bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP262: The Migraine-PFO-Stroke Triangle: Observations From the National Inpatient Sample
Authors: Topiwala Karan , Patel Smit , Tarasaria Karan , Rath Subhendu , Pervez Mubashir
Published: January 2019

Introduction:
Patients with migraine are known to have a higher risk of stroke. Migrainous-infarction, and more recently, paradoxical embolism via a patent foramen ovale (PFO) are proposed to be the causative pathophysiology. The prevalence of PFO in migraineurs with cryptogenic stroke has been shown to be as high as 80%.

Objective:
To determine from the Nationwide Inpatient Sample (NIS), the prevelance of acute ischemic stroke (AIS) in migraineurs with PFO who have had a PFO-closure procedure and compare them to those without a PFO-closure.

Methods:
Using the NIS from 2005-2014, patients carrying a diagnosis of migraine with aura (ICD 9: 346.0, 346.3, 346.5, and 346.6), migraine without aura (ICD9: 346.1, 346.2, 346.4, 346.7, 346.8, and 346.9) and PFO (ICD 9: 745.61, 745.5) were identified. From them, those who had a PFO closure (ICD 9: 35.52, 35.51, 35.71, 35.61) were identified. SAS 9.4 was used for data analysis with categorical and continuous variables tested using the Chi-Square test of proportions and Student’s t-test, respectively. Cox proportional hazard regression was used to adjust for confounders.

Results:
A total of 45,00,000 patients with migraine were identified, among which 3% (n=132,349) had migraine with aura. PFO detection rates in migraineurs with and without aura were 2% (n=2620) and 0.5% (n=23,225) respectively. In migraineurs with aura, PFO closure was performed in 10.5% (n=274) among which 12% (n=33) had an AIS as compared to 27.5% (n=647) AIS within the non-closure group (p<0.095, OR 0.48). However in migraineurs without aura, PFO closure was performed in 17% (n=3845) among which 7% (n=266) had an AIS as compared to 26.2% (n=5046) AIS within the non-closure group (p<0.0001, OR 0.29).

Conclusion:
In a nationally representative sample, PFO closure was associated with a lower prevalence of AIS in migraineurs without aura. A trend was observed favoring PFO-closure in migraineurs with aura, but lacked statistical significance which maybe secondary to the low PFO-detection rate observed in our sample. These findings may support the hypothesis of a paradoxical embolic phenomenon as being the predominant underlining pathophysiology for acute ischemic stroke in patients with migraine.
Abstract WP264: Relationship between Left Atrial Volume and Ischemic Stroke Subtype
Authors: Kamel Hooman , Okin Peter M , Devereux Richard B , Weinsaft Jonathan W
Published: January 2019

Introduction:
Embolic strokes of undetermined source (ESUS) are thought to mostly arise from occult cardiac sources or large-artery atherosclerotic lesions. Atrial cardiopathy in the absence of atrial fibrillation (AF) has been proposed as one potential cardiac source of ESUS.

Methods:
We compared left atrial volume across ischemic stroke subtypes in the Cornell Acute Stroke Academic Registry (CAESAR). All patients with acute ischemic stroke at our hospital have been prospectively registered in CAESAR since 2011. Stroke subtype was determined by a panel of neurologists per the TOAST classification and consensus ESUS definition using all data available during the index hospitalization. The left atrial volume index (LAVI) was pulled directly from our hospital’s echocardiographic image management system (Xcelera, Philips Healthcare). We used t-tests and analysis of variance (ANOVA) for unadjusted comparisons and multiple logistic regression for demographic-adjusted comparisons.

Results:
Among 2,116 patients registered in CAESAR from 2011-2016, the 1,577 with LAVI data were younger (mean age, 71.3 vs 73.4 years), had less severe strokes (mean NIHSS score, 7.5 vs 10.1), less often had AF (20.8% vs 25.3%), and more often had diabetes (26.8% vs 19.3%). LAVI varied significantly across stroke subtypes (
P
<0.001) from 49.5 (±31.6) mL/m
2
in cardioembolic strokes to 29.4 (±10.3) mL/m
2
in small-vessel strokes. Patients with cryptogenic stroke had significantly larger LAVI (35.0 ±14.6 mL/m
2
) than those with small- or large-vessel strokes (30.5 ±10.6 mL/m
2
) (
P
< 0.001). The association between LAVI and cryptogenic stroke (compared to small- or large-vessel stroke) persisted after adjustment for demographics (OR per mL/m
2
, 1.03; 95% CI, 1.02-1.04). Results were similar when comparing ESUS versus non-cardioembolic strokes.

Conclusions:
We found significantly larger left atria among patients with cryptogenic stroke vs non-cardioembolic stroke. At the same time, there was significant overlap in left atrial size between cryptogenic and non-cardioembolic stroke patients, highlighting that not all cryptogenic strokes are cardioembolic.
Abstract WP266: Association between Left Ventricular Ejection Fraction, Wall Motion Abnormalities and Embolic Strokes of Undetermined Source
Authors: Ramasamy Shobana , Yaghi Shadi , Omran Setareh S , Lerario Michael P , Devereux Richard , Okin Peter M , Navi Babak B , Kamel Hooman , Merkler Alexander E
Published: January 2019

Introduction:
Severely reduced left ventricular (LV) ejection fraction (EF) is an established risk factor for ischemic stroke. It is uncertain whether a modest reduction in LVEF (between 35%-50%) or the presence of LV wall motion abnormality may be a potential explanation for some embolic strokes of undetermined source (ESUS).

