bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P438: A Reassessment of Hemoglobin and Hematoma Expansion in Intracerebral Hemorrhage
Authors: Stretz Christoph , Mac Grory Brian C , Mahta Ali , El JAMAL SLEIMAN , Sacchetti Daniel C , Burton Tina , Cutting Shawna M , Madsen Tracy , Wendell Linda , Thompson Bradford B , Furie Karen L , Reznik Michael
Published: March 2021

Background:
Prior studies identified an increased risk of hematoma expansion (HE) in patients with spontaneous intracerebral hemorrhage (ICH) and lower admission hemoglobin (Hgb) levels. We aimed to externally validate these findings in a separate cohort of ICH patients.

Methods:
We performed an observational cohort study on consecutive patients with ICH admitted to a Comprehensive Stroke Center over 2 years, using data from an institutional ICH registry. We excluded patients with secondary, non-spontaneous ICH etiologies, as well as patients who arrived >24 hours from symptom onset. Data on HE (defined as an increase of >33% or >6 mL) and 3-month outcomes were prospectively collected, while admission laboratory values were retrospectively abstracted. We compared admission Hgb, INR, and platelet count (Plt) between patients with and without HE, then determined associations between Hgb, HE, and unfavorable 3-month outcomes (modified Rankin Scale 4-6) after adjusting for established ICH predictors, any anticoagulant use, and laboratory markers of coagulopathy with multivariable logistic regression analysis.

Results:
Of 375 patients, mean age was 73.6 [SD 13.5], 50% (n=187) were male, 85% (n=317) were white, and 19% (n=71) had HE. Admission Hgb values were similar in patients with and without HE (mean [SD] 13.1 [1.8] g/dl vs. 13.1 [1.9] g/dl, p=0.98), as were INR values (median [IQR] 1.1 [1-1.3] vs. 1.1 [1.0-1.2], p=0.15), although patients with HE had modestly lower Plt (median [IQR] 181 [155-230] x 10
9
/l vs. 207 [170-253] x 10
9
/l, p=0.02). In our multivariable models, Hgb was not associated with HE (OR 0.97, 95% CI 0.83-1.12), but odds of unfavorable 3-month outcome increased with lower Hgb levels (OR 0.81 per 1 g/dL Hgb, 95% CI 0.68-0.96).

Conclusion:
Our study did not confirm prior associations between Hgb and HE, suggesting that if Hgb is implicated in HE, its effects are likely modest. However, Hgb may mediate outcomes in ICH patients via alternative mechanisms.
Abstract P441: Dental Caries a Risk Factor for Intracerebral Hemorrhage
Authors: La Valley Elizabeth A , Sen Souvik , Curtis James , Gottesman Rebecca F , Rosamond Wayne D , Moss Kevin , Beck James D
Published: March 2021

Introduction:
Streptococcus mutans is a known cause of dental caries that contains a collagen-binding protein, Cnm, and shows inhibition of platelet aggregation and matrix metalloproteinase-9 activation. This strain has been linked to aggravation of experimental intracerebral hemorrhage (ICH) and may be a risk factor for intracerebral hemorrhage.

Methods:
Presence of dental caries was assessed in subjects from the Dental Atherosclerosis in Communities Study (DARIC) without prior stroke or intracerebral hemorrhage. This cohort was followed for a period of incident intracerebral hemorrhage, subsequently verified by chart abstraction. Cox regression with time-dependent covariate was used to compute crude and adjusted hazards ratio stratified as <15 years and ≥15 years from the initial dental assessment.

Results:
Among 6506 subjects, dental caries were recorded in 1227 (19%) subjects. 47 (1%) had ICH over a period of 30 years. Those with dental caries versus those without dental caries had a greater proportion of younger (mean age 61.8±5.6 vs. 62.5±5.6, p<0.001), male (24% vs. 16%, p<0.001), African-American (53% vs 12%, p<0.001) and hypertensive (24% vs. 16%, p<0.001) patients. The association between dental caries and ICH in the first 15 years was not higher (crude HR 1.0, 95% CI 0.4-2.3) and remained so after adjusting for age, gender, race, and hypertension (adj. HR 1.1, 95% CI 0.5-2.9). The association between caries and ICH in the second 15 years was higher (crude HR 3.7, 95% CI 1.1-12.0) and strengthened after adjustment (adjusted OR 4.5, 95% CI 1.3-15.5). This is depicted in the Kaplan-Meier curve below.

Conclusion:
We report a significant association between dental caries and ICH. Future studies are needed to determine if early treatment of dental caries can reduce the risk of ICH.
Abstract P454: Do Not Resuscitate Orders in Intracerebral Hemorrhage Patients. Impact on Mortality
Authors: Chaudhry Mohammad Rauf A , Gill Hussan , Chaudhry Saqib , Singh Baljinder , Bandaru Harathi , Vellipuram Anantha Ramana , Piriyawat Paisith , Maud Alberto , Rodriguez Gustavo , Cruz-Flores Salvador
Published: March 2021

Introduction/background:
Do not resuscitate (DNR) orders have been associated with higher mortality in hospitalized patients which the question if they these patients are victims of the self-fulfilling prophecy; that the odds of their survival is made worse by withholding aggressive treatment. In addition, previous reports show that racial and ethnic minorities tend to opt for more aggressive and lifesaving procedures as compared to Whites.

Methods:
We analyzed the data from Nationwide Inpatient Sample (2005-2014) for all intracerebral hemorrhage (ICH) patients. DNR code status was identified using the International Classification of Disease, 9th Revision, Clinical Modification codes. Baseline characteristics, discharge outcomes (mortality, length of stay) were compared between the two groups. DNR code status was compared between different racial groups.

