bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WMP119: An MRI Surveillance Protocol for Pediatric Sickle Cell Anemia
Authors: Taylor J. Michael , Quinn Charles , Vadivelu Sudhakar , Luchtman-Jones Lori
Published: January 2019

Background:
Sickle cell anemia (SCA) is a leading cause of stroke and neurologic disability in children. In the 20 years since the publication of the STOP trial, chronic transfusion therapy and hydroxyurea have shown efficacy as disease-modifying therapies, especially by improvement of transcranial Doppler (TCD) velocities and reduction in the incidence of overt stroke. Despite the publication of the SIT Trial 2014, screening for silent stroke is not universally implemented. Here we report our center’s experience with screening neuroimaging in young children with SCA.

Methods:
This is a single center, retrospective case series of patients with SCA (HbSS and HbSb
0
-thalassemia) managed in a comprehensive sickle cell center. Patients undergo TCD screening per STOP guidelines beginning at age 24 months. Screening MRI/MRA brain are also recommended at 5, 10, 15, and 20 years of age. Imaging data for the children 5-9 years of age are reported.

Results:
There were 39 subjects within the defined age range, 37 of whom were receiving disease-modifying therapy (hydroxyurea, N=34; chronic transfusions, N=3). Mean age of initiation of disease-modifying therapy was 4.2 years. MRI/MRA of the brain was obtained according to our screening protocol in only 21 (54%), indicating incomplete screening and opportunity for quality improvement. Indeed, most MRIs were obtained for a clinical concern and/or a non-normal TCD (85%). Abnormal parenchyma and/or vasculature was identified in 11 of 21 (52%) imaged subjects. In patients imaged before starting disease modifying therapy, 2 of 9 had stroke (22%). In patients imaged after starting disease modifying therapy, 7 of 12 had stroke and or arteriopathy (58%).

Conclusions:
Over half (52%) of young children (5-9 years) with SCA in our center who had an MRI/MRA had abnormal findings, indicating a high yield for potentially actionable results. This may be an under-estimate of CNS disease burden, because 46% of the population did not undergo screening MRI/MRA. Proactive screening for cerebrovascular complications in SCA may allow early intervention that further improves patient outcomes.
Abstract WMP120: The Role of Age, Lesion Location and Volume in Predicting Long-Term Neurological Outcomes in Pediatric Ischemic Stroke
Authors: Singh Jaspal , Krishnan Pradeep , Slim Mahmoud , Pontigon Ann-Marie , Paterson Julie , Moharir Mahendranath , MacGregor Daune , Dlamini Nomazulu , Westmacott Robyn , deVeber Gabrielle
Published: January 2019

Introduction:
The balance of plasticity versus vulnerability to acute ischemic injury in the immature brain across development remains controversial. We aimed to investigate the relationship between age at stroke and lesion location and volume with long-term outcomes following arterial ischaemic stroke (AIS).

Hypothesis:
Age at stroke onset interacts with lesion location and volume to predict long-term neurological outcomes.

Methods:
In a single-centre prospective study, children aged term birth to 18 years with acute symptomatic AIS from 1992 to 2016 who underwent neuroimaging (CT/MRI) within 14 days of stroke onset were studied. Long term outcomes were assessed with the Pediatric Stroke Outcome Measure (PSOM). Outcomes were defined as normal (score 0-0.5 on 1-5 PSOM subscales), otherwise abnormal. AIS lesions were classified based on major (anterior, middle, posterior, other) cerebral arteries and branch sub-territories (e.g. MCA-lateral lenticulostriate). For each vascular territory, the proportion of infarcted brain was estimated as ‘small’ (≤50% territory) or ‘large’ (>50% territory). Factors predictive of long term outcomes were evaluated using logistic regression models.

Results:
Among 285 children, median age at stroke onset was 22 months (IQR: 0.03-101), 41% were females. PSOM scoring at median 9 years (IQR: 4-15) post-stroke was normal in 61%. Abnormal outcome was associated with age 1-4 years (OR=2.2, 95% CI: 1.02-4.9), ‘large’ proportion infarcts involving cortex within any major artery territory (OR=6.1, 95% CI: 2.6-14.4), and subcortical infarcts: OR= 2.7 (95% CI: 1.4-5.4) for small proportion infarcts; OR=8.3 (95% CI: 4.2-16.6) for large proportion infarcts in either medial or lateral lenticulostriate arteries; OR=15.8 (95% CI: 5-50.3) for large volume lesions in both lenticulostriate territories. In multivariate logistic regression, age, cortical and subcortical infarcts predicted long-term neurologic outcomes.

Conclusions:
In addition to age at stroke onset, infarct location including volume plays a key role in predicting long-term neurological outcomes in children. While the relationship between age and neurological outcomes seems to be bimodal, a linear effect of lesion volume on stroke outcomes is evident.
Abstract WMP15: Flat Panel Detector CT Assessment in Stroke to Reduce Times to Intra-Arterial Treatment (FAST-IA): A Study of Multi-Phase CTA in the Angiography Suite to Bypass Conventional Imaging
Authors: Bouslama Mehdi , Haussen Diogo , Grossberg Jonathan , Barreira Clara , J. van der Bom Imramsjah Martijn , van Nijnatten Fred , Grünhagen Thijs , Moyer Larry , Frankel Michael , Nogueira Raul
Published: January 2019

Background:
Bypassing the emergency department (ED) and the CT suite by directly transporting to the neuroangiography suite for imaging assessment and treatment may shorten reperfusion times while maintaining proper patient selection.

Methods:
Single-center prospective study of consecutive patients with anterior circulation LVO strokes transferred to our facility for consideration of endovascular therapy (ET) from 5/2016 to 12/2017. Those with basilar strokes and/or presenting to the ED were excluded. Patients were categorized into two groups: (1)
F
lat-Panel Detector CT
A
ssessment in
S
troke to Reduce
T
imes to
I
ntra-
A
rterial Treatment (FAST-IA) group, with patients transferred directly to the suite for Flat-Panel Detector multiphase CT angiography (FD-mCTA); and (2) Patients undergoing standard protocol including CT+/-CTA/CTP. The groups were matched for age, baseline NIHSS and pre-treatment glucose. Baseline characteristics, time metrics and outcomes were compared.