Methods:
We performed a retrospective cross-sectional study of patients with acute ischemic stroke enrolled in the Cornell AcutE Stroke Academic Registry (CAESAR) from 2011 through 2016. For this analysis, we restricted the study cohort to patients with ESUS and, as controls, those with small- and large-artery ischemic strokes who received an echocardiogram within 14 days of stroke. A single investigator blinded to stroke subtype recorded LVEF and the presence of LV wall motion abnormalities from reports of echocardiograms performed for routine evaluation of stroke. These variables are uniformly reported in echocardiogram reports at our institution. Multiple logistic regression models adjusted for demographics and stroke risk factors were used to evaluate whether LVEF or LV wall motion abnormality was associated with ESUS.

Results:
We identified 885 patients with ESUS or small- or large-artery strokes. The mean LVEF was 62.4% (+/- 7.9%). There was no difference in LVEF in patients with ESUS (62.4%; 95% CI, 61.8-63.1%) as compared to patients with small- or large-artery strokes (62.3%; 95% CI, 61.4-63.2%;
P
=0.8). After adjustment for demographics and stroke risk factors, LVEF was not associated with ESUS (OR per 10% incremental increase in LVEF, 0.9; 95% CI, 0.8-1.0;
P
= 0.4). LV wall motion abnormality was present in 5.9% of patients, and in multivariable analysis, its presence was not associated with ESUS (OR 0.9; 95% CI, 0.5-1.6;
P
= 0.7).

Conclusions:
We found that neither a modest reduction in LVEF nor the presence of LV wall motion abnormality was associated with ESUS.
Abstract WP267: Lower Left Ventricular Longitudinal Contraction is Associated With Early-onset Cryptogenic Ischemic Stroke
Authors: Pirinen Jani R , Järvinen Vesa , Martinez-Majander Nicolas , Sinisalo Juha , Putaala Jukka
Published: January 2019

Introduction:
At least one third of ischemic strokes at a young age (<50 years) remain cryptogenic after complete diagnostic work-up. We hypothesized that based on their neuroimaging presentation majority of these strokes may originate from the heart and that advanced cardiac ultrasound imaging might reveal hints from underlying left ventricular pathology.

Methods:
We prospectively recruited 26 patients aged 18-49 with cryptogenic ischemic stroke and 26 age- and sex-matched stroke-free controls. We examined all participants with transthoracic echocardiography and analyzed the left ventricular (LV) ejection fraction (LVEF) with 3-dimensional volumetry. We used speckle-tracking imaging in three planes (apical 4-chamber, 3-chamber and 2-chamber views), to determine LV global longitudinal strain (GLS), and only patients with visibility allowing analysis of all 18 LV segments were included. Tissue Doppler velocity imaging was used to determine the mitral annular plane systolic excursion (MAPSE), as a mean of six annular points in the 3 apical planes. Measurements were normally distributed and group-level differences were analyzed by paired-samples T-tests.

Results:
A total of 26 pairs had adequate visibility to examine LVEF, 20 to assess GLS, and 25 to examine MAPSE. There was no significant difference in LV ejection fraction between patients and controls (mean 59.0 vs 61.4 (%); P=0.300). LV global longitudinal strain was significantly lower in patients compared with controls (mean 18.0 vs 19.9 (%); P=0.012). Furthermore, MAPSE was lower in patients (mean 13.3 vs 14.2(mm); P=0.044).

Conclusion:
Young patients with cryptogenic ischemic stroke had lower longitudinal LV contraction than stroke-free individuals of the same age—without differences in LVEF—suggesting that subclinical LV systolic dysfunction may play a role in cryptogenic strokes.
Abstract WP268: Association of Serum Troponin Obtained During Stroke Codes With Cardioembolic Stroke
Authors: Nisar Taha , Kamin Stephen
Published: January 2019

Introduction:
Troponin is a marker of cardiac ischemia and is elevated in about 30 % of stroke patients. We investigated if the elevation of troponin during an acute stroke code is associated with a cardioembolic source.

Methods:
We performed a retrospective chart review of patients evaluated for acute strokes from July 2014 to March 2018. Patients included in the study were all given intravenous alteplase, had blood drawn for troponins during the acute stroke code and had confirmation of a new stroke on neuroimaging during hospitalization. Patients who were on dialysis or had a glomerular filtration rate of ≤40 ml/min on initial laboratory evaluation were excluded. Stroke etiology was classified as large vessel, cardioembolic, small vessel, other determined etiology or undetermined, according to Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Stroke subtypes were treated as categorical variables. Troponin was considered as a trichotomous categorical variable, with cut-off points at ≥0.01 ng/ml and ≥0.05 ng/ml.

Results:
144 patients met the inclusion criteria. In this cohort, 42.31% of patients in the cardioembolic group had troponin levels of ≥0.05 ng/ml compared to 0% in the small vessel group, 5.88% in the large vessel group and 15.87 % in the undetermined origin group. A troponin level of ≥0.05 ng/ml obtained during a stroke code showed a significant difference between cardioembolic and non-cardioembolic strokes (OR, 5.40; 95% CI, 2.34-12.46; P<0.001), with high specificity (88.04%) but low sensitivity (42.31%) to exclude non-cardioembolic stroke.

Conclusions:
A troponin level of ≥0.05 ng/ml obtained during a stroke code showed a significant difference between cardioembolic and non-cardioembolic strokes. This finding may have implications for patient treatment, as anticoagulation is the treatment of choice for secondary prevention of stroke in most cases of cardioembolic stroke. A troponin level of ≥0.05 ng/ml may prompt a more thorough search for a cardioembolic source in cases in which such a source is not identified on initial evaluation.
Abstract WP269: Direct Oral Anticoagulant “Pseudo-Failure” vs. “True Failure” to Prevent Ischemic Stroke in Nonvalvular Atrial Fibrillation
Authors: Beltagy Abdelrahman , Yi Xiyan , Chang Jane Y , Hilker Nicholas C , Rose David Z
Published: January 2019

Background:
Despite the efficacy of Direct Oral Anticoagulants (DOACs) in Nonvalvular Atrial Fibrillation (NVAF), some patients may still develop an ischemic stroke while taking this medication. This can be from a primary efficacy problem, called DOAC “True failure” (due to drug absorption, metabolism, or clearance), or DOAC “Pseudo-failure” (due to alternate causes of stroke, not the NVAF). We aim to study the factors contributing to DOAC Pseudo-failures and isolate DOAC True Failure rates.

