bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP434: The SAH score: An Outcome prediction model
Authors: Naval Neeraj S , Kowalski Robert , Chang Tiffany , Caserta Filissa , Carhuapoma Juan R , Tamargo Rafael J
Published: July 2021

Objective:
To create a reliable model for predicting mortality following aneurysmal subarachnoid hemorrhage (aSAH) based on admission variables.

Background:
Hunt & Hess grade is commonly used as a grading scale to predict mortality following aSAH. The scale relies only on clinical presentation and does not incorporate other admission factors making it suboptimal for outcome prediction.

Methods:
Prospectively collected data of aSAH patients admitted to our institution between 1991-2009 were reviewed. We analyzed factors that impacted in-hospital SAH mortality following multiple logistic regression analysis. Scores were ‘weighted’ based on relative risk of mortality following stratification of each of these variables. Hunt & Hess grade was subdivided into grades I/II, III, IV and V; age was split into 4 subgroups: 18-49, 50-69, 70-79 and >80. Medical co-morbidities were subdivided into none, 1 or >/=2 based on co-morbidities derived either from Charlson index or other factors (hypertension, cocaine) historically known to impact SAH outcomes, only if they were associated with increased mortality on univariate analysis.

Results:
1134 patients were included; all-cause SAH hospital mortality was 18.3%. Hunt & Hess Grade, age and medical co-morbidities significantly impacted mortality following multivariate analysis (P< 0.05). Association with mortality based on Hunt & Hess Grade was 7%(I/II; score 0), 16%(III; score 1), 31%(IV; score 2) and 65%(V; score 4). Mortality based on age was 13%(18-49; score 0), 18%(50-69; score 1), 34% (70-79; score 2) and 46% (>80; score 3). Relationship of co-morbidities and mortality was 9%(none; score 0), 17%(one; score 1) and 32%(two/more; score 2). Summated Scores ranged from 0-9 with progressively increasing mortality at higher scores (0=1%/ 1=4%/ 2=9%/ 3=13%/ 4=22%/ 5=52%/ 6=77%/ 7=88%/ 8=100%/ 9=100%). PPV for scores in the range 7-9 was 90%; 6-9 was 83%. NPV for range 0-3 was 93% and 0-4 was 91%. The area under the curve (AUC) was 0.825 (good accuracy), which was superior to Hunt & Hess Grade (AUC 0.775, fair accuracy).

Conclusions:
The SAH score is a more accurate prediction model than the Hunt & Hess grade in estimating likelihood of hospital mortality following SAH.
Abstract WP438: Rho Kinase-mediated Di-phosphorylation of Myosin Light Chain in the Sub-membranous Regions and Circumferential Actomyosin Contraction Mediate Thrombin-induced Barrier Disruption in Vascular Endothelial Cells
Authors: Hirano Mayumi , Hirano Katsuya
Published: July 2021

The disruption of blood-brain barrier plays a critical role in the pathophysiology of cerebrovascular diseases. Thrombin is one of the major factors which cause barrier disruption. The phosphorylation of myosin light chain (MLC) is a key signal of barrier disruption. MLC is thought to be di-phosphorylated sequentially at Ser19 and then Thr18, thereby inducing stress fiber formation to generate traction force to disrupt cell-cell contact. However, it is unclear how the phosphorylation at two sites contributes to barrier disruption. The present study investigated the role of mono- and di-phosphorylation of MLC (MLC-P and MLC-PP) in thrombin-induced barrier disruption. Thrombin (1 u/mL) decreased the transendothelial electrical resistance (TEER) with a peak at 3-5 min in porcine aortic endothelial cells (PAEC). A Phos-tag SDS-PAGE method was used to quantify the amount of MLC-P and MLC-PP. PAEC at confluence contained 25% MLC-P and 2% MLC-PP before stimulation. Upon thrombin stimulation, MLC-P marginally increased, while MLC-PP transiently increased to a peak of 35% at 3-5 min. MLC-P was localized mainly in the peri-nuclear region, while MLC-PP was localized mainly in the sub-membranous region of cell-cell contact. MLC-PP was also co-localized with the peripheral actin bundles. In contrast, thrombin induced stress fiber formation and localization of MLC-P and MLC-PP on the stress fibers when the cell-cell contact was loosed by removing extracellular Ca
2+
or in the cells at the growing phase with sparse cell-cell contact. Two different Rho kinase inhibitors, Y27632 and H1152, inhibited the thrombin-induced increase in MLC-PP, sub-membranous localization of MLC-PP and decrease in TEER, while having no effect on the level of MLC-P. Inhibition of myosin ATPase activity by 100 μmol/L blebbistatin inhibited the thrombin-induced decrease in TEER. The present study suggests that MLC-P and MLC-PP are independently regulated in endothelial cells, and that Rho kinase-mediated MLC-PP in the sub-membranous regions and the circumferential, but not radial, contraction plays a critical role in the thrombin-induced barrier disruption. Inhibition of MLC-PP thus provides a crucial strategy for restoring normal function of the blood-brain barrier.
Abstract WP441: Photodynamic Therapy Using Protease-Mediated Theranostic Photodynamic Agent Reduces Cathepsin-B Activity in Mouse Carotid Atheromata In Vivo
Authors: Shon Soo-Min , Choi Yongdoo , Lee Dong Kun , Kim Jeong-Yeon , Park Jin-Yong , Lee Su-Kyoung , Schellingerhout Dawid , Kim Dong-Eog
Published: July 2021

Background
Carotid atherosclerosis is a major cause of ischemic stroke. Nanotechology-based theranostics for atherosclerosis and stroke is still in its infancy.

Objective
—To investigate if an intravenously-injected cathepsin-B activatable theranostic agent (L-SR15) would be cleaved in and release a fluorescent agent (chlorine-e6) in mouse carotid atheromata, allowing both the diagnostic visualization and therapeutic application of these fluorophores as photosensitizers during photodynamic therapy (PDT) to attenuate plaque-destabilizing cathepsin-B activity by selectively eliminating macrophages.