Results:
Out of 419 patients that underwent ET over the study period, 210 patients fit inclusion criteria, with 54 (25.7%) in the FAST-IA group. After matching, 49 FAST-IA/Control pairs were generated and analyzed. Baseline characteristics were well-balanced. FAST-IA patients had significantly shorter median door-to-puncture (33[26.5-47] vs 55[44.5-66] minutes, p<0.001), door-to-reperfusion (85[57.5-115.5]vs110[80-153],p=0.005) and picture-to-puncture (18[13.5-22.5]vs 42[32-47.5]minutes, p<0.001)times. There were no differences in rates of successful reperfusion (mTICI 2b-3, 95.9% vs 100%, p=0.5), parenchymal hematomas type-2 (4.1% vs 2%, p=1.00), good outcome (90-day mRS-0-2, 44.9% vs 40.8%, p=0.68) and 90-day mortality (14.3% vs 22.4%,p=0.30).

Conclusions:
Directly transferring patients to angiography and using FD-mCTA to determine eligibility for ET is safe and results in significant reduction in treatment times. Future larger studies are warranted.
Abstract WMP21: Underestimation of Ischemic Core on Perfusion CT in Patients With Acute Large Vessel Occlusion: Results From the BEST Prospective Cohort Study
Authors: Siegler James E , Messé Steven R , Sucharew Heidi , Mehta Tapan , Arora Niraj , Starosciak Amy K , De Los Rios La Rosa Felipe , Barnhill Natasha R , Mistry Akshitkumar , Patel Kishan , Assad Salman , Tarboosh Amjad , Dakay Katarina , Wagner Jeff , Bennett Alicia , Jagadeesan Bharathi , Streib Christopher , Weber Stewart A , Chitale Rohan , Volpi John J , Mayer Stephan , Yaghi Shadi , Jayaraman Mahesh , Khatri Pooja , Mistry Eva A
Published: January 2019

Background:
The 2018 AHA guidelines recommend patients with acute large vessel occlusion (LVO) be considered for thrombectomy in the 6 to 24-hour window based on perfusion imaging. Within 6 hours, CT perfusion (CTP) core estimates may underestimate volume of irreversible infarction visualized on the unenhanced CT; however this has not been well characterized in later time windows.

Methods:
Using a multi-center prospective cohort of consecutive patients who underwent thrombectomy for LVO 0-24 hours after last known normal, we correlated baseline CTP core infarct volume (rCBF<30%) and unenhanced CT ASPECTS score, as recorded by local investigators. We compared CTP findings between patients with an unfavorable ASPECTS (<6) against those with a favorable ASPECTS (≥6), and assessed findings over time.

Results:
Of 443 enrolled patients, 165 who underwent CTP were included (median age 69y [IQR 57-80], 83 [50%] female, with a median ASPECTS of 8 [IQR 6-9] and core of 9cc [IQR 0-28]). ASPECTS and core volume moderately correlated (r=-0.35, p<0.01). An absent core (0cc) was observed in 52/165 (32%) patients, among whom the median ASPECTS score was 8 (IQR 8-10). Of the 28 patients with unfavorable ASPECTS, 3 had a normal core volume (11%, 95%CI 2 - 28%). As time to recanalization progressed, the ASPECTS score worsened (common OR 1.05, 95%CI 1.01-1.09, p=0.02) whereas the core (p=0.66) and penumbra volumes (p=0.70) remained unchanged. After adjustment for age and baseline NIHSS, the decline in ASPECTS remained significant (cOR 1.05, 95%CI 1.01-1.10, p=0.01), while the core (p=0.69) and penumbra volumes (p=0.74) remained unchanged.

Conclusion:
In this multi-center prospective cohort of patients who underwent thrombectomy, one-third of patients had normal core infarct volumes despite half of these patients showing irreversible infarction on the unenhanced CT (ASPECTS ≤8). As time progresses, the unenhanced CT demonstrates evolution of irreversible infarction, whereas the perfusion core appears static. This finding emphasizes the need to carefully assess both unenhanced CT and CTP when considering thrombectomy eligibility in the late time window, as was required by both DAWN and DEFUSE 3 selection criteria.
Abstract WMP22: High Baseline Blood Pressure is Associated With Better Collaterals but Not Better Clinical Outcome in Acute Ischemic Stroke
Authors: Hong Lan , Cheng Xin , Lin Longting , Bivard Andrew , Dong Qiang , Parsons Mark
Published: January 2019

Background and Purposes:
The relationship between post-stroke blood pressure (BP), collaterals and functional outcome in acute ischemic stroke patients is still controversial. The purpose of this study is to explore the influence of post-stroke baseline BP on collateral flow and functional outcome in acute ischemic patients with large vessel occlusion/stenosis.

Methods:
Patients identified with large vessel occlusion/stenosis with baseline multimodal computed tomography, clinical data, follow-up imaging, and clinical outcomes recruited from 2011 to 2017 in the International Stroke Perfusion Imaging Registry (INSPIRE) were included in this study. A modified Rankin Score of 0-1 at 90 days after stroke was defined as an excellent functional outcome. Collateral flow was quantified by the volume of tissue with severely delayed contrast transit (delay time>6 seconds) within the delay time>3 seconds perfusion lesion. The association between baseline BP, collateral flow and 3-month outcome were retrospectively investigated using multivariate models.

Results:
There were 306 patients included in this study. With every increase of 10mmHg in baseline systolic BP, the odds of achieving an excellent functional outcome decreased by 12% in multivariate analysis (OR 0.88, 95% CI 0.76-0.995, P=0.048). Conversely, every increment of 10mmHg in baseline BP (regardless of systolic, diastolic and mean BP) was associated with better collateral flow, and was also associated with reduced final infarct volumes (FIV). In subgroup analysis of patients with major reperfusion, higher BP was associated with decreased FIV. For patients without reperfusion, higher BP was associated with increased FIV and decreased odds of a favorable clinical outcome.

