bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract T P67: The Role of PGF2-alpha FP Receptor in a Mouse Model of Intracerebral Hemorrhage
Authors: Mohan Shekher , Narumiya Shuh , Dore Sylvain
Published: July 2021

Background:
Prostaglandin F
2α
(PGF
2α
) has been described to exert beneficial and detrimental effects in various neurological disorders. Brain damage following an intracerebral hemorrhagic (ICH) stroke is associated with the release of inflammatory molecules such as PGF
2α
; however, the role of PGF
2α
and its cognate FP receptor in ICH remains unclear.

Methods:
Using age (2.5-3.5 months) and weight-matched (20-30g) adult male WT and FP
-/-
C57BL/6a single unilateral intrastriatal injection of collagenase VII-S [0.04 Units in 0.2μL saline] was given using specific stereotaxic coordinates. To measure for functional outcomes, neurobehavioral assays were performed 24, 48 and 72h post-ICH. These included neurological deficit scoring (NDS) using a 24-point scale, accelerating speed rotarod test to measure motor deficits and forepaw grip strength (in grams) using a grip strength meter (GSM) to measure of sensorimotor ability.

Results:
NDS
: 72h after ICH, FP
-/-
mice showed significantly higher deficits as compared to WT mice (4.6±0.8 vs 0.5±0.4;
p
<0.01, n=4-8).
Rotarod
: 24h post-ICH, FP
-/-
mice showed a greater reduction in the total time on the rotarod as compared to WT mice (36.0±9.8s vs 58.6±7.1s).
Forepaw grip strength
: FP
-/-
mice showed a significantly less strength as compared to WT mice at 72h post-ICH (96.4±17.0g vs 129.6±5.9g;
p
<0.01). Additional studies in process include determining the lesion volume and assessing neuronal death using Cresyl Violet and Fluoro-Jade staining, respectively. In addition to
in vivo
protocols,
in vitro
experiments with primary cultures are planned to determine the mechanism responsible for these novel findings.

Conclusion:
We have shown that deletion of the FP receptor exacerbates behavioral impairments following ICH compared to WT controls. However, the complete mechanism responsible for these novel results is actively being pursued.
Abstract T P8: Comparison of Large Vessel Stroke Patient Outcomes Before and After Initiation of On-Site Endovascular Stroke Treatment Services
Authors: Shwe Yamin , Ortega-Gutierrez Santiago , Otokiti Ahmed , Altschul David , Paramasivam Srinivasan , Berenstein Alejandro , Fifi Johanna T
Published: July 2021

Rational:
Availability of an on-site endovascular program for large vessel stroke decreases the time to acute treatment. Since expanding our program to a Manhattan hospital in July 2009, we have seen a decreased time to treatment. We hypothesize that the expansion was associated with improved discharge outcomes in patients with anterior circulation large vessel strokes.

Methods:
A retrospective chart review of consecutive patients before and after the initiation of the program was conducted. Adults presenting to the hospital with an NIHSS greater than 8, within 6 hours from stroke onset, and with carotid terminus or middle cerebral artery occlusion were included. Exclusion criteria were INR or creatinine >3 and premorbid modified Rankin score (MRS) >1. Comparison was made between the groups before and after initiation of the program. Modified Rankin at discharge was set as a primary outcome. Secondary outcomes included admission-discharge delta NIHSS, discharge disposition, mortality and stroke volume on MRI or CT scan. P<0.05 was set as statistically significant.

Results:
70 patients were included in the study. 30 were admitted before July 2009 and 40 after. There was no difference between patient demographics. Only 3/30 patient received endovascular treatment prior to July 2009 versus 34/40 after that. Patients admitted after availability of on-site endovascular treatment were less likely to be dependent (OR: 0.14; 95% CI: 0.019-1) or discharged other than home (OR: 0.233; 95% CI: 0.062-0.876) after adjusting for age and admission NIHSS. In addition there was a significant increase in median admission-discharge NIHSS change in patients treated after July 2009 (p=0.007). No difference between median stroke volume was observed (66 vs 57.2 cm3; p=0.8)

Discussion:
For every 30 minutes until reperfusion, the probability of good recovery after a large vessel stroke is decreased by about 10%. Transfer delays may impede or limit the benefit of endovascular recanalization. In the absence of strategic air transportation systems, rapid deployment of an endovascular team might decrease the time to recanalization and improve patient outcomes.
Abstract T P89: Unilateral Cerebral Atrophy Secondary to Extracranial Carotid Stenosis
Authors: Khalid Shahram , Seraji-bozorgzad Navid
Published: July 2021

Background:
Moderate to severe or bilateral carotid stenosis is associated with cerebral atrophy and cognitive decline. Prior studies have evaluated global atrophy and its correlation with the degree of stenosis. It is unclear whether carotid stenosis can lead to unilateral cerebral changes.

Objective:
To evaluate for unilateral cerebral atrophy in asymptomatic patients with moderated to severe extracranial unilateral carotid stenosis.

Methods:
Subjects were selected from patients who had undergone carotid vascular imaging and MRI of the brain, from January 2007 to January 2013 at our institution. Patients with history of TIA or ischemic stroke were excluded. Carotid stenosis (CS) group consisted of patients with unilateral moderate to severe carotid stenosis (n=9). Patients without any stenosis (n=5) were used as controls. T1-weighted brain images (FOV 256 x 256 x128, resolution 1.5 x 1.5 x 5 mm) were registered to Talairach space using FSL software. Non-brain tissue was removed using the BET module. Segmentation into gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) was done with the FAST tool. Total brain volume (TBV) was calculated as the sum of three tissue types (GM + WM + CSF). Total number of voxels in each hemisphere was calculated for GM, WM and CSF. Index of Asymmetry (IoA), was defined as the absolute value of inter-hemispheric voxel difference divided by TBV. IoA for each tissue type was compared between subjects and controls using Student’s t-test.