Results:
Of the 884379 patients with ICH, 81968 (9.26%%) had DNR order. ICH patients with DNR order had higher proportion of females (55.1% versus 49.1%, P <.0001) and were older (74.2 years versus 66 years, P <.0001) compared to ICH patients without DNR. The in-hospital mortality was also higher (53.4% versus 23.3%, p≤.0001) among patients with DNR both univariate and multivariate analysis (OR = 3.24 (3.07 -3.41), p<.0001) after adjusting for potential confounders. Whites have a higher rate (11.5% versus 8.08%) of DNR order as compared to other racial/ethnic groups

Conclusions:
While there may be other explanations at play, the higher mortality and shorter LOS suggest that early DNR orders do lead to the self-fulfilling prophecy. The lower proportion of DNR orders among minorities suggest a sociocultural aspect in accepting the concept of DNR. These two facts raise concerns about what the real vs perceived meaning of DNR orders.
Abstract P457: Cerebral Small Vessel Disease and Depression Severity Among Intracerebral Hemorrhage Survivors
Authors: Castello Juan Pablo , Pasi Marco , Kubiszewski Patryk P , Abramson Jessica R , Charidimou Andreas , Kourkoulis Christina , DiPucchio Zora , Schwab Kristin , Anderson Christopher D , Gurol Edip M , Greenberg Steven M , Rosand Jonathan , Viswanathan Anand , Biffi Alessandro
Published: March 2021

Introduction:
Intracerebral Hemorrhage (ICH) is an acute manifestation of underlying Cerebral Small Vessel Disease (CSVD), usually Cerebral Amyloid Angiopathy (CAA) or Hypertensive Arteriopathy (HTNA). CSVD-related imaging and histopathology findings were previously associated with increased depression incidence in the general population. CSVD evaluation via neuroimaging may therefore provide insight on depression risk among ICH survivors. We sought to determine whether hematoma location and CSVD MRI markers are associated with depression risk (before and after ICH) and resistance to treatment.

Methods:
We analyzed data from the single-center longitudinal ICH study conducted at Massachusetts General Hospital (MGH-ICH) since 1994 and currently ongoing. All participants underwent CT and MRI imaging, and were then followed longitudinally via a combination of semi-automated review of Electronic Medical Records (EMR) and phone-based research interviews. We extracted information for hematoma location and MRI neuroimaging markers of CSVD subtype and severity. We conducted univariable and multivariable analyses of depression prevalence before ICH, new-onset of depression after ICH, and resolution of depressive symptoms during follow-up.

Results:
We enrolled 612 ICH survivors, and followed them for a median of 46.3 months (Inter-Quartile Range: 35.5-58.7). Multiple CSVD-related markers were associated with depression outcomes of interest. Survivors of CAA-related lobar ICH were at highest risk for depression (before and after ICH), as well as treatment resistance (all p<0.05). CAA disease burden on MRI was also associated with depression risk and treatment resistance, whereas HTNA disease burden was only associated with risk of depression after ICH.

Conclusions:
CSVD severity on neuroimaging is associated with depression prevalence and treatment-resistance among ICH survivors. CAA-related ICH survivors are at higher risk for depression (both before and after ICH) than patients diagnosed with HTNA-related ICH. The potential role of CSVD evaluation in guiding care of ICH survivors with -or at high risk for- depression warrants additional investigative efforts
Abstract P468: Functional Outcome of Patients Undergoing Mechanical Thrombectomy Outside of the Dawn and Defuse Criteria
Authors: Gulati Asish , Owens Owen , Reynolds Patrick , Guzik Amy K , Datar Sudhir
Published: March 2021

Background:
The DAWN and DEFUSE trials (D&D) extended the mechanical thrombectomy (MT) window to 16-24 hours from last known normal (LKN) in patients with internal carotid artery (ICA) or proximal middle cerebral artery (M1) large vessel occlusions (LVO), with limits on core infarct and penumbra size. With advances in imaging and procedural techniques, many have extended these results to patients outside of the study criteria, yet there is limited analysis of outcomes in those receiving MT beyond these guidelines. This study evaluates the functional outcome of MT in acute stroke patients presenting within 24 hours of LKN outside of the D&D criteria vs those meeting study criteria at a single Comprehensive Stroke Center.

Methods:
An IRB approved study was performed in which consecutive anterior circulation ischemic stroke patients presenting to Wake Forest Baptist Health from 12/1/18-12/31/19 within 0-24 hours of LKN were retrospectively studied. Patients were grouped by eligibility for DAWN or DEFUSE (mRS ≦1, ICA/M1 occlusion, age <80 NIHSS ≧10 and core 0-30, or age <80 NIHSS ≧20 and core 31-51, or age ≧80 NIHSS ≧10 and core 0-20; or mRS ≦2, NIHSS ≧6, ICA/M1 occlusion with core <70, mismatch volume >15, and mismatch ratio >1.8) or neither. Good outcome was defined as mRS ≦3 within 3 months of discharge. If not available, discharge mRS was used. A multivariate logistic regression model analyzed the outcome controlling for confounding factors.

Results:
Of 130 patients, 57 (44%) fell outside D&D criteria. There was no significant difference between age, rate of IV tPA, admission NIHSS, baseline co-morbidities, or core infarct size between groups. Median mismatch volume was greater in the D&D group compared to patients in the non D&D group (97cc, IQR 67-146 vs 67cc, IQR 30-111; p=0.002). Good outcome was seen in 34 (47%) D&D patients vs 30 (53%) in the non D&D group; controlling for confounding factors affecting 3 month mRS (age, NIHSS, time to revascularization, atrial fibrillation, prior stroke), this was not statistically significant (p=0.25).

