bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP234: New Clinical Application of Measurement of Blood Viscosity With an Electromagnetically Spinning Sphere Viscometer in Acute Ischemic Stroke Patients
Authors: Abumiya Takeo , Furukawa Koji , Sakai Keiji , Hirano Miki , Osanai Toshiya , Shichinohe Hideo , Nakayama Naoki , Kazumata Ken , Aida Toshimitsu , Houkin Kiyohiro
Published: July 2021

Introduction:
Blood viscosity (BV) is an important blood property for determining the hemodynamic status. High BV causes blood stagnation and subsequent thrombotic reactions leading to cerebral infarction. However, clinical application of the measurement of BV is out of fashion due to the stereotype that the measurement results are within expectations with less clinical value.

Hypothesis:
Since the importance of BV remains unchanged in the pathogenesis of vascular diseases, BV values should still contain important information. We hypothesize that BV values may differ among stroke subtypes based on pathological condition.

Methods:
A new type of viscometer was recently developed using an electromagnetically spinning sphere (EMS) method, which enable us to measure small amount of samples quickly and sequentially in non-contact disposable manner. We measured BV in 100 healthy outpatients and 67 acute ischemic stroke patients (atherothrombotic: 28, lacunar: 23, and cardioembolic: 16) with EMS viscometer. The relationships between BV and hematological parameters were analyzed. The measurements in the acute stroke patients were performed a total of 4 times (Day0, Day2, Day7, and Day14 from the admission).

Results:
BV values in the healthy outpatients correlated more strongly with the total count of red blood cells and platelets (R2=0.6957) than with the hematocrit (R2=0.6435) in an exponential approximation. Compared with BV values in the healthy outpatients (4.57±0.76 mPa·s), Day0 BV values in the lacunar patients (5.37±1.11 mPa·s) were significantly higher (p<0.01), but those in the atherothrombotic patients (4.82±0.98 mPa·s) and in the cardioembolic patients (4.66±0.93 mPa·s) were not significantly different. In comparison between the values at Day 0 and Day 14, the lacunar patients alone showed a significant decrease from Day0 to Day14, suggesting that the lacunar patients suffered from dehydration at the onset.

Conclusion:
BV values at Day0 of lacunar infarction were significantly increased, which indicated contribution of dehydration to the onset of lacunar infarction. These measurements were performed with only 0.3ml of blood quickly and sequentially; therefore, the clinical application of the EMS viscometer appears to be promising.
Abstract TP240: Missed Ischemic Stroke Diagnosis in the Emergency Department at an Academic Center and Community Hospital
Authors: Arch Allison E , Weisman David C , Coca Steven , Nystrom Karin V , Wira Charles R , Schindler Joseph L
Published: July 2021

Introduction:
The failure to recognize an ischemic stroke in the emergency department (ED) is a missed opportunity for acute interventions and for prompt treatment with secondary prevention therapy. Our study examined the characteristics of misdiagnosed strokes in the ED of an academic teaching hospital and a large community hospital.

Methods:
A retrospective chart review was performed from February 2013 to February 2014. A stroke was “missed” if practitioners in the ED did not initially consider stroke in the differential, or the diagnosis was delayed causing the patient to miss the therapeutic window for thrombolytic therapy.

Results:
A total of 465 ischemic stroke patients were included; 280 patients from the academic hospital and 185 patients from the community hospital. One hundred three strokes were initially misdiagnosed. Fifty-five of these were missed at the academic hospital (22%) and 48 were at the community hospital (26%, p=0.11). Of the missed stroke patients, 26 at the academic hospital (47%) and 10 at the community hospital (21%) presented within 3 hours of symptom onset. At the academic hospital where a neurologist is consulted on all potential acute strokes, a neurologist was called for 95% of the accurate stroke diagnoses but only 36% of the stroke misses (p<0.001).

Factors independently associated with greater odds of a missed stroke diagnosis were nausea/vomiting (OR=4.02, 95% CI=1.60-10.1), dizziness (OR=1.99, 95% CI=1.03-3.84), and a positive stroke history (OR=2.40, 95% CI=1.30-4.42). Thirty-seven percent of posterior strokes were initially misdiagnosed compared with 16% of anterior strokes (p<0.001).

Conclusion:
Greater than 20 percent of stroke patients admitted through the ED at both an academic center and community hospital had a missed diagnosis. These strokes were more likely to be posterior circulation strokes and associated with nausea, vomiting and dizziness. A neurologist consultation decreased the likelihood of a missed stroke. Next steps are the development of improved identification systems and tools in the ED to improve the accuracy of stroke diagnosis.
Abstract TP26: The Outcome of Patients With Tandem Occlusion Remains Poor Despite Mechanical Thrombectomy
Authors: Fahed Robert , Redjem Hocine , Blanc Raphaël , Labreuche Julien , Smajda Stanislas , Robert Thomas , Ciccio Gabriele , Abrivard Marie , Piotin Michel
Published: July 2021

Introduction:
Ischemic strokes with tandem occlusions are associated with a poor prognosis. Recent studies demonstrating the effectiveness of endovascular treatment for large vessel occlusions have shown less impressive results in patients with tandem occlusions than in those with isolated intracranial occlusions. Besides, the indications and effects of ICA stenting remain unclear.

Hypothesis:
To determine the factors associated with favorable outcome at 3-month in this subtype of AIS.