Results:
Mean age was 63.7±7.8 and 57.4 ±6.0 for the CS and control groups, respectively. Average gray matter IoA for CS was significantly increased compared to controls (1.4% v. 0.7, p < 0.02). Average white matter IoA was similar between the groups (0.6% v. 0.7%, p< 0.36). There was a trend for increased CSF IoA in the CS group compared to controls, but it did not reach statistical significance (1.8% v. 0.9%, p < 0.10).

Conclusion:
Moderate to severe carotid stenosis can lead to unilateral cerebral atrophy in the absence of other neurological symptoms. Further prospective studies with larger cohorts of the patients are required.
Abstract T P96: Short-term and Mid-term Results of Carotid Artery Revascularization as Carotid Artery Stenting for First-line Treatment: Single Center Experience in Japan
Authors: Miyata Haruka , Nakahara Ichiro , Matsumoto Shoji , Ohta Tsuyoshi , Fukushima Yutaka , Ishibashi Ryota , Gomi Masanori , Nishi Hidehisa , Watanabe Sadayoshi
Published: July 2021

Objective:
Penetration ratio of carotid artery stenting (CAS) in carotid revascularization caught up that of carotid endarterectomy (CEA) in 2005, exceeding more than 60% in recent years after CREST in Japan. We choose CAS for first-line treatment, while CEA is applied to CAS high-risk patients dependent on factors including accessibility, plaque diagnosis, and symptom. The aim of this study is to evaluate short-term and mid-term results of single center experience of 266 consecutive cases with CAS / CEA.

Materials / Methods:
This is a retrospective analysis of 227 CAS and 39 CEA during January 2009 to March 2013. The primary outcome measures (short-term results) were any periprocedural (within 30 days after procedure) death, stroke, and acute coronary syndrome, and the rate of postoperative positive lesion in diffusion weighted imaging (DWI) on MRI. The mid-term results include death, stroke, and restenosis requiring retreatment during the follow-up periods.

Results:
There were no significant differences in age, underlying disease, and the severity of stenosis in both CEA and CAS group. However, the percentage of symptomatic lesion and the MRI T1WI plaque-sternocleidomastoid muscle ratio (index of the vulnerability of plaque) were higher in CEA than CAS group (69% vs. 48%, p=0.015; 1.79±0.46 vs. 1.31±0.37, p<0.0001). Short-term results revealed no mortality in both groups, any stroke 2.6% CEA vs. 4.9% CAS (p=1); major stroke 2.6% CEA vs. 0.9% CAS (p=0.38); acute coronary syndrome 0% CEA vs. 0.9% CAS (p=1); the rate of DWI-positive 24% vs. 39% (p=0.10). Mid-term results during the follow-up periods (CEA 18.3±13.5 month, CAS 20.3±14.1 month): death 5.1% CEA vs. 5.7% CAS (p=1), stroke 7.7% CEA vs. 11.0% CAS (p=0.78), restenosis requiring retreatment 0% vs. 6.6% (p=0.14).

Conclusion:
The short-term and the mid-term results were excellent and equivalent in CAS and CEA although we apply CEA to high-risk lesions such as fragile plaque or symptomatic lesion. Our protocol, in which most patients undergo less invasive CAS as the first-line while CEA is selected for CAS high-risk patients, enables to provide high quality treatment for carotid artery revascularization.
Abstract T P98: Effect of Atrial Fibrillation and/or Large Artery Atherosclerosis on Stroke Recurrence and Long-term Outcome in Japanese Minor Stroke ~Fukuoka Strok Registry~
Authors: Fujimoto Shigeru , Ohsaki Masato , Kumamoto Masaya , Ishitsuka Takao , Kitazono Takanari
Published: July 2021

Background & Purpose:
Atrial fibrillation (AF) and large artery atherosclerosis (LAA) can be associated with a bad outcome even in minor stroke. We investigated stroke recurrence and outcome in Japanese minor stroke patients with AF and/or LAA.

Subjects & Methods:
Among the consecutive 6246 stroke patients who were admitted to the 7 stroke centers within 7 days after the onset, 3725 patients with acute ischemic stroke with the initial NIH stroke scale score of 7 or less and prior modified Rankin scale (mRS) of 0 or 1 were included in the present study. In accordance with AF and intracranial or extracranial LAA (stenosis of 50% or more in diameter), they were classified into 4 subgroups: patients without both AF and LAA (Group A, n=2154), patients with only AF (Group B, n=475), patients with only LAA (Group C, n=937), and patients with both AF and LAA (Group D, n=159). We observed stroke recurrence and outcome during one year.

Results:
On the multivariate analysis, age (OR, 0.94; 95%CI 0.93~0.95), initial NIH stroke scale score (OR, 0.70; 95%CI, 0.67~0.74), chronic kidney disease (OR, 0.72; 95%CI, 0.55~0.95), initial HbA1c value (OR 0.87, 95%CI 0.79~0.95), and LAA (OR 0.70, 95%CI 0.55~0.88) had a negative association with a good outcome. Acute stroke recurrences within 3 weeks after the onset were observed in 2.0%, 2.5%, 6.1%, and 9.4% in Group A-D patients respectively (p<0.0001). Stroke recurrences during 1 year were observed 7.0%, 10.7%, 11.6%, and 13.8% in Group A-D patients respectively (p<0.0001). A good outcome (mRS of 0-1) 1 year after the onset was observed in 77.0%, 6.4%, 67.9%, and 65.8% in Group A-D patients respectively (p<0.0001). With regard to the Kaplan-Meier method, there was a significant difference in stroke recurrence among the 4 subgroups, and stroke recurrences were most frequent in Group D (p<0.0001, Log-rank test).

