bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 117: Optimizing Triage in Patients With Acute Ischemic Stroke Initially Transported to Non-thrombectomy Centers
Authors: Boulouis Gregoire , Siddiqui Ahmer Khawdja , Lauer Arne , Charidimou Andreas , Regenhardt Robert , Viswanathan Anand , Rost Natalia , Leslie-Mazwi Thabele , Schwamm Lee
Published: June 2021

Introduction:
Guideline-based eligibility criteria for endovascular thrombectomy (EVT) are commonly used as criteria to select patients for transfer from referring hospitals (RH) to thrombectomy capable stroke centers (TCSC), resulting in a large amount of futile transfers. We sought to determine the baseline clinical and imaging factors associated with greater likelihood of receiving EVT after transfer, and explored the impact of simulated vascular imaging availability at RH on reducing the number of futile transfers for EVT.

Methods:
We identified stroke patients transferred from 30 RH between 2010 and 2016 for which (1) the RH computed tomography (CT) and (2) either CT/CT angiography or MRI at arrival were available for review. Initial ASPECT scores and baseline imaging characteristics were evaluated by 2 raters. The main outcome variable was pre-defined as receiving EVT at the TCSC after transfer. To analyze different options for improving triaging criteria for EVT at the RH, we generated various data-based situations accounting for the presumed vascular occlusion status based first on data available only at the RH and then by imputing vascular imaging information gathered at the TCSC presuming it could have been captured at the RH. The predictive ability of each situation, using varying NIHSS thresholds, was evaluated to find an optimal sensitivity (Se) - specificity (Sp) threshold.

Results:
A total of 508 patients were included in the analysis (mean age 69.7 ± 14.8, 41.9% females). Application of current guidelines for EVT eligibility (NIHSS >6, ASPECTs≥6, Time<6h) yielded a sensitivity (Se) of 92% (95%CI, 0.84-0.96) and a specificity (Sp) of 53% (95%CI, 0.48-0.57) for receiving EVT. Repeated simulations identified an optimal selection threshold of NIHSS≥9 if accompanied by RH vascular imaging (Se=91%; 95% CI, 83%-95%and Sp=80%; 95% CI 75%-83%). Using these criteria, for every 5 patients transferred for EVT, 2.5 would receive the treatment and one futile transfer would be prevented.

Conclusion:
Implementation of vascular imaging at RH would result in significantly fewer futile transfers for EVT. The optimal trade-off between time, cost and imaging will impact the number needed to transfer and will depend on local resources and capabilities.
Abstract 119: Magnitude of Benefit of Prehospital Mobile Stroke Unit vs Conventional ED Thrombolysis: Preliminary Estimate Based on PHANTOM-S Observational Registry Study
Authors: Nour May , Starkman Sidney , Sharma Latisha K , Saver Jeffrey L
Published: June 2021

Background:
Prehospital thrombolysis in a mobile stroke unit (MSU, CT ambulance) reduces onset to treatment times compared with conventional ED delivery of IV tPA. Studies to determine if MSU thrombolysis improves final functional outcome have been underpowered, but can provide preliminary estimates of benefit magnitude.

Methods:
We analyzed group outcome data from the PHANTOM-S Observational Registry Study (Kunz et al, 2016). For all possible dichotomizations of the modified Rankin Scale (mRS) of global disability (mRS), net benefit per thousand (BPT) treated patients were derived by multiplying absolute risk differences by 1000 and number needed to treat (NNT) by taking the inverse of absolute risk difference. For benefit in shifting patients to any lower disability level across all 6 functional transitions on the mRS, BPT and NNT were derived using the algorithmic joint outcome table method.