Methods:
From a prospectively gathered registry, we analyzed the data of 70 consecutive patients who underwent mechanical endovascular treatment for acute stroke with tandem occlusions from November 2011 to August 2014. Clinical (including demographics, NIHSS, and stroke etiology), imaging (including DWI-ASPECTS), and endovascular treatment data were assessed and reviewed in consensus by two observers. Good clinical outcome was defined as a modified Rankin Scale (mRS) of ≤2 at 3-month follow-up. The mRS at 3 months follow-up was available in 67 patients.

Results:
At 3-month follow-up, 33 of 67 (49.3%) patients had a good clinical outcome and 34 (50.8%) had a poor clinical outcome, including 9 deaths (13.4%). Lower NIHSS (initial, at day 1, and at discharge) and successful recanalization (TICI 2b-3) were associated with a good clinical outcome (P<0.05). There were no statistically significant differences between patients with a good or poor clinical outcome in terms of intravenous tissue plasminogen activator use, delay between symptom onset and recanalization, and endovascular technique, including the ICA stenting.

Conclusions:
Despite the recent randomized control trials demonstrating the effectiveness of thrombectomy, there is still a research gap about tandem occlusions. This subtype of stroke, which usually responds poorly to intravenous thrombolysis, is also difficult to treat by endovascular means.
Abstract TP261: Clot Integration Factor for
in-vitro
Quantification of Stent-retriever Configuration Using Cone-beam CT
Authors: van der Marel Kajo , Brooks Olivia W , King Robert M , Chueh Ju-Yu , Marosfoi Miklos , Langan Erin , Carniato Sarena L , Nogueira Raul G , Wakhloo Ajay K , Gounis Matthew J , Puri Ajit S
Published: July 2021

Objective:
Mechanical thrombectomy using stent-retriever technology provides acute ischemic stroke patients with beneficial treatment of emergent large vessel occlusion. Still, the disparity between recanalization rates and clinical outcomes calls for enhanced device designs and treatment strategies with better reperfusion efficiency. Intuitively, sufficient device integration with the embolus is pursued to maximize chances of first-pass success, thereby limiting clot fragmentation and intimal trauma during extensive clot manipulation. Our aim was to develop an imaging-based measure of device integration in reproducible phantom experiments that could help identifying differences in aspects of thrombectomy procedures that may be related to angiographic and clinical outcomes.

Methods:
Deployment variations of the Trevo(TM) ProVue/XP retriever were tested in an in-vitro model system that mimicked a MCA-occlusion with a silicone vascular replica and two visible clot models (soft elastic, and hard inelastic) with 8 trials/group. High-resolution cone-beam CT imaging was performed prior to retriever retraction. An image processing pipeline was devised that used level-set segmentation, path-tracing, and Steiner circumellipse fitting to extract and determine the interior volumes of the clot and the three visible wires. Clot Integration Factor (CIF) was calculated as the ratio of the volume of clot-device intersection to the clot volume.

Results:
Example of the device, its wires, and the clot: Average clot volumes were 90.4±12.2mm3. CIF was significantly different for two deployment variations when the device engaged a hard clot (difference between means, 95%CI=[0.003,0.187], p=0.043), but not a soft clot model (95%CI=[-0.152,0.263], p=0.567).

Conclusion:
In-vitro imaging-based quantification of clot integration can detect differences in deployment configuration relative to a clot, which may support procedural and design improvements.
Abstract TP265: Metformin Stimulates Sirtuin1 Expression and Inhibits Ischemic Brain Damage
Authors: Lee Eun-Hye , Zhong Wenliang , Xue Xiehua , Cho Suin , Kwon Ye-Rim , Zheng Yi , Qiu Yujie , Jun Hyun Jung , Lim Chi-yeon , Gozel Omer Suat , Choi Won Cheol , Qiu Jianhua , Koh Seong-Ho , Kim Hyung-Hwan
Published: July 2021

Background and Purpose:
Metformin is a well-known medication for type 2 diabetes mellitus. Metformin lowers blood glucose levels, but also activates survival proteins such as sirtiuns in cells. Since sirtuins have a broad range of survival functions like anti-aging, anti-oxidative stress, and longevity, we examined the extent to which metformin possibly via sirtuin activation, reduced ischemic brain damage after metformin treatment.

Methods:
We induced transient and permanent middle cerebral artery occlusion (MCAO) model in littermate controls and tested the effect of metformin (30 mg/kg, p.o.) on sirtuin expression, as well as the impact of ischemia in brain specific sirtuin overexpressing transgenic (BRASTO) mice. Also, we examined infarction volume and neurological deficit score in BRASTO mice after transient focal cerebral ischemia. PCR was used to confirm BRASTO genotype and western blotting for evaluating protein levels in mice brain tissue lysates.

Results:
Overall, sirtuins expression decreased following transient focal cerebral ischemia. Sirt1 and Sirt6 were especially reduced. Sirt1 expression in brain lysates was increased by 4 fold compared to WT control in BRASTO mice under basal conditions. Treatment with metformin significantly restored sirtuin levels and this effect appeared independent of reduction in blood glucose levels. Sirt1 expression was significantly increased by 2 fold at 3 hrs following metformin treatment compared to controls. Furthermore infarction volume decreased by 31.5 % and neurological deficit score improved in BRASTO mice suggesting that among the sirtuins, Sirt1 is important following ischemic injury.