Conclusions:
In Japanese minor stroke, age, NIH stroke scale score, chronic kidney disease, HbA1c, and LAA were significant predictors for the long-term outcome. In patients with both AF and LAA, stroke recurrences were most frequent, especially in the acute phase, and a long-term good outcome was least frequent consequently.
Abstract W MP102: Disparities in Access to Primary Stroke Centers: Geography, Not Gender, Race, or Ethnicity
Authors: Mullen Michael T , Bowman Ariel , Wiebe Douglas , Wolf Catherine S , Albright Karen C , Roy Jason , Balcer Laura , Branas Charles C , Carr Brendan G
Published: July 2021

Background:
Primary Stroke Centers (PSCs) have lower mortality than non-PSCs. Disparities in access to PSCs could widen existing disparities in cerebrovascular disease. We examined whether the proportion of the US population with ≤ 60 minute access to PSCs varies based on geography, gender, race, or ethnicity.

Methods:
A cross-sectional geographic analysis of the US was conducted at the block group level (n=208,667). Prehospital time from the population weighted center of each block group to the nearest PSC (as of 12/31/10) via ground ambulance was estimated using validated prehospital time intervals and accounting for existing road networks. Neilsen-Claritas 2010 Census estimates were used to describe the population of each block group. The population with ≤ 60 minute access was calculated overall, and stratified by urbanicity (major cities, minor cities, suburbs, rural). Access was compared by stroke belt location (AL, AR, GA, LA, MS, NC, SC, TN vs. all other states), gender, race, and ethnicity.

Results:
There were 811 PSCs in the US on 12/31/2010. Of the 309 million people in the US, 65.8% had ≤ 60 minute PSC access by ground ambulance. The proportion of the population with PSC access ≤ 60 minutes was: 87% in major cities, 59% in minor cities, 9% in suburbs, and 1% in rural areas. PSC access was lower in stroke belt states, due to poor access in stroke belt cities (Table). Non-White and Hispanic individuals were more likely to have PSC access than Whites and non-Hispanics; there was no meaningful difference in access by gender (Table).

Conclusions:
There are significant geographic and demographic disparities in access to PSCs. Access is poor in suburban and rural areas. Despite the higher burden of cerebrovascular disease in stroke belt states, access to care is lower in these areas. Public policy and systems planning is needed to ensure acute stroke therapies are available in these areas.
Abstract W MP111: Prevalence and Risk Factors of Silent Cerebral Infarcts in Children with Hemoglobin SC Disease
Authors: Guilliams Kristin , Sun Jennifer , Hulbert Monica
Published: July 2021

Background:
Hemoglobin (Hb) SC disease comprises 22% of all sickle hemoglobinopathies and is the second most common form of sickle cell disease. Silent cerebral infarcts (SCI) are common in Hb SS disease and are associated with male sex, higher systolic blood pressure (SBP), and lower baseline Hb concentration among children with Hb SS. However, SCI prevalence and risk factors are less well characterized in Hb SC disease. We tested the hypothesis that risk factors for SCI in Hb SC and Hb SS are similar.

Methods:
Retrospective chart review of children with Hb SC seen at St. Louis Children’s Hospital (SLCH) Sickle Cell Clinic 2004-2012 who had brain magnetic resonance imaging (MRI) available. At SLCH, all children with sickle cell disease undergo screening brain MRI after their 6
th
birthday; additional MRIs are obtained for concerning symptoms. Cerebral infarctions were identified as T2- or FLAIR-weighted hyperintensities identified in at least 2 planes or decreased diffusion; silent infarcts were diagnosed when the patient had no neurological symptoms that correlated with the infarct lesions. Hb concentrations and SBP were obtained from clinic well visits within a year before and after MRI. Human Studies Committee approval and waiver of consent were granted for this study.

Results:
Thirteen of 96 patients with Hb SC disease had SCI on MRI. The prevalence of SCI was 13.5%. Twelve (92%) subjects had subcortical lesions; 11 (85%) had SCI in the frontal lobe; and 10 (77%) subjects had bilateral infarctions. Seven (50%) of subjects with SCI were male. The mean age at identification of SCI was 11.9 years (range, 6.2-19.3 years). Ten children with SCIs had repeat MRI (range 0.1-6.4 years) following the SCI diagnosis. No child had progression or additional SCI on repeat imaging. Sex, SBP, and Hb concentration were not significantly different between children with and without SCIs (p=0.4).

Conclusion:
Our cohort of children with Hb SC had a SCI prevalence of 13.5%. The majority of children had bilateral subcortical lesions. SCIs had frontal lobe predominance. Unlike children with Hb SS, gender, elevated SBP or lower baseline Hb were not risk factors for SCIs in this cohort.
Abstract W MP114: Arterial Spin Label Perfusion Imaging in Acute Neonatal Stroke Reveals Hyperperfusion in Association With Cerebral Ischemic Injury
Authors: Rivkin Michael J , Watson Christopher G , Dehaes Mathieu , Gagoski Borjan A , Grant P. E
Published: July 2021

Introduction:
Perfusion magnetic resonance imaging (pMRI) in adults reveals a hypoperfused region, the ischemic penumbra, related to the fixed ischemic injury shown by diffusion weighted imaging (DWI) in acute stroke. Neonatal stroke has pathophysiology and optimum treatment that remain elusive. We hypothesized that altered regional perfusion accompanies the ischemic injury in focal neonatal stroke.