Methods:
IRB-approved, retrospective study of NVAF patients on DOAC who developed ischemic stroke between Jan 2012 and Dec 2017. Variables reviewed include DOAC Pseudo-failure causes listed in the mnemonic CHAMP: C for Compliance concerns (adherence [held for procedure, ran out, or discontinued], incorrect dose, or incorrect frequency [QD vs BID]); H for Hypertensive lacunar disease; A for Arterial diseases (such as Atherosclerosis [intra- or extra-cranial, carotid or vertebral arterial stenosis or dissection]); M for Malignant cancer or other hypercoagulable states; and P for Patent Foramen Ovale (PFO).

Results:
We identified 87 NVAF patients on DOAC who presented with ischemic stroke: 18 on Dabigatran, 37 on Apixaban and 32 on Rivaroxaban. Of those, 67 patients (77%) had at least one of the CHAMP variables (DOAC Pseudo-failure) while 20 (23%) were DOAC True failures. Compliance concerns were responsible for nearly half (49%) of the Pseudo-failures, followed by Malignancy/hypercoagulability (26%), Arterial disease (17%), HTN (5.7%) and PFO (2.3%). True Failure was lowest for Dabigatran (5.6%) followed by Apixaban (16%) and highest with Rivoraxaban (41%) despite its high compliance rate of 66%. Compliance for the BID DOACs (Dabigatran and Apixaban) were similar at 39 % and 43%, respectively.

Conclusion:
Patients on DOAC for NVAF who develop ischemic stroke are three times more likely to have another identifiable etiology. Compliance concerns, Cancer/Hypercoagulability, and arterial disease represent over 90% of DOAC Pseudo-failures. Thus, providers should educate patients on correct DOAC doses and frequencies, and screen presumed DOAC failures with scans of the chest, abdomen and pelvis in addition to intracranial and extracranial vessel imaging.
Abstract WP270: Can Left Atrial Volume Index Be Used to Identify Patients With Asymptomatic Atrial Fibrillation After Acute Ischemic Stroke or Transient Ischemic Attack?
Authors: Vu Quang D , Lisle Benjamin N , Barghouthi Tamara T , Guzik Amy K , Bishop Laura E , El Husseini Nada N , Tegeler Charles H , Reynolds Patrick S , Bushnell Cheryl D
Published: January 2019

Introduction:
Detecting atrial fibrillation (AF) after an ischemic stroke may be challenging. We aimed to determine whether using the left atrial volume index (LAVi) can help screen patients at risk of having AF after an ischemic stroke or transient ischemic attack (TIA).

Methods:
All adult patients who were admitted to our comprehensive stroke center with ischemic strokes or TIA from January 2017 to January 2018 were retrospectively analyzed. Demographics, risk factors, stroke etiology and transthoracic echocardiography (TTE) data were collected. AF detection was based on either in-hospital cardiac telemetry and/or a 14-day or 30-day ambulatory ECG monitoring. Reference values for LAVi were derived from 2015 Guidelines from the American Society of Echocardiography. TTE and ECG parameters were analyzed using Fisher’s exact test for categorical variables and non-parametric tests for continuous variables.

Results:
We identified 334 patients with ischemic strokes and TIA without documented AF (66 ± 11 years, 49% females, 70% White, 23% African American, 6% Other). The mean total days of cardiac monitoring was 9.8 ± 7.2 days and it was lower in patients with AF vs without AF (3.8 ± 5.0 days vs. 10.6 ± 7.1 days, p < 0.0001). Newly diagnosed AF was detected in 37 of 334 patients (11%). Of the 241 patients with normal left atrium (LA), 15 (6%) were diagnosed with AF; 10 of 49 (20%) with mildly dilated LA; 5 of 23 (22%) with moderately dilated LA; 7 of 21 (33%) with severely dilated LA. The proportions of AF detection differed significantly between the LA categories (
p
< 0.0001). The mean LAVi was higher in patients with AF vs without AF (40.0 ± 13.8 mL/m
2
vs. 28 ± 10.5 mL/m
2
, p < 0.001), and in those with cardioembolic strokes (34.7 ± 13.3 mL/m
2
, p < 0.0001). The mean LAVi for non-cardioembolic strokes including cryptogenic, small vessel and large vessel were 29.3 ± 10.2 mL/m
2
, 28.6 ± 8.5 mL/m
2
, 26.2 ± 12.8 mL/m
2
, respectively.

Conclusion:
Our data demonstrates a significant association between higher LAVi on routine TTE and detecting AF using non-invasive ECG monitoring in patients with ischemic strokes or TIA. Use of LAVi measured during the stroke hospitalization may help identify patients who would benefit from additional non-invasive cardiac monitoring post-discharge.
Abstract WP271: A Comparison of Bedside Echocardiography with Point of Care Ultrasound to Standard Transthoracic Echocardiography in the Setting of Acute Stroke and TIA
Authors: Bacheler Christian , Ajiboye Norman , Bell Rodney , Tzeng Diana , Rincon Fred , Koka Anish
Published: January 2019

Background:
Transthoracic Echocardiography (TTE) is routinely performed in the setting of acute stroke and transient ischemic attack (TIA) to evaluate for a cardiac source of emboli. Although standard of care, guidelines remain ambiguous on the indications and recommendations for its routine use. Point-of-care ultrasound (POCUS), a quick bedside method of echocardiography using an easily portable, hand-held device, has been studied extensively in the ED, trauma, and ICU settings, but not for acute stroke and TIA. Here, we demonstrate the feasibility of using POCUS for the purpose of screening echocardiography in acute stroke & TIA patients. Additionally, we compare POCUS with TTE in order to evaluate the veracity of the point-of-care method with the gold standard.

