bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP225: Prognosis of Cerebral Venous Thrombosis and Provoking Risk Factors
Authors: Lee Eun-Jae , Noh Sang-Mi , Kang Dong-Wha , Kim Jong S , Kwon Sun U
Published: July 2021

Background and hypothesis:
Little is known about the relationships between the presence/type of provoking risk factors and the prognosis and optimal duration of anticoagulation in patients with cerebral vein and dural sinus thrombosis (CVT). We aimed to analyze data of treatment and long-term prognosis in patients with CVT classified by the presence and type of provoking risk factors.

Methods:
Prospectively recorded data of a tertiary medical center were retrospectively reviewed. Patients with CVT were categorized into three groups by risk factors: unprovoked, those with possibly resolved provoking factors (PR), and those with persistent provoking factors (PP). The baseline characteristics, treatment, and prognosis of these three groups were analyzed.

Results:
From 2000 to 2015, 61 patients were registered for CVT, 19 (31.1%) with unprovoked, 11 (18.0%) with PR, and 31 (50.9%) with PP. Median follow-up and duration of anticoagulation were 35 and 8 months, respectively. The PR group consisted of patients with causative drugs or arteriovenous fistula successfully treated. Despite the similarities in baseline characteristics of the three groups, deaths (n=3; P = 0.256) and recurrences (n=7; P = 0.020) were observed only in the PP group. The median interval to death and recurrence were 9 and 13 months, respectively. Death was associated with underlying disease activity, not with CVT progression. Recurrences were associated with lack of initial administration of anticoagulation (P = 0.028); of the seven patients with recurrence, five (71.4%) did not receive anticoagulation at the second event.

Conclusions:
Although the prognosis of CVT is generally benign, recurrence and death were observed in the patients with persistent risk factors, suggesting their need for long-term treatment with anticoagulants.
Abstract WP229: Prolonged Monitoring of Cardiac Rhythm With Wireless Cardiophone for Real Time Detection of Atrial Fibrillation After a Cerebral Ischemic Event (PEAACE II Study) The Edmonton Alberta Experience
Authors: Hasan Saad , Manosalva Herbert , Pervez Arif , Mohammad Askar , Hussain Dulara , Kalashyan Hayrapet , Saqqur Maher , Khan Khurshid , Tarhuni Wadea , Buck Brian , Butcher Kenneth , Jeerakathil Thomas , Hasan Yousef , Shuaib Ashfaq
Published: July 2021

Introduction:
Atrial fibrillation (AF) is a leading cause of preventable stroke and can be prevented with anticoagulants. Prolonged cardiac monitoring can lead to better detection of AF. Real time cardiac monitoring may lead to earlier diagnosis and treatment.

Objective:
Primary objective is to detect AF using wireless cardiophone for 14 days in stroke patients.

Secondary objective is to determine the reduction of time of AF diagnosis resulting in a prompt change in clinical management.

Method:
This was a Cohort/Prospective study at the Univesity of Alberta Hospital. Patients ≥40 years of age (without known AF on ECG/Holter) who had an ischemic stroke or TIA within ≤90 days were eligible. The signals from cardiophone were analyzed in real time at Canadian cardiac center in Windsor, Ontario. The incidence and time of onset of AF and change in medical treatment (anti-coagulation) was recorded.

Results:
Out of 120 patients, 118 completed monitoring for more than 48 hours. Twenty out of these 118 subjects (≈ 17 %) were shown positive for AF. When compared with the incidence of 5% reported in historical controls wearing 24 hour holter, the difference was significant (chi square p=0.004). Fourteen out of 20 AF subjects (70%)had AF duration of < 30 seconds, while 6/20 (30%) had a duration of >30 seconds. Mean time from onset of arrhythmia to report was ≈48 hours; shorter than the time for report with Holter (≈10 days in Alberta). Ninety percent of AF positive subjects were started on anti-coagulation therapies.

Conclusion:
Prolonged cardiac monitoring for 14 days increased the detection of AF approximately 3 fold as compared to 24 hour Holter. Cardiophone device allowed feasible real time monitoring of heart rhythm and faster reporting time (within 48 hours) that lead to prompt change in medical treatment by the health care physician.
Abstract WP233: Validation of Multi-parametric Ultrasonography Criteria With Catheter Angiography in Internal Carotid Artery Disease: a Multicenter Study
Authors: Barlinn Kristian , Rickmann Henning , Rabahi Ali , Kitzler Hagen H , Abramyuk Andrij , Strohm Henning , Krogias Christos , Kepplinger Jessica , Siepmann Timo , Graehlert Xina , Schwanebeck Uta , Mönnings Peter , Pallesen Lars-Peder , Bodechtel Ulf , Mudra Harald , Linn Jennifer , Reichmann Heinz , Alexandrov Andrei V , Gahn Georg , Weiss Norbert , Puetz Volker
Published: July 2021

Introduction:
Novel multi-parametric criteria for duplex ultrasonography (DUS) grading of extracranial internal carotid artery (ICA) steno-occlusive disease have been recently introduced by the German ultrasound expert panel (DEGUM). We sought to determine diagnostic accuracy of the DEGUM criteria against the gold standard catheter angiography.

Methods:
We prospectively enrolled consecutive patients who routinely underwent diagnostic or therapeutic catheter angiography of the extracranial carotid arteries in four German study sites. Internal carotid artery disease was graded according to the DEGUM multi-parametric criteria for DUS. On angiography, extracranial ICA disease was graded using the NASCET approach. Ultrasonography and endovascular raters were blinded to clinical data and any other imaging modalities. To correspond to clinically relevant NASCET groups, all stenosis measurements were stratified into ranges: normal, mild (1-49%), moderate (50-69%), severe (70-99%) and occlusion.