Methods:
Neonates (0-28 days of life) underwent MR imaging at 3T fieldstrength. pMRI employed a pseudocontinuous arterial spin labeling (PCASL) sequence with multi-slice echo planar readouts at 3x3x5mm3 resolution with TE/TR = 12ms/3.5s, labeling time = 1.6s, a post-labeling delay = 1.5s, 9 axial slices acquired, scan time ~5 min. Forty label/control image pairs were acquired, subtracted and averaged to obtain contrast maps proportional to quantified cerebral blood flow (CBF). DWI, susceptibility weighted imaging and T2-weighted series were obtained with standard protocols. Acute stroke was classified as arterial or venous. Core infarction was considered to lie in hypointense regions on DWI apparent diffusion coefficient maps. Regional perfusion signal was compared to the ischemic core on DWI and to the homologous uninvolved region in the contralesional hemisphere.

Results:
Data were collected on 20 neonates, (13 males; median/mean gestational age=38/38.5 weeks) with acute stroke (11 arterial ischemic stroke (AIS); 9 venous) scanned at median postnatal age=1.5 days. Evidence of regional hyperperfusion existed in 10/11 (91%) neonates with AIS and 4/9 (44%) with venous stroke. Hyperperfusion was part of a heterogeneous pattern of hypo- and hyperperfusion in 4 infants with AIS and 3 infants with venous infarct. Electroencephalography data obtained at presentation were available for 19 (95%) of the neonates. Fourteen infants (70%) had either electrographic seizure or focal sharp waves in the same hemisphere as the acute infarction.

Conclusion:
Arterial spin labeling pMRI can be successfully obtained in acute neonatal stroke. Unlike adults, pMRI often reveals hyperperfusion rather than hypoperfusion in neonates. This hyperperfusion may be due to early spontaneous reperfusion or to the neuronal hyperexcitability of stroke-associated seizure.
Abstract W MP40: Pyruvate Protects Post-Hypoxic Neuronal Cells and a Blood Brain Barrier Model From rtPA Toxicity
Authors: Ryou Myoung-Gwi , Choudhury Gourav Roy , Winters Ali , Xie Loukun , Mallet Robert T , Yang Shao-hua
Published: July 2021

Recombinant tissue plasminogen activator (rtPA) is the only FDA-approved treatment for ischemic stroke. However, rtPA’s therapeutic window is limited to 4.5 h after stroke onset due to hemorrhagic transformation and neurotoxicity. Here, we demonstrated that the intermediary metabolite pyruvate protects neuronal cells and a blood brain barrier (BBB) model from delayed rtPA toxicity in an
in vitro
oxygen-glucose deprivation (OGD, 0.5% O
2
)-reoxygenation model of ischemic stroke. After 3 or 6 h OGD, neuronal cells were reoxygenated with 11 mM glucose ± 8 mM pyruvate and/or 10 μg/ml rtPA. Cellular viability, reactive oxygen species (ROS), matrix metalloproteinase-2 (MMP2) activity, and cellular contents of NADPH, NADP
+
, ATP, MMP2, tissue inhibitor of metalloproteinase-2 (TIMP2), and phosphor-activation of anti-apoptotic p70s6 kinase, Akt and Erk were measured. Pyruvate treatment after 3 h OGD decreased cell death by 80% in the absence (P < 0.01) and 64% in the presence (P < 0.01) of rtPA. After 6 h OGD, rtPA exacerbated cell death; pyruvate dampened this effect. Three hours OGD and 4 h reoxygenation + rtPA increased ROS formation by 50%. Pyruvate prevented this ROS formation and doubled antioxidant NADPH/NADP
+
ratio and ATP content. In the BBB model, 3 h OGD and 24 h reoxygenation increased FITC-dextran leakage, indicating disruption of intercellular junctions. Although rtPA exacerbated this effect, pyruvate prevented it while sharply lowering MMP2/TIMP2 ratio and increasing phosphorylation of p70s6 kinase, Akt and Erk. Pyruvate protects neuronal cells and BBB tight junctions from OGD-reoxygenation and rtPA toxicity while reducing ROS and activating anti-apoptotic signaling. These results support the use of pyruvate as an adjuvant to dampen rtPA’s side effects, thereby extending rtPA’s therapeutic window.
Abstract W MP5: The Global Impact of Recent Intra-Arterial Therapy (IAT) Randomized Controlled Trials on Current and Future Stroke Practice
Authors: Sarraj Amrou , Bibars Wafi , Boehme Amelia K , Martin-Schild Sheryl , Grotta James C , Savitz Sean I
Published: July 2021

Background and Objective:
Recent RCTs have failed to show benefit of intra-arterial therapy (IAT). We sought to determine whether these trials have affected the views and practice of IAT amongst stroke-treating physicians.

Methods:
An international web-based survey was sent to 753 stroke-treating physicians across the globe.

Results:
322 physicians responded (43% rate); 25% were interventionalists; 80% practice in 24/7 IAT capable centers (fig 1). IAT volume per year prior to the RCTs (fig 2) has now decreased according to nearly half of the respondents. Physicians are now more selective (59%) while a third made no changes in pursuing IAT and 6% “do not pursue IAT anymore” (fig 3). Although 76% still perceive IAT is effective under certain criteria, two thirds said they feel “less obligated” to offer IAT. When asked about the RCTs, respondents felt the devices were outdated (36%), patient selection methods were “not optimal” (32%), recanalization rates could have been better (25%) or the trials should have been better designed (20%). Interestingly, centers currently enrolling in IAT trials intervene on large proportions of patients outside of studies (fig 4). The single most important factor in patient selection is shown in fig 5. Over half prefer a CT modality for patient selection; while 16% chose MRI and 11% use clinical criteria only when deciding to pursue IAT. Finally, three quarters of the contributors said that patients should be taken to IAT only in the context of clinical trials to test its efficacy, 21% said IAT should be continued “outside of trials” and only 3% pronounced it not useful (fig 6).