Methods and Results
Thirty-week-old Apolipoprotein-E knock-out mice received intravenous injection of L-SR15 theranostic agent (n=5), control agent D-SR16 (n=5), or PBS (n=5) three times at days 0, 7, and 14. Twenty-four hours after each injection, the bilateral carotid arteries were exposed and Cy5.5 near-infrared fluorescent (NIRF) imaging was performed. Fluorescent signal progressively accumulated in atheromata of the L-SR15 group animals only, indicating that photosensitizers had been released from the theranostic agent, and were accumulating in the plaque. After each imaging session, PDT was applied with a continuous-wave diode-laser. Additional Cy7 near infrared imaging with a CatB-sensing activatable NIRF imaging agent reduced CatB-realated signal only in the L-SR15, with activity at day 22 significantly lower than at baseline. Histological studies demonstrated that L-SR15-based PDT eliminated macrophages by inducing apoptosis without affecting plaque size or smooth muscle cell numbers.

Conclusion
This is the first study showing that macrophage-secreted cathepsin-B activity could be attenuated by PDT using a protease-mediated theranostic agent.
Abstract WP60: Can Early Statin Administration in the Acute Stage of Ischemic Stroke Intensify the Effect of Thrombolysis?
Authors: Kang Jihoon , Kim Nayoung , Lee Ji Sung , Lee Juneyoung , Park Tae Hwan , Bang Oh Young , Han Moon-Ku , Park Seong-Ho , Bae Hee-Joon
Published: July 2021

Objective:
We aimed to determine whether early statin use improves functional outcome and reduces post-thrombolytic symptomatic intracerebral hemorrhage (sICH) in acute symptomatic steno-occlusion of major cerebral arteries.

Method:
Using a prospective stroke registry, we identified a consecutive series of 337 patients who arrived within 6 h of stroke onset, had symptomatic stenosis (>50%) or occlusion, received thrombolysis, and were followed up at 3 months. We compared the 3-month modified Rankin Scale (mRS) score and sICH incidence during hospitalization according to post-thrombolytic statin use. Statin use was categorized into early use (≤1 day of onset; EU), late use (> 1 day of onset, LU), and no use (NU). sICH was defined as type-2 parenchymal hemorrhage with a more than 4 point decrease in NIHSS or death.

Result:
The patients’ mean age was 6e8.8 years (55.8% males; median baseline NIHSS, 13). Thrombolysis modalities were as follows: intravenous only (25.5%), intra-arterial only (31.2%), and combined (43.4%). EU was 34.1% (N = 115); LU, 15.4% (N = 52); and NU, 50.4% (N = 170). Percentages of favorable outcome (mRS, 0-1) differed significantly by statin use (39.1% in EU, 34.6% in LU, and 22.4% in NU; P = 0.007); sICH rates also differed (2.6%, 0.0%, and 10.0%, respectively; P = 0.005). Multivariable analyses showed an independent increase in the odds of favorable outcome and decrease in those of sICH after early stain use (Figure).

Conclusion:
Early statin use may improve functional outcome and reduce the occurrence of post-thrombolytic sICH.
Abstract WP72: Safety of Label- and Protocol Violations in Acute Stroke tPA Administration
Authors: Lyerly Michael J , Albright Karen C , Boehme Amelia K , Shahripour Reza Bavarsad , Houston James T , Rawal Pawan V , Kapoor Niren , Alvi Muhammad , Sisson April , Alexandrov Anne W , Alexandrov Andrei V
Published: July 2021

Background:
IV-tPA remains the only FDA approved therapy for acute ischemic stroke, however less than 10% of patients receive treatment. This is partially due to the large number of contraindications on the drug label and continued use of NINDS trial criteria for patient selection.

Methods:
We retrospectively analyzed consecutive patients who received IV-tPA at our stroke center for label or NINDS protocol violations, as well as safety according to the NINDS t-PA Stroke Study definition of sICH. Other outcome variables included systemic hemorrhage, mRS at discharge and disposition.

Results:
A total of 308 patients were identified in our tPA registry between 2009 and 2011. Ninety six patients were excluded because they received tPA at an outside facility prior to transfer, leaving 212 patients for analysis. Median patient age was 68 (IQR 55, 82), median pretreatment NIHSS score was 8 (IQR 5, 14). Protocol violations occurred in 103 patients (49%). The most common violations were tPA delivery beyond 3 hours (26%), aggressive blood pressure management with nicardipine (15%), elevated PT/PTT (6.6%), minor or resolving deficits (4.2%), unclear time of onset (3.9%) and stroke within 3 months (3%). Three patients had a history of ICH. There were no significant differences in any of the safety outcomes between patients with or without protocol violations (Table). Furthermore, after controlling for age, admission NIHSS and glucose, there was no significant increase in the rate of any hemorrhagic transformation (OR 1.046, p= 0.905) or sICH (OR 0.569, p= 0.613) in patients with protocol violations.

Conclusions:
Despite nearly half of patients receiving tPA off label or in violation of the NINDS protocol, overall rates of hemorrhage remained low and did not differ from those who did not have violations. Our data support the need to mitigate restrictions for IV-tPA in patients presenting with acute ischemic stroke.
Abstract WP84: Temporal Trends in Nimodipine Use Among Aneurysmal Subarachnoid Hemorrhage Patients in The U.S.
Authors: Jimenez Lincoln , Ferioli Simona , Herbers Patricia , Khoury Jane , Adeoye Opeolu , Khatri Pooja , Kleindorfer Dawn
Published: July 2021

INTRODUCTION:
Delayed cerebral ischemia (DCI) is a major cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). Nimodipine is the only available treatment shown to prevent DCI and AHA guidelines have recommended its use since 1994 (Class I; Level of Evidence A). We queried the PREMIER database to investigate current utilization of nimodipine in the United States.