Conclusions:
Higher baseline BP in acute ischemic stroke patients with large vessel occlusion/stenosis was associated with better collateral flow. However, for patients without reperfusion, higher baseline BP was associated with increased infarct growth, and led to an unfavorable clinical outcome. To our knowledge, this is the first time that the association between BP and collaterals has been quantified by perfusion imaging, and this is also the first study to demonstrate that higher BP is correlated with infarct growth.
Abstract WMP25: In Comatose Survivors of Cardiac Arrest, DWI-based Measurements of Hypoxic-Ischemic Thalamic Injury are Associated With Neurologic Prognosis
Authors: Copen William A , Greer David M , Wu Ona
Published: January 2019

Background:
Hypoxic-ischemic brain injury caused by cardiac arrest often leaves survivors initially comatose, and with highly variable long-term neurologic outcomes that may be difficult to predict. As the thalamus plays an important role in arousal, we hypothesized that using diffusion-weighted MRI (DWI) to detect acute thalamic ischemic lesions may be helpful in predicting these patients’ long-term neurologic impairment. Because long-term outcome may be influenced by self-fulfilling prophecy bias (SFPB) due to early withdrawal of life sustaining treatment, we also investigated the association of thalamic lesion burden with arousal recovery, which is less influenced by SFPB.

Methods:
Images from 79 comatose post-arrest patients were analyzed retrospectively. A neuroradiologist measured lesion burdens as fractions of total thalamic volumes. Group related differences in thalamic lesion burden between patients with good vs. poor outcomes (6-month modified Rankin scale ≤4 or >4, respectively), and between patients who did vs. did not exhibit early arousal recovery (AR+, AR-), as manifested by eye opening in response to a noxious stimulus during the first 7-days post-arrest, were assessed by 2-tailed Wilcoxon exact test.

Results:
AR and good outcomes occurred in 38% (30/79) and 18% (14/79) of patients, respectively. Lesion burdens were significantly greater in AR- vs. AR+ patients (mean±SD 37±23% vs. 20±19%, p = 0.001), and greater in patients with poor vs. good outcomes (34±23% vs 11±13%, p < 0.001). All patients with lesion burdens over 56% were AR-, and all patients with lesion burdens over 39% had poor outcomes.

Discussion:
In comatose cardiac arrest survivors, the extent of early hypoxic-ischemic damage to the thalamus, as measured on early DWI, is related to long-term neurologic outcome. We also found that more severe thalamic burden was associated with failure to recover arousal in the first week. Our results are consistent with the thalamus’ key role in consciousness as a modulator of peripheral sensory input to the cortex. As comatose cardiac arrest patients’ outcomes are often difficult to predict based on clinical factors alone, the extent of thalamic injury on DWI may be helpful in treatment planning and goals-of-care assessment.
Abstract WMP26: Using Machine Learning Pattern Recognition in Aneurysmal Subarachnoid Hemorrhage Patients to Determine Patterns in Central versus Infectious Fever
Authors: Ch'ang Judy , Tran Nate , DeVoe Catherine , Hu Xiao
Published: January 2019

Introduction:
Patients with acute neurologic injury such as aneurysmal subarachnoid hemorrhage (aSAH) are at risk of central fever and infections. Fever has been found to independently increase morbidity and mortality. These patients are at risk of exposure to antibiotic overuse, resistant infections, and extensive fever work-ups as central fever remains a diagnosis of exclusion.

Methods:
We included 28 patients who underwent treatment for aSAH at the University of California, San Francisco’s Neurointensive Care Units from 2012-2016. We retrospectively reviewed their fever curves, with every 2 seconds temperature data, and used strict CDC infection criteria to delineate between central and infectious fever. For every patient, we extracted one or multiple 12-hours-fever-windows (FW) for a total of 289 FW. We then extracted 40 features in either time or frequency domain such as signal skewness, kurtosis, and variance for each FW, and trained a Random Forest model to classify between central and infectious fever. Our model was trained and cross-validated using 19 patients and tested using the remaining 9 patients.

Results:
Our initial machine learning model shows a cross-validated ROC AUC score of 0.825 ± 0.150, and a testing ROC AUC score of 0.75 on 30% test patients.

Conclusion:
These preliminary results suggest that there are combinations of characteristics or patterns that can differentiate between central and infectious fever through a machine learning model. To our knowledge, this has never been done before. Our next steps include the development of a more robust features matrix and the use of other machine learning models such as the Recurrent Neural Network (RNN). If this machine learning model can effectively identify central versus infectious fevers, we can optimize antibiotic stewardship, tailor the work up and treatment of this critically ill population and open the door for prospective central fever and temperature management research.
Abstract WMP27: Selective Cerebral Vasodilatation and Anti-Apoptotic Therapy With Shockwave-Induced Release of Nitric Oxide Using Nano Au-polymersomes/S-nitrosoglutathione
Authors: Chang Wei-Tien , Wang Woan-Yi , Hsu Min-Hsuan , Kao Po-Tsung , Chang Yu-Chen , Wang Chih-Hung , Tsai Min-Shan , Cheng Hsiao-Ju , Huang Chien-Hua , Chen Wen-Shiang , Liau Ian , Yeh Chen-Sheng , Chen Wen-Jone
Published: January 2019

Introduction:
Cerebral vasoconstriction is often encountered in the post-CPR phase, which inevitably worsens neurological prognosis. Nitric oxide (NO) confers vasodilatation and anti-apoptotic protective effect, but may cause systemic hypotension. We designed an Au-polymersomes/S-nitrosoglutathione (Au-PLGA/GSNO) nanoparticle that can be selectively triggered by shockwave (SW) to release NO, and investigated its role in mitigating post-CPR cerebral vasoconstriction and apoptotic neuronal injury.