Conclusion:
While the results of recent RCTs have changed the views of stroke treating physicians, IAT continues to be practiced worldwide. The majority of our respondents is more selective and awaits results of new trials with the stent retrievers and better selection methods. Despite endorsing the practice of IAT only within trials, over half are still treating cases outside studies.
Abstract W MP55: Inflammatory Biomarkers and Incident Stroke in the Framingham Offspring Study.
Authors: Shoamanesh Ashkan , Preis Sarah R , Beiser Alexa S , Kase Carlos S , Wolf Philip A , Benjamin Emelia J , Romero Jose R , Seshadri Sudha
Published: July 2021

Background:
Inflammatory cascades are believed to be involved in pathogenesis of small vessel disease and atherothrombosis. We related a comprehensive panel of inflammatory biomarkers to risk of incident ischemic stroke (IS) in a community-dwelling sample

Methods:
Stroke-free Framingham Offspring attending exam cycle 7 (1998-2001) had multiple serum inflammatory biomarkers measured. Fourteen biomarkers representing various components of the inflammatory cascade, including systemic inflammation (C-reactive protein [CRP], interleukin-6, monocyte chemotactic protein 1, tumor necrosis factor-α, tumor necrosis factor receptor 2 [TNFr2], osteoprotegerin and fibrinogen), vascular inflammation (intercellular adhesion molecule-1, CD40 ligand, P-selectin, lipoprotein-associated phospholipase A2 mass and activity, total homocysteine [tHcy] and vascular endothelial growth factor [VEGF]) and oxidative stress (myeloperoxidase) were selected. Cox proportional hazard models were used to relate individual biomarkers to risk of incident IS. Model A included age and sex. Model B additionally adjusted for systolic blood pressure, hypertension treatment, current smoking, diabetes, cardiovascular disease, and atrial fibrillation. Hazard ratios (HR) are presented as per 1 SD increment.

Results:
In 3224 participants (age: 61±9 years, 54% women), 98 experienced incident IS (mean follow-up of 9.8 [±2.2] years). In Model A, log-CRP (HR: 1.28 [95%CI 1.04-1.56]), log-TNFR2 (HR: 1.33 [95%CI 1.09-1.63]), tHcy (HR: 1.32 [95%CI 1.11-1.58]) and VEGF (HR: 1.25 [95%CI 1.07-1.46]) were associated with risk of incident IS. All associations, except for CRP, remained significant in Model B {log-TNFR2 (1.24 [1.02-1.51]), tHcy (1.20 [1.01-1.43]), VEGF (1.21 [1.04-1.42]) and CRP (1.13 [0.92-1.40])}. Addition of these 4 biomarkers to the clinical Framingham Stroke Risk Profile score improved stroke risk prediction (net reclassification improvement: 0.34; p<0.05 using boundaryless models).

Conclusions:
Higher levels of four biomarkers: CRP, tHcy, TNFR2 and VEGF increased risk of incident ischemic stroke. Further research is required to confirm their utility in improving stroke risk prediction, and explore their role as potential therapeutic targets.
Abstract W MP58: The Relationship Between Carotid Stiffness, Diastolic Diameter, and White Matter Hyperintensity Volume:
The Northern Manhattan Study
Authors: Markert Matthew S , Dong Chuanhui , Della-Morte David , Roberts Eugene , Bartels Susanne , Elkind Mitchell S , Sacco Ralph L , Wright Clinton B , Rundek Tatjana
Published: July 2021

Background:
Changes in the extracranial vasculature may be associated with small vessel disease in the brain. We sought to examine the association of carotid stiffness and carotid diastolic diameter with white matter hyperintensity volume (WMHV), a magnetic resonance imaging (MRI) measure for cerebral small vessel disease, in a multi-ethnic community-based cohort.

Methods:
We evaluated 1140 stroke-free participants in the Northern Manhattan study who underwent brain MRIs and high-resolution carotid ultrasounds. We used linear regression to examine carotid stiffness and diastolic diameter with WMHV after adjusting for sociodemographics, lifestyle behaviors, and traditional vascular risk factors.

Results:
Among 1140 participants (mean age: 70.6±9.0 years; 61% women; 15% White, 16% Black, 59% Hispanics), the mean carotid stiffness was 8.19 ± 5.39, mean carotid diastolic diameter was 6.16 ± 0.93 mm, and mean WMHV 0.68 ± 0.84. In a fully adjusted model, diastolic diameter was associated with log-WMHV (β=0.10, p=0.001). In a stratified multivariable linear model, greater carotid arterial stiffness and diastolic diameter were associated with log-WMHV among Hispanics (β=0.15, p=0.005 and β=0.13, p<0.001, respectively), but not among blacks or whites.

Conclusion:
Greater carotid stiffness and diastolic diameter were associated with greater WMHV independent of demographics and traditional vascular risk factors, especially among Hispanics. Further studies are needed to understand how these large artery characteristics relate to WMH formation and lesion load. Carotid ultrasound may be a useful tool to assess the risk of increased brain white matter disease in a pre-clinical stage.
Abstract W P103: Rates and Predictors of Five Year Survival in Asymptomatic Medicare Beneficiaries Undergoing Carotid Revascularization
Authors: Suri M Fareed K , Chaudhry Saqib A , Qureshi Adnan I
Published: July 2021

Background:
Current American Heart Association guidelines recommend carotid revascularization for asymptomatic patients based on co-morbid conditions and life expectancy.

Objective:
To determine the rates and predictors of five year survival in elderly patients with asymptomatic carotid artery stenosis who underwent either surgical or endovascular treatment.