Results:
We studied 130 patients who underwent both DUS and catheter angiography for assessment of carotid arteries (mean age, 64±11 years; 67% men; median time between DUS and angiography, 1 day [interquartile range, 2.5]). To date, fifty-two carotid artery pairs were independently rated and available for comparative analysis. Compared with catheter angiography, DUS had the following positive (PPV) and negative predictive values (NPV): PPV 50% and NPV 72% (3 true positive, 3 false positive, 33 true negative, 13 false negative) for detection of moderate, and PPV 57% and NPV 77% (20 true positive, 15 false positive, 13 true negative, 4 false negative) for detection of severe stenosis.

Conclusions:
Our preliminary data indicate that the novel DEGUM multi-parametric ultrasonography criteria do not eliminate the need for a confirmatory test for identification of clinically relevant grades of extracranial ICA disease.
Abstract WP238: Thrombolytic Use in Stroke Mimics via Telestroke
Authors: Asaithambi Ganesh , Castle Amy L , Sperl Michael A , Gupta Aditi , Ravichandran Jayashree , Ho Bridget M , Hanson Sandra K
Published: July 2021

Background:
It has been established that safety and outcomes of intravenous thrombolysis (IVT) to stroke patients via telestroke (TS) is similar to those presenting to stroke centers. Little is known on the accuracy of TS diagnosis among those receiving IVT. We sought to compare the rate of stroke mimic (SM) patients receiving IVT in our TS network to those who present to our comprehensive stroke center (CSC).

Methods:
Consecutive patients receiving IVT between August 2014 and June 2015 were identified at our CSC and TS network. The rates of SM patients in each cohort were calculated. Outcomes measured included rates of symptomatic intracerebral hemorrhage (sICH), in-hospital mortality, and discharge to home or an acute rehabilitation unit (ARU).

Results:
During the study period, 132 patients (mean age 71±15 years, 49% women) receiving IVT were included in the analysis (75 CSC, 57 TS). Rates of SM patients receiving IVT were similar (CSC 12% vs TS 7%, p=0.39). One stroke patient developed sICH, and three other stroke patients experienced in-hospital mortality; neither outcome was found in the SM cohort. Discharge to home or ARU was similar between stroke (76.5%) and SM (76.9%) patients (p=1). Patients with SMs had significantly higher diagnoses of migraine (p=0.045) and psychiatric disorders (p=0.0002) compared to stroke patients.

Conclusion:
The rate of IVT among SM patients via TS is low and similar to those who present directly to a stroke center. Continued efforts should be made to further minimize IVT in SM patients despite the low rate of complications.
Abstract WP240: Ultra-acute Diagnostics for Stroke: Large-scale Implementation of Prehospital Biomarker Sampling
Authors: Mattila Olli S , Harve Heini , Pihlasviita Saana , Ritvonen Juhani , Sibolt Gerli , Pystynen Mikko , Strbian Daniel , Curtze Sami , Kuisma Markku , Tatlisumak Turgut , Lindsberg Perttu J
Published: July 2021

Background and purpose:
Blood-based biomarkers could enable early and cost-effective diagnostics for acute stroke patients in the prehospital setting to support early initiation of treatments. However, large prehospital sample sets required for biomarker discovery and validation are missing, and the feasibility of large-scale blood sampling by emergency medical services (EMS) has not been determined. We set out to establish extensive prehospital blood sampling of thrombolysis candidates in the catchment area of our comprehensive stroke center, with a 1.5 million population base.

Methods:
EMS personnel were trained to collect prehospital blood samples using a cannula-adapter technique. Time delays, sample quality and performance bottlenecks were investigated between May 20, 2013 and May 19, 2014.

Results:
Prehospital blood sampling and study recruitment were successfully performed in 430 thrombolysis candidates, of which 55.3% were admitted outside office hours. The median (interquartile range) emergency call to prehospital sample time was 33 minutes (25-41), and the median time from reported symptom onset or wake-up to prehospital sample was 53 minutes (38-85; n=394). Prehospital sampling was performed 31 minutes (25-42) earlier than admission blood sampling, and 37 minutes (30-47) earlier than admission neuroimaging. Quality control data from 25 participating EMS units indicated a 4-minute increase in median transport time (from arrival on-scene to hospital door) for study patients compared to patients of the preceding year. The hemolysis rate in serum and plasma samples was 6.5% and 9.3% for EMS samples, and 0.7% and 1.6% for admission samples collected with venipuncture.

Conclusions:
Prehospital biomarker sampling is feasible in standard EMS units and provides a median timesaving of over 30 minutes to obtain first blood samples. Large biobanks of prehospital blood samples will facilitate development of ultra-acute stroke biomarkers.
Abstract WP246: Acute Ischemic Stroke Patients With a Primary Language Other Than English Do Not Have Significantly Increased Door-to-Needle Times for Intravenous TPA
Authors: Cheng Natalie T , Cahill Elizabeth A , Tesfasilassie Tomas , Burnett Molly M , Zimmermann Lara , Kim Anthony S
Published: July 2021

Background:
Rapid administration of intravenous alteplase (IV tPA) leads to better outcomes, but language barriers have the potential to introduce delays and to hinder effective communication with patients and collateral historians during the acute evaluation.

Hypothesis:
Acute ischemic stroke patients with a non-English primary language will have significantly longer door-to-needle times for IV tPA.

Methods:
We abstracted information on primary language for all adults that received IV tPA for acute ischemic stroke in the emergency department of an academic referral center in San Francisco, CA, from February 2008 to May 2015. Approximately 38% of San Francisco residents speak a language other than English at home. Primary language was determined from the electronic medical record and was confirmed by reviewing specific documentation in subsequent speech therapy evaluations and admission notes. Age, sex, race, presenting NIHSS, aphasia as a presenting symptom, whether the patient was accompanied to the emergency department by a family member or caregiver, discharge disposition, and door-to-needle (DTN) administration time for IV tPA were abstracted from clinical records and quality improvement registries.