Methods:
Using an established rat model of asphyxia cardiac arrest and CPR, Au-PLGA/GSNO (7500 PPM, 3.33 mg/kg Au and 42 ug/kg GSNO) was infused into carotid artery together with the same volume of SonoVue 10 min after CPR, with simultaneous stimulation by SW (PiezoWave, 134 mJ/mm
2
) distal to the infusion site. The blood pressure (BP) was continuously monitored and brain tissue perfusion recorded by OxyFLO probe. Cerebral vasculature was video-taped by CytoCam. The blood was sampled 2 h post-CPR for measurement of nitrate/nitrite. The brain was harvested for measurement of casepase-3, endothelial NO synthase (eNOS) and protein kinase B (Akt). In a subgroup the brain was harvested at 24 h for TUNEL stain.

Results:
Marked cerebral vasoconstriction was noted after CPR with brain perfusion reduced to about half that of baseline. With infusion of Au-PLGA/GSNO + SonoVue and SW stimulation, the cerebral vasoconstriction was ameliorated and brain perfusion improved to baseline level (
P
< 0.05 vs. CPR control), while BP showed no significant difference. The plasma nitrate/nitrite 2 h post-CPR was significantly increased (
P
< 0.05). The cleaved caspase-3 of the brain was reduced (
P
< 0.001) and TUNEL stain of the CA1 and CA3 regions of hippocampus significantly abrogated. Interestingly, the phosphorylated (P)-eNOS and P-Akt were also increased (both
P
< 0.001), suggesting reciprocating activation of the upstream Akt-eNOS signaling.

Conclusion:
Nano Au-PLGA/GSNO with SW-induced release of NO selectively mitigates post-CPR cerebral vasoconstriction and apoptotic neuronal death without systemic hypotension. Being effective and safe, such therapeutic strategy can be applied not only in post-CPR care but in other diseases such as subarachnoid hemorrhage.
Abstract WMP28: Endocannabinoid 2-Arachidonoylglycerol is Associated With Outcome After Aneurysmal Subarachnoid Hemorrhage
Authors: Ament Zsuzsanna , Hansen Christina , Wolcott Zoe , Patel Aman , Kimberly W. Taylor
Published: January 2019

Introduction:
Aneurysmal subarachnoid hemorrhage (aSAH) is a cause of significant morbidity and mortality. Cumulative research highlights the importance of neuroinflammation following aSAH. The endocannabinoids (eCBs) are key mediators of inflammation and we therefore sought to determine whether eCBs and related bioactive lipids are implicated in aSAH.

Methods:
We developed and validated a bioanalytical approach to measure eCBs using liquid-liquid extraction, followed by liquid chromatography and triple quadrupole tandem mass spectrometry. Chromatography was carried out using a modified C18 stationary phase (C18-PFP, 3μm, Ultra-Inert HPLC Column, 150 x 2.1mm, ACE, Mac-Mod Analytical). In a cohort of 192 aSAH patients admitted to Massachusetts General Hospital in Boston from 2013-2016, we quantified 13 eCBs and 10 precursors or breakdown free fatty acid compounds in serial blood samples. Functional outcome was assessed using the modified Rankin Scale (mRS) at 90 days and was dichotomized into 0-2 versus 3-6. Repeated measures mixed effects models and a non-parametric decision-tree based Random Forest (RF) algorithm were used to identify eCBs that predicted outcome.

Results:
A total of 192aSAH patients (mean age 57+/-12 years; 60% female) were included in the analysis. Median levels of 2-Arachidonoylglycerol (2-AG) and its isomerization product 1-AG were 5.6 ng/mL [IQR 1.8-24.9] and 1.2 ng/mL [IQR 0.6-4.2], respectively. Repeated measures mixed effects modeling identified higher 1-AG/2-AG as a predictor of poor outcome (OR 1.8, 95% CI 1.3-2.4, p<0.001). After adjustment for age, sex and WFNS score, 1-AG/2-AG was an independent predictor of poor outcome (OR 1.5, 95% CI 1.1-2.2, p=0.02). Accordingly, a non-parametric RF algorithm identified the out-of-bag error rate of 39%.

Conclusion:
Elevated 1-AG/2-AG level predicts worse outcome after aSAH. Replication in an independent aSAH cohort and further study of the potential link between 2-AG and neuroinflammation is warranted.
Abstract WMP29: Detection and Segmentation of Subarachnoid Hemorrhages With Deep Learning
Authors: Sales Barros Renan , van der Steen Wessel E , Ponomareva Elena , Boers Anna M , Zijlstra IJsbrand J , van der Berg Rene , Verbaan Dagmar , Vandertop W. P , Majoie Charles B , Olabarriaga Silvia D , Marquering Henk A
Published: January 2019

Introduction:
About 5% of all strokes are subarachnoid hemorrhages (SAHs). Accurate segmentation and detection of SAH in CT scans is important because the SAH volume is linked to delayed cerebral ischemia and poor patient outcome. SAH segmentation is a difficult task with high interobserver variability. Previous studies reported a limited average Dice of 0.66 between expert radiologists. We studied the use of deep learning for fast and accurate detection and segmentation of SAH in CT scans.

Methodology:
A convolutional neural network (CNN) was designed for segmentation and detection of SAH in CT scans. This CNN was trained to classify each voxel as “SAH” or “no SAH”. The input of this CNN was the local information around the voxel and its output was the probability that this voxel is “SAH” or “no SAH”. We used active learning for optimal selection of training samples. By doing so, we boosted the learning performance while keeping a balanced representation of both classes of voxels.