Conclusion:
The outcome of MT in patients with anterior circulation LVO is not different between those meeting and not meeting D&D criteria. MT should be considered in patients presenting within 24 hours outside study guidelines.
Abstract P494: Automatically Predicting Modified Treatment in Cerebral Ischemia Scores From Patient Digital Subtraction Angiography Using Deep Learning
Authors: Lall Ayush , Scalzo Fabien , Ullman Henrik , Liebeskind David S , Chien Aichi
Published: March 2021

Introduction:
We propose a new method for quantifying the effect of endovascular therapy for acute ischemic stroke. Currently, an mTICI (modified treatment in cerebral ischemia) score is assigned manually to document the success of endovascular revascularization therapy. The mTICI score based on Digital Subtraction Angiography (DSA), due to visual assignment, has limitations in settings where standardization is pertinent.

Methods:
We hypothesize that mTICI scores can be classified successfully by deep learning and thus be used as a standardized imaging biomarker. We aim to develop a regression framework using classification models that can assign continuous score to patients depending on the success of therapy, resulting in a score that is more granular than the mTICI. We use deep learning and 3D Convolutional Neural Networks (CNN) to classify frontal post-intervention DSA 2D time series into the mTICI score categories of 0, 1, 2a, 2b, and 3. An mTICI score of 0 represents no perfusion and a score of 3 represents full perfusion. The DSA series serve as features where the time dimension is the third dimension for the CNN. For our preliminary research we have condensed our groupings into binary {0,1} (0 refers to mTICI of 0, 1, 2a while 1 refers to mTICI of 2b, 3) of frontal DSA to see if Deep Learning models can categorize between the different mTICI classes.

Results:
We reduced our original data size of 181 patients to 93 patients in binary group 0 and 88 patients in group 1. Using a train/test split of 0.2, we have achieved a test classification accuracy of 73%, and F1-Score of 72.2% on the binary dataset. This is a good statistical indication that neural networks are able to classify between DSA.

Conclusion:
Neural network models show promise as a method of distinguishing between DSA to be used as an automatic standardized scoring method for acute ischemic stroke procedures. We aim to expand this research to frontal and lateral DSA images to get more vascular information to improve model accuracies. We propose using the softmax score of the classifier as a new score which will be a standardized measurement for endovascular therapy success.
Abstract P499: The Effect of Small Vessel Disease Burden on Core/Penumbra Mismatch and Outcomes in Extended Window Thrombectomy
Authors: Hooper Destiny , Nisar Tariq , Poursheykhi Meryim , Lin Andy , McCane C. David , Lee Jason , Ling Ken C , Chiu David , Vahidy Farhaan S , Gadhia Rajan
Published: March 2021

Objective:
Recent studies have shown the benefit of revascularization in select patients with extended window large vessel occlusion (EWLVO). We sought to assess the effect of cerebral small vessel disease (CSVD) burden on eligibility for intervention with mechanical thrombectomy (MT) and functional outcomes in patients with EWLVO.

Methods:
We conducted a retrospective single-center study of 135 patients with anterior circulation LVO who presented in the extended time window, 6 to 24 hours from LKW, between August 2018 and March 2020. All patients underwent perfusion imaging at initial presentation and those with target ischemic core to penumbra mismatch profiles, as defined by DAWN/DEFUSE3 criteria, were treated with MT. Included patients were evaluated for CSVD burden using T2-FLAIR MRI. The Fazekas scale (0-3) was used to quantify the amount of white matter T2 hyperintense lesions in both the periventricular (PVWM) and deep white matter (DWM). Patients’ functional outcomes were assessed at 90 days using the mRS. Multivariate ordinal logistic regression models were used and adjusted for age, gender, thrombus location and LKW to perfusion imaging time. Patient information was collected from the Houston Methodist Hospital Outcomes Based Prospective Endpoints in Stroke (HOPES) registry.

Results:
Of the 135 patients, 111 met imaging inclusion criteria for revascularization with MT for EWLVO. MT was deferred in 44 of these patients due to other clinical exclusions or patient refusal. Patients ineligible for MT were approximately 13 times more likely to have a higher PVWM Fazekas grade (OR =13.53, 95% CI. [2.94 - 62.39], p=0.001) and 17 times more likely to have a higher DWM Fazekas grade (OR =17.54, 95% CI. [4.20 - 73.17], p<0.001), when compared to patients who were eligible for MT. Patients who did not meet criteria for MT were nearly 7 times more likely to have poor functional outcomes at 90 days (OR =6.85, 95% CI. [2.09 - 22.44], p=0.001).

Conclusion:
Based on our analytical cohort of EWLVO patients, those with severe CSVD burden were more likely to be excluded from MT and had worse functional outcomes. Poor cerebrovascular reserve and diminished collateral flow leading to rapid infarct progression in patients with greater CSVD burden may be a potential explanation.
Abstract P503: Inter-Rater Reliability and Validity of Pre-Hospital Vision-Aphasia-Neglect Assessment for Triage of Patients With Suspected Large Vessel Occlusion: Analysis of Data From Three Comprehensive Stroke Centers in New Orleans (VAN NOLA Study)
Authors: Navalkele Digvijaya , Vahidy Farhaan S , Nisar Tariq , Emily Nichols , Salmeron William , Hargrove Paige , Salerian Justin A , Vidal Gabriel , Jennings Bethany , Alyana Samai , Franco Lia , Martin-Schild Sheryl
Published: March 2021

Background:
The Louisiana pre-hospital routing protocol for acute stroke patients is modeled after Mission Lifeline Stroke. The Vision-Aphasia-Neglect (VAN) assessment was adopted for large vessel occlusion (LVO) screening after education was provided to pre-hospital providers (EMS). We sought to establish the inter-rater reliability (IRR) of VAN between EMS and experienced stroke team members at comprehensive stroke centers (CSC) and assessed validity of EMS and CSC VAN.