Conclusions:
These results indicate that metformin increases Sirt1 expression in brain during ischemia and the increased Sirt1 may contribute to metformin's neuro-protective and therapeutic benefit in ischemic stroke.
Abstract TP27: Endovascular Treatment Within 6 Hours is Safe and Benefitial in IV-tPA Ineligible Patients
Authors: Rebello Leticia C , Haussen Diogo , Frankel Michael , Anderson Aaron , Lima Andrey , Belagaje Samir , Nogueira Raul
Published: July 2021

Background:
Treatment with IV tPA in acute stroke has restricted applicability due to its many contraindications. Indeed, the recent AHA guidelines provide only limited support to endovascular therapy (ET) in non IV-tPA patients as only few of these patients were included in the recent randomized ET trials. Our study aims to access the safety and efficacy of ET within 6 hours of stroke onset in patients ineligible to IV-tPA.

Methods:
Retrospective analysis of a prospectively collected ET database between September/2010-April/2015 for patients presenting within 6 hours of symptom onset. Patients who underwent ET alone due to IV-tPA ineligibility were compared to those who underwent IV-tPA + ET. Primary and secondary efficacy outcome included the rates of good outcome (90-day mRS 0-2) and successful reperfusion (mTICI 2b-3), respectively. Safety outcome was accessed by rates of any parenchymal hematoma (PH-1 and PH-2) and 90-day mortality.

Results:
422 patients were included in the analysis, 253 received combined IV-tPA + ET (59% overall cohort) and 169 were treated with ET alone (41%). Patients in the ET alone group were slightly older (65±16 vs. 68±15 years-old, p=0.05) and more frequently had basilar occlusions (3% vs. 8%, p=0.02) but the remaining baseline characteristics were otherwise well balanced including NIHSS (19±5 vs. 18±6, p=0.85), ASPECTS (7.7±1.6 vs. 7.9±1.5, p=0.24), time stroke onset to puncture (235±70 vs. 240±81 min, p=0.27), and glucose levels (135±50 vs. 143±60 mg/dL, p=0.13). There were no differences in the rates of 90-day mRS≤2 (45% vs. 38%, p=0.21), mTICI 2b-3 (83% vs. 80%, p=0.52), or any PH (3% vs. 5%, p=0.21) across the combined therapy and ET alone groups. The 90-day mortality was higher in patients in the ET alone (e.g. IV t-PA ineligible) patients (21% vs. 34%, p<0.01). However, after multivariate analysis adjustments the use of IV-tPA was not associated with any significant differences in the rates of good outcome, successful reperfusion, any PH, or 90-day mortality.

Conclusion:
Our data supports aggressive treatment with ET in IV tPA ineligible patients within 6 hours of stroke onset as these patients appear to have similar outcomes to IV tPA eligible patients and are known to have a poor natural history in the absence of reperfusion.
Abstract TP273: Nuclear Receptor NR4A1-deficiency Leads to Worsened Functional Outcome, Increased Inflammation but Inhibited Microglial Activation Following Cerebral Ischemia in Mice
Authors: Strecker Jan-Kolja , Hucke Stefanie , Diederich Kai , Schmidt Antje , Klotz Luisa , Minnerup Jens
Published: July 2021

Introduction:
The sterile inflammation in consequence of cerebral ischemia is accompanied by the immigration and activation of hematogenous and brain resident immune cells. It has been shown that the nuclear receptor NR4A1 (or Nerve Growth Factor IB) exerts a crucial role within the inflammatory response via regulating macrophage activation. In this study, we aimed to investigate the influence of NR4A1 in a loss-of-function paradigm on the activation and recruitment of both, brain resident and hematogenous immune cells following experimental stroke in mice.

Methods:
Wildtype (n=19) and NR4A1-deficient (n=18) mice were subjected to ischemia of the MCA (MCAO, 30 min). Animals were tested for functional outcome and were sacrificed on day 1 and 3 after reperfusion. Infarct volume, expression of inflammatory genes and activation/immigration of immune cells were analyzed via RT-PCR, (immuno-)histology and FACS analyses.

Results:
Lack of NR4A1 led to worsened functional outcome (p<0.001) and increased infarct volume (p<0.01) compared to wildtype mice. NR4A1-deficient mice showed enlarged astroglial scar formation (p<0.01) and increased COX2 expression (p<0.05). Histological evaluation showed increased macrophage counts on day 3 (p<0.05) following MCAO in NR4A1-deficient mice. Flow cytometric quantification of CD11b+/CD45low-cells showed a significantly diminished amount of microglia in NR4A1-deficient mice on day 3 compared to the wildtype group (p<0.001). NR4A1-deficiency resulted in an increased immigration of Ly6G+-granulocytes on day 3 after ischemia (p<0.001). Furthermore, Ly6G+-cells of NR4A1-deficient mice showed an excessively increased expression of MHC-class-II compared to wildtype mice (p<0.001).

Conclusion:
NR4A1-deficient mice developed enlarged infarcts and aggravated functional outcomes. Lack of NR4A1 led to impaired microglia activation and increased influx of Ly6G+-neutrophil granulocytes. NR4A1-deficient mice showed a strikingly increased number of MHC-II-presenting neutrophils compared to the wildtype group. Taken together, these results reveal a prominent influence of the receptor NR4A1 in regulation and activation of the cellular immune response and development of subsequent brain injury.
Abstract TP282: Eotaxin Shows a Sex-specific Association With Positive Ischemic Stroke Outcomes and Post-stroke Peripheral Leukocyte Activation
Authors: Roy-O'Reilly Meaghan , Conway Sarah , Staff Ilene , Fortunado Gilbert , Levy Madeline , McCullough Louise
Published: July 2021

Background and Purpose:
Eotaxin, a TH2 chemokine, has been shown to increase in mouse brain and plasma following experimental stroke. While eotaxin has been associated with age-related deficits in neurogenesis, little is known about its role in ischemic injury.

Hypothesis:
We tested the hypothesis that serum eotaxin levels are associated with long-term stroke outcome, with follow up mechanistic studies in a mouse model of ischemic stroke.