Methods
For this analysis, we utilized the Premier database, a representative sampling of US hospitals with pharmacy data from 2006 to 2010. Patients >18 years old with an aSAH (ICD-9 code 430) primary diagnosis and survival to hospital day 2 were included. Descriptive univariate analyses were performed utilizing student’s t-test, Wilcoxon rank sum or Chi square as appropriate. Logistic regression was used to analyze nimodipine use over time.

Results
Among 13,267 aSAH cases identified, 7,990 (62.2%) received at least one dose of nimodipine. See Table for patient characteristics. Nimodipine use steadily decreased from 65.4% (2006, 1st quarter) to 51.2% (2010, 4th quarter; p<0.001) during 5-year study period.

Conclusions
Despite Class I recommendations, only approximately 2/3 of patients with aSAH received nimodipine from 2006 to 2010 in this US sampling. Younger age, academic institutions, and longer length of stay were associated with predictors nimodipine use. Our finding of decreased utilization of nimodipine over time is unexpected and the explanation is not readily apparent. Further research should be performed to evaluate the reasons for these practice patterns and their clinical significance.
Abstract 1: Antegrade Flow Across an Intracranial Occlusion Can be Reliably Assessed on Ct Perfusion Source Images and it Predicts Recanalization With Intravenous Tpa
Authors: Mishra Sachin , Eesa Muneer , Almekhlafi Mohammed , Qazi Emmad , Goyal Mayank , Menon Bijoy , Demchuk Andrew
Published: July 2021

Background:
We aimed to see if antegrade flow observed on CT Perfusion Source Images (CTPSi) across an intracranial occlusion correlated with first run of DSA and predicted recanalization on DSA or repeat CTA.

Methods:
Patients with acute ischemic stroke and large vessel intracranial occlusion on CTA who had a CT Perfusion study followed by DSA or repeat CTA 4-6 hours later were included. CT Perfusion parameters were 8 cm coverage in static mode, acquisitions at 5 mm thickness, 5 seconds delay after contrast & 24 passes over 66 seconds. Antegrade flow was defined as the presence of ‘clot enhancement’ sign on the 1st pass of CTPSi and increasing density of contrast permeating the clot and filling the vessel distal to the occlusion on the 2nd and 3rd passes of CTPSi (Fig 1 & 2). This was correlated with the first run of DSA and recanalization was assessed on DSA (Group 1) or repeat CTA (Group 2).

Results:
Total 56 patients were included. In group 1(n=35), antegrade flow on CTPSI was present in 14/35 patients (40%). All these patients had antegrade flow on DSA and 12 of them showed early recanalization (TICI 2a, 2b or 3). IV t-PA was received by 29/35 patients. The sensitivity and specificity of CTPSi to predict antegrade flow when compared to DSA was 86.7% (95% CI, 59.5 - 98.3) and 95% (95% CI, 75.1 - 99.9) respectively. In Group 2 (n=21), antegrade flow was seen on CTPSI in 13 patients (62%) and all of them recanalized with IV t-PA. Six out of 8 patients without antegrade flow on CTPSi did not recanalize.

Conclusion:
Antegrade flow across an occlusion can be reliably assessed on initial passes of CTPSi and it predicts recanalization with IV t-PA.
Abstract 115: Snapshot MR-OEF for Simultaneous Imaging of Tissue Oxygenation and CVR in 90 Seconds
Authors: Cantrell Charles G , Menon Rajiv G , Vakhil Parmede , Chatterjee Neil , Jeong Yong , Ansari Sameer , Prabhakaran Shyam , Carroll Timothy J
Published: July 2021

Introduction:
Asymmetric hemispheric cerebral Oxygen Extraction Fraction (OEF) has been shown to be an independent predictor of stroke risk. Furthermore, the NIH/NINDS Progress Review Group has recently named tissue oxygenation imaging as a primary research goal in its August 2013 review. We have developed a novel method of imaging OEF with MRI. We present an analysis of MR-OEF images using breath-hold and cardiac-gating as inducers of physiologic stress.

Methods:
We acquire a 2D k-space volume using a novel rosette trajectory in 65 ms for simultaneous imaging of OEF and vascular reserve. Subjects were tested under 2 transient stress conditions: breath-hold and cardiac-gated. Breath-hold: 20 susceptibility weighted measurements were taken (Δt = 3 secs) with an induced 15 second breath-hold. Cardiac-gated: Because of the speed of PARSE (65 ms) we are able to see the transient hemodynamic fluctuations induced from the cardiac cycle. Images were acquired in 25 ms intervals from the R-wave trigger.

Results:
Measured mean OEF in normal brain parenchyma of 36.87 ± 6.6% and regions in symptomatic patients reaching 84.05 ± 4.54% correlate well with literature. OEF images taken during the first 125 ms of the cardiac cycle in a symptomatic patient with a right ICA stenosis are shown in Figure 1. Asymmetric hemispheric OEF (right hemispheric 13.06% elevation) is clearly visible. We also see a non-uniform flush in of de-oxygenated hemoglobin with a subsequent uneven outflow, unseen in healthy volunteers, suggesting regions of compromised cerebral vascular reserve.

Discussion/Conclusion:
Our novel acquisition allows us to simultaneously image single slice OEF and vascular reserve in 65 ms (with total scan time less than 90 seconds). Move over, because of its unprecedented speed, we for the first time, have the temporal resolution to examine the cerebral hemodynamic fluctuations caused by the pressure waveforms induced by the cardiac cycle.
Abstract 163: Carotid Stenosis and Stroke Recurrence in Minor Stroke Patients With Atrial Fibrillation
Authors: Fujimoto Shigeru , Ohsaki Masato , Kumamoto Masaya , Ishitsuka Takao , Kitazono Takanari
Published: July 2021

Background & Purpose:
Both atrial fibrillation (AF) and carotid stenosis (CS) can be associated with acute stroke recurrence and consequent bad outcome even in minor stroke. We investigated stroke recurrence and outcome in Japanese minor stroke patients with AF and/or CS.