Methods:
The EMS run reports were linked with stroke registries from three CSCs in New Orleans, Louisiana from 2/2019-7/2019. EMS-VAN was compared to that of CSCs in all patients who presented within 6 hours of last seen normal. Validity analyses were performed comparing EMS-VAN and CSC-VAN with radiologically confirmed (CTA) LVO as the gold standard. Kappa (k) and 95% confidence interval (CI) are reported as a measure of IRR. Likelihood of VAN non documentation by EMS and VAN discordance between EMS and CSC was determined as Odds Ratios (OR) and CI.

Results:
EMS documented VAN in 63.2% of stroke codes brought to CSCs. Advanced age (OR, CI: 1.02, 1.01 - 1.04) and pre-existing disability (OR, CI: 1.53, 1.32 - 1.76) increased the likelihood that VAN was not documented by EMS. Both EMS and CSC VAN assessments were documented for 166 patients Concordance was 66.9%; the k, CI was 0.35, 0.20 - 0.50. Discordance was more likely when EMS assessed a patient as positive than when assessed as negative, but no clinical predictor of discordance was identified. The accuracy of EMS-VAN was 60.2% for distinguishing LVO positive and negative patients; CSC-VAN was 65.5% accurate.

Discussion:
VAN assessment as performed by trained EMS providers had only fair correlation with experienced stroke team members. Further education is needed to increase the inter-rater reliability and accuracy of the VAN assessment in order to improve its utility in meeting the goal of routing patients with LVO to the thrombectomy centers.
Abstract P519: Higher Number of Thrombectomy Passes Significantly Increases Risk of Mass Effect, Poor Functional Outcome, and Mortality
Authors: Ringheanu Victor M , Preston Laurie , TEKLE WONDWOSSEN G , Sarraj Amrou , Hassan Ameer E
Published: March 2021

Background:
Endovascular treatment (EVT) is a widely proven method to treat patients diagnosed with intracranial large vessel occlusion (LVO). Through this method of treatment, it has been hypothesized that a lower number of thrombectomy passes is an indicator of higher rates of modified Thrombolysis in Cerebral Infarction 2b-3 (mTICI) and favorable outcomes defined as modified Rankin Scale 0-2 (mRS).

Methods:
Through the utilization of a prospectively collected endovascular database between 2012-2020, variables such as demographics, co-morbid conditions, intracerebral hemorrhage, mass effect, mortality rate, and good/poor outcomes in regard to mTICI score and mRS assessment at discharge were examined. The outcomes between patients receiving EVT who were treated with < 3 thrombectomy passes or ≥ 3 passes were compared.

Results:
Out of 454 patients treated with mechanical thrombectomy of qualifying intracranial internal carotid artery or middle cerebral artery occlusion, site of occlusion (internal carotid artery, M1 and M2), a total of 372 (81.9%) were treated with < 3 thrombectomy passes (average age 70.34 ± 13.75 years, 46.0% women), and 82 (18.1%) were treated with ≥ 3 thrombectomy passes (average age 70.30 ± 13.72 years, 48.8% women). Significantly higher rates of mass effect (p=0.043), mRS score 3-6 (p=0.029), and mortality (p=0.025) were noted in patients treated with ≥ 3 thrombectomy passes. Further analysis revealed that patients presenting 6-24 hours from symptom onset had significantly lessened chance of effective recanalization (TICI 2B-3; p=0.021).

Conclusion:
A higher number of thrombectomy passes, characterized as ≥ 3 passes in this study, was associated with significantly worsened patient outcome in regard to functional outcome, and mortality. Further research is required to determine whether the number of thrombectomy passes is an accurate indicator of treatment outcome and whether delayed presentation time increases risk of poor outcome.
Abstract P523: Mechanical Thrombectomy for in Hospital Stroke: A Single Center Study
Authors: Bae Jeonghoon , Lee Eung-joon , Yoon Byung-woo
Published: March 2021

Purpose:
There are many differences between in hospital ischemic stroke(IHS) and community onset ischemic stroke(COS), and there are several comparative studies. Although the importance of mechanical thrombectomy(MT) in the treatment of acute ischemic stroke is becoming increasingly important, there are not many studies on the effectiveness of MT in IHS. We aimed to compare the clinical features and outcomes between IHS and COS patients who received MT.

Methods:
We analyzed cases of mechanical thrombectomy performed at Seoul National University Hospital from January 2012 to June 2020. We selected patients with previous mRS(modified Rankin Scale) 0-1 and then divided them into two groups: IHS and COS, and compared successful recanalization, discharge mRS, 3month mRS, and 3month functional independence (mRS 0-2).

Results:
A total of 41 patients with IHS and 213 patients with COS were included. The baseline characteristics(age, sex, underlying disease, occlusion site) of the two groups were similar, but malignancy tended to be more common in IHS than COS(19.5% vs 7.5%). The median/mean LNT(last normal time)-to-puncture time was 341min/399min in IHS and 370min/461min in COS. The percentages of successful recanalization (92% vs 89%), discharge mRS (mean, 2.19 vs 2.97), 3 month mRS (mean, 2.05 vs 2.56), 3 month functional independence (61% vs 49%) were comparable between the two groups. In the multivariable analysis of the 3 month functional independence, initial NIHSS and successful recanalization were the most important predictors. In addition, a multivariable analysis was performed on successful recanalization, and LNT to puncture time was the most important predictor.