Results:
The CNN segmented 469 scans from SAH patients and achieved an average Dice of 0.62 ± 0.16 [0.19, 0.92] (avg. ± std. [min., max.]). The CNN also segmented 383 scans from patients with repeated bleeding after an initial SAH. Because most of these patients were treated with endovascular coiling, strong metal artefacts were present in these 383 scans. Regardless of these metal artefacts, an average Dice of 0.66 ± 0.19 [0.05, 0.92] was achieved. Finally, the CNN was used for detection of SAH in 35 scans from SAH patients and 35 images from ischemic stroke patients. The proposed CNN achieved an accuracy of 96% for detection of SAH in these 70 images. The CNN took less than 40 seconds to analyze a CT scan.

Conclusion:
The proposed CNN can produce SAH segmentations with a similar accuracy as expert radiologists. This CNN was able to reach state-of-the-art SAH segmentation results and SAH detection accuracy.
Abstract WMP3: DEFUSE-3 Eligible but DAWN Ineligible Patients Treated Within 16-24 Hours: Results From BEST Prospective Cohort Study
Authors: Mistry Eva A , Sucharew Heidi , Mehta Tapan , Arora Niraj , Starosciak Amy , De Los Rios La Rosa Felipe , Siegler James E , Barnhill Natasha , Mistry Akshitkumar M , Patel Kishan , Assad Salman , Tarboosh Amjad , Dakay Katarina , Wagner Jeff , Cruz Aurora , Fortuny Enzo , James Robert , Jagadeesan Bharathi , Streib Christopher , Weber Stewart , Chitale Rohan , Volpi John J , Mayer Stephan , Yaghi Shadi , Jayaraman Mahesh , Khatri Pooja
Published: January 2019

Background:
The 2018 ASA guidelines recommend endovascular stroke treatment (EVT) for patients who meet DEFUSE 3 (D3) trial criteria within 6-16 hrs and those who meet DAWN criteria within 6-24 hrs of last known well (LKW). Recommendation to use more restrictive DAWN and not D3 criteria between 16 and 24 hrs is not strictly followed in clinical practice. Using the prospective multi-institutional cohort study, “Blood Pressure after EVT (BEST),” we determined the frequency and outcomes of EVT-treated patients within the 16-24 hrs of LKW who met D3 but not DAWN criteria.

Methods:
BEST enrolled consecutive EVT-treated adult patients with ICA, M1, or M2 occlusions at 12 comprehensive stroke centers from 11/2017 to 7/2018. D3-but not DAWN-eligible patients were defined as those with ICA/M1 occlusions, a mismatch volume 15cc, and any of the following: 1) NIHSS 6-9, 2) infarct core 51-70 cc, 3) age 80 yrs and infarct core 21-70 cc, or 4) NIHSS 11-19 , age <80 yrs and infarct core 31-70 cc. We compared mTICI score, symptomatic ICH, discharge disposition, and 90-day mRS in patients who met D3 but not DAWN criteria (16-24 hrs) to those who strictly met criteria for 1) D3 (6-16 hrs) and 2) DAWN (6-24 hrs).

Results:
Of 457 patients, 159 (35%) underwent EVT within 6-24 hrs (mean age 66 yrs; 51% female; median NIHSS 14 [IQR: 9, 19]), and 26 (16%) were within 16-24 hrs. Of the 16-24 hr group, 8 (31%) met D3 but not DAWN criteria. Proportion of mTICI 2b-3, symptomatic ICH, and discharge disposition distribution were not different compared those who met full D3 or DAWN criteria. 90-day functional outcomes were better than those who met the full DAWN criteria (table).

Conclusion:
One in three patients treated with EVT within 16-24 hrs of LKW at major academic comprehensive stroke centers did not meet current guideline recommendations (DAWN criteria). In this small sample size study, safety and outcome results are comparable to those who met guideline criteria. Dedicated studies are needed to confirm this finding.
Abstract WMP30: F
2
-Isoprostanes and Isofurans as Markers of Oxidative Stress and Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage
Authors: Gomes Joao , Shriver Leah , Bain Mark , Milne Ginger , Kallianpur Asha
Published: January 2019

Background:
F
2
-Isoprostanes (F
2
-IsoP) and Isofurans (IsoF), specific markers of lipid peroxidation in vivo, have been reported to be elevated and have prognostic implications in aneurysmal subarachnoid hemorrhage (aSAH). We examined associations between these biomarkers and the risk of delayed cerebral ischemia (DCI) following aSAH.

Methods:
Eighteen patients with aSAH and 7 controls with normal neuroimaging and CSF analysis results underwent CSF sampling and abstraction of clinical, demographic, and laboratory data. Samples (two) of CSF were collected on day 1 and once on days 5-8 post-bleed. F
2
-IsoP and IsoF assays were performed at Vanderbilt Eicosanoid Core Lab by gas chromatography/mass spectroscopy. Levels are expressed in median (IQR) for non-parametric data. Repeated sample measurement were compared using the Wilcoxon signed-rank test, whereas the Mann Whitney test was used for other non-parametric data.

Results:
Mean age was 62
+
15 (aSAH cases) vs. 52
+
14 (controls) years,
p
=0.07, and 80% were female. Median Hunt-Hess score was 3 (2-4) and modified Fisher scale 3 (3-4). Thirty five percent of patients developed DCI. F
2
-IsoP were significantly higher in cases than controls 47.5 (30.2-53.5) vs. 26.0 (21.2-34.5) pg/mL,
p
0.01. No significant differences were observed in patients with or without DCI (41 (33.5-52) vs. 44 (28.5-55.5) pg/mL). IsoF were elevated in the second CSF sample (41.5 (34-72) pg/mL) in 9 patients, but undetectable in the remainder cases and all controls. Cases who developed DCI had significantly higher IsoF than cases who did not (57 (34-72) vs. 0 (0-34) pg/mL,
p=
0.001). Median PaO2 in both groups was similar (130.5 (89.2-189.7) vs. 115 (77.5-176) mmHg).