Methods:
A retrospective comparison was made between routine TTE and POCUS results performed by a cardiologist during consultation. 99 patients were included, each admitted for workup of stroke, TIA, or retinal artery occlusions, and had a cardiology consultation for any reason. Parameters compared included left ventricular (LV) function, left atrial (LA) size, mitral valve (MV) and aortic valve (AV) pathology, and the presence of LA or LV thrombi, masses, or aneurysms.

Results:
All 16 cases with significant abnormalities (LV dysfunction, LV thrombi, or AV/MV vegetations) that were found on TTE were also identified by POCUS. Of the 13 patients with severely abnormal LV function on TTE, 12 were identified as severe on POCUS, and one as mild-moderate. Findings in 9 of these 16 patients led to a change in management, including one case where a large LV thrombus requiring a heparin infusion was identified hours earlier by POCUS.

Conclusions:
POCUS was comparable and non-inferior to the gold standard TTE for the purpose of screening echocardiography in the workup of acute ischemic stroke & TIA. Significant findings on TTE were all identified by a bedside POCUS (with the only discrepancy in the degree of LV dysfunction in a single case). All TTE findings resulting in management changes were also identified by POCUS. Importantly, POCUS can be used as a quick diagnostic screening tool to help establish an earlier diagnosis of life threatening conditions, and may lead to earlier management and treatment decisions.
Abstract WP272: Left Atrial Enlargement is Associated With Neuroworsening and Worse Short-Term Outcomes in Acute Ischemic Stroke
Authors: Samai Alyana A , Albright Karen , Navalkele Digvijaya , Alemayehu Carmel , Martin-Schild Sheryl
Published: January 2019

Background:
While left atrial enlargement (LAE) is associated with increased risk for incident acute ischemic stroke (AIS), the association between LAE and outcomes following AIS is not well described. This study aimed to examine the relationship between LAE and short-term functional outcomes in the setting of AIS.

Methods:
This is a cross-sectional study of consecutively admitted AIS patients at a single high-volume stroke center. Patients over 18 years old diagnosed with AIS between 2008-2015 were included. After adjusting for key covariates, we analyzed whether patients with LAE (LAE+) experienced worse outcomes compared to patients without LAE (LAE-). The primary outcome of interest was poor functional outcome, defined as a modified Rankin Scale score (mRS) of 4-6 at discharge. The secondary outcome of interest was neuroworsening, defined as an increase in NIHSS score of 2 points of more within 24 hours.

Results:
Of 1,082 patients included, 50.6% were LAE+. Patients in the LAE+ group had a higher median age (67 vs. 62, p<0.001) and admission NIHSS (6 vs. 5, p<0.001). Patients the LAE+ group also differed significantly in frequency of history of hypertension (87.2% vs. 74.0%, p<0.001), history of diabetes (40.4% vs. 33.1%, p=0.015), history of atrial fibrillation (19.7% vs. 3.2%, p<0.001), and history of congestive heart failure (19.3% vs. 4.2%, p<0.001). After adjustment for age, baseline NIHSS, and tPA exposure, the odds of poor functional outcome was 1.83 times greater in the LAE+ group compared to the LAE- group (OR 1.83, 95% CI 1.33-2.52). Additionally, after adjustment for age, baseline NIHSS, and tPA exposure, the odds of neuroworsening was 1.48 times greater in the LAE+ group compared to the LAE- group (OR 1.48, 95% CI 1.10-1.99).

Discussion:
The results of this study suggest that LAE may herald neurological worsening and worse functional outcomes following AIS. Stroke-treating neurologists may regard detection of LAE as an opportunity to heighten monitoring and early intervention for neurological worsening.
Abstract WP277: Clinical Utility and Cost-Effectiveness of Transthoracic Echocardiogram in Lacunar Strokes
Authors: Thakkar Vismay , Ume Kiddy , Kraus Riley , Forgas David , Fleming Aaron , Hendricks Gary , Abou Chaar Widad , Siddiqui Fazeel
Published: January 2019

Background:
The average annual cost of inpatient stroke care in the United States exceeds $35 billion. The lack of clear recommendations for the use of transthoracic echocardiography (TTE) in patients with Acute ischemic stroke (AIS) has made this test a universal component of every stroke work-up. We evaluated the clinical utility and cost-effectiveness of TTE performed in patients with lacunar strokes.

Methods:
This is a single-center retrospective analysis of AIS patients from October 2015 through December 2017 (27 months). Brain MRI was used to select patients with a single acute/subacute lacunar infarct and no T2FLAIR evidence of previous cortical embolic strokes. Patients with cardiac symptoms (chest pain, shortness of breath, pedal edema) or an abnormal ECG (Atrial fibrillation, other arrhythmias, ST-T changes) on admission were excluded. Results of TTE were reviewed and their utility in decision making was evaluated. TTE associated costs were calculated.

Results:
Out of the 442 patients diagnosed with AIS in the given timeframe
,
98 met the above criteria for inclusion. Mean age was 55 and 40 patients were female.TTE revealed no patients with an ejection fraction below 40%. Incidence of cardiac thrombus was 0%. Small patent foramen ovale was found in 5 (5.1%) patients, out of which none had right to left shunting or associated atrial septal aneurysm. Obtaining TTE did not change the management in any of the cases. Average cost of inpatient TTE was $2616, totaling $266,832 in all patients. Based on the current incidence of lacunar strokes (15-25%), this corresponds to approximately $500 million of nationwide spending annually.