Methods:
The study cohort included a representative sample of fee-for-service Medicare beneficiaries aged ≥65 years who underwent endovascular or surgical treatment for asymptomatic carotid artery stenosis with post-procedure follow-up of 3.4 (±1.7) years. The rates of 5 year survival were determined using Kaplan Meir survival methods. Cox proportional hazards analysis was used to assess the relative risk (RR) of all-cause mortality for patients in presence of selected co-morbidities including ischemic heart disease, chronic renal failure, and atrial fibrillation after adjusting for potential confounders such as age, gender, race/ethnicity and procedure type.

Results:
A total of 22177 patients with asymptomatic carotid artery stenosis were treated with either endovascular (n=2144) or surgical treatment (n=20033). The overall estimated 5 year survival rate was 95.3% (95% CI 95.0-95.6 %); and 95.5% and 93.8% in patients treated with surgical and endovascular treatments, respectively. After adjusting for potential confounders, relative risks of all-cause five year mortality was significantly higher among patients with atrial fibrillation (relative risk [RR] 1.9, 95% confidence interval [CI] 1.6-2.2) and those with chronic renal failure (RR 2.1, 95% CI1.7-2.6). Concurrent ischemic heart disease did not affect the all-cause mortality (RR 1.1, 95% CI0.9-1.3).

Conclusion:
Risks and benefits must be carefully weighed prior to carotid revascularization in elderly patients with asymptomatic carotid artery stenosis who have concurrent atrial fibrillation or chronic renal failure.
Abstract W P121: Stroke Severity in Men and Women: What Proportion of the Disparity Can Be Explained by Differences in Cardiovascular Risk Factors?
Authors: Albright Karen C , Boehme Amelia K , Sen Bisakha , Aswani Monica , Mullen Michael T , Gonzales Nicole , Savitz Sean I , Martin-Schild Sheryl
Published: July 2021

Background:
Prior studies have shown that women present with more severe stroke. It has been suggested that sex differences in stroke severity are related to age, stroke subtype, or cardiovascular risk factors. We aimed to determine the proportion of sex disparity in stroke severity that can be explained by differences in these variables using Oaxaca decomposition, an econometric technique which quantifies the differences between groups.

Methods:
White and Black ischemic stroke patients who presented to two academic medical centers in the US (2004-2011) were identified using prospective stroke registries. In-hospital strokes were excluded. Patient demographics and medical history were collected. Stroke severity was measured by NIHSS. Linear regression was used to determine if female sex was associated with NIHSS score. This model was then adjusted for potential confounders including: age, race, stroke subtype, and cardiovascular risk factors. Oaxaca decomposition was then used to determine the proportion of the observed sex differences in stroke severity that can be explained by these variables.

Results:
4925 patients met inclusion criteria. Nearly half (n=2346) were women and 39% (n=1942) were Black. Women presented with more severe strokes (median NIHSS 8 vs. 6). In addition, women were older on average (68 vs. 63 years) with more frequent atrial fibrillation (18% vs. 13%), diabetes (34% vs. 30%), and hypertension (78% vs. 72%). Oaxaca decomposition revealed that age, race, atrial fibrillation, large vessel etiology, diabetes, hypertension account for only 63% of the sex differences seen in NIHSS score on presentation.

Conclusion:
In our biracial sample, women presented with more severe strokes than men. This difference remained significant even after adjustment for age, stroke subtype, and cardiovascular risk factors. Further, over 1/3 of the observed gender difference in stroke severity was unexplained.. Additional study is warranted to investigate the etiology of the gender differences in stroke severity.
Abstract W P127: Epidemiology of Cerebrovascular Disease: Association Between Geographic Location and In-Hospital Mortality
Authors: Mizrahi Moshe A , Rincon Fred
Published: July 2021

Background:
Extant literature suggests that the South has the lowest ground and air access to Neurocritical Care Units (NCUs) and has the highest number of admissions for subarachnoid hemorrhages (SAH) and intracerebral hemorrhages (ICH) than in other regions. NCUs have been shown to improve outcomes for patients with SAH and ICH, and delayed access may be potentially harmful. Evaluating for in-hospital mortality after SAH or ICH in regions with less access to NCUs may prove useful in determining the need for adequate access.

Objectives:
We sought to determine the in-hospital mortality trends for SAH and ICH from 1979 to 2008 per geographic region in relation to the US 2000 standard death rate to derive adjusted comparisons.

Methods:
The sample was obtained from the National Hospital Discharge Survey (NHDS) and cases were identified using the ICD-9-CM codes 430 for SAH and 431 for ICH. Age and geographic regions were divided into subgroups according to NHDS recommendations. Annual data was divided into 6 epochs for analysis of temporal changes.

Results:
We identified 612,600 cases of SAH and 1,530,613 cases of ICH in the US over a 30-year study period. Overall, crude in-hospital mortality after SAH or ICH was highest in the South [32% (95% CI, 29-35%) and 34% (95% CI, 32-35%), respectively] (
p
= 0.001). Crude in-hospital mortality after SAH and ICH per epoch demonstrated a positive temporal trend supported by the Cochran-Armitage trend test (p < 0.0001) and was highest in the South during the sixth epoch (2004-2008) at 24% (95% CI, 22-26%) (
p
= 0.001). After adjusting to the US 2000 standard death rate, there was excess mortality in the South with a standard mortality ratio of 1.25 (99% CI, 1.24-1.26) (
p
< 0.01) as compared to other regions except for in the Northeast, which was an unanticipated finding.