Conclusions:
F
2
-IsoP and IsoF serve as overall indicators of oxidative injury following aSAH, but IsoF may also be related to the development of DCI and cerebral vasospasm. Whether IsoF serve as mediators of vasospasm/ischemia or are merely favored byproducts of oxidative damage warrants further investigation. In the absence of higher oxygen tensions, we hypothesize the possibility of neuronal mitochondrial dysfunction in patients with elevated IsoF.
Abstract WMP36: Surpass™ IntraCranial Aneurysm EmbolizatioN System Pivotal Trial to Treat Large OR Giant Wide Neck Aneurysms (SCENT Trial): One Year Outcomes
Authors: Meyers Philip M , Coon Alexander , Kan Peter , Wakhloo Ajay , Hanel Ricardo
Published: January 2019

Introduction:
Surpass™ Flow Diverter was developed to treat large or giant wide-neck intracranial aneurysms (IA) not amenable to surgical or current standard endovascular treatment due to location, morphology, or known treatment challenges. FDA approved on July 13 2018, Surpass™ fulfills an unmet clinical need. Indications for Use allow for placement in the entire intracranial internal carotid artery (ICA). Surpass™ is available in diameters of 3 to 5 mm and lengths of 15 to 50 mm.

Methods:
SCENT Trial is an international, multi-center, prospective, non-randomized trial comparing the outcomes of Surpass™ Flow Diverter treatment to historical control. It is designed to evaluate the safety and efficacy of Surpass™ for treatment of wide-neck (≥4mm), large or giant IA ≥10 mm in size. The primary safety endpoint is the percent of subjects experiencing neurologic death or major ipsilateral stroke at 12 months. The primary effectiveness endpoint is the percent of subjects with 100% occlusion (Raymond Class 1) without clinically significant stenosis (≤50% stenosis) of the parent artery, and any retreatment of the target aneurysm at 12-month.

Results:
From 2012 to 2015, 180 subjects were treated at 26 sites. Mean age was 61.0 years and 91.7% (165/180) were females. Aneurysms were most frequently located in the carotid-ophthalmic segment (33.3%; 60/180), followed by the cavernous segment (28.9%; 52/180), posterior communicating artery (21.1%; 38/180), supraclinoid carotid artery (11.1%; 20/180), superior hypophyseal artery (3.3%; 6/180), and the petrous segment (2.2%; 4/180). Mean aneurysm dimension included dome height 13.4±5.7 mm. Mean neck width was 6.7 mm. Technical success occurred in 97.8% (176/180) of subjects while the mean number of Surpass™ devices used was 1.1 per procedure, with 86.7% (156/180) of aneurysms treated with a single flow diverter. The 12-month primary effectiveness rate was 62.8% [(113/180), 95% CI 55.3, 69.9] and 12-month major ipsilateral stroke or neurological death rate of 10.6% [(19/180), 95% CI 55.3, 69.9]

Conclusions:
Surpass™ Flow Diverter is safe and effective to treat large and giant aneurysms intracranial internal carotid aneurysms.
Abstract WMP37: Assessment of Intracranial Atherosclerotic Stenosis Using 4D Flow MRI Derived Hemodynamic Biomarkers
Authors: Vali Alireza , Aristova Maria , Vakil Parmede , Abdalla Ramez , Ansari Sameer , Prabhakaran Shyam , Markl Michael , Schnell Susanne
Published: January 2019

Introduction:
Despite medical management, 12% of patients with intracranial atherosclerotic disease (ICAD) experience recurrent stroke. Degree of stenosis, the current standard for risk stratification, does not reflect the hemodynamic significance of the lesion. We hypothesized that 4D flow MRI derived parameters including flow rate (FR) and peak velocity (PV) in major cerebral arteries, as well as the pressure drop (PD) in the atherosclerotic stenosis (AS) could be new imaging biomarkers for the hemodynamic impact of AS on local and global cerebrovascular flow redistribution.

Methods:
Intracranial dual-
venc
4D flow MRI and time-of-flight (TOF) MRA were acquired in 23 controls and 13 ICAD patients at 3T (Fig. 1a). AS was graded as moderate (50-69%) and severe (70-99%) based on TOF MRA. 4D flow MRI data was corrected for phase offsets and noise and subsequently processed using an automated analysis tool (Fig. 1b-f). At each analysis plane (Fig.1e), the lumen region was determined from the TOF MRA (registered with 4D flow MRI), and area, PV and FR were calculated. The PD in AS was estimated from the Bernoulli equation using PV and area at AS and the area proximal to the AS. PV and FR ratios between left and right hemispheres for controls and affected to nonaffected hemispheres for patients were also calculated.

Results:
The PV ratio was significantly different (ranked sum test, p=0.003, Fig. 1g) between control and patient cohorts while FR ratio was similar (p=0.5). In addition, there was a significant correlation between PD in AS and PV ratio for the patient cohort (Spearman correlation, r=0.64, p=0.03, Fig. 1h).

Conclusions:
In this pilot study, we demonstrated the feasibility of two 4D flow MRI derived hemodynamic parameters, peak velocity and pressure drop, for the characterization of the impacts of ICAD on local and global cerebral flow distribution. Future studies are warranted to assess the prognostic value of these parameters for improved ICAD risk stratification.
Abstract WMP39: Laser Angioscopy in Carotid Artery Disease: Imaging Findings and Histopathological Correlation
Authors: Savastano Luis E , Gordon David , Bhambri Ankur , Pandey Aditya , Cockrum Joshua , Thompson B. Gregory , Reddy Adithya , Seibel Eric
Published: January 2019

