 326,534 analyzed ischemic patients, only 42,293 (13.0%) were transported by EMSs. Multivariable-adjusted results indicated that younger age, less education, non-urban employ medial insurance, lower income level, less stroke severity, smoking, history of stroke/transient ischemic attack, carotid stenosis, hypertension, diabetes and peripheral vascular disease were associated with decreased risk of EMSs usage. However, coronary heart disease or myocardial infarction, atrial fibrillation and heart failure were associated with increased risk of EMSs usage. Compared to self-transportation, EMS-transported patients were associated with significantly shorter onset-to-door time (Median (IQR): 210 (105-586) vs. 1020 (290-2250) minutes, P<0.0001), higher chance of arrival at hospitals within 2 hours (32.0% vs 9.4%, OR=3.77, 95% CI: 3.53-4.02) or within 3.5 hours (50.1% vs 19.0%, OR=3.60, 95% CI, 3.35-3.86) after symptom onset, and treated with IV tPA (13.8% vs 3.6%, OR=3.06, 95% CI:2.75-3.41).

Conclusions:
EMSs utilization is far from optimal among Chinse ischemic stroke patients. Nevertheless, use of EMSs transportation is associated with substantial reductions in prehospital delay and improved chance of timely treatment. Therefore, community education efforts are needed to improve EMSs activation.
Abstract WP395: Improved Outcomes After Stroke Unit Establishment in a Regional Public Hospital
Authors: Lee Seung Hyun , Park Moo-Seok , Park Sang-Soon , Kim Min Ky , Park Tai Hwan
Published: January 2019

Background:
Stroke unit care is recommended as a standard care for acute stroke. We sought to determine whether morbidity and mortality of patients who admitted for acute ischemic stroke have been improved after implementation of stroke unit care in a regional public hospital.

Methods:
Seoul Medical Center is a regional public hospital in Seoul, the capital of Korea. Stroke unit has been established at June, 2011. Information of all consecutive stroke patients admitted to our hospital including functional outcome has been collected prospectively from April, 2008 as a part of a nationwide multicenter stroke registry. We compared outcomes of pre and post commencement of stroke unit, obtained from April, 2008 to December, 2010 and from January 2012 to November 2017, respectively. Primary outcome was a good functional outcome defined as a modified Rankin scale score of 2 or less at 3 months. A secondary outcome was death at 3 months.

Results:
Of all acute ischemic stroke, 366 and 1540 patients were identified as pre and post commencement of stroke unit. There were no significant differences in mean age (69.5±13.1 years versus 69.2±12.2 years;
p
=.684), sex distribution (male, 59.8% versus 59.4%,
p
=.906) and mean National Institutes of Health Stroke Scale score at admission (5.7±5.4 versus 5.6±5.9,
p
=.759) between two epochs. Good functional outcome was increased from 46.4% to 53.6% (
p
=.015) while mortality at 3 months dropped from 11.7 % to 5.4% (
p
<.001). Adjusted odds ratio for good functional outcome and mortality of post-stroke unit epoch was 1.74 (95% CI, 1.29-2.34), 0.34 (95% CI, 0.22-0.53), respectively, controlling for age, sex, stroke severity, prestroke disability, vascular risk factors, thrombolytic treatment, relevant steno-occlusive artery lesion.

Conclusions:
Our study shows the improvement of outcomes in patients with acute ischemic stroke after commencement of stroke unit care. Stroke unit care service needs to be expanded in other regional public hospitals in Korea.
Abstract WP396: Simultaneous Patient Presentation for Endovascular Thrombectomy
Authors: Kansagra Akash P , Dalsania Ankur K
Published: January 2019

Introduction:
Increased demand for endovascular thrombectomy has increased the likelihood of simultaneous patient presentation leading to competing demand for time-sensitive treatment. The occurrence of simultaneous demand has not been well studied. In this work, we quantified the occurrence of simultaneous patient presentation at different patient volumes.

Methods:
Distributions for time of patient presentation and case duration were derived from local data. These distributions were used to probabilistically generate arrival time and case duration for annual patient volumes ranging from 5 to 500 cases per year, with 8000 independent trials at each volume. Time series were generated for each trial to represent the number of concurrent cases at each minute of the year. Time series were used to calculate the occurrence of simultaneous demand.