Methods:
Serum was taken from patients (n=158) 24 hours after ischemic stroke onset. Levels of serum eotaxin were quantified by ELISA, then analyzed for outcome association. For murine studies, animals (n=14) underwent 90-minute middle cerebral artery occlusion and were sacrificed at 24 hours, with sham surgery mice serving as controls. Blood was incubated with or without eotaxin (100 ng/ml) and stained for leukocyte markers and CD62L (L-selectin).

Results:
Although eotaxin protein levels were not significantly different between sexes, a multivariate analysis controlling for age, stroke severity and cardiovascular risk factors revealed a male-specific association between higher eotaxin levels at 24 hours post-stroke and a positive functional outcome at three months (p=.010). Analysis of peripheral leukocytes isolated from both sham and stroke mice revealed that addition of eotaxin to whole blood significantly increased the activation of myeloid cells in both in male (p=.0031) and female (p=.0048) animals, as measured by shedding of L-selectin. Further experiments demonstrated that shedding of L-selectin on CD8+ T-cells after treatment of whole blood with eotaxin was significant only in female animals (p=.0008).

Conclusion:
In conclusion, the results of this study suggest that eotaxin has a sex-specific association with improved stroke outcomes. Murine studies demonstrate that eotaxin causes activation of peripheral leukocytes (as measured by loss of L-selectin), with a sexually dimorphic effect on CD8+ T-cell activation that may alter the character of the post-stroke immune response and support a pro-recovery inflammatory phenotype in males. This research underscores the importance of studying both sexes in future ischemic inflammatory research.
Abstract TP286: A Literature Review of Cost-effectiveness of Intravenous Recombinant Tissue Plasminogen Activator for Treating Acute Ischemic Stroke
Authors: Wang Guijing , Joo Heesoo , George Mary G
Published: July 2021

Introduction:
Intravenous recombinant tissue plasminogen activator (IV rtPA) is recommended treatment for acute ischemic stroke patients, but the cost-effectiveness of IV rtPA within different time windows after the onset of acute ischemic stroke is not well reviewed.

Objectives:
We conducted a literature review of the cost-effectiveness studies about IV rtPA.

Methods:
A literature search was conducted using PubMed, MEDLINE, and EconLit, with the key words stroke, cost, economic benefit, saving, cost-effectiveness, tissue plasminogen activator, and rtPA. The review is limited to original research articles published during 1995–2014 in English-language peer-reviewed journals.

Results:
We found 15 studies meeting our criteria for this review. Nine of them were cost-effectiveness studies of IV rtPA treatment within 0-3 hours after stroke onset, 2 studies within 3-4.5 hours, 3 studies within 0-4.5 hours, and 1 study within 0-6 hours. IV rtPA is a cost-saving or a cost-effectiveness strategy from most of the study results. Only one study showed incremental cost-effectiveness ratio of IV rtPA within one year was marginally above $50,000 per QALY threshold. IV rtPA within 0-3 hours after stroke led to cost savings for lifetime or 30 years, and IV rtPA within 3-4.5 hours after stroke increased costs but still was cost-effective.

Conclusions:
The literature generally showed that intravenous IV rtPA was a dominant or a cost-effective strategy compared to traditional treatment for acute ischemic stroke patients without IV rtPA. The findings from the literature lacked generalizability because of limited data and various assumptions.
Abstract TP288: Does Transferring Patients to Stroke Centers Increase Length of Stay
Authors: Cossey TC , Jagolino Amanda L , Bozorgui Shima , Vahidy Farhaan S , Wu Tzu-Ching , Savitz Sean I
Published: July 2021

Objective:
Due to geographic disparities in stroke care, many acute ischemic stroke (AIS) patients are transferred to stroke centers for treatment with intravenous (IV) tissue plasminogen activator (tPA) or for post-tPA care. Advances in stroke treatment have improved patient outcomes and decreased hospital lengths of stay (LOS).

Hypothesis:
We hypothesize that post-tPA patients transferred to stroke centers have longer LOS than those presenting to our emergency department (ED).

Methods:
In a retrospective chart review from 2/14 - 5/15, we identified 400 patients who received tPA and were treated at our facility. Nine patients with in-hospital stroke were excluded. Baseline characteristics and clinical variables were abstracted. We compared the LOS (days - admit to discharge) of those presenting to our ED with those who were transferred to our facility. The baseline characteristics and clinical outcomes were compared between the two groups.

Results:
Table 1 depicts baseline characteristics and clinical variables. Of the 391 patients included, 181 (46.3%) received tPA after presenting to our ED, and 210 (53.7%) patients were treated with tPA and transferred to our facility. The median length of stay was the same for the two groups (p=0.43). There was no difference in most baseline characteristics or clinical outcome variables, though arrival NIHSS was slightly lower in the transferred group (9 vs 11, p<0.05).

Conclusion:
There was no difference in LOS or any clinical outcomes between the ED and transferred patients. Additionally, transferred patients did not receive more advanced procedures such as intra-arterial therapy or hemicraniectomy. Further studies exploring non-tPA patients and transient ischemic attack patients would be informative, as well as non-home, discharge location relative to the patient’s residence.
Abstract TP292: Telestroke vs Phone Consultation in Stroke Patients Eligible for Intra-Arterial Therapy
Authors: Osteraas Nicholas , Conners James , Cutting Shawna , Song Sarah , Cherian Laurel , Diebolt Elizabeth , Bock Josh , Lee Vivien
Published: July 2021

Background and Objective:
Intra-arterial therapy (IA) is beneficial for acute ischemic stroke patients with large vessel occlusions who have received intravenous tissue plasminogen activator (IVtPA). Telestroke has not been associated with increased IVtPA utilization rates when compared to phone consultations. We sought to determine whether telestroke improved the process of evaluation and transfer of patients who may be eligible for intra-arterial therapy (IA).