Results:
A total of 237 patients received IV tPA for acute ischemic stroke in the emergency department during the study period. Median age was 76 years (IQR 64-86), 53% were female, and median DTN time was 62 minutes (IQR 48-86). A total of 34% of patients had a primary language other than English (20% Cantonese, 6% Russian, 3% Spanish). These patients were more likely to be older (median age 80 vs. 73 years, p = 0.001), to be accompanied by a family member or caregiver (80% vs. 59%, p = 0.003), and to have a higher NIHSS (median 9 vs. 11, p = 0.03), but DTN times were similar among English and non-English primary language speakers (median 62 vs. 62, p=0.88) and short-term outcomes were not significantly different (in-hospital mortality 9% English primary language vs 14% non-English primary language, p=0.27; discharge to home 43% vs 32%, p=0.16) .

Conclusions:
At a center serving a multiethnic population, a patient’s primary language did not appear to predict DTN times for acute ischemic stroke.
Abstract WP250: Prehospital Initiation of Neuroprotection Followed by Endovascular Therapy for Acute Ischemic Stroke
Authors: Nguyen Peggy L , Sanossian Nerses , Mack William J , Liebeskind David S , Starkman Sidney , Hamilton Scott , Conwit Robin , Saver Jeffrey L ,   FAST-MAG Investigators and Coordinators
Published: July 2021

Background:
Neuroprotective can be administered soon after symptom onset may preserve brain tissue potentially leading to better outcomes after endovascular treatment. We describe prehospital treatment with magnesium sulfate among endovascular treated cases.

Methods:
Subjects enrolled in the NIH Phase 3 Field Administration of Stroke Therapy Magnesium (FAST-MAG) clinical trial of prehospital treatment with magnesium or placebo initiated <2 hours from symptom onset who underwent endovascular treatment. Timing and exposure to treatment prior to procedure and the effects of magnesium compared to placebo are described.

Results:
Of 1235 subjects with cerebral ischemia, 76 (6%) underwent endovascular therapy (38 magnesium, 38 placebo), mean age 69 (SD13), 50% women, median NIHSS 17 (IQR 11-23). Median (IQR) time from onset to study drug initiation was 39 (33-46) minutes, to TPA (N=49) 135 (114-175) and to groin puncture was 247 (169-287) minutes. There were no significant differences in baseline demographics or times. Assignment to Mg was not associated with improved NIHSS at 24 hours (12 vs.13.5, p=0.904) or disability at 3-months (mRS 3 vs. 3, p=0.867).

Conclusions:
Although treatment with magnesium was neutral, the strategy of prehospital Neuroprotection initiation strategy exposed subjects to 3 hours and 28 minutes of potential brain stabilizing therapy prior to groin puncture. With more recent groin puncture times prehospital Neuroprotection could provide 3 hours of stabilization prior to endovascular therapy initiation.
Abstract WP256: Serum Glutamate Level but Not NMDAR Antibody - A Potential Biomarker of Early Ischemia in Rat Stroke Model
Authors: Nahrir Shahpar , Al-Shardan Muhammad , Chentoufi Aziz A , AlMohanna Falah , Assiri Abdullah M , Al-Senani Fahmi
Published: July 2021

Introduction:
Identifying a biomarker for early detection of ischemia is indispensable as millions of stroke patients are in dire need of a screening tool that is fast in diagnosis whilst obviating the need of expensive neuroimages.

Hypothesis:
A key element in ischaemic cascade is the failure of energy dependent ion channels that leads to influx of calcium ions. This influx triggers multifold release of Glutamate - an Excitatory Neurotransmitter that activates NMDA receptor which further augments the spread of depolarization from ischaemic core to the viable penumbra. We assessed the hypothesis that Glutamate is a credible early biomarker of ischaemic insult to the brain. This proposition was trialed on an animal stroke model.

Methods:
The stroke model was created through permanent Middle Cerebral Artery Occlusion(pMCAO) on 39 male Wistar Albino rats (250-300g). The rats were divided into Stroke group(n 24) and Sham/Control group(n 15). The blood samples were collected 0 hour (before stroke induction/sham procedure) and also at 1, 3 or 6 hours post procedure. The serum was tested for Glutamate and anti-NR2 Antibody using ELISA assay.

Results:
Serum Glutamate increased 4-fold at 1 hour of stroke induction (from 0.24+0.3nmol to 3.7+0.8nmol(p<0.0001))(Fig. 1A). No significant difference in Glutamate levels were observed between two groups at 3 or 6 hour(Fig. 1B & 1C). Serum Glutamate of Stroke rats at 3 different time-point showed that it can be detected as early as 1 hour of stroke induction but plummets to pre-stroke level at 3 to 6 hours(Fig. 2).

The levels of anti-NR2 antibody were below detectable limits in both Stroke and Sham Control rats throughout the experiments.

Conclusions:
Serum Glutamate level rose significantly within 1 hour of stroke in our rat pMCAO model, but no detectable antibody was obtained for NR2 subunit of NMDAR indicating delay in antibody formation. Translational research can validate Glutamate as marker of early ischaemia. ischaemia.
Abstract WP261: Sex Differences in Circulating Leukocyte Subtype and Activation Following Ischemic Stroke
Authors: Roy-O'Reilly Meaghan , Mistry Hetal , Levy Madeline , McCullough Louise
Published: July 2021

Background and Purpose:
Females exhibit a more robust immune response in many disease models, yet sex differences in the inflammatory response to ischemia remain largely unexplored. We conducted flow cytometry and RNA sequencing of blood from ischemic stroke patients, with follow-up studies in mice.

Hypothesis:
We assessed the hypothesis that there are sex differences in the acute immune response to ischemic stroke.

Methods:
Patient samples were drawn at 24 hours post-stroke for flow cytometry (n=6) and RNA sequencing Analysis (n=40). For murine studies, male and ovariectomized (OVX) female animals (n=14) were subjected to 90-minute middle cerebral artery occlusion or sham surgery and sacrificed at 24 hours. Murine blood was stained for leukocyte markers and CD62L (L-selectin). Results were analyzed by student T-test and two-way ANOVA.