Results:
Annual simultaneous demand by two or more patients was far lower than annual demand by a single patient at all tested volumes. The median patient volume at which there was at least one occurrence per year of simultaneous demand by two patients was 45 (IQR 30-65). The median patient volume at which there was at least one occurrence per year of simultaneous demand by three patients was 220 (IQR 160-275).

Conclusions:
The occurrence of simultaneous presentation for endovascular thrombectomy varies with patient volume. Understanding these trends can inform intelligent strategies for optimizing patient care within real-world financial and operational constraints.
Figure:
Annual duration of concurrent demand by (A) one patient, (B) two patients, and (C) three patients. Solid line = median, dark gray = 50% confidence bound, light gray = 95% confidence bound.
Abstract WP397: Effect of Anti-Hypertensive Medications on Hemorrhagic Transformation in Ischemic Stroke
Authors: Roman Yoram , Jillella Dinesh , Qeadan Fares , Sorte Danielle , Calder Christopher , Huy Tran
Published: January 2019

Introduction:
Ischemic Stroke is one of the leading causes of mortality and morbidity in the US. Hemorrhagic Transformation (HT) is one the most feared complications of ischemic stroke increasing its mortality and disability, especially in the setting of administration of TPA (tissue plasminogen activator) and intervention with thrombectomy. The objective of this study is to understand the effect of anti-hypertensive medications (AHMs) on hemorrhagic transformation in ischemic stroke patients.

Methods:
This is a retrospective study in patients who underwent TPA and/or thrombectomy from 2016 to 2017 at a tertiary referral center. . Primary outcome measure was HT at 24 hours in the setting of use of AHMs. Subject stratification was done based on patient’s age, sex, stroke side and location, blood pressure, anti-hypertensive medications (AHMs), admission type (direct emergency room admission versus outside hospital transfer), and lab values on admission.

Results:
140 patients were included in this study. Use of AHMs was done in 53 (37.8%) patients. With regards to individual AHMs used, nicardepine was used in 35 (25.00%), labetolol in 50 (35.71%), hydralazine in 15 (10.7%), esmolol in 19 (13.57%) and others in 3 (2.14%) of these patients. Logistic regression model including only admission type and use of any antihypertensive medication as predicting variables was performed, and the use of any anti-hypertensive medications was statistically significant in predicting the odds of HT. Subjects in whom no AHMs were used were found to have 121% higher odds for HT relative to those who were given any AHMs(OR=2.210, 95% C.I. 1.031-4.740, p=0.0416). Individual AHMs nicardepine, labetolol, hydralazine, esmolol or others and admission type did not differ significantly in predicting the odds of HT.

Conclusion:
Our study shows the use of AHMs to be associated with decreased risk of hemorrhagic transformation in patients who received TPA, thrombectomy or both. There was no statistical significance in relation to specific antihypertensive medications used with regards to hemorrhagic transformation.
Abstract WP399: Sex and Age Differences in Non-traditional Stroke Symptom Presentation in Acute Stroke
Authors: Eddelien Heidi Shil , Amtoft Andre Christian , Hornes Agnete Hviid , Danielsen Anne Kjærgaard , Kruuse Christina
Published: January 2019

Background:
So far, little is known about the impact of sex and age on the presentation of stroke symptoms. However, there is an increased awareness that stroke symptoms vary and not only cover traditional symptoms like: Balance, Eyes, Face, Arm and Speech (BEFAST) but also include non-traditional symptoms as pain and sensory deficits.

Purposes:
The aim was to detect a possible difference relating to sex and age in reporting of non-traditional and traditional symptoms by stroke patients or by their proxies.

Methods:
In a single-center prospective cross-sectional study we applied an in-person structured interview on which traditional (BEFAST: Balance, Eyes, Face, Arm, Speech) and non-traditional (e.g. pain, sensory deficits) stroke symptoms that led to admission. Regression analysis was used to determine sex and age association in traditional or non-traditional symptoms.