Conclusions:
The importance of MT is still high even in the in hospital stroke. In addition, IHS has more factors that can reduce the onset to puncture time compared to COS such as well designed on-call system and patient transfer system, well arrangement of nursing manpower. Therefore, more attention is needed for MT in IHS.
Abstract P530: Safety of Intravenous Cangrelor in Acute Ischemic Stroke
Authors: Salahuddin Hisham , Dawod Giana , Zaidi Syed F , Jumaa Mouhammad A
Published: March 2021

Introduction:
Mechanical Thrombectomy often requires immediate antiplatelet therapy when emergent stenting is needed. Intravenous cangrelor (CGR) is a potent reversible intravenous antiplatelet with a fast onset, a short half-life, and predictable pharmacokinetics. We sought to evaluate the safety and efficacy of this drug in MT patients.

Methods:
We performed a retrospective case control study at a CSC between 3/2016 and 4/2020. Patients who received intravenous CGR within 6 hours of admission (between 10/2019 - 4/2020) were compared with patients with anterior circulation tandem MCA occlusions who required stenting and oral antiplatelet therapy (between 3/16 - 10/19), prior to the availability of CGR at our facility.

Results:
We identified 35 patients, 12 of whom received IV CGR and 23 received acute oral antiplatelets for tandem occlusions. Average age of the cohort was 68.5 ± 13.4. Baseline characteristics including co-morbidities, rate of IV tPA, and time metrics were similar between the two groups.

In the CGR group, nine patients had tandem anterior circulation occlusions, two had basilar occlusions, and one patient had an MCA occlusion secondary to severe stenosis. Eleven of the twelve patients in the CGR group required acute stenting. Intravenous CGR was used for an average of 20.2 hours after which patients were transitioned to aspirin and ticagrelor (33%) or clopidogrel (67%).

Successful recanalization was achieved in all patients who received IV-CGR and in 95.7% of the tandem group. Final infarct volumes were comparable between the CGR and tandem cohorts (7.1 vs 15.5 ml; p=0.75). There were two cases of asymptomatic hemorrhage in both the CGR group and the tandem cohort, and one case of symptomatic ICH in the tandem cohort. Final functional outcomes (83.3% vs 60.9%; p=0.259) and mortality at three months (13% vs. 17%; p=1) were similar between the two groups.

Conclusions:
IV CGR is a promising medication for patients with acute ischemic stroke who require an immediate antiplatelet effect and is comparable in safety and efficacy to oral antiplatelets in the acute period of ischemic stroke. Larger prospective studies on the efficacy and safety of CGR in neurointervention are warranted.
Abstract P531: Cerebral Blood Flow Analysis Using Flow Wire Measurements and CFD Analysis
Authors: Chien Aichi , Dinh Huy , Szeder Viktor , Vinuela Fernando
Published: March 2021

Introduction:
Clinical reports show that cerebral blood flow conditions are indicative of cerebral vascular disease. While methods for characterizing cerebral vascular flow have been extensively reported in the past, comparative analyses between direct flow measurements (DM) and computational flow dynamic (CFD) analysis remain limited. We
hypothesize
that flow data can be reliably measured both directly and through CFD in normal vessels.

Methods:
A left heart replicator was used as a realistic cardiac pump which maintained systolic pressure at 120 mmHg and diastolic pressure at 80 mmHg. A stenotic model with 50% stenosis for the ICA was connected to the replicator. A ComboWire was used for DM and recorded flow pressure and velocity. CFD was used to study flow.

Results:
In areas at the proximal end of the stenosis, the pressure and flow velocity derived from DM and CFD were in good agreement. At the end of systole and diastole, DM pressure were 145.42 mmHg and 73.53 mmHg, respectively. CFD simulation for the same system obtained the pressure at the end of systole and diastole of 147.16 mmHg and 74.64 mmHg, respectively. The velocity data collected from DM was at 15.40 cm/s and 7.74 cm/s for systolic flow and mean flow velocity. CFD measured flow was 17.85 cm/s and 11.37 cm/s, respectively. In areas at the distal end of the stenosis, pressure data showed good agreement between DM and CFD analysis. The DM were 138 and 70.81 mmHg at the end of systole and diastole, respectively; CFD simulation yielded 145.95 and 74.51 mmHg, respectively. Variations in the velocity data were observed at this location (Fig, pink arrows).

Conclusion:
DM of pressure showed good agreement with CFD simulation in all areas of the vessel. DM of velocity using the flow wire were highly affected by location of the measurement. CFD analysis can provide more consistent flow data for flow information collection along the vasculature.
Abstract P54: Endothelial Cells and Pericytes Collection Using Laser Capture Microdissection in Spontaneously Hypertensive Stroke Prone Rats
Authors: Moore Jordan T , Ewees Mohamed , Zweier Jay L , Gallego-perez Daniel , Hannawi Yousef
Published: March 2021

Introduction:
Neurovascular unit (NVU) dysfunction plays a key role in cerebral small vessel disease (cSVD) pathogenesis. Spontaneously Hypertensive Rats - Stroke Prone (SHRSP) is a relevant model for cSVD where prominent impairment of the NVU has been identified. Previous studies of SHRSP and Wistar-Kyoto control rats (WKY) were performed at tissue level failing to capture the NVU cellular components where the early pathological events occur. Therefore, we developed a novel method for selective endothelial cell (EC) and pericytes capture using Laser Capture Microdissection (LCM).