Methods:
The Rush telestroke program consists of an academic hub (comprehensive stroke center) that serves 10 spoke emergency departments (EDs). For sites outside of the telestroke program, the patient receives telephone consultation from the same pool of telestroke neurologists. IA therapy is considered for patients clinically suspected of having a large vessel occlusion who could potentially be treated with IA within 6 hours of last known normal (LKN). We compared IA eligible stroke patients transferred via the telestroke program to those non-telestroke transfer patients.

Results:
From July 1, 2013 to July 1, 2015, 126 patients were transferred from outside hospital ERs to our institution for potential IA; 6 patients were excluded for non-stroke diagnosis. Among 119 patients, 79 (66%) were evaluated via telestroke and 40 (34%) via phone consultation. There was no difference between groups for age (63.3 vs 59.3 years, p=0.14) female gender (52% vs 58%, p=0.70), hypertension (66% vs 78%, p 0.21), atrial fibrillation (27% vs 20%, p=0.50), initial arrival NIHSS (17 vs 19, p=0.12), frequency of IA (66% vs 55%, p=0.31), mean time from LKN to IVtPA administration (139 vs 138 minutes, p=0.96), mean time from IVtPA administration to arrival (106 vs 94 minutes, p=0.31), and mean time from arrival to IA start (35 vs 31 minutes, p=0.44). More patients who were evaluated via telestroke received TPA compared to those evaluated via phone (80% vs 63%, p<0.05).

Conclusions:
Telestroke improves the evaluation of IA eligible stroke transfer patients by increasing the rates of IVtPA compared with telephone consultation alone. Comprehensive stroke centers may benefit patients by incorporating telestroke systems into their IA transfer programs.
Abstract TP295: Predictability of Stroke Symptoms in Acute Stroke
Authors: Bruzzone Maria J , Vlahovic Luka , Durazo Ramon , Ruland Sean
Published: July 2021

Background:
Prompt signs and symptoms recognition and intervention are essential to achieve the best outcome after stroke. Stroke codes were developed to expedite assessment and treatment. Their optimal use requires accurate identification of stroke patients. In order to improve diagnostic accuracy in our institution, we analyzed the predictive value of individual stroke signs and symptoms in patients in whom stroke codes were activated from the emergency department (ED) by physicians and nurses and from inpatient wards by nurses, residents and hospitalists.

Methods:
We retrospectively analyzed 501 consecutive stroke codes in our stroke log from May 2013 to May 2015. Age, gender, presenting signs and symptoms, medical history and final diagnosis were assessed. Patients were classified as stroke (ischemic and hemorrhagic) or non-stroke based on the final impression after the completed work-up. X2 statistic was utilized to assess associations.

Results:
Overall, 202 (40.3%) patients were classified as stroke and 299 (59.7%) non-stroke. 78% of stroke codes were activated from ED and 22% from the inpatient wards. Unilateral limb weakness, aphasia and facial weakness were associated with stroke (p<0.05) with PPVs of 0.57 (95%CI 50-64%), 0.56 (43-68%), 0.51 (43-60%), respectively. Altered mental status (AMS) and sensory symptoms were associated with non-stroke (p<0.05). The PPV and NPV for stroke were 0.21 (95%CI 13-31%) and 0.55 (50-60%) for AMS respectively and 0.25 (14-39%) and 0.58 (43-63%) for sensory symptoms. Location of the stroke code (ED or inpatient ward) did not impact the results.

Conclusion:
Previous studies, based on evaluation of acute stroke by paramedics and ED physicians, demonstrated that some signs or symptoms are more likely to be present in patients experiencing acute stroke. In our experience, unilateral limb weakness, aphasia, and facial weakness as identified by diverse provider disciplines and experience levels are associated with a final diagnosis of acute stroke. However, isolated altered mental status or sensory symptoms seldom result in a final diagnosis of stroke. These data can assist healthcare providers, to more accurately identify stroke patients, thus improving outcomes as well as resources utilization.
Abstract TP301: Improving Stroke Door-to-Needle Time Through a Recognition Program
Authors: Kucey Whitney , Martineau Isabelle , Dowlatshahi Dar , Stotts Grant
Published: July 2021

Introduction:
In 2010, the Champlain Regional Stroke Network (CRSN) identified door-to-needle (DTN) time performance as a strategic goal, as the Regional Stroke Centre (RSC) was not consistently meeting the Best Practice Standard DTN time of ≤60minutes. The CRSN began to track DTN performance in real-time, which helped identify bottlenecks that prevented the delivery of tPA within 60 minutes. The Recognition Program (RP) started at the RSC, with the plan to apply at other stroke-centers in our region.

Hypothesis:
We assessed the hypothesis that by creating a collaborative RP, DTN performance would improve.

Methods:
The CRSN collaborated with the RSC, Regional Paramedic Program for Eastern Ontario (RPPEO), and Ottawa Stroke Program (OSP), to develop the RP as an incentive to improve thrombolysis DTN times. The RP awards a letter and a pin to all team members involved in stroke codes where tPA is administered in ≤40minutes (e.g. RNs, CT-techs, Paramedics, Orderlies, Physicians, Residents). Performance improved significantly over the first year, which resulted in the elimination of the 40 minute pin and the introduction of time-specific pins for 35, 30, 25, 20 and 15 minutes. We also launched a Quality Pin to recognize staff for providing excellent stroke patient care, that might not involve tPA administration. DTN times are reported quarterly to review performance and ensure consistency over time.