Results:
Group data were available for 305 patients treated with IV tPA in an MSU and 353 patients treated conventionally in the ED. Of the 6 cutpoints on the mRS, 5 showed more favorable outcomes with MSU care and 1 more favorable outcome with conventional care. The Table shows resulting Benefit per Thousand and NNT values. For the 6 possible dichotomizations of the mRS, the benefit per thousand patients ranged from -21 to 93, with the greatest benefit seen at 0-3, and a BPT of 58 for the study primary outcome of freedom from disability (mRS 0-1). For benefit of improving by 1 or more mRS levels across all 6 transitions of the mRS, the BPT was 182 and NNT 5.5.

Conclusions:
This preliminary estimate indicates that, out of every 1000 patients treated with prehospital, MSU thrombolysis rather than conventional ED thrombolysis, care, 182 will have a less disabled final outcome, including 58 more who would be free from disability. If confirmed in larger controlled clinical trials, these findings suggest that MSU-based thrombolysis would have a substantial clinical benefit.
Abstract 123: Outcomes and Complications of Aruba-eligible Cerebral Arteriovenous Malformation Patients Treated at Cleveland Clinic
Authors: Lang Min , Moore Nina Z , Witek Alex M , Rasmussen Peter M , Bain Mark D
Published: June 2021

Introduction:
Despite the findings of the ARUBA trial, the optimal management of unruptured cerebral AVMs remains unclear. Current interventions to treat cerebral AVMs include microsurgery, radiosurgery, and embolization, with a goal of complete obliteration while minimizing complications. We conducted this study to determine the risk of stroke and death as well as long-term complications in ARUBA-eligible AVM patients following invasive interventions.

Methods:
Retrospective analysis was performed on 673 patients with cerebral AVMs who were treated at the Cleveland Clinic between 2007 and 2014. Of the 673 patients, 105 were ARUBA-eligible. Mean follow-up period was 56 months (range 4-136 months). The primary outcome is the composite of stroke and death. Secondary complications recorded include hydrocephalus, cerebral edema, cysts, meningocele, CSF leakage, infections, and seizures.

Results:
Of the 105 ARUBA-eligible patients, 44 (42%) patients had microsurgery as the final intervention and 61 (58%) patients had Gamma Knife as the final intervention. Of the 44 patients that had microsurgery as the final intervention, 5 (11.4%) patients had a stroke or died, 3 (6.8%) was complicated by infection, 2 (4.5%) developed hydrocephalus, 1 (2.3%) develop cerebral edema, 2 (4.5%) had CSF leakage, 1 (2.3%) developed psychosis, 2 (4.5%) developed meningocele, and 5 of the 15 patients with a history of seizures continued to have seizures. Of the 61 patients that had Gamma Knife as the final intervention, 3 (4.9%) had a stroke or died, 6 (9.8%) developed cerebral edema, 1 (1.6%) developed cerebral cyst, 3 (4.9%) developed hydrocephalus, and 8 of the 20 patients with a history of seizure continued to have seizures. 3 (4.9%) patients treated by Gamma Knife and 4 (9.1%) patients treated by microsurgery who did not have a history of seizures developed seizures follow intervention.

Conclusion:
We report a lower rate of stroke or death, 7.6%, in our ARUBA-eligible patients population than the ARUBA-trial itself. However, there are potential complications associated with each intervention of AVMs and these should be taken into consideration prior to treatment. Further investigation is required to establish the standard of care for patients with unruptured cerebral AVM.
Abstract 131: TICI 2A Reperfusion Increases Risk of Parenchymal Hemorrhage After Endovascular Treatment for Acute Ischemic Stroke
Authors: Jones Erica , Haussen Diogo , Nogueira Raul , Nahab Fadi , Frankel Michael , Rangaraju Srikant
Published: June 2021

Background:
Endovascular reperfusion therapy (ERT) for acute large vessel occlusion limits infarct expansion and improves clinical outcomes but successful reperfusion may also increase risk of reperfusion injury and parenchymal hemorrhage (PH). We explored the association between levels of reperfusion and risk of PH.