Subjects & Methods:
Among the consecutive 6246 stroke patients who were admitted to the 7 stroke centers within 7 days after the onset, 634 patients with acute ischemic stroke with AF, 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. We observed an acute stroke recurrence during 3 weeks.

Results:
Acute stroke recurrence was observed in 27 (4.3%) patients. Major cerebral artery stenosis of 50% or more in diameter was observed in 159 (25.1%) patients, and among them 43 (6.8%) had carotid stenosis. Any major artery stenosis was more frequent in patients with than without stroke recurrence (55.6% vs 23.7%, p=0.0002). Carotid stenosis was more frequent in patients with than without stroke recurrence (25.9% vs 5.9%, p<0.0001). The initial NIHSS score was not different between patients with and without an acute stroke recurrence. Dyslipidemia, diabetes mellitus, and history of brain hemorrhage were more frequent, and HDL cholesterol and estimated GFR values were lower, and HbA1c, fasting glucose, BUN, and D-dimer values were higher, intima-media thickness 0f the common carotid artery was thicker in patients with than without an acute stroke recurrence. On the multivariate analysis, carotid stenosis (OR 4.93, 95%CI 1.60~15.2) and D-dimer value (OR 1.13, 95%CI 1.00~1.28) had a positive association with an acute stroke recurrence. Among 43 patients with both AF and CS, 7 had an acute stroke recurrence. With regard to the acute antithrombotic treatment, 5 patients were treated with only anticoagulant agents and other 2 patients were treated with both anticoagulant and antiplatelet agents.

Conclusions:
Carotid stenosis was a significant predictor for an acute stroke recurrence in patients with atrial fibrillation. Optimal antithrombotic treatment in the acute phase in stroke patients with both AF and CS should be investigated.
Abstract 173: Effects of Ischemic Preconditioning on Microglial Phenotype and Transcriptome
Authors: Weinstein Jonathan R , Lee Richard V , Noor Shahani , Dodge Ryan , Colman Jamie , Savos Anna , Murphy Sean P , Möller Thomas
Published: July 2021

Background:
Ischemic preconditioning (IPC) is a robust neuroprotective phenomenon in which a brief period of cerebral ischemia confers transient tolerance to subsequent ischemic challenge. Microglia are critical in stroke pathophysiology however their role in IPC is unknown.

Methods:
We performed middle cerebral artery occlusion (MCAO) or sham surgery on 12 - 14 week old wild-type male mice following established paradigms for IPC ± stroke. We assessed infarct volume with 2,3,5-triphenyltetrazolium staining and used ex vivo flow cytometry (exFC) to quantify immune cell populations in cortex following IPC. We performed immunofluorescent microscopy (IFM) with stereology (optical dissector), Cavalieri point counting and Ki67 staining to characterize ionized calcium-binding adapter 1 molecule (IBA1)-positive immune cell number, morphology and proliferation, respectively. Finally, we performed mouse ST gene arrays (Affymetrix) on RNA isolated from sorted cortical microglia and carried out bioinformatic (Ingenuity Systems) and promoter analyses to characterize the effects of IPC on the microglial transcriptome.

Results:
IPC reduced infarct volume from 53±6 (mean±SEM) to 26±8 mm3 (p<0.01, n = ≥5 mice per group) and induced robust increases in the number of ipsilateral cortical microglia and macrophages relative to both sham and contralateral controls (n = ≥13 and ≥4 mice per group for exFC and IFM, respectively). IPC also induced marked increases in IBA1+ cell volume (processes and somata). Microarray analysis demonstrated marked changes in microglial transcriptome [2,230 gene probesets (6.5% of total) were significantly regulated]. The top three IPC-induced canonical gene expression pathways were: (i) DNA replication, recombination and repair, (ii) Cellular assembly and (iii) Cell cycle.

Conclusions:
Our novel in vivo microglia-specific, IPC-targeted, genomic dataset indicates profound activation of cell proliferation-related gene expression. This finding correlates well with the IPC-induced increases we found in microglia/macrophage cell number. These unexpected findings indicate that cell cycle regulation of CNS immune cells may be important in IPC-mediated neuroprotection.
Abstract 58: Rates of In-Hospital Adverse Events and Discharge Outcomes Among Ischemic Stroke Patients Admitted to Joint Commission Primary Stroke Centers in United States
Authors: Chaudhry Saqib A , Zafar Taqi T , Umair Muhammad , Sachdeva Gautam , Afzal Mohammad , Adil Malik M , Jani Vishal , Hussain Syed I , Qureshi Adnan I
Published: July 2021

Background:
The beneficial impact of certification by Joint Commission (JC) for primary stroke centers (PSCs), on in hospital adverse events and outcomes remains unproven.

Objective:
To compare the rates of in-hospital adverse events and discharge outcomes among ischemic stroke patients between PSC and no PSC hospitals in United States.

Methods and Results:
We obtained the data from Nationwide Inpatient Sample from 2010 and 2011. The analysis was limited to states that publicly reported hospital identity. PSCs were identified by matching the NIS hospital files with the list provided by JC. The analysis was limited to patients (age ≥18 years) discharged with a principal diagnosis of ischemic stroke (ICD9 codes 433.x1, 434.x1, 436).

Results:
We identified a total of 123,131 ischemic stroke patients from 28 states. A total of 72,982 (59.3%) patients were admitted at PSCs. Patients admitted at PSCs were more likely to be men (48.3 vs. 46.7, p<0.0001), white (75.2 vs. 73.3, p<0.0001) and younger in age (71.1±14.7 vs. 72.3±14.3 p<0.0001. Total length of stay was similar among PSCs and non-PSCs (5.09±6. vs. 5.14±6.15 p<0.0001), while total charges were higher at PSCs ($48828 vs. $35946±14.3 p<0.0001). After adjusting for age, sex, race co-morbidities, DRG-based disease severity, and hospital characteristics, patients admitted at PSCs were at lower risk of in hospital adverse events complications; pneumonia (OR, 0.8; 95% CI, 0.7 to 0.9)-, urinary tract infection (OR, 0.97; 95% CI, 0.0.92 to 1.02), sepsis (OR, 0.65; 95% CI, 0..56 to 0..76), deep venous thrombosis (OR, 1.0; 95% CI, 0.76 to 1.33) and pulmonary embolism (OR, 0.58; 95% CI, 0.43 to 0.72). Patients evaluated at PSCs were more likely to receive rt-PA (OR, 1.32; 95% CI, 1.19 to 1.45) with less impatient mortality (OR, 0.88; 95% CI, 0.81 to 0.96) and more likely to get discharge to home (OR, 1.11; 95% CI, 1.07 to 1.15).