Result:
In total 225 patients with confirmed acute stroke (46.7 % women, median age 74 (IQR 63-82) completed the interviews. We found no significant difference in BEFAST symptoms between men and women, however, men reported less frequently altered sensibility, odds ratio (OR) 0.53 (CI 95% 0.28-0.99) P = 0.048. Increase in age was associated with less of the untraditional symptoms: altered sensibility OR 0.95 (0.93-0.98), P < 0.001 and headache OR 0.97 (0.94-0.99) and the traditional symptom altered vision OR 0.97 (0.94-0.99), P=0.02, but with more reports of dysphagia OR 1.07 (1.02-1.12), P=0.01.

Conclusion:
In conclusion, women reported more frequently than men index symptoms of altered sensibility. Interestingly, also non-traditional symptoms including headache, altered sensibility and vision often seen in stroke mimics, were more frequent in younger patients. A larger multicenter study is underway to clarify if such findings can be generally confirmed.
Abstract WP40: Endovascular Therapy 6 to 24 Hours After Stroke With a Mismatch Between Neurological Deficit and Alberta Stroke Program Early CT Score on Diffusion Weighted Imaging in a Real-World Setting
Authors: Ando Daisuke , Yamagami Hiroshi , Uchida Kazutaka , Inoue Manabu , Sonoda Kazutaka , Tanaka Kanta , Koga Masatoshi , Toyoda Kazunori , Morimoto Takeshi , Sakai Nobuyuki , Yoshimura Shinichi
Published: January 2019

Background and Purpose:
The DAWN trial showed the efficacy of endovascular thrombectomy between 6 to 24hours after time last known well (TLKW) in acute stroke patients with clinical-imaging mismatch. We examined the validity of patient selection using Alberta Stroke Program Early CT Score on diffusion weighted imaging (DWI-ASPECTS) in a real-world setting.

Methods:
In a Japanese nationwide registry study, 2420 patients with acute stroke due to large vessel occlusion within 24 hours from onset/TLKW were registered between October 2014 and January 2017. Among them, patients were included according to the inclusion criteria of the DAWN trial where ischemic core volume was replaced with DWI-ASPECTS: occlusion of the internal carotid artery or the middle cerebral artery M1 portion, 6 to 24 hours from onset/TLKW, DWI-ASPECTS ≥7 and initial NIHSS ≥10, and DWI-ASPECTS ≥6 and NIHSS ≥20 in patients younger than 80 years old. The favorable outcome was defined as a modified Rankin Scale of 0 to 2 at 90 days after onset.

Results:
Of 78 patients who were eligible to inclusion criteria, 54 (69%, mean 75±13 years old) underwent endovascular therapy (EVT) and 24 (31%, mean 76±14 years old) did not. Median initial NIHSS was 18 (IQR, 13-23) and 20 (IQR, 14-23), respectively (p = 0.67). Initial DWI-ASPECTS was significantly higher in the EVT group than in the non-EVT group (median [IQR], 8 [7-9] vs 7 [7-8], p = 0.009). The favorable outcome was achieved in 52% of the EVT group and 13% of the non-EVT group (adjusted odds ratio, 8.1; 95% CI, 2.0-33.3, p = 0.004). In terms of safety outcome, any intracranial hemorrhage within 72 hours was not different between the two groups (24% vs 33%, p = 0.56). The recurrence of stroke (5.6% vs 4.2%, p = 1.00) and mortality (4.2% vs 3.7%, p = 1.00) within 90 days were also not different.

Conclusions:
Patient selection using clinical-DWI mismatch can be useful to determine the indication of endovascular treatment in late presenting stroke with anterior large vessel occlusion.
Abstract WP400: Healthcare Utilization (HCRU) Among Non-Valvular Atrial Fibrillation (NVAF) Patients Who Switched From Warfarin to an Novel Oral Anti-Coagulant (NOAC)
Authors: Franchino-Elder Jessica , Gilligan Adrienne , Song Xue , Wang Cheng , Henriques Caroline , Nguyen Amy
Published: January 2019

Introduction:
This study compared HCRU among NVAF patients (pts) who switched from warfarin to dabigatran (DA), rivaroxaban (RV), or apixaban (AP).