Methods:
In a post-hoc analysis of the endovascular arm of the Interventional Management of Stroke-III randomized clinical trial, we assessed the association between levels of reperfusion (TICI0-1, 2A and 2B/3) and hemorrhage risk (PH1/2) in unadjusted and adjusted models controlling for stroke severity, final infarct volume (FIV) and level of occlusion.

Results:
Out of 434 participants who received ERT, 311 had documented TICI reperfusion grades (TICI 0-1: 84 [27%], TICI 2A: 108 [34.7%], TICI 2B/3: 119 [38.3%]). PH occurred in 42 (13.5%) patients. Patient characteristics are shown in Figure A. Higher reperfusion scores were associated with lower FIV (N=264, Mann-Whitney p<0.001 Figure B). Univariable predictors (p<0.10) of PH included FIV (p<0.0001), 24-hour NIHSS (p<0.0001) and TICI reperfusion grade (p=0.08). Compared to the TICI 0-1 group, TICI 2A was associated with higher odds of PH (OR=3.9, 1.26-12.1, p=0.014) while odds of PH in TICI 2B/3 reperfusion was similar to the TICI 0-1 category (OR=1.76, 0.73-4.26, p=0.2) after controlling for FIV or 24-hour NIHSS (Fig. C).

Conclusions:
Risk of PH appears to be highest in patients with intermediate levels of reperfusion even after adjusting for infarct size. While the reasons for this need investigating, we propose that the infarct size-mitigating effect of intermediate reperfusion may be partially offset by increased risk of PH. Our exploratory results emphasize the importance of achieving complete reperfusion during the treatment of acute LVO stroke patients.
Abstract 135: Towards Automated Incidence Rate Reporting: Leveraging Machine Learning Technologies to Assist Stroke Adjudication in a Large-scale Epidemiological Study
Authors: Ni Yizhao , Alwell Kathleen , Moomaw Charles J , Woo Daniel , Adeoye Opeolu , Flaherty Matthew L , Ferioli Simona , Mackey Jason , De Los Rios La Rosa Felipe , Martini Sharyl , Khatri Pooja , Khoury Jane C , Kleindorfer Dawn , Kissela Brett M
Published: June 2021

Introduction:
Epidemiological studies utilizing administrative databases typically use International Classification of Diseases (ICD) codes to identify stroke cases and estimate incidence rates. However, they are limited by sensitivity/specificity across study designs and stroke types. Few studies utilize physician chart review of patient records to confirm cases for improved accuracy, as this is labor intensive. We sought to develop a machine learning (ML) approach that could adjudicate potential stroke events.

Methods:
We utilized 8081 hospitalized stroke events in the Greater Cincinnati/Northern Kentucky Stroke Study. The study coordinators identified events with stroke-related diagnoses (ICD9 codes 430-438) from 17 regional hospitals in 2005 and 2010 and performed detailed chart abstraction. The information (e.g. diagnostic tests) was abstracted from patients’ medical records for each event, followed by physician case adjudication. Utilizing all clinical variables, a ML algorithm (logistic regression) was used to predict stroke cases and subtypes (ischemic, hemorrhagic, TIA, and non-strokes). Linear regression (LR) was applied to calibrate ML outputs and estimate prediction intervals based on gold-standard physician adjudication. The ML and LR models were trained on one year of data and tested on the other year. The model results were compared with using ICD-9 (ischemic: 434/436; hemorrhagic: 430-432; TIA: 435; non-stroke: other codes) calibrated by LR analysis.

Results:
Prediction intervals generated by ML covered the majority of true numbers of stroke events (Table). Compared with ICD9 codes, the ML algorithm achieved better sensitivity/specificity and more “hits” with narrower prediction intervals.