Results:
RNA sequencing revealed that 24 hours after ischemic stroke, female patients had 79 significantly upregulated genes, compared to male patients with 6 significantly upregulated genes. Human flow cytometry revealed that male stroke patients had a significantly higher percentage of monocytes (p=.026), while females had a greater percentage of CD8+ T-cells (p=.023). Murine flow cytometry showed a post-stroke increase in peripheral myeloid cells at 24 hours in male mice only (p=.0046), whereas female mice had a higher CD8/CD4 T cell ratio (p=.0027). Neutrophils from male sham animals displayed greater L-selectin positivity, with stroke-induced shedding of L-selectin seen only in males (sex/stroke p=.0266). Male monocytes and lymphocytes also displayed higher L-selectin positivity (p=.0079, p=.0004).

Conclusion:
These results suggest that the immune response to ischemic stroke is different in male and female patients, a phenomenon that can be recapitulated in a mouse model of experimental stroke. Female immune cells exhibit a higher level of baseline activation (reduced L-selectin expression) and post-stroke activity, which may enable a quicker and more robust response to immune challenges. Understanding sex differences in the acute immune response is crucial to developing future immunomodulatory drugs for the safe and effective treatment of ischemic stroke in both sexes.
Abstract WP263: Mutagenesis Studies Revealed Minimal Impact of Human A120T Variant of Protease-activated Receptor 4 on Receptor function or Pharmacological Response to a Potent and Selective Antagonist
Authors: Callejo Mario F , Colin Jeffrey , Desmeules Sophie , Sum Chi , Wang Tao , Feder John , Mintier Gabe , Xu Ke , Wang Zhaoqing , Ismat Fraz , Ma Xuewen , Rémillard Roger , Banville Jacques , Marinier Anne , Priestley Scott , Bouvier Michel , Yang Jing
Published: July 2021

Introduction:
Protease-activated receptor 4 (PAR4) is a platelet thrombin receptor and a novel target for ischemic stroke treatment. Recent reports suggested a subtle racial difference in platelet responses to submaximal concentrations of PAR4 agonist peptide (PAR4-AP). One of the PAR4 variants, A120T, is more common in African American than white (63% vs. 19%, Edelstein et al., Blood 2014). It was suggested that this variant contributes to the difference in response to PAR4-AP and impacts the in vitro response to YD-3, a PAR4 antagonist. In this study, site-directed mutagenesis was used to evaluate the effect of the A120T variant on PAR4 function and response to a newly discovered potent and selective PAR4 antagonist, UDM-001651. Unlike YD-3, UDM-001651 inhibited thrombin-induced platelet aggregation and prevented thrombosis in a monkey model and thus served as a relevant PAR4 pharmacology tool.

Methods:
Human PAR4 cDNAs expressing A120 and T120 variants were stably expressed in HEK293 cells. Cell surface expression of PAR4 was analyzed by FACS. Functional responses of cells were evaluated by monitoring calcium mobilization induced by BMS PAR4-AP, which was optimized based on AYPGKF. The potency of UDM-001651 was derived from an 11-point concentration response curve in the calcium assay using PAR4-AP at the EC80 concentration. Transient transfection studies were also performed to confirm the results.

Results:
Comparable levels of expression and functional responses were observed between A120 and T120 expressing cells. Results from side-by-side comparison between the two cell lines demonstrated no detectable difference in the mean EC50 values (0.42±0.054 versus 0.46±0.051 uM standard error, n=9) in calcium responses to PAR4-AP stimulation. Similarly, the potency of UDM-001651 in the same assay were similar between these two cell lines. Moreover, preliminary clinical results did not show differences in PAR4-mediated platelet response between African-American and white subjects.

Conclusion:
In contrast to the previous report, the results reported herein from site directed mutagenesis studies indicate that the A120T variant of PAR4 has no apparent impact on calcium signaling in response to agonist stimulation or response to a PAR4 antagonist.
Abstract WP28: Eligibility for Mechanical Thrombectomy in Acute Ischemic Stroke: a Phase IV Multi-center Screening Log Registry
Authors: Tsivgoulis Georgios , Goyal Nitin , Mikulik Robert , Zand Ramin , Roussopoulou Andromachi , Volny Ondrej , Pandhi Abhi , Zompola Christina , Elijovich Lucas , Chang Jason , Alexandrov Anne W , Alexandrov Andrei V
Published: July 2021

Background & Purpose:
No eligibility screening logs were kept to support recent mechanical thrombectomy (MT) RCTs establishing safety and efficacy for acute ischemic stroke (AIS). We sought to evaluate the potential eligibility for MT among consecutive AIS patients in a prospective multicenter study.

Methods:
We prospectively evaluated consecutive patients admitted with the diagnosis of AIS in three tertiary care stroke centers during a twelve-month period. Admission stroke severity was documented using NIHSS-score, while all patients underwent baseline neurovascular imaging using MRA/CTA. Potential eligibility for MT was evaluated using inclusion criteria from MR CLEAN & REVASCAT as these protocols utilized imaging and selection methods that most closely mirrored everyday clinical practice.

Results:
Our study population consisted of 1161 AIS patients (mean age 66±14 years, 55% men, median admission NIHSS-score: 5 points, IQR 2-8). A total of 86 (7%, 95%CI: 6%-9%) and 66 (6%, 95%CI: 4%-7%) patients fulfilled the inclusion criteria for MR CLEAN & REVASCAT respectively, while 57 cases were eligible for inclusion in both trials (5%, 95%CI: 4%-6%). There was no evidence of heterogeneity (p>0.150) regarding the eligibility of AIS for MT across the three participating centers. Absence of proximal intracranial occlusion (70%), followed by hospital arrival outside the eligible time window (31% for MR CLEAN 6-hour window & 29% for REVASCAT 8-hour window), low baseline NIHSS-score (16% below the 2 point cut-off of MR Clean & 46% below the 6 point cut-off of REVASCAT) and posterior circulation cerebral ischemia (16%) were the four most common reasons for ineligibility for MT.