Conclusions:
In-hospital mortality specific to SAH and ICH is higher in US regions identifiable with less access to NCUs when adjusted for all-cause mortality in the US. This study raises numerous questions regarding impact of NCU access and highlights the need for additional data and efforts to maximize access in an efficient manner.
Abstract W P156: Perioperative Low Arterial Oxygenation is Associated With Increased Risk of Stroke After Cardiac Surgery
Authors: Miller Alexandra M , Grega Maura , McKhann Guy M , Selnes Ola A , Baumgartner William , Gottesman Rebecca F
Published: July 2021

Background:
Postoperative stroke occurs in up to 5% of cardiac surgery patients, contributing significantly to mortality and morbidity. Patient characteristics as well as intraoperative factors have been associated with a higher risk of stroke. We hypothesized that poor systemic blood oxygenation in the perioperative period is associated with increased risk of stroke following cardiac surgery.

Methods:
This was a case-control study of 311 adult patients who underwent cardiac surgical procedures at a single center from 2003-6. Patients having a postoperative stroke were matched 1:2 with controls. Minimum and average pO2 values, as measured from arterial blood gas values during and up to 24 hours after the start of surgery, were recorded and evaluated as continuous and categorical (in quartiles) predictors. Conditional logistic regression models adjusted for hypertension, diabetes, hyperlipidemia, cardiopulmonary bypass time, and prior stroke were used to evaluate associations between minimum and average pO2, each, and stroke status.

Results:
Lower nadir pO2 values were significantly associated with postoperative stroke. Per 10 mm Hg decline in nadir pO2, odds of stroke increased nearly 25% (OR 1.23, 95% CI 1.09-1.39). Nonlinear models of oxygen levels predicting stroke were explored (figure) but results remained similar; the linear model had the best statistical fit. Each equivalent decrease in mean pO2 was associated with smaller but significantly increased odds of stroke (OR 1.08, 95% CI 1.01-1.15). Having a nadir pO2 value in the lowest vs highest quartile was associated with 3.3-fold increased odds of stroke (95% CI 1.51-7.23).

Conclusion:
Odds of stroke after cardiac surgery is significantly increased in patients with a low minimum or average pO2 within 24 hours of surgery. This relationship is independent of other potential confounders of operative outcome.
Abstract W P167: Lacunar Infarction and Hypertensive Intracerebral Hemorrhage-Similarities and Differences of Two Different Clinical Entities of Cerebral Small-Vessel Disease
Authors: Suzuki Satoshi , Fujimoto Shigeru , Inoue Takuya , Tsuchimochi Ryosuke , Ishitsuka Takao
Published: July 2021

Introduction:
Lacunar infarction (Lac) and hypertensive intracerebral hemorrhage (ICH) are known as cerebral small-vessel disease in which hypertension plays a pivotal role in the development of pathology. However, it is unclear why some patients suffer from cerebral infarction and others bleed. We compared the background of these two groups, and examined differences and similarities between them.

Methods:
Between February 2008 and January 2013, 1149 patients were admitted to our institution within 1 week after the onset of stroke. A database was prospectively constructed with this consecutive patients’ cohort and data were analyzed retrospectively. Among the patients, 138 had Lac and 109 had ICH.

Results:
Age, sex, and BMI were not different between the groups. Medication prior to the onset of stroke was more common in Lac than in ICH (77.5% vs. 55.1%; p<0.001). The frequency of antiplatelet therapy, blood pressure-lowering therapy, and lipid-lowering therapy was not different between the groups. Treatment for diabetes mellitus (DM) was significantly more frequent in Lac than in ICH (29.0% vs. 8.3%; p<0.001). Calcification of the aortic arch was significantly more common in Lac than in ICH (62.2% vs. 43.3%; p=0.009). Smoking, past history of stroke, and familial history of stroke were not different between the groups. Left-sided stroke was significantly more common in Lac than in ICH (63.8% vs. 50.4%; p=0.004). On admission, triglycerides, total cholesterol (Chol), HDL-Chol, LDL-Chol, total protein, serum albumin, and blood sugar levels were not different between the groups. HbA1c levels on admission were significantly higher in Lac than in ICH (6.4+/-1.3% vs. 5.9+/-1.0%; p=0.004).

Conclusions:
Lac and ICH have similar backgrounds. However, left-sided stroke, calcification of the aortic arch, and a medical history of DM are more common in Lac than in ICH patients. HbA1c values on admission are higher in Lac than in ICH patients. This suggests that there are subgroups of Lac in which the pathological process is different from that in ICH. Therefore, endothelial damage induced by DM may play a role in some patients with Lac, and left-sided propensity and a tendency for aortic arch calcification suggest that some aortogenic embolisms may be diagnosed as Lac.
Abstract W P186: Usefulness of the New Prehospital Cerebrovascular Disease Triage Score for Patients With Impaired Consciousness by Emergency Medical Services
Authors: kajimoto katsufumi , Kanki Hideaki , Nagatsuka Kazuyuki
Published: July 2021

Background and Purpose:
Early stroke recognition optimizes patients’ opportunities to benefit from therapeutic options; however, accurate stroke recognition by emergency medical services (EMS) is difficult in patients with impaired consciousness. Here we attempted to establish a new prehospital stroke triage score for such patients.

Methods:
In 2010, 713 patients (average age, 71 years; 421 men) presenting with impaired consciousness (score of <15 on the Glasgow coma scale) on EMS arrival, who were brought to our hospital, were included. We compared the relation between the symptoms and the vital signs on EMS arrival and the final diagnosis.