Conclusions:
The ML algorithm showed promise in matching physician adjudication and subtyping stroke cases. Future work is required to refine the methods to automate stroke epidemiology with improved accuracy and granularity.
Abstract 142: Enhanced Neuroprotection by Synergistically Induced Hypothermia with Pharmacological and Physical Approach in Experimental Stroke
Authors: Liu Kaiyin , Zhang Jun , Duan Yuexia , Wu Di , Geng Xiaokun , Ji Xunming , Ding Yuchuan
Published: June 2021

Background and Purpose:
This study combined Transient Receptor Potential Vanilloid channel 1 (TRPV1) receptor agonist, dihydrocapsaicin (DHC), with physical hypothermia (PH) (ice pad) to achieve faster cooling to enhance its neuroprotective effects, thus potentially avoiding side effects brought on by monotherapies of high dose DHC and physical hypothermia.

Methods:
Middle cerebral artery (MCA) occlusion (2 h) was achieved using an intraluminal filament. Rats (n=8) were randomized to 7 groups: sham surgery, stroke only, PH, low DHC (0.5 mg/kg), low DHC/active rewarming (AR), high DHC (1.5 mg/kg) or combination (low DHC plus PH). The treatments were maintained for 3 h at the onset of reperfusion, which was 24 h. Rate to target hypothermia (31 °C) onset was measured. Extent of brain injury was determined by infarct volume, neurological deficit, and apoptotic cell death. Expressions of pro- and anti-apoptotic proteins were evaluated through Western blotting. Metabolic changes and oxidative injury were determined by ATP and ROS productions.

Results:
Combination had 28.6% faster cooling than PH, 350% faster than low DHC group and 200% faster than high DHC group. Combination had 63.2% reduction in infarct volume and low DHC had 25.9% reduction in infarct volume compared to stroke only. High DHC, DHC (AR) and PH and did not induce significant neuroprotection. Combination therapy significantly decreased apoptotic cell death by 48.5%, as compared to 24.9% with low DHC, in association with significantly increased anti-apoptotic and reduced pro-apoptotic protein expression. Combination therapy largely increased ATP levels by 42.9%, as compared to 25% increase with low DHC. Only combination therapy and PH had significant reductions in ROS at 6 and 24 h post-reperfusion. Neurological testing showed that combination therapy had the best outcomes at 24 h of reperfusion.

Discussion:
Combination of DHC and PH enhanced the neuroprotective effect produced by each alone. This synergistic protection is associated with faster cooling and more dramatic reduction in apoptotic cell death and more favorable cellular metabolism. The combination therapy is promising in clinical settings for its non-invasive, quick and effective outcomes.
Abstract 153: Prior Statin Therapy is Not Associated With Cerebral Bleeding-prone Angiopathies in Patients With Ischemic Stroke Who Start Long-term Oral Anticoagulation
Authors: Martí-Fàbregas Joan , Prats-Sánchez Luis , Camps-Renom Pol , Marín Rebeca , Delgado-Mederos Raquel , Martínez-Domeño Alejandro , Medrano Santiago , Merino Elisa , González de Echavarri José María , Rodriguez-Campello Ana , Cocho Dolores , Casado-Naranjo Ignacio , Fuentes Blanca , Gómez-Choco Manuel , Freijo Mari Mar , De Felipe Alicia , Canovas David , Bravo Yolanda , Lara Lidia , Calleja Ana , Sanahuja Jordi , Llull Laura , Hernández María , Zandio Beatriz , Lago Aida , Zedde Marialuisa , Boix Amelia , Reverté Silvia , De Arce-Bordas Ana María , Palomeras Ernest
Published: June 2021

Introduction:
Statin therapy might be associated with an increased risk of hemorrhagic stroke, which has been attributed to low LDL-cholesterol levels and antithrombotic effects.

Hypothesis:
Previous statin therapy is associated with surrogate markers of amyloid and hypertensive angiopathies in patients with cardioembolic stroke who need to start long-term oral anticoagulation (OA).