Conclusion:
Our everyday clinical practice experience suggests that approximately one out of fourteen to seventeen consecutive AIS may be eligible for MT if inclusion criteria for MR CLEAN and REVASCAT are strictly adhered to. Delayed presentation from symptom onset represents the only modifiable MT exclusion factor.
Abstract WP285: Sex Disparities in Stroke Care in Puerto Rico Hospitals Participating in the Florida-Puerto Rico Collaboration to Reduce Stroke Disparities (FL-PR CReSD) Study
Authors: Zevallos Juan C , Ciliberti-Vargas Maria A , Wang Kefeng , Gutierrez Carolina M , Garcia-Rivera Enid J , Nobo Ulises , Santiago Fernando , Romano Jose G , Asdaghi Negar , Dong Chuanhui , Carrasquillo Olveen , Waddy Salina P , Robichaux Mary , Perez Enmanuel J , Waters Michael F , Rundek Tatjana , Sacco Ralph L
Published: July 2021

Background:
Sex is a contributing factor to inequalities in stroke care. In line with the aims of the FL-PR CReSD Study to assess Get With The Guidelines-Stroke (GWTG-S) quality improvement data, we sought to compare stroke performance metrics by sex among 9 GWTG-S participating Puerto Rico hospitals from 2010-2014.

Methods:
Age and NIHSS-adjusted hierarchical generalized linear models, stratified by sex, were evaluated for the following GWTG-S performance metrics: IV tPA treatment, early antithrombotic therapy, DVT prophylaxis, antithrombotic therapy at discharge, anticoagulation therapy for atrial fibrillation (AF) at discharge, statin medication at discharge, smoking cessation counseling, defect-free care (compliance with all performance measures), in addition to CT scan ≤25 minutes and door-to-IV tPA administration ≤60 minutes of hospital arrival.

Results:
Among 3,277 acute ischemic stroke cases, 48% were women. As compared to men, women were older (72±14 vs. 68±13 years, P<0.0001) with higher NIHSS scores (10±8.5 vs. 9±7.7, P=0.005). Women were less likely to receive IV tPA ≤ 4.5 hours among eligible patients arriving ≤ 3.5 hours (OR 0.71, 95% CI 0.51-0.98, P=0.04), early antithrombotic therapy (OR 0.86, 95% CI 0.75-0.97, P=0.02), DVT prophylaxis (OR 0.93, 95% CI 0.88-0.99, P=0.03), statin medication at discharge (OR 0.85, 95% CI 0.78-0.93, P=0.0001), and anticoagulation for AF at discharge (OR 0.67, 95% CI 0.49-0.92, P=0.01) despite having higher rates of AF at admission (11% vs. 7%, P=0.001). Rates of IV tPA for patients arriving ≤ 2 hours, antithrombotic therapy at discharge, and smoking cessation counseling showed no sex differences. While women were less likely to have a CT scan ≤ 25 minutes of hospital arrival compared to men (OR 0.83, 95% CI 0.74-0.93, P=0.002), no difference was found in door-to-IV tPA administration ≤ 60 minutes. Although an overall temporal improvement in defect-free care was observed from 2010-2014 (31% to 63%, P<.0001), women were less likely to receive this measure than men (OR 0.91, 95% CI 0.85-0.97, P=0.007).

Conclusions:
Overall, stroke care remains lower for Puerto Rican women than men. Continued adoption of the GWTG-S quality improvement program may help reduce sex disparities in quality of care across the island.
Abstract WP286: Race and Gender Differences Among Patients With First or Recurrent Ischemic Stroke
Authors: George Mary G , Tong Xin
Published: July 2021

Introduction:
Little information is known about the race and gender differences in stroke severity of acute ischemic stroke (AIS) among those presenting with and without a recurrent stroke (RS).

Methods:
The study is limited to white and black patients who were admitted with an AIS in the Paul Coverdell National Acute Stroke Program from 2012-2014. There were 157 967 admissions from 453 hospitals identified. After excluding those with missing NIHSS (33 017), the analysis focused on 124 950 patients.

Results:
The median age of blacks and females was greater than for whites and males, 74 vs 63 and 75 vs 68, respectively. RS accounted for 21.8% of AIS in white males, 21.2% in white females, 28.3% in black males, and 30.0% in black females. The median NIHSS was higher among females with initial stroke or RS stroke (4.0 vs 3.0 and 5.0 vs 4.0, respectively, p<0.0001) and higher among blacks with initial stroke or RS (4.0 vs 3.0 and 5.0 vs 4.0, respectively, p<0.0001). Overall in-hospital death was greater among whites and females compared to blacks and males (4.1% vs 2.9%, p<0.0001; 4.2% vs 3.5%, p<0.0001, respectively), and this pattern was consistent for initial AIS and RS. Use of tPA was greater among whites and males compared to blacks and females (11.6% vs 10.3%, p<0.0001; 11.5 vs 11.1%, p=0.02, respectively). This pattern was consistent for initial AIS and RS by race and for initial AIS by gender, but not for tPA for RS by gender. Females and blacks were less likely to have a mild stroke (NIHSS score 0-4) than males and whites for both initial and RS (p<0.0001). After adjusting for age, state, hospital, and year, the odds of having an NIHSS ≥5 was 16% lower among males, 36% greater among blacks, and 38% greater for those with a RS (data not shown).

Conclusion:
Race and gender differences on age, stroke severity, receipt of tPA, and in-hospital death among initial AIS patients persist for RS. Blacks, females, and those with a RS have more severe AIS.
Abstract WP287: Characteristics of Incident and Recurrent Stroke in Taiwan, 2000 to 2011
Authors: Lee Meng , Wu Yi-Ling , Ovabiagele Bruce
Published: July 2021

Background:
The burden of stroke is comparatively greater in Asian countries than in the Western world. While there has been a documented recent decline in the incidence of stroke in several Western nations due to better risk factor management, much less is known about the nature and trajectory of stroke in Asia over the last decade.