Our understanding and management of carotid artery disease has largely relied on angiography, US and MR. However, existing modalities cannot accurately identify the spectrum of thrombogenic lesions on the vascular surface or reliably detect structural markers of instability. Thus, the natural history of the different histopathological hallmarks of advanced or complicated plaques is unknown, and many patients with culprit substenotic plaques are misdiagnosed with cryptogenic stroke. An intraluminal approach to directly inspect the endovascular surfaces at unprecedented resolutions would enable detailed structural analysis of carotid plaques and the identification of the root cause of carotid-related strokes. A scanning fiber angioscope (SFA), a high-definition 1.2-mm forward-viewing camera that generates videos by spirally scanning low-power laser beams, was developed for clinical use and employed to analyze the endovascular surfaces of
ex vivo
human carotid arteries (n=95) and endarterectomized plaques (n=20). Specimens were then imaged with US and micro-CT, and all vascular diagnostic tests obtained in the patients undergoing carotid revascularization were accessed. Imaging findings in the vascular surfaces were then validated by histomorphological analysis of >300 lesions, and an angioscopic classifier for atherosclerosis was generated. Full-color videos at 30Hz and at a resolution >200,000 pixels were generated from the entire endovascular circumference in all specimens with depth-of-focus larger than 5cm in saline solution. The ability to analyze the surface anatomy with unparalleled detail allowed the identification of early, intermediate, advanced and complex atherosclerotic lesions, including ulceration of fibrotic cap, excavation of the necrotic core leading to pseudolumens, intimal flaps, exposed necrotic core to the lumen, erosions, recent and remote intimal hemorrhages, luminal thrombus, eruptive calcified nodules and calcified intimal sheaths and plates. SFA offers a direct view of the endoluminal surfaces with unparalleled resolution and has the potential to revolutionize research, diagnosis, prognosis and image-guided therapy in carotid atherosclerosis.
Abstract WMP40: Accuracy of Extracranial Vertebral Artery Hemodynamic Parameters in the Evaluation of Intracranial Vertebral Artery Steno-Occlusive Disease
Authors: Li Qiuping , Hua Yang , Jia Lingyun , Yang Jie
Published: January 2019

Objectives:
To explore the accuracy of the hemodynamic parameters of the extracranial segment of vertebral artery (EVA) for evaluating the intracranial segment steno-occlusive disease.

Methods:
A total of 275 consecutive patients who were diagnosed as posterior circulation ischemic stroke with unilateral intracranial VA (IVA) stenosis or occlusion in our hospital from January 2015 to December 2017 were enrolled. All patients were examined by neck vascular ultrasound, CT angiography (CTA) and / or digital subtraction angiography (DSA) within one week. According to the results of DSA or CTA,the patients were divided into mild,moderate,severe stenosis and occlusion groups. The peak systolic velocity (PSV), end diastolic velocity (EDV), resistance index (RI value) of the EVA (V2 segment) were recorded and analyzed. The area under the receiver operating characteristic curve (AUC) of the PSV, EDV, RI values were calculated. The sensitivity, specificity, and accuracy of the above hemodynamic parameters were compared.

Results:
With the severity of the IVA stenosis, the PSV and EDV of the V2 segment were gradually decreased, and the RI value was gradually increased (
P
<0.001). The AUC of the PSV, EDV, and RI values were gradually decreased when compared the occlusion before PICA(posterior inferior cerebellar artery),occlusion after PICA and severe stenosis. When EDV≤0 cm/s or RI value≥1.00, the accuracy of IVA occlusion before PICA was the highest (97.8%), with a specificity 98.7% and a sensitivity 91.9%. When EDV≤10cm/s, the accuracy of occlusion after PICA was 89.1%, with a sensitivity 91.2%, a specificity 87.9%. The accuracy of PSV≤39cm/s and RI value≥0.76 was less than that of EDV (86.2% , 84.7%).The accuracy for IVA severe stenosis were less than 85%.

Conclusion:
The ultrasonic hemodynamic parameters of the EVA can accurately diagnose the occlusion of the IVA and distinguish the occlusion site, but the diagnostic accuracy of the severe stenosis is relatively low.
Abstract WMP42: Revascularization of Symptomatic Chronically Occluded Internal Carotid: A Meta-Analysis
Authors: Howard Susanna , Zanaty Mario , Starke Robert M , McCarthy David , Samaniego Edgar A , Jabbour Pascal , Kung David , Hasan David M
Published: January 2019

Objective:
The overall annual risk of stroke from a chronically occluded internal carotid artery (COICA) is approximately 5%-7%, despite maximal medical management. In addition, patients with COICA have neurocognitive impairment. This emphasizes the importance of identifying candidates who will have more favorable outcomes with intervention compared to medical management. There has not been a comprehensive analysis of existing literature related to treatment of COICA to compare with the natural history of the disease. We conducted a meta-analysis of all studies reporting on patients with COICA receiving endovascular intervention.

Methods:
Studies that involve patients with COICA that underwent recanalization using endovascular interventions or hybrid (combination) technique were included if they reported on: morbidity, mortality, successful revascularization rate and duration of occlusion.

Results:
Sixteen studies on 333 patients with COICA were included. The mean age of the patient sample was 67.2 years old (SD = 9.3). The mean duration of occlusion was 7.4 months (SD = 9.4). 70% of patients had a successful recanalization. 3.9% of patients experienced major complications and 2.4% experienced minor complications following the procedure. Among the most common complications were severe periprocedural hypotension/bradycardia (5.4%), hemorrhagic complications (2.4%), and ischemic strokes (2.1%). Depending on the type of occlusion , the total complication rate was 6.25% in favorable types of COICA compared to 31.25% (5/16) in unfavorable ones, with a successful rate of recanalization of 100% in favorable types compared to 37.5%. Neurocognitive outcomes improved after successful recanalization in all cases.

Conclusion:
This meta-analysis shows that the complication rate for intervention in some cohort was less then the natural history of the disease. It is thus important to identify the favorable types of COICA for intervention. Furthermore, the definition of symptomatic COICA did not include the neurocognitive impairment in this population, which seems to respond to recanalization, arguing thus in favor of intervention.
Abstract WMP44: Endovascular Approaches for Vertebral Artery Stump Syndrome Including the Novel Method of Angioplasty by Retrograde Approach
Authors: Mori Kentaro , Abe Hiroyuki , Fukui Issei , Kita Daisuke , Matsunaga Yuuki , Takasu Mutsuki , Nakano Tatsu , Kitamura Yoshihisa
Published: January 2019

Introduction:
Vertebral Artery Stump Syndrome (VASS) has previously been reported as a mechanism of embolism to posterior circulation (PC) that is due to flow stagnation caused by VA origin occlusion. We report the efficacy of endovascular treatment (EVT) for VASS including the novel method of approach.