Conclusions:
Patients admitted to PSCs are less likely to have in hospital adverse events and better discharge outcomes.
Abstract 94: Blacks Arrive Later After Stroke Onset Than Whites in Chicago
Authors: Aggarwal Neelum , O'Neill Kathleen , Beckstrom Heather , Song Sarah , Hoelzel Sandy , Joyce Bridget , Gavras Heather , Martin Santrice , Richards Christopher , Masor Minna , Jenkins-West Dinene , Owens Laura , Prabhakaran Shyam
Published: July 2021

Objective:
To assess if ethnic disparities exist in the use of intravenous tissue plasminogen activator (tPA) for acute ischemic stroke (AIS) at primary stroke centers (PSCs) in Chicago, Illinois.

Background:
Ethnic disparities in stroke care include observed differences in stroke incidence, severity, mortality, acute management, and rehabilitation. There are less data regarding race disparities in the use of emergency medical services (EMS) and delivery of tPA.

Methods:
A retrospective analysis of the Get With The Guidelines (GWTG) Stroke registry was performed using a benchmark group of 11 PSCs that collected data on stroke admissions in 2012. We analyzed use of EMS, time from onset to arrival, tPA use, door to needle (DTN) time, and documented reasons for not administering tPA between blacks and white stroke patients.

Results:
In 2012, there were 2,682 stroke patients admitted to Chicago PSCs. The mean age was 65.2 years with 54.3% women, 50.4% black, and 38.5% white. Among ED arriving ischemic stroke patients, 12% received tPA; however, it differed by race (whites: 21.6% vs. black: 8.3%; p<0.001). Use of EMS (whites: 55.8% vs. blacks: 51.6%, p=0.172) did not differ by race but pre-notification was less frequent for black patients arriving by EMS (59.5% vs. 78.5%, p<0.001). Time from onset to ED arrival was longer in blacks (median 152.5 minutes vs. 85 minutes in whites), even among those using EMS (blacks: median 100.5 minutes vs. whites: 66 minutes). Among thrombolysed patients, DTN times were similar (81 vs. 83 minutes) between groups. However, blacks who did not receive tPA but presented in the 4.5 hour window were less likely to have documented contraindications to thrombolysis (67.1% vs. 82.5%, p=0.008) and more likely to have in-hospital delays (33.3% vs. 17.4%, p=0.243) compared to whites.

Conclusions:
At Chicago’s PSCs, blacks are much less likely than whites to receive tPA for stroke despite similar proportions accessing EMS. While some of this disparity may be accounted for stroke severity and type of stroke symptoms, delays in calling EMS and differences in pre-hospital notification and hospital evaluation are potential targets for public and professional education.
Abstract NS20: Improving Stroke Evidenced-Based Best Practices Across a Multi-State Healthcare System
Authors: Camp Deborah , Mroz Ann , Cronin Tina , Fernandez Maria
Published: July 2021

Background and Purpose:
As a National effort to provide a framework to improve stroke best practices, a multi- center healthcare system with 48 hospitals across ten states established a stroke collaborative working group. The purpose was to develop a forum to standardize and improve stroke evidenced-based best practices with sister facilities.

Methods:
A questionnaire was developed and distributed to the stroke collaborative group. A telephone conference was held to review survey results and organizational trends from the 2010 Get With The Guidelines (GWTG) stroke quality metrics. Three quality metrics, dysphagia screening, patient education and door to needle (DTN) were initially identified along with establishing three subcommittees to focus upon improving best practices for each of these measures. Educational webinars, best practice successes and barriers were shared on monthly conference calls as well as a development of an email stroke distribution list serve to improve communication.

Results:
The three chosen GWTG stroke quality metric score aggregates from 2010 to 2013 second quarter were: dysphagia screen 78.8% to 85.7%, patient education 86% to 94.6%, DTN 60 minutes or less 31% to 72.8% with a mean DTN time of 91 minutes to 68.8 minutes.

Conclusion:
Formation of a stroke collaborative group for this organization had a positive effect on improving stroke best practices. Areas of focus identified were standardized best practice processes which included creation of system-wide electronic stroke order sets, development of staff and patient educational materials, implementation of templates and development of a DTN challenge. As the Stroke Collaborative expanded three additional working subcommittees were established, Patient Satisfaction, Emergency Medical Service collaboration and Stroke Support Group Development. In conclusion facilitation of communication and collaboration utilizing individual talents and resources is an effective way to improve stroke evidenced-based best practice across a multi-state healthcare system.
Abstract T MP1: Predictive Factors of Favorable Outcome in Patients With Acute Large Vessel Occlusion
Authors: Yoshimura Shinichi , Sakai Nobuyuki , Okada Yasushi , Kitagawa Kazuo , Kimura Kazumi , Tanahashi Norio , Yamagami Hiroshi , Egashira Yusuke , Hyogo Toshio
Published: July 2021

Background:
The data of the nationwide prospective registry of acute cerebral large vessel occlusion (RESCUE-Japan Registry) was analyzed to know the predictive factors of favorable outcome at 90 days

Methods:
In this registry, patients with acute cerebral large vessel occlusion admitted within 24 h after onset were prospectively registered. The effect of various factors including endovascular treatment (EVT), intravenous tissue plasminogen activator (IV-tPA), and other medication on favorable outcome (modified Rankin scale 0-2) was analyzed.