Objective:
To explore risk factors, medication use, incidence, and one-year recurrence of stroke in Taiwan.

Methods:
We conducted a nationwide cohort study by retrieving all hospitalized patients (≥ 18 years) with a primary diagnosis of ischemic stroke between 2001 and 2011 from Taiwan National Health Insurance Research Database.

Results:
A total of 291,381 first-ever ischemic stroke patients were enrolled between 2000 and 2011. The average age was about 70 years and approximately 58.6% of them were men. While prevalence of diabetes mellitus and hyperlipidemia, as well as use of statins, antiplatelet agents, and oral anticoagulant agents for atrial fibrillation significantly increased; incidence (142.3 vs. 129.5 per 100,000 in 2000 and 2011, respectively; Figure 1) and one-year recurrence (9.6% vs. 7.8% in 2000 and 2011, respectively; Figure 2) of stroke declined during this period of time.

Conclusion:
Over the last decade in Taiwan, rates of primary ischemic stroke and one-year recurrent stroke decreased by 9% and 18% respectively.
Abstract WP29: Clot Size: Speaking the Same Language in Endovascular Stroke Therapy Across the Globe
Authors: Liebeskind David S , Sanossian Nerses , Scalzo Fabien , Xiang Bin , Gupta Rishi , Jovin Tudor G , Albers Gregory W , Lutsep Helmi L , Smith Wade S , Killer-Oberpfalzer Monika , Macho Juan M , Jansen Olav , Wahlgren Nils , Nogueira Raul G ,   for the TREVO and TREVO 2 Investigators
Published: July 2021

Background:
Clot size in acute ischemic stroke has been ascribed to time from onset, used in imaging selection with varying techniques or definitions, and cited as a factor in both revascularization success and clinical outcomes. We analyzed clot size on noncontrast CT, CT angiography (CTA) and digital subtraction angiography (DSA) in the multicenter TREVO and TREVO 2 trials.

Methods:
Imaging core labs of the TREVO and TREVO 2 trials conducted pooled analyses of the CT/CTA and DSA datasets. Clot size was independently measured by hyperdense middle cerebral artery sign (HMCAS) length on noncontrast CT thin-slice reconstruction, CTA length, clot burden score (CBS) and DSA prior to thrombectomy. Statistical analyses included descriptive statistics and correlation analyses among clot size measures, and time from onset to CT or onset to DSA. Logistic regression analysis was used to model 90-day good outcome and revascularization success.

Results:
116 TREVO and TREVO 2 subjects from the pooled imaging dataset were analyzed with respect to clot size. Clot size estimated from thin-slice reconstruction of HMCAS was mean 7.6±9.2 mm, however, 41% of cases with proven arterial occlusion did not have HMCAS. CTA length of clots was mean 12.3±7.3 mm, with corresponding HMCAS CTA length in 41%. CBS (range 0-10) was mean 6.7±1.8. DSA clot length was mean 10.6±5.7 mm. Moderate correlations were noted between clot size on CT, CTA and DSA. Time from onset to CT or onset to DSA was unrelated to any clot size, yet worse ASPECTS scores were linked with larger clots (HMCAS length, ρ=-0.290, p=0.004; CTA length, ρ=-0.302, p=0.009). Revascularization success (TICI≥2B) was lower with CTA clot length > 8 mm (OR 0.32 [0.11, 0.99], p=0.047) when distal opacification via collaterals was present, yet unrelated to any HMCAS clot length. Good clinical outcome (mRS 0-2 at 90 days) was unrelated to any measure of clot size.

Conclusions:
Clot size varies depending on imaging technique and definitions, with a substantial proportion of occlusions that cannot be measured on either noncontrast CT or CTA and “time is clot” requires further study. Larger clots are associated with worse ASPECTS, possibly negating potential clinical benefit of successful revascularization.
Abstract WP290: Impact of TIA Training for General Practitioners on 90-Day Stroke Outcomes Following TIA
Authors: Ranta Annemarei , Dovey Susan , Gommans John , Weatherall Mark
Published: July 2021

Introduction:
The FASTEST trial demonstrated benefit of a TIA/stroke electronic decision support tool for the management of patients with TIA or minor stroke in primary. As part of the trial general practitioners (GPs) were offered an educational session on TIA and stroke prior to trial begin.

Hypothesis:
GP TIA/stroke education has a beneficial effect on patient outcomes especially if combined with the use of electronic decision support.

Methods:
The FASTEST trial was a multi-centre, single blind, parallel group, cluster randomised controlled trial comparing TIA/stroke electronic decisions support guided primary care management with usual care. A one-hour pre-trial TIA education session was offered to all participating GPs.

Results:
Of 181 participating GPs 79 (43.7%) attended a pre-trial education session and 140/291 (48.1%) trial patients were managed by GPs who attended education. Overall, there was no significant difference in 90-day stroke events in patients treated by GPs who attended (2/140 (1.4%)) versus those who did not attend the education session (5/151 (3.3%)); cluster adjusted OR 0.42, 95% CI 0.08-2.21; p=0.30). GP education that was reinforced by subsequent access to the electronic decision support tool during the trial did result in fewer 90-day strokes (0/71; 0%) when compared with patients treated by GPs who neither accessed education nor the TIA/stroke tool (3/50; 6.0%); p=0.033. Similarly there were fewer 90-day vascular events or deaths when education was combined with access to the tool (1/71 (1.4%) versus 8/50 (16%); cluster adjusted OR 0.075, 95%CI 0.02-0.62; p=0.016). When either only the tool or only training were accessed results fell between the extremes with the tool alone performing better than training alone (90-day vascular event or death rate 6/101; 5.9% versus 9/69 13%).