Results:
Over 4 years, the RSC has had steady performance and improved median tPA DTN time from 94 minutes to 40.5 minutes. There have been over 110 cases where pins have been distributed (DTN≤40minutes) and over 50 Quality Pins awarded. The telestroke centres in the Champlain region have adopted the RP and continue to see improvements in their DTN performance.

Conclusion:
The RP is a collaborative effort that can be applied to various projects to drive performance, as evidenced by our introduction of stroke Quality Pins for staff that go above and beyond providing stroke care.
Abstract TP303: Real-world Eligibility for Revascularization in Acute Stroke: A 12 Year Single Center Statistics
Authors: Vanacker Peter , Lambrou Dimitris , Eskandari Ashraf , Michel Patrik
Published: July 2021

Aims:
Endovascular treatment (EVT) for acute ischemic stroke (AIS) is the new standard of care for well selected, large vessel occlusive strokes.

Hypothesis:
We aimed to determine the frequency of patients potentially eligible for IV thrombolysis (IVT) and EVT based on the latest AHA/ASA guidelines.

Methods:
Data from a prespecified consecutive AIS registry (ASTRAL, 2003-2014) of a single comprehensive stroke center were examined. All AIS admitted <24hours and sufficient data to determine EVT-eligibility according to AHA/ASA guidelines (class I and IIa recommendations) on IVT and EVT were selected. Another set of more liberal criteria from different EVT trials and clinical practice was also tested. Time windows for EVT-eligibility was 4.5h (allowing for a door-to-groin delay ≤90min) and for IVT 3.5h (door-to-needle delay ≤60min).

Results:
A total of 2’704 AIS were included, of whom 26.8% were secondary transferrals. Proportion of IVT-eligible patients was 12.4% for all AIS, and 24.6% and 36.2% for patient arriving <24h and 6h respectively. Frequency of EVT-eligibility differed between the AHA/ASA guideline and the more liberal approach: 2.9% vs. 4.9% of all AIS and 10.5% vs. 17.7% of all patients arriving <6hours. These numbers are in line with the effective number of EVT applied in 2013 (15%) and 2014 (12%).

Conclusions:
Of patients arriving within 6h at a comprehensive stroke center, 10.5% are EVT eligible according to AHA/ASA criteria, nearly double (17.7%) with more liberal criteria, and again double for IV thrombolysis (36.2%). These figures may be useful for planning resource needs of stroke care on a regional level.
Abstract TP304: Use, Time Delay and Outcomes of the Drip-and-Ship Thrombolysis Paradigm for Patients With Acute Ischemic Stroke
Authors: Choi Jay Chol , Park Man-Seok , Lee Ji Sung , Park Tai Hwan , Cho Yong-Jin , Hong Keun-Sik , Park Jong-Moo , Kang Kyusik , Lee Kyung Bok , Lee Soo-Joo , Ko Youngchai , Lee Jun , Choi Kang-Ho , Oh Mi-Sun , Yu Kyung-Ho , Lee Byung-Chul , Cha Jae-Kwan , Kim Dae-Hyun , Lee Juneyoung , Kim Dong-Eog , Kim Beom Joon , Bae Hee-Joon
Published: July 2021

Introduction:
The utilization of drip-and-ship thrombolysis paradigm, clinical characteristics and outcomes of patients treated with the paradigm could vary with regional stroke care system.

Hypothesis:
We hypothesized that clinical characteristics and functional outcomes of patients treated with drip-and-ship paradigm would be different from those of patients treated via direct visit.

Methods:
From a multicenter stroke registry, we identified acute ischemic stroke patients treated with tPA who arrived hospital within 6 hours from the symptom onset. Functional outcomes at three months after the stroke were classified as favorable (modified Rankin Scale score [mRS] 0 to 1) or unfavorable (mRS 2-6). Using multivariable analysis, we compared the modified Rankin scale (mRS) score at 3 months and symptomatic intracranial hemorrhages (SICH) between patients treated with drip-and-ship paradigm and those treated via direct visit.

Results:
Among 1,843 patients who met the eligible criteria, 244 patients (13.2%; 95% CI, 11.7-14.9) were treated using drip-and-ship paradigm. Patients treated with drip-and-ship paradigm had shorter onset to needle time compared with patients treated via direct visit (median[IQR], 110 minutes[79-150] vs 126 minutes[90-173], p<0.001). After multivariable analysis, patients treated with drip-and-ship paradigm had significantly greater risk of unfavorable functional outcome (mRS 2-6) at 3 months after the stroke compared with patients treated via direct visit (OR 2.15; 95% CI, 1.50-3.08; p < 0.001). SICH also occurred more frequently in patients treated with drip-and-ship paradigm (OR 1.78; 95% CI, 1.02-3.12; p =0.04). Of 1,843 patients, 509 patients (27.6%, 71 patients with drip-and-ship paradigm and 438 patients via direct visit) received subsequent endovascular recanalization therapy. The use of drip-and-ship paradigm caused approximately 105 minute delay in onset to groin puncture time compared with those treated via direct visit (305 minutes[260-345] vs 200 minutes[155-245], p<0.001).