Results:
A total of 1,315 patients were analyzed. The number of patients in favorable outcome was 422 (32.1%). Logistic regression analysis revealed that higher NIHSS (OR 0.875, 95%CI 0.858-0.894) and advanced age (OR 0.963, 95% CI 0.952-0.975) were significantly related to unfavorable outcome (Fig. 1). In contrast, IV-tPA (OR 2.489, 95% CI 1.867-3.319), EVT (OR 1.375, 95% CI 1.013-1.865), and free radical scavenger, edaravon, (OR 1.483, 95% CI 1.027-2.143) were significantly associated with favorable outcome. Combination with IV-tPA or EVT with free radical scavenger was better than without it (Fig. 2).

Conclusions:
This analysis indicated that IV-tPA, EVT and free radical scavenger were effective to obtain favorable outcome in the patients with acute large vessel occlusion. Combination with free radical scavenger was also effective.
Abstract T MP101: Association of Obstructive Sleep Apnea and Cardioembolic Stroke: A Retrospective Case Control Study
Authors: Lipford Melissa C , Calvin Andrew D , Mandrekar Jay , Somers Virend K , Brown Robert D , Flemming Kelly D , Caples Sean M
Published: July 2021

Introduction:
Obstructive sleep apnea (OSA) is an independent risk factor for ischemic stroke; however the causal mechanisms are unknown. Understanding etiology of stroke in OSA patients may: (1) aid in ascertaining how OSA exerts its influence in increasing stroke risk, and (2) facilitate tailoring recurrent stroke prevention management strategies in OSA patients. Our study compares stroke subtypes in OSA cases versus controls without significant sleep disordered breathing.

Hypothesis:
We hypothesized cardioembolic (CE) strokes would occur more frequently in OSA cases than in controls.

Methods:
Consecutive patients were identified who underwent polysomnography (PSG) at Mayo Clinic and suffered an ischemic stroke within one year after PSG. Patients with an apnea-hypopnea index (AHI) ≤ 10 were classified as controls; AHI > 10 classified as OSA cases. Mechanism of stroke was determined using (1) the Causative Classification System for Ischemic Stroke (CCS) and (2) the phenotype definitions used in the Trial of Org 10172 in Acute Stroke Treatment (TOAST). Information on cardiovascular risk factors, neuroimaging, and echocardiography data were collected on each patient.

Results:
In 53 total subjects, CE strokes were more common among OSA cases (72% vs 33%, p=0.01). Large artery atherosclerosis and small vessel occlusion strokes were more common in controls. Atrial fibrillation (AF) was more frequent in OSA patients (59% vs 24%, p=0.01). Frequency of CE stroke increased with OSA severity. The association between OSA and CE stroke remained significant after controlling for AF (p=0.03, OR 4.5). Echocardiogram data revealed CE stroke risk factors were more frequent in OSA cases (84% vs 52% p=0.02). There were no significant differences between groups for left ventricular ejection fraction, left atrial volume index, or right ventricular systolic pressure.

Conclusions:
The results demonstrate a strong association between OSA and CE stroke. In OSA patients presenting with cryptogenic stroke, high clinical suspicion for cardioembolism is warranted. This may lead to consideration of further studies (eg, transesophageal echocardiography, Holter monitoring, or extended cardiac monitoring) to identify cardioembolic risk factors such as paroxysmal AF.
Abstract T MP104: The Role of Antithrombotics Therapy in Recent Ischaemic Stroke Patients with Atrial Fibrillation: Analysis from VISTA
Authors: Abdul-Rahim Azmil H , Fulton Rachael L , Benedikt Frank , Tatlisumak Turgut , Paciaroni Maurizio , Caso Valeria , Diener Hans-Christoph , Lees Kennedy R ,   VISTA Collaborators
Published: July 2021

Background and Purpose:
There is uncertainty on the optimal latency after acute ischaemic stroke at which antithrombotic treatment should commence for atrial fibrillation (AF) patients, in order to prevent recurrent stroke (RS) without provoking symptomatic intracranial haemorrhage (SICH). We sought to describe the risk factors and patterns of RS and SICH in a cohort of patients with AF and recent stroke.

Methods:
We assessed the association of antihrombotic treatment (i.e. anticoagulants and antiplatelets) with the distribution of the modified Rankin Scale (mRS) at day 90, and the occurrence of RS and SICH. We developed statistical models for the prediction of RS and SICH in the first 90 days after stroke, using univariate and multivariate analysis.

Results:
Data were available for 1,644 patients. Combined antithrombotic therapy with both anticoagulation and antiplatelet (n=782) was associated with more favourable functional outcome across full scale mRS OR=1.785 (95% CI: 1.316, 2.421; P=0.0002), and significantly lower risk of mortality by day 90, SICH by day 90 and RS by day 90: Mortality day 90 OR=0.344 (95% CI: 0.235, 0.502; P<0.0001), SICH day 90 OR=0.18 (95% CI: 0.086, 0.37; P<0.0001) and RS day 90 OR=0.33 (95% CI: 0.21, 0.53; P<0.0001). Patients with ischaemic stroke who had high baseline glucose had a high risk of both RS and SICH events after stroke. Additionally, patients who had increased neurological impairment, previous history of TIA and received no antithrombotic treatment were at increased risk of RS. The relative risk of RS versus SICH appeared constant over time.

Conclusions:
It seems justified to initiate anticoagulation immediately the patient attains medical and neurological stability, taking into account the potential of haemorrhagic transformation as part of the natural progression in stroke and the increasing risk of recurrent stroke with time if left untreated. Antiplatelet treatment pending introduction of anticoagulation is reasonable.
Abstract T MP107: Ischemic Strokes While on Aspirin: Initiation of Clopidogrel Is Better than Re-initiation of Aspirin for Prevention of Future Vascular Events
Authors: Lee Meng , Wu Yi-Ling , Saver Jeffrey L , Lee Hsuei-Chen , Lee Jiann-Der , Chang Ku-Chou , Wu Chih-Ying , Lee Tsong-Hai , Wang Hui-Hsuan , Ovbiagele Bruce
Published: July 2021

Background:
It is currently unclear about what to do for the patient who has a breakthrough ischemic stroke while receiving aspirin, the so-called ‘aspirin treatment failure’.