Methods:
We retrospectively investigated 1381 consecutive cases of ischemic stroke treated in our institution. Diagnosis of VASS was performed on cases of embolism in PC area alone with VA proximal occlusion accompanied by distal flow stagnation and without other embolic sources. EVT was performed on cases in which infarction recurred in medical treatment resistance or in which BA acute occlusion was present. Approach of EVT was selected depending on state of the case. In addition to conventional methods of parent artery occlusion (PAO) and angioplasty by antegrade approach (AA), we devised and performed a novel method of approach for angioplasty by retrograde approach (RA) via collateral circulation or contralateral VA.

Results:
Embolism of the PC area alone was 323 cases, 10 of which (3.1%) were diagnosed as VASS. EVT was performed on 6 cases. No symptomatic complications due to the procedure were observed. In all cases, recurrence of infarction was not observed, but retreatment was required in 1 case. The treatment contents were as follows: 1 case of PAO, 4 cases of angioplasty by AA, and 2 cases of angioplasty by RA (via deep cervical artery; 1, via contralateral VA; 1).

Conclusion:
There are several reports of anticoagulant therapy and EVT as a treatment for VASS, but it has not been established. Since EVT can be performed relatively safely, it may be the first choice for treatment. Appropriate approach should be considered according to the condition of the lesion. In occlusion of VA, the orifice of VA is often flattened, in which case AA is difficult. RA to occluded vessels, which is a common procedure in cardiovascular vessels, may be applicable to the neurovascular region.
Abstract WMP47: Traditional Doppler Measures Do Not predict Cognition in a Cohort With Advanced Atherosclerosis
Authors: Mitchell Carol , Wilbrand Stephanie M , Cook Thomas D , Meshram Nirvedh H , Steffel Catherine N , Nye Rebecca , Varghese Tomy , Hermann Bruce P , Dempsey Robert J
Published: January 2019

Introduction:
Traditional Doppler measures have been used to predict cognitive performance in patients with carotid atherosclerosis. Novel measures, such as carotid strain indices (CSI) have shown associations with cognitive performance. We hypothesized that lower mean middle cerebral artery (MCA) velocities, higher bulb-internal carotid artery (ICA) velocities, MCA pulsatility index (PI) and CSI would be associated with poorer cognitive performance in individuals with advanced atherosclerosis.

Methods:
Neurocognitive testing, carotid ultrasound, transcranial Doppler and CSI were performed on 40 subjects scheduled for carotid endarterectomy. Kendall tau correlations were used to examine relationships between cognitive tests and the maximum peak systolic velocity (PSV) (from bulb, proximal, mid or distal ICA), mean MCA velocity and PI (on surgical side) and CSI (maximum axial, lateral and shear strain indices used to characterize plaque deformations with arterial pulsation). Cognitive measures included age adjusted indices of verbal fluency, verbal and visual learning/memory, psychomotor speed, auditory attention/working memory, visuoconstruction, and mental flexibility.

Results:
Participants were median age 71.0 (IQR 9.75) years, 26 male (65%) and 14 female (35%). Median stenosis was 70.00 (IQR 10.00) percent. Traditional Doppler parameters, PSV, mean MCA velocity and MCA PI did not predict cognitive performance (p values all >0.05). Maximum strain values were significantly associated with cognitive performance (p<0.05).
Table
.

Conclusions:
Traditional velocity measurements of maximum bulb-ICA PSV, mean MCA velocity and PI were not associated with cognitive performance in patients with advanced atherosclerotic disease, however maximum strain indices were associated with cognitive performance. Findings suggest that cognition may be associated with unstable plaque (plaques at greater risk for rupture) rather than blood flow.
Abstract WMP51: Estimates of Trends in 30 Days Readmission Among Patients With Stroke in the United States, 2010-2015
Authors: Saxena Anshul , Rubens Muni , Das Sankalp , Salami Joseph , McGranaghan Peter , Veledar Emir
Published: January 2019

Background:
Hospital Readmissions Reduction Program requires CMS to reduce payments to hospitals with excess readmissions. Trend in 30 days readmission among patients with index hospitalization for stroke in the United States is largely unknown. In this study, national trend was examined to estimate quality of care in the US population.

Methods:
Patients, ≥40 years, with index hospitalization for stroke were extracted from the Nationwide Readmission Database (2010-2015). They were identified using ICD9 and ICD10 codes (433.x, 434.x, 435.x, 436.x, I63.x). Readmissions were defined as all cause readmission during 30 days post index hospitalization discharge, and were divided into planned and unplanned according to AHRQ guidelines. Weighted percentages and Joinpoint analysis were used to evaluate 30 days readmission trends and the annual percentage change (APC).

Results:
Older patients (≥75 years) and those with a higher comorbidity burden were readmitted frequently. Overall, there was a downward trend in unplanned 30 days readmissions between 2010 and 2015; the lowest rate (95% CI), was seen in 2014 (10.7%; 10.5% - 10.8%) and the highest in 2010 (11.6%; 11.4% - 11.8%). From 2010 to 2015, reduction in APC was 1.3% (
P
> .08).

Conclusions:
Around 10%-12% of patients with stroke get readmitted within 30 days post discharge. Not only there is a high clinical and economic burden associated with readmissions due to stroke, it is also associated with poor survival. This highlights the need for interventions ensuring appropriate level of service and early outpatient follow-up after discharge. Reducing postoperative complications; managing behavioral risk factors (smoking, alcohol, diabetes management); or choosing appropriate carotid revascularization technique such as endarterectomy over stenting may reduce 30 days unplanned readmission and the high risk of mortality among stroke patients. Efforts should be made among elderly patients so that there is a decrease in trend.