Conclusions:
Drip-and-ship thrombolysis paradigm was used in less than 15% of patients treated with tPA, and use of the paradigm caused a significant delay in onset to groin puncture time for endovascular therapy.
Abstract TP307: Promising Practices to Improve the Quality of Pre-Hospital Stroke Care Transitions
Authors: Teixeira-Poit Stephanie M , Amoozegar Jacqueline , Elmi Joanna , Chambard Megan , Emery Kyle , Tzeng Janice , Mirambeau Alberta , Foltz Jennifer , King Sallyann
Published: July 2021

Introduction:
Between 2012-2015 the Centers for Disease Control and Prevention’s (CDC) Paul Coverdell National Acute Stroke Program (PCNASP) funded 11 state health departments to improve the quality of stroke care across the continuum, beginning with the initial signs and symptoms of stroke through the transition from hospital to post-hospital setting.

Hypothesis:
We assessed the hypothesis that PCNASP quality improvement activities enhanced the quality of pre-hospital stroke care transitions.

Methods:
We conducted 72 semi-structured telephone interviews with stakeholders of the 11 PCNASP grantees, including program administrators, epidemiologists, quality improvement consultants, partners, emergency medical services (EMS) and hospital staff. Using grounded theory (Glaser and Strauss), we developed and applied a coding scheme to the interview transcripts to identify emerging themes related to pre-hospital quality improvement activities.

Results:
Many PCNASP grantees provided training and support for EMS and hospital staff that improved calling of a stroke code team and recognition of stroke, improved EMS pre-notifications about suspected stroke patients, advanced hospital holding of CT scanners in anticipation of suspected stroke patients, and reduced door-to-CT and door-to-needle time. PCNASP grantees had different approaches to balancing timeliness and quality of care. Some grantees developed statewide destination protocols that required EMS to bypass proximate hospitals for certified stroke care hospitals. Other grantees had challenges implementing statewide destination protocols because EMS agencies were decentralized with local authority to determine where to transport patients. In other cases, grantees promoted a “drip and ship” model where EMS transported patients to proximate hospitals for IV-tPA and then to a primary stroke center and focused on increasing the reach of stroke telemedicine.

Conclusion:
PCNASP grantees developed promising practices to improve the quality of pre-hospital stroke care transitions that accounted for their unique state context. These approaches may become the basis for best practices for improving pre-hospital transitions of stroke care across the nation.
Abstract TP31: Variability of Stroke Patients Meeting Endovascular Stroke Trial Criteria in a Non-clinical Trial Setting
Authors: Fugate Jennifer E , Brinjikji Waleed , Cloft Harry , Kallmes David F , Rabinstein Alejandro A
Published: July 2021

Introduction:
Five randomized trials proving the efficacy and safety of mechanical embolectomy for ischemic stroke patients used differing radiological methods to select patients for treatment.

Hypothesis:
The percentage of patients evaluated in a non-clinical trial setting that would meet radiological criteria to be included in the five trials will differ substantially.

Methods:
Retrospective study of consecutive ischemic stroke patients who were considered for endovascular stroke therapy based on confirmed intracranial large vessel occlusion (M1, M2, or carotid terminus) at an academic medical center from April 2010 - November 2014. All patients underwent CT perfusion and CT angiogram.

Results:
The table shows baseline characteristics of 119 patients. Median age was 69 years (IQR 57-79) and median NIHSS 18 (IQR 14-21). Most patients had ASPECTS score ≥ 6 (n=105, 88.2%). The M1 segment of MCA was the most common vessel occluded (n=81, 68%). All 119 patients (100%) met radiological criteria for MR CLEAN while 105 (88.2%) met criteria for SWIFT-PRIME, 96 (80.7%) for REVASCAT, 80/116 (69.0%) for EXTEND IA, and 74 (62.2%) for ESCAPE. IV TPA was given to 58 patients (48.7%) and acute endovascular stroke therapy attempted in 66 (55.5%). Any intracranial hemorrhage was more common in the patients treated with endovascular therapy than in those who were not (36% vs. 17%, p=0.025). The frequency of symptomatic ICH did not significantly differ between these two groups (6.1% vs 3.8%, p=0.691).

Conclusions:
The percentage of patients with acute stroke and large vessel occlusion that would qualify for endovascular stroke trials based on radiological criteria varies considerably (62%-100%) in a non-clinical trial cohort from an academic comprehensive stroke center. Additional individual patient characteristics influence treatment decisions in non-clinical trial settings.
Abstract TP310: Overcoming Barriers to Reduce Door to Needle Times in Acute Ischemic Stroke Patients: Field to CT
Authors: Panezai Spozhmy , Chukwuneke Florence , Arango Audrey , Brar Jaskiran , Daniel Joshua , Korya Daniel , Mehta Siddhart , Moussavi Mohammad , Kirmani Jawad
Published: July 2021

Background:
Time lost is brain lost. The ASA’s Target Stroke strategies were reviewed to improve Door to CT (DTCT) and Door to Needle (DTN) times. Taking acute stroke patients direct from triage to the CT scanner can reduce thrombolysis treatment times, which may improve patient outcomes. In April 2015, the JFK Comprehensive Stroke Center introduced a Direct to CT policy for acute stroke patients who are assessed to be acute by the JFK EMS service.

Method:
We performed a prospective pilot study comparing door-to-CT times (DTCT) and door-to-needle (DTN) times pre- and post-implementation of Direct to CT policy, and analyzed patient characteristics, Emergency Department (ED) presentation time, adverse effects, protocol violations and patient outcomes. Delays in treatment, enablers and barriers to treatment were also examined. The purpose was to look at feasibility and maintenance of quality when applied to a larger subset of patients.