Methods:
Adult NVAF pts switched from warfarin to DA, RI, or AP were identified in MarketScan databases between 10/2010-12/2015. Pts had 12 months pre-period (index date was 1
st
NOAC claim) and were followed for ≤12 months until medication discontinuation, end of enrollment, inpatient death, or 12/2016. DA pts were matched 1:1 to RI and to AP pts based on demographic (age, gender, region, health plan type, payer) and clinical characteristics (e.g., Charlson comorbidity index, stroke risk scores, bleeding risk scores, baseline costs, baseline medication use). Per-patient-per-month (PPPM) HCRU and time to 30-day readmissions were reported.

Results:
8,679 and 5,761 DA pts were matched to RI and AP pts, respectively (mean age 73-74 years). The % of pts with an inpatient (IP) visit was significantly lower for DA pts than RI pts (20.0% vs. 21.6%, p=0.008). PPPM IP visits were comparable between the two cohorts (0.23 vs. 0.22, p=0.45). DA pts had significantly lower PPPM total OP (3.87 vs. 4.06, p=0.002), emergency room (ER) (0.48 vs. 0.52, p=0.026), OP office (1.17 vs. 1.22, p<0.001), and other OP visits (2.71 vs. 2.83, p=0.043) compared to RI pts. While the % of pts with a 30-day readmission was similar for DA and RI, DA pts time post-discharge to readmission was significantly longer (8.2 days vs. 7.8 days, p<0.001). The % of DA pts with an IP visit were comparable to AP pts (20.7% vs. 21.2%; p=0.522). Compared to AP pts, DA pts had more PPPM IP visits (0.23 vs. 0.21, p=0.031), fewer but insignificant total OP (3.99 vs. 4.12), OP office (1.205 vs. 1.212), and other OP (2.81 vs. 2.88) visits, and significantly lower ER visits (0.47 vs. 0.52, p=0.016). The % of pts with a 30-day readmission and time to readmission post-discharge were comparable between DA and AP (22.3% vs. 23.7%; 8.1 days vs. 8.4 days, p>0.05, respectively).

Conclusions:
Among pts who switched from warfarin, DA pts had similar healthcare utilization compared to AP pts, and significantly lower inpatient visits and longer time to readmission than RI pts. This is valuable information for physicians and pts whose NVAF is not well controlled by warfarin therapy and may switch to NOACs.
Abstract WP403: Factors Associated With Patient-Reported Shared Decision-Making for Stroke Prevention in Atrial Fibrillation
Authors: O'Brien Emily C , Pieper Karen , Thiem Rebecca , Fonarow Gregg C , Kowey Peter R , Chan Paul S , Freeman James V , Naccarelli Gerald V , Mahaffey Kenneth W , Ezekowitz Michael D , Go Alan S , Gersh Bernard J , Singer Daniel E , Reiffel James A , Piccini Jonathan P
Published: January 2019

Introduction:
Shared decision making (SDM) incorporates patient and physician values and preferences into treatment selection. While multiple therapeutic options are available for stroke prevention in atrial fibrillation (AF), few studies have examined factors associated with SDM regarding choice of antithrombotic strategy.

Methods:
We evaluated survey data from 1006 patients with new-onset AF enrolled at 56 sites participating in a substudy of the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT II), an outpatient AF registry in the US. Patients were asked: “When choosing your blood thinner(s), who made this treatment decision?”, and SDM was defined as a response of “equally me and my healthcare provider (HCP)”, “mostly me” or “entirely me”, while no SDM was defined as a response of “mostly my HCP” or “entirely my HCP”. Multivariable logistic regression models evaluated associations between 13 patient-level factors, self-reported understanding of treatment options, and SDM for antithrombotic therapy.

Results:
Most patients allowed their HCP to make the therapeutic decisions on antithrombotic strategy, with 246 (24.5%) reporting SDM. Patients reporting SDM were more often female (47.2% vs. 40.5%) and were more frequently insured by Medicare (40.2% vs. 34.5%) than patients reporting no SDM. Among patients taking warfarin, median time in therapeutic range was higher among patients reporting SDM than among those not reporting SDM. In multivariable models, chronic obstructive pulmonary disease was associated with lower odds of SDM while self-reported understanding of blood thinner options was associated with higher odds of SDM (Table).

Conclusion:
One in four patients in an outpatient AF registry reported that their current antithrombotic strategy was the result of a shared decision making process. Additional work is need to determine whether patient-reported SDM is associated with medication adherence and outcomes of therapy.