Methods:
10 SHRSP and 10 WKY male rats were studied at 16 weeks of age. Prior to brain collection, lectin was administered using intracardiac injection for vessel identification. Rapid frozen immunohistochemistry (IHC) staining protocol was optimized by selecting a panel of antibodies that showed first specific staining pattern for EC and pericytes in a routine overnight IHC protocol. LCM collection was subsequently optimized to achieve collection of 1.5-2 million μm
2
of tissue in 30 minutes to ensure RNA stability. RNA was isolated from the LCM samples using PicoPure RNA isolation kit (ThermoFisher Scientific, Inc.) and RNA quantity was measured using NanoDrop technology. qRT-PCR we performed to measure the expression of smooth muscle actin (ACTA2) (pericytes), von Willebrand Factor (vWF) (EC).

Results:
Following optimization of overnight and rapid staining protocols, platelet-derived growth factor (PDGRF) beta (ABCAM, Inc.) (1:10 concentration) showed best results for perdicytes identification while RCA lectin (Vector labs, Inc.) (1:20 concentration) showed best results for EC. Co-staining with CD31 antibody was performed to confirm the specificity of RCA lectin binding to EC. RNA isolation protocol achieved good RNA collection quantity (4-8) ng/μl. qRT-PCR showed higher expression of ACTA2 (9.5-fold increase) in PDGRF+ elements, 2.8-fold increase of vWF (lectin+ elements) compared to (PDGRF-, lectin -) elements confirming the enrichment of these elements by EC and pericytes.

Conclusion:
LCM is feasible in achieving good quality collection of EC and pericyte in SHRSP and WKY allowing for investigation of the proteomic and transcriptomic changes that result in cSVD.
Abstract P547: Cardiac Arrest in Patients Who Present With Subarachnoid Hemorrhage is Associated With Worse Outcomes
Authors: Kaur Gurkamal , Dominguez Jose , Semaan Rosa , Fuentes Leanne , Ogulnick Jonathan , Al-Mufti Fawaz
Published: March 2021

Introduction:
Subarachnoid hemorrhage (SAH) can be a devastating neurologic condition that leads to cardiac arrest (CA), and ultimately poor clinical outcomes. Existing literature on this subject reveal a dismal prognosis when analyzing relatively small sample sizes. We aimed to further elucidate the incidence, mortality rates, and outcomes of CA patients with SAH using large-scale population data.

Methods:
A retrospective cohort study was conducted using the National Inpatient Sample (NIS) database. Patients included in the study met criteria using International Classification of Diseases (ICD) codes 9th and 10th edition of: non-traumatic SAH, CA cause unspecified, and CA due to other underlying conditions between 2008 and 2014. For all regression analyses, a p-value of <0.05 was considered statistically significant.

Results:
We identified 170,869 patients hospitalized for non-traumatic SAH. Within these, there was a 3.17% incidence of CA. The mortality rate in CA with SAH was 82% (vs non-CA 18.4%, p< 0.001). Of the survivors of CA with SAH, 15.7% were discharged to special facilities and services (vs non-CA 37.6%, p<0.0001). The remaining 2.3% were discharged home (vs non-CA 44.0%, p<.0001). Higher NIS SAH severity score (NIS-SSS) was a predictor of CA in SAH patients (p <.0001). Patients treated with aneurysm clipping and coiling had lower odds ratio of CA (p <.0001).

Conclusion:
The study confirms the poor prognosis of patients with CA and SAH using large-scale population data. Patients that underwent aneurysm treatment show lower association with CA. Findings presented here provide useful data for clinical decision making and guiding goals of care discussion with family members. Further studies may identify interventions and protocols for treatment of these severely ill patients.
Abstract P553: Outcomes of Acute Endovascular Cervical Carotid Revascularization in Anterior Circulation Tandem Occlusions During Mechanical Thrombectomy
Authors: Garg Aayushi , Quispe Orozco Darko , Limaye Kaustubh , Zevallos Cynthia , Mendez Ruiz Alan , Dajles Andres , Farooqui Mudassir , Zaidat Osama O , Ortega Santiago
Published: March 2021

Introduction:
Acute ischemic strokes with intracranial large vessel occlusion (LVO) and cervical internal carotid artery (ICA) tandem occlusion have traditionally been known to have a poor prognosis. Recent evidence suggests favorable functional outcomes in patients undergoing emergent carotid artery stenting (CAS) following intracranial mechanical thrombectomy (MT). We aimed to evaluate the outcomes of endovascular carotid revascularization (CR) performed acutely after emergent intracranial MT.

Methods:
We used the Nationwide Readmissions Database 2016-2017 to identify patients admitted with anterior circulation LVO treated with MT. Patients who underwent CAS or carotid artery angioplasty (CAA) during the same hospitalization were also identified. Propensity scores were used to match patients with and without CR in a 1:1 ratio by demographics, comorbidities, use of intravenous thrombolysis and hospital-level characteristics. Logistic regression and survival analyses were used to compare the outcomes.

Results:
We identified 15,137 hospitalizations meeting the study inclusion criteria (mean±SD age:70.1±14.6, female 51.1%). Of these, 1,214 (8.0%) underwent CAS or CAA during the same hospitalization. After propensity score matching, we obtained 1,063 well matched pairs of patients with and without CR. In the matched cohort, patients who underwent CR had higher odds of hemorrhagic transformation (OR 1.34, 95% CI 1.07-1.69, p 0.011) and higher total hospital cost (mean difference $6,232, 95% CI 3,606-8,858, p 0.001) but other clinical outcomes including gastrostomy tube placement, decompressive craniectomy, prolonged mechanical ventilation, in-hospital mortality, length of stay, and discharge disposition did not differ between the two groups. Patients with CR were less likely to have an unplanned 30-day readmission (HR 0.67, 95% CI 0.51-0.87, p 0.004). Further, they had more readmissions due to ICH (HR 1.06, 95% CI 0.41-2.71) and less readmissions due to ischemic events (HR 0.39, 95% CI 0.14-1.08), although the difference was not statistically significant.