Conclusion:
GP training alone does not significantly reduce 90-day stroke events following TIA, however, education in combination with access to TIA/stroke electronic decision can enhance the reduction of 90-day stroke and vascular events.
Abstract WP291: Predictors of 30-day Same Hospital Readmission After Ischemic Stroke
Authors: Hemmen Eema , Botts Emily D , Paulson Debra L , Snyder Andrea G , Hemmen Thomas M
Published: July 2021

Background:
Health systems across the US are focusing on preventable hospital readmissions. Patient care systems are often focused on shorter hospital length of stays and faster discharges, while renewed efforts to regulate this penalizes health systems for readmissions. We aimed to explore factors that predict 30-day same hospital readmission after stroke, the impact on inpatient hospital cost and if a lower length of stay increased readmissions.

Methods:
We included patients discharged from UC Health System with the principle diagnosis ischemic stroke (ICD: 9 433.01-9; 346) from 10/1/2011 to 4/30/2015. We excluded all patients with inhospital death, discharged to hospice or who left against medical advice (AMA). Patients are grouped in: 1) readmitted within 30 days (all cause); 2) not admitted within 30 days. We compared demographics, pre-existing/comorbid conditions and health care metrics (length of stay (LOS), direct cost for the index admission and readmission. Severity of illness adjustments for LOS and cost were made using the University HealthSystem Consortium® (UHC) algorhthm. We used unpaired t-test for comparing means continuous variables) and chi-square to compare frequencies.

Results:
There were a total of 770 discharges, Group 1: 91, Group 2: 679. The groups were balanced in age, sex, race, and ethnicity, direct care cost and insurance status. Patients with readmission had longer adjusted LOS (O/E), 1.15±1.16 versus 0.97±1.11 (p=0.024), more renal failure (33.0 versus 14.0%, p<0.0001), peripheral vascular disease (9.9 versus 4.4%, p=0.048) and chronic atherosclerosis (40.7 versus 24.4%, p=0.002). (Table) Direct cost for readmissions was substantial, but not higher than for the index admission (14,746±21,795 versus 11,830±14,415, NS).

Conclusion:
There is no evidence that lower hospital length of stay contributed to readmission. We identified unique markers for readmission risk, which requires further review in larger samples across regions and health care systems to better understand what factors lead to readmission after stroke and to identify potentially preventable causes of readmission.
Abstract WP294: Utilization of Hospice Care and Patient Characteristics Associated With Discharge to Hospice in Acute Ischemic Stroke Patients
Authors: Ali Syed F , Chauhan Nabeel , Hinduja Archana
Published: July 2021

Introduction:
Hospice is an option in providing terminally ill patients with good quality end of life care. We sought to determine demographic and clinical factors associated with discharge to hospice in acute ischemic stroke (AIS) patients.

Methods:
Using our institutional GWTG database, we analyzed 2,363 consecutive AIS patients who were alive at the time of discharge, from Jan 2009 till July 2015. Univariate and multivariable analysis was performed to determine factors associated with discharge to hospice.

Results:
Out of 2,363 AIS patients, 100 (4.2%) were discharged to hospice care. Patients discharged to hospice care were more likely to be older, Caucasian and less likely to be African American. They more often had Medicare or private insurance, while less likely paid for the care themselves. Patients discharged to hospice more often had atrial fibrillation and heart failure, while less often had diabetes mellitus or were smoker. Altered level of consciousness at presentation was more often in patients discharged to hospice. Although the rates of thrombolysis and pneumonia were similar, UTI was more common in patients discharged to hospice. Thirty-seven percent of patients were made comfort measure prior to discharging them to hospice (Table). On multivariable analysis, older age [OR 1.04 (95% CI 1.01 - 1.07); p<0.001], higher NIHSS [OR 1.15 (95% CI 1.10 - 1.20); p<0.001] and altered level of consciousness at presentation [OR 2.42 (95% CI 1.29 - 4.55); p<0.001] were significantly associated with discharge to hospice care.

Conclusion:
The rates of discharge to hospice following AIS have substantially grown in the past decade and at our institution 4.2% were discharged to hospice. These patients were older, had higher median NIHSS and more often had altered level of consciousness upon presentation. Large, multicenter studies are needed to address the variation in the rates of hospice care across the United States.
Abstract WP295: Prediction of Discharge Destination for Patients With Acute Ischemic Stroke
Authors: Katzan Irene L , Thompson Nicolas , Khawaja Zeshaun , Frost Frederick
Published: July 2021

Introduction:
The ability to predict discharge destination early in the hospital course for patients admitted with acute ischemic stroke can improve efficiency of discharge planning, identify outliers for evaluation, and estimate future resource use.

Methods:
A prediction model for discharge destination was developed using multinomial logistic regression with the response variable categories: Home, Inpatient Rehabilitation Facility (IRF), and either Skilled Nursing Facility or Long-Term Acute Care (SNF/LTAC). Data used to build the model was electronically extracted from the electronic health records of 1,364 patients admitted with acute ischemic stroke to a tertiary care hospital from Dec 6, 2008 to Sept 4, 2012. There were 34 candidate predictors identified based on the literature and clinical expertise. Only data available in the first 2 days of admission were used in the analyses. Multiple imputation was used to handle missing data. Variables retained in the model were selected using the nested bootstrap procedure, which resulted in 2,000 datasets that each underwent backward stepwise selection. Calibration of the final model was assessed graphically. The polytomous discrimination index (PDI) was computed to assess discriminative validity.