Objective:
To compare the effectiveness of clopidogrel vs. aspirin for vascular risk reduction among ischemic stroke patients who were on aspirin treatment at the time of the index stroke.

Methods:
We analyzed the Taiwan National Health Insurance registry which comprises beneficiaries aged ≥ 18 years. Code ICD-9 was used to identify a primary hospitalization diagnosis of ischemic stroke among subjects encountered between 2003 and 2009, and continuously treated with aspirin ≥ 30 days before the index stroke. Follow-up was from time of the index stroke to admission for recurrent stroke or myocardial infarction; withdrawal from the registry; and last medical claim before 1/1/2011. Patients were categorized into 2 groups based on whether clopidogrel or aspirin was prescribed during follow-up period. Patients were excluded if their Medication Possession Ratio was < 80% or they not taking clopidogrel or aspirin within 30 days before an endpoint. Primary endpoints were a major adverse cardiovascular event (MACE: composite of stroke and myocardial infarction) and a recurrent stroke alone. Multivariate-adjusted hazard ratio (HR) and 95% CI for the development of events were estimated using Cox models.

Results:
Among 2281 eligible patients, mean age was 72 years, 41% were female, and mean follow-up duration was 2.2 years. Compared to aspirin, clopidogrel was associated with a significantly lower occurrence of MACE (adjusted HR 0.67, 95% CI 0.55 to 0.81) and recurrent stroke (adjusted HR 0.67, 0.54 to 0.82). The pattern of benefit for clopidogrel users was consistent across several endpoints (Table).

Conclusion:
Among ischemic stroke patients with so called ‘aspirin treatment failure’, clopidogrel may a better choice than aspirin for future vascular risk reduction.
Abstract T MP12: Primary Manual Aspiration Thrombectomy (MAT) for Acute Ischemic Stroke: Safety, Feasibility and Outcomes in 112 Consecutive Patients
Authors: Jankowitz Brian T , Horev Anat , Grandhi Ramesh , Aghaebrahim Amin , Jadhav Ashutosh , Linares Guillermo , Jovin Tudor
Published: July 2021

Background and Purpose:
MAT is increasingly recognized as a valuable endovascular treatment modality for acute stroke. We sought to describe feasibility, safety and clinical outcomes in a consecutive series of patients in whom MAT was performed as the first treatment modality with other techniques used only in case MAT did not yield adequate recanalization.

Methods:
Retrospective review of a prospectively acquired acute endovascular stroke database. Primary MAT was carried out with a preference for the largest catheter considered to be trackable into the target lesion which was wedged into the thrombus followed by manual aspiration with a 20 cc syringe.

Results:
112 consecutive patients were identified. Median age: 67. Median NIHSS: 17. Occlusion location: M1(62.5%), M2(8%), ICA-terminus(18.7%), vertebrobasilar (10.7%).Patients with anterior occlusions had tandem extra/intracranial occlusive lesions in 18.7% Median time from symptoms onset to groin puncture: 267 min and from groin puncture to recanalization: 70 min. Aspiration was carried out with the following catheters makes and sizes (in inches): Navien (Covidien Inc.) 0.072 and 0.058 (84% of cases), Penumbra (Penumbra Inc. 0.054 and 0.041 (23% of cases) and DAC (Stryker Inc.) 0.070, 0.054 and 0.44 (4% of cases). Largest bore catheters (0.070 inch and above) were used in 27% of cases and in 75 % of cases medium size catheters (0.054 -0.058 in) catheter were used. Successful recanalization (TICI 2B-3) following MAT alone was 59% with 41% of patients requiring the use of adjunctive intra-arterial therapy (mainly stentriever and/or t-PA). Recanalization results were: TICI 2b/3- 86%, and TICI 3 -30%. Median number of passes: 2. Parenchymal hematoma of any type (PH1/PH2): 9.9%. Favorable outcomes (90-day modified Rankin Scale ≤2): 46.%. Mortality rate at 3 months:31%. Intracranial distal wire perforations were noted in 4 patients (3.5%).The use of MAT only was associated with faster procedural times (mean 63 min vs 97 min, p<0.0001) but not with higher rates of favorable outcomes. Neither catheter make nor size were associated with higher or faster recanlization rates

Conclusions:
Pure MAT is a safe, efficacious, quick, and potentially cost saving endovascular recanalization technique.
Abstract T MP13: Chagas Disease Related Stroke: Safety of Intravenous Thrombolysis and Endovascular Treatment
Authors: Cougo-Pinto Pedro T , Dos Santos Bruno L , Dias Francisco A , Camilo Millene R , Alessio-Alves Frederico F , Barreira Clara M , Santos-Pontelli Taiza E , Abud Daniel G , Leite João P , Pontes-Neto Octavio M
Published: July 2021

Background:
AND AIM: Chagas disease (CD) is a common cause of stroke in undeveloped countries and has become more frequent in the US, where it is largely underestimated. CD related strokes are believed to be mainly cardioembolic but some studies have suggested concomitant cerebral vasculitis. Data on the safety of recanalization therapies in patients with acute stroke related to CD is still restricted to single case reports. We aimed to assess the rate of symptomatic intracranial hemorrhage (SIH) in a group of patients with CD-related stroke treated with intravenous tissue plasminogen activator (IV TPA) and/or endovascular therapy.

METHODS:
We performed a retrospective analysis of a prospective, single-center, hospital-based registry of acute stroke patients treated with IV TPA and/or endovascular therapy and routinely tested for CD. Demographics, medical history and clinical data were obtained from the registry. CT scans at admission and after 24-48 hours were blindly reviewed by two experienced stroke neurologists, who rated the presence of hemorrhage transformation according to the European Cooperative Acute Stroke Study criteria.