Conclusion:
If indicated, early endovascular CR for anterior circulation tandem occlusions seems to be safe with clinical outcomes comparable to patients undergoing MT alone.
Abstract P554: Effect of Antithrombotic Medications on MMA Embolization for Chronic Sub Dural Hematoma a Case Control Study
Authors: Mir Osman , Riina Howard , Tanweer Omar , Kan Peter , Burkhardt Jan-Karl
Published: March 2021

Background:
Chronic subdural hematoma (CSDH) is a serious problem with an incidence of 20.6 per 100000 in North America and is predicted to grow with aging population and Antithrombotic use. MMA embolization is a therapy for treatment of CSDH, which in retrospective studies has been shown to be effective. It is unclear when and if the antithrombotic medications could be resumed in the setting of CSDH.

Hypothesis:
Among patients with CSDH who undergo MMA embolization outcomes are no different in patients who resume the antithrombotic (AT) medications

Methods:
We did a retrospective review of all cases of MMA embolization done over last 2.5 years in 2 tertiary care centers. Comparison of cases (antithrombotic resumption) vs controls in which antithrombotic medications were stopped. A successful outcome was defined as reduction of at least 50% volume in CSDH. Univariate analysis regarding all outcome measures for baseline variables using Fisher exact test or t-test. Multivariate logistic regression with favorable and unfavorable outcomes as dependent variables controlling for age and surgical evacuation of the hematoma.

Results:
There were a total of 57 MMA embolization cases, 33 of them had no AT started after surgery and 23 of them had AT resumption at a mean of 2.4 days. Almost equal number of patients had AC (12 pt’s) and AP (11 pt’s) resumed. About 40% of patients had surgical evacuation done prior to MMA embolization and there was significant reduction in volume of CSDH on follow up imaging as shown in fig. The significant difference between the patients who had AT resumption vs others, was that these patients had more often CAD (71% vs 21% p= 0.001) and Afib (58% vs 18% p=0.002) necessitating the renewal of AT. There was no significant difference in hematoma reduction or volume even after adjusting for surgical evacuation (OR 1.0039 95% CI 0 .60- 1.67).

Conclusions:
There is no significant difference in CSDH volume reduction in patients who have AT resumption after MMA embolization.
Abstract P557: Hypoperfusion Intensity Ratio and Cerebral Blood Volume Index as Predictors of Outcome for Recanalized Middle Cerebral Artery Occlusions
Authors: Parish Jonathan M , Strong Dale , Prasad Tanushree , Rhoten Jeremy B , Clemente Jonathan D , Defilipp Gary , Bernard Joe D , Hines Andrew , Stetler William R , Karamchandani Rahul R , Asimos Andrew W
Published: March 2021

Introduction:
Preliminary data suggest the Hypoperfusion Intensity Ratio (HIR) and the Cerebral Blood Volume Index (CBVI) derived from Computerized Tomography Perfusion (CTP) imaging predict the rate of collateral flow, speed of infarct growth, and clinical outcome. We hypothesized that functional outcomes at hospital discharge would be significantly better for middle cerebral artery (MCA) occlusion patients achieving Thrombolysis in Cerebral Infarction (TICI) 2b or greater recanalization with presenting hospital CTPs consistent with “good” (HIR <0.5 and CBVI >0.7) versus “poor” (HIR ≥0.5 and CBVI ≤0.7) indices.

Methods:
We conducted a retrospective cohort study. A neuroradiologist confirmed the MCA occlusion based on the initial Computerized Tomography Angiogram (CTA). All TICI scores were confirmed by neurointerventionalists blinded to patient outcomes. We defined independent outcome as mRS ≤2, and favorable outcome as an mRS ≤3. We additionally stratified patients as initially presenting to thrombectomy versus non-thrombectomy centers.

Results:
We identified a total of 162 patients over a 3 ½ year period with an MCA occlusion achieving TICI 2b recanalization or greater, of whom 67 had good indices and 48 had poor indices. For patients with good compared to poor indices, there was a trend for achieving independent outcome (55% vs 37%, p=0.061) that reached significance for favorable outcome (69% vs 50%, p=0.043). Limiting the analysis to only patients presenting to non-thrombectomy centers (n=67), these findings were consistent, with a trend for achieving independent outcome for good versus poor collaterals (48% vs 30% p=0.173), which was again significant for a favorable outcome (66% vs 39%, p=0.036). Across all patients, HIR <0.5 (n=86) or CBVI >0.7 (n=95) were not independently associated with independent outcomes, but for patients presenting to non-thrombectomy centers, an HIR <0.5 alone (n=51) was significantly associated with favorable outcome.

Conclusion:
For MCA occlusion patients achieving TICI 2b recanalization, the combination of good HIR and CBVI is significantly associated with a favorable functional outcome. For patients presenting to non-thrombectomy centers, HIR alone may be sufficient to predict favorable outcome.
Abstract P569: Adherence to Preventive Therapy and Early Recurrent Cerebral Ischemia in Patients With Symptomatic Intracranial Atherosclerotic Disease: Analysis of the Myriad Study
Authors: Del Brutto Victor J , Prabhakaran Shyam , Campo-Bustillo Iszet , cotsonis george , Nizam Azhar , Romano Jose G , Liebeskind David S
Published: March 2021

Background:
Intracranial atherosclerotic disease (IAD) is a common cause of stroke with high rate of early recurrence despite maximal medical therapy. We sought to determine adherence to secondary preventive therapy and its association with early recurrent ischemia in patients with symptomatic IAD.