Results:
A final hospital diagnosis of stroke was made for 353 in 713 patients (49.5%). Systolic and diastolic blood pressure (SBP, DBP) on EMS arrival were significantly higher in the stroke group than in the non-stroke group (SBP: 172 mmHg vs 143 mmHg, p < 0.01, DBP: 93 mmHg vs 78 mmHg, p < 0.01). In contrast, the pulse rate (PR) was lower in the stroke group (84 bpm vs 88 bpm, p < 0.05). Receiver operating characteristic analysis showed that the optimum SBP, DBP, and PR cutoffs for stroke were 150 mmHg (sensitivity 76%, specificity 59%), 90 mmHg (63%, 70%), and 90 bpm (70%, 42%), respectively. Using univariate analysis, SBP of >150 mmHg, DBP of >90 mmHg, PR of <90 bpm and an arrhythmia case in addition to new-onset hemiparesis were significantly associated with stroke, whereas a case with cold sweat was not significantly associated. Using multivariable analysis, new onset hemiparesis (Odds ratio 11.0; 95% CI, 5.76-22.7), SBP of >150 mmHg (2.21, 1.26-3.87), DBP of >90 mmHg (2.88, 1.65-5.09), and PR of <90 bpm (2.25, 0.80-3.80) were significantly associated with stroke. The prehospital stroke triage score was calculated for each patient with 1 point assigned to patients with SBP of >150 mmHg, DBP of >90 mmHg, PR of <90 bpm, and 2 points for new onset hemiparesis. The triage score of >2points revealed stroke with relatively high sensitivity and specificity (sensitivity 63%, specificity 87%, AUC = 0.809).

Conclusion:
The new prehospital stroke triage score was calculated on the basis of vital signs in addition to new onset hemiparesis. This score is very useful for triage of stroke presenting with impaired consciousness.
Abstract W P20: A Model to Calculate the Expected Treatment Effect in Acute Endovascular Stroke Trials
Authors: Lansberg Maarten G , Lemmens Robin , Christensen Soren , Mishra Nishant K , Albers Gregory W
Published: July 2021

Background:
Recent trials have shown no benefit of endovascular therapy. This may, in part, be explained by inaccurate estimates of the treatment effect used in the sample size calculations of these trials. A predictive model which includes variables that modify the expected treatment effect might yield more accurate estimates, and could be valuable in the design of future acute stroke trials.

Methods:
We conducted a literature review to obtain estimates of parameters that are associated with good functional outcome (GFO) following recanalization. We developed a model to estimate the treatment effect in endovascular stroke trials and applied this model to two recently published endovascular stroke trials.

Results:
We estimated a 40% absolute difference in the proportion of GFO (mRS 0-2 at 90 days) associated with reperfusion in patients with ICA or M1 occlusions who have a substantial ischemic penumbra at baseline. To estimate the effect size in trials, this value was multiplied by: 1) the proportion of patients undergoing endovascular therapy in the active treatment arm; 2) the proportion of patients with occlusions of the ICA or MCA-M1; 3) the proportion of patients with a substantial penumbra and a DWI lesion <50mL; and 4) the absolute difference in the proportion of patients with reperfusion, defined as TICI 2B-3, between the endovascular treatment and control arms.

Based on literature review we assumed a reperfusion rate of 20% in the control arms of IMS III and MR Rescue, a 50% prevalence of patients with substantial penumbra and DWI lesions<50 mL in IMS III, and a 75% prevalence in the penumbral arms of MR Rescue. Based on these model inputs, a 2.2% increase in GFO with endovascular therapy was expected in IMS III, which closely matches the observed 2.1% increase. For MR Rescue, the model predicted a 1.5% increase in GFO with endovascular therapy. Considering the small sample size, this equates to 0.5 additional patients with GFO which closely matches the observed result of 3 fewer patients with GFO.

Conclusion:
A simple model shows promise for estimating the treatment effect of endovascular stroke trials. It may be useful for the design of future trials and could lead to different inclusion criteria or larger sample sizes compared to the recently conducted studies.
Abstract W P209: Development of a Useful Brain Ischemic Stroke Model via a Transient Occlusion of Middle Cerebral Artery in the Nonhuman Primate
Authors: Sho Eiketsu , Zhu Zhenghua , Zhao Yuchao , Chen Jiqiao , He Daomei , Wang Weifang , Tu Xiaodie , Ma Junchao , Zheng Weiwen
Published: July 2021

Objectives:
Most experimental stroke research is carried out in rodents, but given differences between rodents and human, the nonhuman primate (NHP) models may provide a valuable tool to study the clinical therapy. We developed a surgical method for transient occlusion of the middle cerebral artery (MCA-M1) in the Cynomolgus monkeys to evaluate the MCA territory blood flow, the model stability, animal clinical neurological behavior, morphology changes under magnetic resonance imaging (MRI) and histopathology.

Methods:
The left brain sylvian fissure was exposed by a small fronto-temporal craniotomy. The MCA-M1 was exposed by microsurgical dissection and clipped for 4 hours. The brain blood flow was measured in the MCA territory during the ischemia period and early phase of reperfusion period. The clinical neurological examinations and MRI were carried out at regular post-operative course till 4 weeks of stroke.

Results:
During MCA occlusion, the MCA territory blood flow was decreased significantly in 80%. This territory was reflowed right after reperfusion and showed an overload in about 20% over pre ischemia flow within 1hr after reperfusion and gradually returned to previous flow (Fig 1). Animal neurological behavior changed significantly within 1 week and became a steady status of neurological impairment. MRI demonstrated extensive MCA territory infarction. Histologically, at the end of 4 week stroke the brain showed a clear board of glia proliferation between infarct and normal brain tissue.

Conclusion:
These results indicate a stable ischemic stroke model in cynomolgus monkeys after complete MCA-M1 occlusion, which will be a useful NHP stroke model for stroke research and the clinical therapeutic studies.

Fig 1 Changes in MCA territory blood flow during ischemia-reperfusion period