Methods:
A prospective multicenter study of patients included in the HERO study (Intracerebral Hemorrhage due to Oral Anticoagulants: Prediction of the Risk by Magnetic Resonance). Patients were naïve for OA and had an acute cardioembolic ischemic stroke (TIA or infarct). A MR examination was performed during admission to evaluate: 1) Microbleeds (-MB-, number, distribution, burden); 2) Leukoaraiosis (-LK- presence and degree); 3) Superficial siderosis (-SS-, presence). We collected data on the specific statin, the dose and the statin intensity (low, medium or high according to accepted classifications). We also recorded demographic data and traditional vascular risk factors.

Results:
We studied 470 patients (age 77.5±6.4 years, 43.7% were men). A total of 193 (41.1%) patients received prior treatment with any statin, of whom 43.5% received simvastatin and 41.3% atorvastatin. Statin intensity was low in 14.5%, medium in 61.1%, high in 16.5% and unknown in 10.8%. LK was detected in 82.5% and was severe in 19.8%. SS was detected in 20 (4.3%) patients. MBs were detected in 140 (29.8%) patients and the distribution was lobar in 55%, deep in 30% and both in 15%. Of the MB group 74 (53%) had 1 MB, 66 (47%) had >1 MB, and 11.4% had >5 MBs. The presence of MB, LK or SS was not related to the pre-treatment with statin. The statin intensity was not related to the presence of SS, the presence/degree of LK, and the presence/distribution/burden of MBs. MBs were detected with increased frequency in hypertensive patients (p=0.09). LK presence and degree were increased in patients with MB (p=0.012) and SS (p=0.041).

Conclusion:
In conclusion, prior treatment with statins is not associated with surrogate markers of bleeding-prone cerebral angiopathies in patients with cardioembolic stroke. Therefore previous statin treatment should not influence the decision to start long-term oral anticoagulation.
Abstract 155: Bone Marrow Mononuclear Cells Enhance Stroke Recovery Through the Release of Fractalkine From the Spleen
Authors: Yang Bing , Parsha Kaushik , Valenzuela Krystal S , Nghiem Duyen M , Xi Xiaopei , Aronowski Jaroslaw , Savitz Sean I
Published: June 2021

Background:
Some types of cell-based therapies may reduce secondary brain injury after stroke by modulating immune responses from the spleen. Here, we hypothesized that fractalkine (FKN; CX3CL1) derived from the spleen mediates cross-talk between the spleen and brain, and that upregulation of FKN in the spleen by bone marrow mononuclear cells (MNCs) is an important mechanism underlying how MNCs enhance recovery after stroke.

Methods:
To model ischemic stroke, we employed rat and mouse middle cerebral artery occlusion (MCAo) models. 24 hours after MCAo, animals received autologous MNCs IV or saline as vehicle controls. Brains and spleens were harvested and serum was collected at various time points after MCAo. FKN gene expression and protein levels were measured. Functional testing was evaluated for up to 28d after MCAo. In parallel experiments, mice were subjected to splenectomy two weeks prior to MCAo and the same experiments were repeated in animals without a spleen. In another experiment, antibody neutralizing FKN receptor (anti-CX3CR1) was injected ICV at 1 hour after MNC to evaluate the impact of blocking the FKN receptor in the brain.

Results:
MNC treatment significantly increased FKN levels in the spleen, serum and brain starting 1 day after MNC treatment, as compared to the vehicle-treated group. Splenectomy significantly attenuated FKN upregulation in response to MNC administration, and also attenuated the treatment-mediated effects on functional recovery. ICV injection of anti-CX3CR1 also abolished the MNCs-mediated beneficial effect on stroke recovery. In cell culture experiment, MNCs increased soluble FKN release by spenocytes and this process required physical MNC-splenocyte interaction and was dependent on the presence of IFN-γ.