Conclusion:
In AIS patients with no cardiac symptoms and normal ECG, it may be safe and clinically reasonable to obtain MRI brain before deciding about the need for TTE. If MRI shows a lacunar stroke, inpatient TTE done routinely may not change the management but adds up unnecessary cost to the healthcare system. Large multi-center studies are warranted.
Abstract WP28: Yield of ASPECTS and CTA-Based Selection Criteria for Mechanical Thrombectomy in Patients Treated Within 6-24 Hours From Symptom Onset
Authors: Krishnaiah Balaji , Goyal Nitin , Tsivgoulis George , Ishfaq Muhammad , Pandhi Abhi , Krishnan Rashi , Bavarsad Shahripour Reza , Elijovich Lucas , Hoit Daniel , Alexandrov Anne , Arthur Adam , Alexandrov Andrei V
Published: January 2019

Background:
Recent extended window (EW) trials support the benefit of mechanical thrombectomy (MT) in anterior circulation emergent large vessel occlusions (ELVO). However, only up to 1.7% of consecutive acute ischemic strokes (AIS) were eligible for EW-MT using clinical trial selection criteria. We examined eligibility and outcomes of EW-MT in consecutive ELVOs using pragmatic selection criteria.

Methods:
We prospectively evaluated consecutive patients presenting between 6-24 hours that underwent MT using selection criteria consisting of only non-contrast CT (ASPECTS
>
6), CTA occlusion
+
good collateral scores (JNIS 2016;8:559-562). Effectiveness outcomes included TICI 2b-3 and 3-month modified Rankin Scores (mRS); safety outcomes included in-hospital mortality and symptomatic intracerebral hemorrhage (sICH).

Results:
767 consecutive AIS patients presented within 6-24 hour window, and of these 48 (6%) anterior circulation ELVOs underwent MT (mean age 63±17 years; 56% men; median NIHSS 16 [IQR 10-19]; median groin puncture to recanalization 53 minutes [IQR 41-85]). Median ASPECTS was 9 (IQR 8-10), and 79% (n=38) of patients had good CTA collateral grade. Occlusions were primarily M1 MCA (46%), with 29% tandem occlusions. Successful recanalization (mTICI 2b or 3) was achieved in 73% (n=35), while 6% (n=3) of patients developed sICH. In-hospital mortality was 25% (n=12), however 40% (n=19) achieved 3-month mRS 0-2.

Conclusions:
The use of standard of care CT/CTA yields an acceptable rate of MT eligibility, allowing a group of patients facing likely death or severe disability to obtain reasonable safety and effectiveness outcomes.
Abstract WP280: Systolic Blood Pressure During Presentation of Acute Ischemic Stroke Predicts Cardioembolic Etiology
Authors: Moores Margaret , Yogendrakumar Vignan , Bereznyakova Olena , Pettem Hailey , Stotts Grant , Dowlatshahi Dariush , Shamy Michel
Published: January 2019

Introduction:
Determining stroke etiology is essential to stroke prevention. Deciding which patients require extensive cardiac investigations, and with what priority, is a topic of controversy.

Hypothesis:
We hypothesize that a lack of hypertension at the time of presentation with acute ischemic stroke predicts cardioembolic etiology.

Methods:
Patients presenting with acute (< 6 hours) ischemic stroke were consecutively enrolled from a single institution between 2015 and 2017. The primary outcome was cardioembolic etiology diagnosis at 6 months. Presenting systolic blood pressure was categorized as: hypotensive (<110 mmHg), normotensive (110-149 mmHg), and hypertensive (>150 mmHg). Multivariable logistic regression was used to adjust for relevant covariates, which were selected via exploratory univariate analysis (p<0.1).

Results:
Of the 151 patients included in primary analysis, 64 (42%) were diagnosed with a cardioembolic source at 6 months. After adjusting for age, known cardiac disease (atrial fibrillation, congestive heart failure, valvular disease), and clinical severity, patients presenting with hypo or normotensive systolic pressure were significantly associated with cardioembolic diagnosis at 6 months (n= 37, aOR 3.25, 95% CI: 1.17- 9.06). The association between systolic pressure and cardioembolic diagnosis increased in a dose-like manner (hypotensive: aOR 7.66, 95% CI: 0.80-73.30, normotensive: aOR 2.99, 95% CI: 1.04-8.58).

Conclusions:
This study provides preliminary confirmation of our hypothesis that patients who are not hypertensive at the time of acute ischemic stroke are more likely to have suffered a stroke that is cardioembolic in origin. These patients may warrant more thorough cardiac investigations or other alterations to management.
Abstract WP281: Histologic Features of Thrombi Retrieved From Ischemic Stroke Patients With Cancer
Authors: Park Hyungjong , Kim Ja young , Hwang In Gun , Song Tae-Jin , Yoo Joonsang , Ahn Sung Hwan , Kim Byung Moon , Kim Dong Joon , Kim Young Dae , Nam Hyo Suk , Kwon Il , Heo Ji Hoe
Published: January 2019

Background:
Systemic cancer is a cause of stroke. However, histologic features of thrombus in stroke patients with cancer are not well-known. We investigated histologic features of intracranial thrombi in acute stroke patients with cancer.

Methods:
We prospectively collected thrombi that were retrieved during mechanical thrombectomy. This study included 32 consecutive patients with any history of systemic cancer (16 patients with active cancer and 16 patients with inactive cancer.) All patients underwent continuous electrocardiographic monitoring for at least 24 h. Echocardiography was performed in all but three patients. Immunohistochemical staining of thrombus was done using anti-CD42b antibody for platelets, anti-glycophorin antibody for erythrocytes, anti-fibrinogen antibody for fibrin, anti-myeloperoxidase antibody for leukocytes, and anti-Histone H3 antibody for neutrophil extracellular traps. After acquiring images of entire thrombus area using the stereo investigator imaging system, quantitative fraction (%) of different thrombus composition was semi-automatically assessed using ImageJ software. We compared the thrombus composition between the active cancer group and the inactive cancer group.