Results:
There was no statistical difference in demographics or clinical factors in patients who presented pre- (2013, 2014, n= 621) or post- Direct to CT (April 20-June 20, 2015 n=22). However, a reduction in mean DTCT times (21 mins vs. 8.7 mins, p<.0001) and DTN times (55 mins vs. 19 mins, p<.0001) was seen. There was no increase in adverse outcomes (7% vs. 0%) in patients taken Direct to CT. There was no difference in patient outcomes, however the current study size is small. Numerous barriers to Direct to CT were identified at the pre-hospital, ED, CT and stroke team levels. These issues included ED resources, hospital geography and space, and stroke team decision making. Some of these concerns are ongoing and will take time and effort to overcome. Strengths noted were the EMS capability of pre-hospital Intravenous line establishment, blood draws, and EKG performance as well as IV tPA initiation in the CT area.

Conclusions:
Taking patients Direct to CT has significantly reduced time to evaluation, DTCT, and DTN and further improvements may be achieved through resolution of identified barriers.
Abstract TP316: Appraising the Quality of Patient Care in Hospitalization for Transient Ischemic Attack
Authors: Rumalla Kavelin , Reddy Adithi Y , Rajan Ashna , Mittal Manoj K
Published: July 2021

Introduction:
The Agency for Healthcare Research and Quality (AHRQ) patient safety indicators (PSIs) and the Centers for Medicare and Medicaid Services (CMS) hospital-acquired conditions (HACs) are federally implemented quality metrics. The necessity of hospitalization for transient ischemic attack (TIA) remains controversial. Here, we report the incidence, risk factors, and in-hospital outcomes associated with HACs and PSIs in this population.

Methods:
The Nationwide Inpatient Sample (2002-2011) was queried for all records coded as primary diagnoses of TIA. The impact of demographics, insurance status, comorbidities, and in-hospital procedures on the occurrence of PSIs and HACs and the effect of these events on length of stay (LOS), hospital costs, and mortality was examined in bivariate and multivariate analyses.

Results:
A total of 52,969 PSIs and 21,612 HACs were identified among 2,117,247 TIA hospitalizations. The most frequent PSIs were pressure ulcers (1,173 per 100,000 patients), deep vein thrombosis (376 per 100,000 patients), and respiratory failure (329 per 100,000 patients) while the most frequent HACs were falls/trauma (942 per 100,000 patients), poor glycemic control (33 per 100,000 patients), and stage III/IV pressure ulcers (31 per 100,000 patients). In adjusted analyses, age 85+ (odds ratios [ORs]: 3.81, 1.50), Medicare (ORs: 1.62, 1.37), Medicaid (ORs: 2.01, 1.34), and 3+ comorbidities (ORs: 2.83, 1.30) were independent predictors of PSI or HAC occurrence, respectively (all p<0.0001). Adjusted risk factors of PSI occurrence included: black race (OR: 1.21), in-hospital ischemic stroke (OR: 1.97), thrombolytic therapy (OR: 2.54), coronary angioplasty (OR: 1.81), and coronary artery bypass graft (OR: 7.18) (all p<0.0001). PSI or HAC in TIA patients independently predicted prolonged LOS, increased total costs, and adverse discharges (all p<0.0001). In TIA patients suffering a PSI or HAC, odds of mortality were increased by factors of 30.1 and 4.08, respectively (all p<0.0001).

Conclusion:
Among TIA hospitalizations, patient age, race, payer status, pre-existing comorbidity, hospital characteristics, and procedural management significantly impact the occurrence of PSIs and HACs, further affecting patient outcomes.
Abstract TP321: Is Weekend Admission Associated With Increased 30-day Stroke Mortality? The Effect of Adjustment Using a Claims-Based Stroke Severity Index
Authors: Hsieh Cheng-Yang , Sung Sheng-Feng
Published: July 2021

Introduction:
Whether weekend admission is associated with increased stroke mortality in Taiwan remains uncertain, partly because of an inadequate case-mix adjustment in other studies using an insurance claims databases.

Hypothesis:
Adding the 7-item claims-based stroke severity index (SSI) to a multivariate logistic regression model might alter the analysis of the effect of weekend admission on 30-day stroke mortality.

Methods:
We identified, in the Taiwan Longitudinal Health Insurance Database, which is linked with the National Death Registry, patients hospitalized for acute ischemic stroke between 2001 and 2013. The primary outcome was mortality 30 days post-admission. In base logistic regression models with and without the SSI, we tested the odds ratio (OR) of 30-day mortality in patient admitted on weekends using the covariates of age, sex, year of admission, Charlson’s comorbidity index, brain surgery, physician specialty and surgical volume, hospital ownership, accreditation, and patient volume.

Results:
We analyzed 46,007 consecutive hospitalized stroke patients (mean age: 68.8 ± 12.0 years; male: 59%), with an SSI of 7.5 ± 5.3 (range: 4.1-27.1), 23.0% were admitted on the weekend, and 4.2% died within 30 days. Patients who died within 30 days were more likely to have been admitted on a weekend (4.9% vs. 4.0%, p < 0.001). Nevertheless, patients admitted on a weekend had a higher SSI than those admitted on a weekday (7.8 vs. 7.4, p < 0.001). In multivariate logistic regression models, weekend admission was associated with 30-day mortality (OR: 1.22, 95% CI: 1.10-1.35) in the base model but not in the base model plus SSI (OR: 1.07, 95% CI: 0.95-1.20).

Conclusions:
We confirmed that, after stroke severity had been adjust by adding the SSI, weekend admission did not increase the 30-day mortality of stroke patients in Taiwan. A case-mix adjustment in comparative outcome studies of stroke patients is important when using an insurance claims database.