Conclusion:
MNCs enhance stroke recovery through mechanisms involving the spleen; FKN may be one of the important signals mediating the cross-talk between the spleen and the brain.
Abstract 159: Improving Chronic Motor and Cognitive Recovery After Stroke Using Injury-site Specific Inhibition of Complement Activation
Authors: Alawieh Ali , Langley Farris , Tomlinson Stephen
Published: June 2021

Introduction:
After stroke, penumbral cells express neoepitopes that are recognized by natural IgM antibodies (NIgM) leading to complement (C) activation and propagation of inflammation. We previously identified NIgMs that specifically recognize ischemic cells, and showed that whereas antibody-deficient Rag1-/- mice are protected from ischemic stroke, administration of B4IgM, a NIgM that recognizes modified annexin-4, restored C activation and injury. We developed a site-targeted C inhibitor by fusing a single chain antibody derived from B4mAb to the C inhibitor Crry. We hypothesize that the targeted fusion construct B4Crry will inhibit the neurodegenerative effects of C and improves outcome after stroke.

Methods:
Stroke was induced in adult and aged mice by 60 min right middle cerebral artery occlusion. Animals were examined for infarct volume and performance on motor and cognitive tasks. Brains were extracted for histological analyses.

Results:
A single dose of B4Crry 6hrs post-ischemia specifically targeted to the ischemic hemisphere and inhibited C activation and IgM deposition in the penumbra, yielding significant reduction in infarct volumes, neuronal loss and neurological deficits (p<0.01) at 24hrs in adult male, female and aged mice. B4Crry-mediated neuroprotection persisted through 15 days of recovery yielding improved performance on corner task, and improved spatial learning and memory retention (p<0.05). Vehicle treated animals showed a sustained chronic inflammatory response with continuous IgM and C3d deposition and robust proinflammatory microglial activation. Acute administration of B4Crry interrupted the chronic inflammatory neurodegenerative cycle by significantly inhibiting C and IgM deposition, and shifting microglial polarity to an anti-inflammatory phenotype at 15 days. Simultaneously, B4Crry resulted in pronounced increase in neurogenesis and neuronal migration. We also showed that B4Crry bound specifically to the ischemic penumbra of postmortem brain samples obtained from acute stroke patients, but not to normal brain tissue from the same patient.

Conclusions:
B4Crry is a novel therapeutic agent that provides local inhibition of C and interrupts neurodegenerative inflammatory cascades after stroke.
Abstract 171: Cerebral Blood Flow and Oxygen Extraction Fraction are Age-dependent in Children and Young Adults with and without Sickle Cell Disease
Authors: Guilliams Kristin P , Fields Melanie E , Binkley Michael M , Ragan Dustin K , Eldeniz Cihat , Chen Yasheng , Hulbert Monica L , An Hongyu , Ford Andria L , Lee Jin-Moo
Published: June 2021

Introduction:
Children with sickle cell disease (SCD) are a high risk population for pediatric stroke. Young children with SCD have a higher stroke incidence than older children. Cerebral oxygen metabolism, the product of CBF, OEF and arterial oxygen content (CaO
2
, [oxygen saturation (SpO
2
) x hemoglobin (Hb) x 1.36]) is age-dependent in healthy children, peaking at 5-9 years of age. CBF is age-dependent, but OEF variation across childhood is not well-studied. In non-SCD adults, elevated OEF confers higher stroke risk. Children with SCD have higher CBF and OEF than healthy controls, but also have lower CaO
2
. It is unknown if age independently influences CBF and OEF. We hypothesized that age, sex and CaO
2
influence components of cerebral oxygen metabolism, as measured by MRI.

Methods:
Subjects with SCD and sibling/relative controls without SCD underwent brain MRI with measurement of CBF and OEF by pseudocontinuous arterial spin labeling and asymmetric spin echo sequences, respectively. Blood samples were obtained for Hb and hematocrit values. A fast inversion recovery sequence measured T1 values in the superior sagittal sinus. A multiple regression model determined significant factors influencing CBF and OEF (age, sex, CaO
2
).