Results:
Comparing with the inactive cancer group, the active cancer group showed higher platelet fraction (median [interquartile range], 20.6 [7.3-27.6] vs 6.1 [2.5-9.9], p=0.002) and lower erythrocyte fraction (1.6 [0.8-11.1] vs 20.7 [13.3-23.7], p=0.001). Fractions for fibrin, leukocytes, and neutrophil extracellular traps were not different between the active and inactive cancer groups. Four patients had vegetation on echocardiography and showed very high platelet fraction (29.5 [26.1-33.9]) and very low erythrocyte fraction (0.8 [0.7-0.9]). Of the active cancer group, 6 patients with negative evaluation also showed high platelet fraction and low erythrocyte fraction, but the thrombus composition in 4 patients with determined etiology (3 atrial fibrillation, 1 >50% stenosis) was similar to that in inactive cancer.

Conclusion:
Thrombi in stroke patients with active cancer were platelet-rich and erythrocyte-poor. These findings may aid to determine the treatment strategy for stroke patients with cancer.
Abstract WP282: Predictors of Candidacy for Endovascular Therapy in Telestroke Patients Transferred to a Comprehensive Stroke Center
Authors: Barghouthi Tamara T , Vu Quang , Lisle Benjamin N , Bushnell Cheryl D , Bishop Laura E , El Husseini Nada , Reynolds Patrick S , Tegeler Charles H , Guzik Amy K
Published: January 2019

Endovascular therapy (EVT), with IV tPA if eligible, is the standard of care for large vessel occlusion (LVO) in acute ischemic stroke. Many patients transferred from outside hospitals to comprehensive stroke centers (CSCs) for potential EVT are found to be ineligible. We aimed to determine predictors of EVT candidacy for suspected LVO strokes in patients transferred from telestroke network hospitals within 24 hours of last known normal time.

Methods:
All adult patients transferred after telestroke consultation to our CSC emergency department with acute ischemic stroke and suspected LVO from November 2017 to June 2018 were retrospectively reviewed. This time frame was chosen due to practice changes following the establishment of an extended EVT time window. Data analyzed included demographics, risk factors, BP, NIHSS, presence of cerebellar signs and cortical signs (i.e., aphasia, gaze palsy, visual field defect, neglect). With EVT candidacy as the dependent variable, stepwise logistic regression was done with the significance level both for a factor to enter and stay in the model set at 0.15.

Results:
A total of 133 patients (mean age 67.5 ± 16 years, 47.4% women, 85.7% White, 14.3% non-White) were identified. EVT was performed in 36 of 133 patients (27%). The mean NIHSS for EVT patients was 13.1 ± 6.7 compared to 8.5 ± 8.0 for non-EVT patients (p=0.0030). Each unit increase in NIHSS was associated with being more likely to receive EVT (p=0.10). Cortical signs were present in 32 of 36 EVT patients (88.9%) compared to 57 of 97 non-EVT patients (58.8%) (p=0.0010). The presence of cortical signs was associated with receiving EVT (OR 4.60, 95% CI 1.30-16.26; p=0.02). A history of CHF was associated with being less likely to receive EVT (OR 0.31, 95% CI 0.10-1.02, p=0.05). There was a trend toward non-White race being associated with receiving EVT (OR 2.91, 95% CI 0.88-9.62; p=0.08).

Conclusion:
The presence of cortical signs, more so than the collinear variable of higher NIHSS, was a significant predictor of candidacy for EVT. Non-White race and CHF are variables that will need to be validated in future studies. These findings, combined with further studies, could help telestroke physicians establish improved selection criteria for transfer of stroke patients to CSCs for EVT.
Abstract WP290: Direct Ambulance to Imaging Based Mission Protocol Improves Thrombolysis Metrics for Prehospital Suspected Acute Stroke Patients
Authors: Keenan Kevin J , Cole Sara B , Martin Christine , Hemphill J C , Madhok Debbie Y
Published: January 2019

Background:
The Mission Protocol was implemented in 2017 to expedite stroke evaluation and reduce door-to-needle (DTN) times at Zuckerberg San Francisco General Hospital. The key system change was emergency medical service (EMS) provider transport of patients directly to CT on arrival.

Methods:
Patients were eligible for a Mission Protocol prehospital stroke activation if an EMS provider found a positive Cincinnati Prehospital Stroke Scale and a last known normal time within 6 hours. We performed a chart review to compare treatment metrics between the first year of Mission Protocol patients and patients from the year prior who were also brought in via ambulance with concern for stroke and a last known normal time within 6 hours. All patients who received thrombolysis as part of their initial evaluation and treatment were included. No outliers were excluded. Median Door to CT and DTN times were compared using two sample Wilcoxon rank-sum (Mann-Whitney) tests.

Results:
The Mission Protocol cohort had 236 patients and the comparison cohort had 112 patients with results described in the table. The Mission Protocol was associated with a 10 minute faster median door to CT time (p<0.00001), a 6 minute faster median DTN time (p=0.0046), a 22% increase in the proportion of patients treated within 45 minutes of hospital arrival (84% vs 62%), and a 12% increase in the proportion of patients treated within 60 minutes (92% vs 80%). There were 8 stroke mimics treated in the Mission Protocol cohort compared to 2 in the comparison cohort. Symptomatic intracranial hemorrhage only occurred in one Mission Protocol patient with an ischemic stroke.