Results:
The final model contained 7 predictors: living with family, requiring help prior to admission (both obtained from nursing flowsheets), history of heart failure, first systolic blood pressure, admission NIHSS, and antibiotic use. PDI was 0.71. Pairwise c-statistics were: Home vs IRF 0.83, Home vs SNF/LTAC 0.91, IRF vs. SNF/LTAC 0.79. (See also Figure)

Conclusion:
Discharge destination of patients admitted with acute ischemic stroke can be predicted with good discrimination using 7 variables available within the electronic health record. Once validated in an external population, this prediction model can be used to help improve the efficiency of hospital stays.
Abstract WP31: Site Experience and Relation to Outcome in the TRevo ACute Ischemic StroKe Thrombectomy Registry: Higher Volumes Translate in Better Outcomes
Authors: Nogueira Raul , Haussen Diogo C , Castonguay Alicia , Rebello Leticia , Abraham Michael , Puri Ajit , Alshekhlee Amer , Majjhoo Aniel , Farid Hamed , Finch Ira , English Joey , Mokin Maxim , Froehler Michael , Kabbani Mo , Taqi Muhammad , Vora Nirav , El Khoury Ramy , Edgell Randy , Novakovic Robin , Nguyen Thanh , Janardhan Vallabh , Veznedaroglu E , Prabhakaran Shyam , Budzik Ron , Ramakrishnan Pankaja , Zaidat Osama
Published: July 2021

Background and Purpose:
It remains unclear how experience influences outcomes after the advent of stent-retriever technology. We studied the relationship between site experience and outcomes in the TRevo ACute Ischemic StroKe (TRACK) multicenter registry.

Methods:
The 24 sites that enrolled patients in the TRACK registry were trichotomized into: low volume (enrolling 1-23 cases, less than 2 cases/ month), medium volume (24-47 cases, 2-4 cases/ month), and high volume sites (> 48 cases, > 4 cases/ month). Demographics, baseline features, and key prognostic presentation characteristics were compared across the three volume strata.

Results:
The 624 TRACK registry patients were divided into three sub groups: low (n=188 patients, 30.1%), medium (n=175, 28.1%), and high (n=261, 41.8%) volume centers. There were no significant differences in terms of age (mean, 66±16 vs. 67±14 vs. 65±15, p=0.2), baseline NIHSS (mean, 17.6±6.5 vs. 16.8±6.5 vs. 17.6±6.9, p=0.43) or site of occlusion across the 3 groups. Times from stroke onset to groin puncture were shorter in the medium volume sites (310 min) but similar in the low vs. high volumes sites (397 vs. 378 min). Higher efficiency and better outcomes were seen in higher volumes sites as demonstrated by faster times from groin puncture to reperfusion (mean, 89 vs. 82 vs. 65 min, p<0.0001), lower general anesthesia usage (60% vs. 70% vs. 59%, p=0.06), higher balloon guide catheter use (40% vs. 36% vs. 59%, p=<0.0001), higher reperfusion rates (mTICI ≥2b, 75.8% vs. 79.4% vs. 83.9%, p=0.10), and higher rates of good outcome (90-day mRS≤2, 39% vs. 50% vs. 53.4%, p=0.02). There were no appreciable differences in sICH (4.5% vs. 9.8% vs. 7.3%, p=0.2) or 90-day mortality (20.3% vs. 25% vs. 17.1%, p=0.2). After adjustments in multivariate analysis, there were significantly higher chances of achieving good outcomes in high vs. low volume (OR: 1.7, 95%CI 1.04-2.75, p=0.035) and medium vs. low volume (OR: 1.8, 95%CI 1.1-2.9, p=0.03) centers but there were no significant differences between high and medium volume centers (p=0.84).

Conclusions:
Clinical volumes have a significant influence in terms of efficiency and outcomes across stroke centers.
Abstract WP314: Renal Insufficiency Worsens Outcomes in Cerebrovascular Disease
Authors: Park Sea mi , Lahiri Shouri , Moheet Asma , Schlick Konrad , Song Shlee , Mann Jaspreet , Rosengart Axel
Published: July 2021

Introduction/Hypothesis:
We were interested in studying patient outcomes with acute cerebrovascular disease (ACVD) who had concomitant acute or chronic renal insufficiency (RI).

Methods:
We used the Healthcare Cost and Utilization Project Nationwide Inpatient Sample database (1998-2009) and identified 1,760,415 adult ACVD patients among 92,848,710 patients enrolled. Using SAS 6.4 and applying SPSS 22 the outcome variables mortality, length of hospital stay (LOS), HC (HC) >$20,000, and disposition (home or any care facility) were selected. Logistic regression analyses were performed adjusting for the covariates hypertension (HTN), diabetes mellitus (DM), age, race, sex, number of comorbidities, and care complexity (numbers of inpatient procedures) among all ACVD with and without RI.

Results:
Mean age was 71 years (SD 15) with 76% >65 years old; 54% female gender; 55% Whites, 11% Blacks, 6% Hispanics. Among all ACVD, 66% had HTN, 28% DM, RI 9%, LOS 7.6 days (SD 9.8), in-patient mortality 12%; disposition home 42% and facility 44%, and mean HC $36,010 (SD $63,331). After covariate adjustment, the mortality rate of ACVD patients with RI was 24% vs 11% (P<0.001) for those without RI; LOS ≥7 days 50% vs 29% (P<0.001); and facility discharge 62% vs 51% (P<0.001). In subgroup analysis, adjusted HC were significantly greater in patients with acute RI (78% vs 43%; P<0.001). The frequency of hemodialysis (HD) in all ACVD patients was 2.3%. Notably, HD was associated with LOS ≥7 days (61% vs 30%; p<0.001), increased mortality rate (25% vs 12%; p<0.001), and HC (76% vs 44%; p<0.001). However, there was no difference in disposition to facility (57% vs 52%; p<0.350).

Conclusions:
Acute or chronic RI was present in 9% of patients with ACVD. RI was associated with significantly greater risks of in-patient mortality, LOS, and discharge to a facility. In subgroup analyses, the overall HC were greater in patients with acute RI. Patients undergoing HD experienced a similar negative impact on all outcome parameters except for disposition status. The negative impact of RI on vital outcome parameters in ACVD patients should be considered, i.e., when indicating the administration of contrast for imaging.