Methods:
The Mechanisms of Early Recurrence in Intracranial Atherosclerotic Disease (MyRIAD) study included patients with recent stroke or transient ischemic attack due to moderate-to-severe IAD. Although MyRIAD did not mandate treatment, patients were recommended to follow standard secondary preventive management including antiplatelet therapy, lipid-lowering medications, antihypertensives for blood pressure (BP) goal <140/90 mmHg, smoking cessation and regular physical activity. Patients underwent 6-8 weeks assessment for medication adherence, smoking status, and physical activity compliance. Adherence to preventive therapy was correlated with new infarcts in the affected vessel territory on brain MRI.

Results:
Eighty-nine out of 105 patients enrolled in MyRIAD completed 6-8 weeks clinical and brain MRI assessment (mean age 64 +/- 12 years; 57% men). During follow up, 99% were on antiplatelets, 89% on lipid-lowering medications, 81% on antihypertensives, 48% had systolic BP at goal, 79% had diastolic BP at goal, 93% were not active smokers, and 47% were compliant with physical activity. Overall, new infarcts on brain MRI were found in 25% patients. Although no significant differences were found, patients with uncontrolled BP, active smokers and those not compliant with physical activity had a higher frequency of new infarcts in the affected vessel territory (Table).

Conclusions:
Medication adherence was high after IAD-related stroke. However, a noteworthy fraction of patients had uncontrolled BP, continue to smoke, and were not compliant with physical activity. The latter may represent important therapeutic targets to prevent early recurrent ischemia.
Abstract P570: Arterial Stenosis in Posterior Reversible Encephalopathy Syndrome
Authors: Scarsella Monica , Purohit Meghan , Toljan Karlo , Uchino Ken , Wisco Dolora R
Published: March 2021

Objectives:
Posterior Reversible Encephalopathy Syndrome (PRES) is characterized as reversible vasogenic cerebral edema in a posterior-dominant distribution. Some patients with PRES have diffusion-weighted imaging (DWI) changes on MRI, as well as transient arterial stenosis. We examined the association between arterial stenosis and presence of hemorrhage and MRI-DWI changes in PRES.

Methods:
We retrospectively identified patients with PRES in electronic health records at a single health system from January 2008 to December 2018. We included patients age 18 years or older with clinical and radiographic evidence of PRES and arterial imaging (CT or MR angiography or digital subtraction angiogram). Any arterial stenosis was noted, with reversibility determined by repeat imaging. Patient characteristics, disease presentation, hospital lengths of stay and discharge dispositions, as well as imaging findings were collected and statistical analysis was used.

Results:
Of 281 patients with PRES, 169 had arterial imaging. Thirty-two (18.9%) had arterial stenosis and 60% had resolved arterial stenosis on follow-up imaging. Patients with arterial stenosis were younger compared to those without (47 v 55 years, p =0.03), however they did not differ in symptoms of presentation or comorbid conditions. Of note, arterial stenosis was associated with intracerebral hemorrhage[34% with stenosis and 18% without stenosis, p=0.05). However, the presence of MRI DWI lesions did not correlate with arterial stenosis [14/32 (44%) with stenosis, 49/137 (36%) without stenosis, p=0.42]. Among 97 patients with follow-up MRI, the presence of arterial stenosis was not associated with greater FLAIR reversibility. Furthermore, hospital length of stay or discharge disposition was not associated with arterial stenosis in PRES.

Conclusions:
Arterial stenoses are found in 19% of PRES patients, and most are reversed on follow-up imaging. They are also associated with hemorrhagic PRES, but not with MRI-DWI lesions or degree of FLAIR reversibility.
Abstract P580: Prevalence and Natural History of Large Vessel Occlusion in Childhood Acute Ischemic Stroke
Authors: Bonnet Wilmot , Dowling Michael M , Plumb Patricia
Published: March 2021

Introduction:
Many studies have reported endovascular revascularization therapy (ERT) in children with Childhood Acute Ischemic Stroke (CAIS). With the recent expansion of thrombectomy windows via DAWN/DEFUSE3, more pediatric stroke patients are likely to be potential candidates for intervention. The prevalence of Large Vessel Occlusion (LVO) in the adult population is 25-33% however the prevalence and natural history of LVO in the pediatric population have not yet been described.

Methods:
This is an IRB approved single center observational study by retrospective chart review of all CAIS who presented acutely to our center from 2004 to 2019. Components of Chart review: Vessel involvement, Mortality/dependency, PSOM and MRS, Etiology, Intervention/Time window of presentation/eligibility for DAWN/DEFUSE, treatment (thrombolysis, ERT), and outcome.

Results:
48/218 (22%) of patients with CAIS had an acute presentation consistent with LVO (95% CI 16.7-28.1%). Of the patients with LVO, 23 (46%) were due to large vessel arteriopathy, 15(30%) were cardioembolic, 4 had a hypercoagulable state and 7 were cryptogenic. Ages ranged from day of life 1 to 18 years. 6 (12%) patients died within 2 years of LVO (3 of stroke, 3 from other causes). 5 of the 218 patients reviewed received thrombolysis, with 4/48 LVO patients received thrombolytics. 5/49 LVO patients underwent ERT (4 with at least TICI 2A reperfusion). Average age of LVO patients 14.2 years. PSOM/ comparative outcome data collection is ongoing.

Conclusion:
Prevalence of LVO has not yet been described in the pediatric population. At our center, 22.4% of CAIS patients had imaging consistent with large vessel occlusion at presentation. This rate is close to that of the adult population (25-33%). Many children have tolerated ERT with good outcomes. Time windows may be less applicable in children given presence of better collaterals and good cardiovascular function. More data is needed regarding the use of advanced imaging modalities for patient stratification in acute neurovascular intervention. Different inclusion criteria may be necessary given improved outcomes among children without intervention.