Conclusion:
The EMS direct to CT based Mission Protocol was associated with faster median door to CT and DTN times. There was a 22% increase in the proportion of thrombolysis patients treated within 45 minutes or less. More stroke mimic patients received thrombolysis but symptomatic intracranial hemorrhage only occurred in one ischemic stroke patient.
Abstract WP292: Differential Ability of Prehospital Large Vessel of Occlusion Scales to Identify Intracranial Hemorrhage
Authors: Shkirkova Kristina , Sabra Mark , Saver Jeffrey , Liebeskind David S , Hamilton Scott , Starkman Sidney , Sanossian Nerses
Published: January 2019

Background:
Prehospital scales have been developed to identify patients with acute cerebral ischemia large vessel occlusion (ACI LVO) for direct routing to endovascular procedures. However intracranial hemorrhage patients can benefit significantly when directed to comprehensive stroke centers with neurosurgical services, but few prehospital scales have been validated for the detection of intracranial hemorrhage.

Purpose:
Differentiate the ability of prehospital large vessel of occlusion scales, such as LAMS, FAST-ED, RACE, and C-STATS to identify intracranial hemorrhage

Methods:
We analyzed early assessment and outcome data prospectively gathered in the FAST-MAG trial (Field Administration of Stroke Therapy-Magnesium phase 3) among patients with acute cerebrovascular disease (cerebral ischemia and intracranial hemorrhage) within 2 hours of onset, transported by 315 ambulances to 60 receiving hospitals.

Results:
Among 1700 patients (age 69±13 years, female 42.6%) 73.3% of patients had final diagnosis of cerebral ischemia, 22.8% diagnosis of intracranial hemorrhage, and 3.9% had stroke-mimicking conditions. Time from onset to prehospital LAMS was median 30 minutes (IQR 20-50), onset to hospital arrival LAMS was 145 minutes (IQR 119-180). All 4 scales performed moderately well in identifying ICH among patients with ACI: LAMS 0.75 C statistic; 0.63 accuracy; FAST-ED 0.72 C-statistic, 0.65 accuracy; RACE 0.70 C-statistic, 0.64 accuracy; C-STATS 0.71 C statistic, 0.67 accuracy.

Conclusions:
The prehospital LAMS and ED-performed C-STAT, RACE, and FAST-ED performed roughly equally at identifying Intracranial Hemorrhage patients with good accuracy.
Abstract WP293: A Prospective Validation of Stroke Network of Wisconsin (snow) Scale to Predict Large Vessel Occlusion (lvo) and Comparison With Other Stroke Scales
Authors: Panichpisal Kessarin , Hess Maureen , Singh Maharaj , Dellemann Elizabeth , Vilar Paul , Babygirija Reji P , Erpenbeck Sarah , Chohan Adil , Wolfe Thomas , Sajjad Rehan , Rovin Richard A
Published: January 2019

Background:
Prior retrospective analysis confirmed that the Stroke Network of Wisconsin (SNOW) scale was highly predictive of large vessel occlusion (LVO) in patients with Acute Ischemic Stroke (AIS). In this study, we prospectively validated the SNOW scale for the identification of LVO. We also compared its accuracy to other stroke scales retrospectively applied to the same dataset.

Methods:
The SNOW scale consists of 3 exam elements: expressive aphasia/Speaking difficulty (S), neglect (N) and Ocular deviation (O). The scale is positive if any one of these items is present. We prospectively evaluated all acute ischemic stroke (AIS) patients who presented within 24 hours after onset at Aurora St. Luke’s Medical Center between July 2017-February 2018 and calculated the SNOW score. We retrospectively calculated Rapid Arterial Occlusion Evaluation (RACE), the Field Assessment Stroke Triage for Emergency Destination (FAST-ED), the Vision Aphasia and Neglect Scale (VAN), the Cincinnati Prehospital Stroke Severity (CPSS), the Los Angeles Motor Scale (LAMS), the Prehospital Acute Stroke Severity Scale (PASS) for all patients. The predictive performance of all scales and National Institute of Health Stroke Scale (NIHSS) cut offs ≥6 were determined and compared. LVO was defined by total occlusions involving the intracranial internal carotid artery, middle cerebral artery (M1), or basilar arteries

Results:
Among 344 AIS patients, 283 (82%) had vascular imaging and were included in the analysis. LVO was detected in 43 (15%). Positive SNOW scale showed: sensitivity = 0.84, specificity = 0.63, positive predictive value = 0.29, negative predictive value= 0.96, and area under the curve =0.74. SNOW scale had comparable accuracy to predict LVO as other scales and NIHSS cut offs ≥6. If LVO includes M2, positive SNOW had sensitivity of 0.85, specificity of 0.70, positive predictive value of 0.49, negative predictive value of 0.93 and area under the curve of 0.77. SNOW had the highest sensitivity but lowest specificity among other scales.

Conclusion:
The SNOW scale is a simple and accurate tool to help identify AIS due to LVO, and it compares favorably to the other scales evaluated. A prospective validation study of the SNOW scale in the prehospital setting is underway.

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Abstract WP296: Access to Comprehensive Stroke Centers in Los Angeles County
Authors: Marehbian Jonathan , Dworkis Daniel , Arora Sanjay , Sanossian Nerses
Published: January 2019

Introduction:
In 2018, the Los Angeles County (LAC) model for routing of Emergency Medical Service (EMS) transports of suspected large vessel occlusion stroke patients changed from transport to the nearest primary stroke center to transport directly to the nearest CSC. While the goal is to reduce transport time to a center with a high level of stroke care, it is not known how CSCs relate spatially to EMS transports for suspected strokes.

Hypothesis:
Patients in LAC requiring EMS transport for suspected acute stroke do not have uniform access to CSCs.

Methods:
This is a retrospective spatial analysis of the locations of EMS suspected acute stroke transports between Jan 1, 2012 and Sept 30, 2017. Data on the origin locations of EMS transports was obtained from the LAC EMS agency and compared to the locations of the 16 CSCs in LAC. Access to a CSC was defined using circular spatial buffers of various sizes centered on each CSC. All studies were performed using the R programing language extended by the SP, lubridate, rgdal, and tidyverse packages, and were approved by local IRB.