RESULTS:
From 2001 to 2012, 197 patients met the inclusion criteria for this study. CD was diagnosed in 30 patients (15.2%). Patients with CD had higher admission scores on the National Institute of Health Stroke Scale [median: 19; interquartile range (IR): 16-22; no CD: 14; IR: 9-19; P<0.01]. Among patients treated with IV TPA, the rate of SIH was similar among patients with CD (1/24; 4.2%) and patients without CD (8/150; 5.3%; OR: 0.77, 95% CI: 0.09-6.46; P=0.99). Among those treated with rescue endovascular treatment, SIH occurred in 2/6 (33.3%) patients with CD and in 3/17 (17.6%) patients without CD (OR: 2.33, 95%CI: 0.28-19.17, P=0.58). Overall, there was no difference in mortality between groups [CD: 6 (20%); no CD: 24 (14.4%); OR: 1.49; 95% CI: 0.55-4.0; P=0.42].

CONCLUSIONS:
In the largest series of patients with acute stroke related to CD treated with recanalization therapies ever reported, we found that IV TPA appears to be safe in these patients. Further studies are necessary to confirm the safety and efficacy of endovascular recanalization strategies in patients with CD.
Abstract T MP4: The Rapidity of Recanalization is an Independent Factor to Achieve Good Clinical Outcome After Intraarterial Thrombectomy
Authors: Jeong Hye Seon , Song Hee-Jung , Kwon Hyon-Jo , Koh Hyeon-Song , Kim Jei
Published: July 2021

Background:
The present study evaluated whether the time interval from symptom onset to recanalization (onset-to-recanalization time) was independently related with the clinical outcomes after intraarterial thrombectomy (IAT) in acute ischemic stroke patients.

Methods:
We analyzed clinical and radiological data of 140 consecutive patients who underwent IAT for terminal internal carotid and/or middle cerebral artery occlusions. The patients were classified into 4 groups by the onset-to-recanalization time; <4.5, 4.5-6, >6 hours, and no recanalization (NR). Subsequent changes of the National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were compared between the four time interval groups. The independent relationship of the onset-to-recanalization time with the clinical outcomes was analyzed with other clinical and radiological parameters simultaneously checked before and after IAT using multivariate analyses.

Results:
Successful recanalization after IAT was performed in 47 (34%) <4.5hours, 39 (28%) 4.5-6 hours, 31 (22%) patients >6 hours groups, no recanalization in 23 patients (16%). Even though initial NIHSS score was not different between the four groups (<4.5 hrs, 12.2±4.0; 4.5-6hrs, 12.2±4.2; >6hrs, 12.1±3.3; NR, 12.8±3.3,
p
>0.05), two first groups who recanalized within 6 hour showed more significant reductions of NIHSS at discharge (<4.5 hrs, 5.4±5.8; 4.5-6hrs, 6.5±6.7; >6hrs, 9.6±6.0; NR, 12.7±4.0,
p
<0.001). The first two groups showed more favorable outcome (mRS 0-2) at discharge (<4.5hrs, 51%; 4.5-6hrs, 51%; >6hrs, 13%; NR, 0,
p
<0.001) and 3 months later (<4.5hrs, 62%; 4.5-6hrs, 63%; >6hrs, 23%; NR, 0,
p
<0.001) rather than other 2 groups. On the multiple regression analysis, recanalization within 6 hours was an independent parameter related with the favorable outcome at 3 months after IAT (OR 15.5, 95% CI 2.0-119.8,
p
=0.009) along with less extensive lesions on initial brain image (OR 13.2, 95% CI 1.7-103.3,
p
=0.014) and high recanalization grade (OR 13.0, 95% CI 1.5-115.6,
p
=0.022).

Conclusions:
The present study showed that the successful recanalization within 6 hours might be an independent clinical parameter to achieve favorable outcome after IAT for ischemic stroke patients.
Abstract T MP46: Stroke-Related Neuroplasticity During Steering of Human Gait
Authors: Paquette Caroline , Soucy Jean-Paul
Published: July 2021

Background:
The risk of falling is higher in stroke survivors than among the general population. These falls are more frequent during walking and transfers or during turning. The neuronal substrates involved in steering of locomotion are poorly understood due to methodological limitations in quantifying brain activations during whole-body movements. Thus, no data is currently available to study the mechanisms of post-stroke brain plasticity for steering of gait. This study tested the hypothesis that stroke-induced neuroplastic changes for steering of gait can be quantified using 18F- fluorodesoxy-glucose (18F-FDG) Positron Emission Tomography (PET) in-vivo in humans

Methods:
PET imaging with 18F-FDG tracer was used to quantify cerebral glucose metabolism (CMRGlc) during two locomotor tasks (straight walking and turning) measured on separate days. Immediately prior to each walking task, a 5 mCi bolus of 18F-FDG was injected. Subjects walked for 40 minutes (duration of 18F-FDG uptake). Subjects were scanned on an ECAT HR+ scan (20min emission followed by 10min transmission) within 10 minutes of completing the walking task, well within reaching the 2h half-life of 18F. Images obtained during straight walking were subtracted from the ones acquired during steering

Results:
Subjects post-stroke showed an asymmetrical pattern of CMRGlc in sensorimotor areas and superior parietal lobule where the affected hemisphere shows no increase in CMRGlc. Differences between groups were also observed in the cerebellum where CMRGlc was increased in the vermis for controls, an area predominant for the control of trunk and gait. Stroke subjects, in contrast, showed increased CMRGlc in the hemishperes, associated with goal-directed leg movements.

Conclusions:
Neuroplasticity in complex locomotor tasks such as steering can be quantified using 18F-FDG PET in subjects post-stroke. This study showed that changes affect several brain regions remote to the infarct. Understanding stroke-related changes in brain activity during steering of locomotion is crucial for improving rehabilitative strategies to minimize falls and injuries in stroke survivors.