Results:
Of the 25,597 EMS stroke transports 22,585 had exact spatial coordinates. Of these, 17,539 (77.7%) originated within 10Km of a CSC. Figure 1 shows CSCs clustered in the southern aspect of LAC, with highly heterogenous transports across LAC. A large concentration of northern LAC transports are far from CSCs.

Conclusions:
While most EMS transports for suspected acute stroke in LAC originate in areas with good access to CSCs, the geospatial distribution of EMS transports is heterogeneous and includes an area in northern LAC with little to no CSC access. Further work is needed to understand the characteristics of acute stroke in this northern area, to understand how these differences in access may result in differences in time to definitive therapy and patient outcomes, to identify strategies for improving CSC access, and highlights the utility of using EMS transport data to inform stroke care policy.
Abstract WP298: Communication Center Guided Prehospital Stroke Assessment Scoring has High Inter-rater Agreement
Authors: Gazi Melissa , Fadairo Abimbola , Minor Michael , Acker Joe , Gropen Toby I
Published: January 2019

Introduction:
We are prospectively validating a model of communication center guided prehospital identification of stroke patients with large vessel occlusion (LVO).

Goal:
Assess the inter-rater agreement between a Vascular Neurologist and Alabama Trauma Communication Center (ATCC) personnel in diagnostic classification of stroke patients.

Methods:
The ATCC is staffed by paramedic-trained dispatchers who field calls from Emergency Medical Service (EMS) responders and maintain up-to-the-minute status of hospitals and resources 24/7. We trained ATCC personnel in stroke pathology, pathophysiology, appropriate patient selection for thrombolytic and endovascular therapies; and the previously derived 6 point Emergency Medical Stroke Assessment (EMSA). ATCC personnel guided EMS responders in the Birmingham Regional Emergency Medical Services System (BREMSS), and paged-out a hospital stroke prenotification that included specific EMSA scale items (gaze, facial droop, arm drift, leg drift, naming, and repetition). All interactions between the ATCC and EMS responders were recorded, allowing review of audio files and ongoing quality improvement. ATCC personnel and a vascular neurologist separately reviewed recordings and assigned scores to each patient according to the deficit stated by the EMS. To determine inter-rater reliability we utilized the Kappa statistic with a significance level of 0.05, and 95% confidence intervals (CI).

Results:
We sampled a total of 146 patients. We observed statistically significant agreement between the raters for all EMSA components, with 71% (CI=45-97%, p<0.0001) agreement in rating the gaze component, 54% (CI=26-82%, p=0.002) for the face, 57% (CI=29-85%, p=0.001) for the arm, 60% (CI=33-86%, p<0.0006) for the leg, 56% (CI=30-81%, p<0.001) for naming, and 34% (CI=6-61%, p<0.04) for repetition.

Conclusion:
We conclude that there is moderate to substantial agreement in most stroke assessment items by a paramedic staffed communication center and a vascular neurologist. There was only fair inter-rater agreement for repetition. Paramedic-trained dispatchers can reliably guide EMS responders and score the Emergency Medical Stroke Assessment.
Abstract WP3: Decreases in Blood Pressure During Endovascular Stroke Therapy are Associated With Larger Infarct Volumes and Poor Functional Outcome
Authors: Petersen Nils H , Wang Anson , Zhen-Li Binbin , Strander Sumita , Kodali Sreeja , Silverman Andrew , Sansing Lauren H , Lopez Gloria V , Schindler Joseph L , Matouk Charles , Hebert Ryan M , Sheth Kevin N , Ortega Gutierrez Santiago
Published: January 2019

Background:
After large-vessel occlusion (LVO), the fate of the ischemic penumbra, and ultimately final infarct volume, largely depends on compensatory collateral perfusion. Blood pressure (BP) management is critical for avoiding cerebral hypoperfusion and further secondary neurological injury. In this study, we examined the effect of BP reductions and sustained relative hypotension during endovascular therapy (EVT) on infarct volume and functional outcome.

Methods:
We retrospectively studied patients with LVO stroke who underwent mechanical thrombectomy. Intra-procedural MAP was monitored using a non-invasive BP cuff or an intra-arterial catheter. ΔMAP was calculated as the difference between admission MAP and lowest MAP during EVT. Sustained hypotension (aMAP) was measured as the area between admission MAP and continuous measurements of intra-procedural MAP until recanalization was achieved or procedure was completed. Final infarct volume was measured on MRI at 24hrs. Functional outcome was assessed using the modified Rankin Scale (mRS) at discharge and 90 days. Associations with outcome were analyzed using linear and ordinal regressions and adjusted for age, gender, admission NIHSS and TICI score.

Results:
262 patients (mean age 71±16, 58% F, mean NIHSS 17) were included in the analysis. Mean admission MAP was 106 mmHg. 86% of patients experienced ΔMAP reductions during EVT (mean 25±24 mmHg). ΔMAP was associated with larger final infarct volume (n=189, p=0.042). Median ΔMAP among patients with favorable outcomes (mRS 0-3) was 19 mmHg (IQR 3-39) compared to 33 mmHg (IQR 8-49) among patients with poor outcome (p=0.024). ΔMAP was independently associated with higher (worse) mRS scores at discharge (n=255, OR 1.013, 95% CI 1.004-1.023, p=0.008) and at 90 days (n=156, OR 1.014, 95% CI 1.001-1.023 p=0.034). The association between aMAP and outcome was highly significant at discharge (p=0.003) and 90 days (p=0.018).

Conclusions:
BP reduction prior to recanalization may lead to larger infarct volumes and worse functional outcomes for patients affected by LVO stroke. These results underline the importance of BP management during EVT, and highlight the need for further investigation of active BP management strategies to optimize clinical outcomes.