Results:
We scanned 25 subjects without SCD (ages 6-27) and 56 subjects with SCD (ages 5-28). In multiple regression analysis, age (p=0.0009) and CaO
2
(p < 0.0001) were significantly predictive of CBF, controlling for sex. Age (p=0.027) and CaO
2
(p<0.0001), were also significantly predictive of OEF, controlling for sex.

Conclusion:
Age is an independent predictor of CBF and OEF. Younger children have higher CBF and OEF, even after controlling for the lower CaO
2
associated with SCD. This may explain the increased stroke incidence in young children with SCD.
Abstract 177: The Association of Blood Pressure and Pretreatment Arterial Collaterals in Acute Ischemic Stroke
Authors: Jiang Beisi , Churilov Leonid , Kanesan Lasheta , Dowling Richard , Mitchell Peter , Dong Qiang , Davis Stephen , Davis Stephen , Yan Bernard
Published: June 2021

Introduction:
Leptomeningeal collaterals maintain arterial perfusion in acute arterial occlusion but may fluctuate subject to arterial blood pressure (ABP). We aim to investigate the relationship between ABP and collaterals as assessed by CT perfusion in acute ischemic stroke.

Methods:
We retrospectively analyzed acute anterior circulation ischemic stroke patients with CT perfusion from 2009 to 2014. Collateral status using relative filling time delay (rFTD) determined by time delay of collateral-derived contrast opacification within the Sylvian fissure, from 0 seconds to unlimited count. The data were analyzed by zero-inflated negative binomial regression model including an appropriate interaction examining in the model in terms of occlusion location and onset-to-CT time (OCT).

Results:
Two hundred and seventy patients were included. We found that increment of 10mm Hg in BP, the odds that a patient would have rFTD equal to 0 seconds increased by 27.9% in SBP (P=0.001), by 73.9% in diastolic blood pressure (DBP) (P<0.001) and by 68.5% in mean blood pressure (MBP) (P<0.001). For patients with rFTD not necessarily equal to 0 seconds, every 10mm Hg increase in BP, there was a 7% decrease in expected count of seconds for rFTD in SBP (P=0.002), 10% decrease for rFTD in DBP and 11% decrease for rFTD in MBP. The arterial occlusion location and OCT showed no significant interaction in the BP-rFTD relationship (P>0.05).

Conclusions:
In acute ischemic stroke, higher ABP is associated with improved leptomeningeal collaterals as identified by decreased rFTD.
Abstract 183: Effect of Statin in Acute Cardioembolic Stroke Patients Who Are not Indicated According to Current Guidelines
Authors: Park Hong-Kyun , Kim Beom Joon , Han Moon-Ku , Park Jong-Moo , Kang Kyusik , Lee Soo Joo , Kim Jae Guk , Cha Jae-Kwan , Nah Hyun-Wook , Park Tai Hwan , Lee Kyung Bok , Lee Jun , Hong Keun-Sik , Cho Yong-Jin , Lee Byung-Chul , Yu Kyung-Ho , Oh Mi-Sun , Kim Dong-Eog , Ryu Wi-Sun , Kim Joon-Tae , Choi Kang-Ho , Choi Jay Chol , Kim Wook-Joo , Shin Dong-Ick , Yeo Min-Ju , Sohn Sung Il , Hong Jeong-Ho , Lee Ji Sung , Lee Juneyoung , Bae Hee-Joon
Published: June 2021

Background:
There is no specific recommendation on statin therapy for cardioembolic stroke (CES) patients in current stroke guidelines. We evaluated the effect of statin on major vascular events following acute ischemic stroke in patients with CES and no other indications for statin.

Methods:
Using a prospective multicenter stroke registry database, we identified acute ischemic stroke patients who were hospitalized between 2008 and 2015 and were categorized into CES according to the Trial of Org 10172 in Acute Stroke Treatment classification. Patients who had established indications for statin in accordance with the recent stroke guidelines were excluded. Primary outcome measure was a major vascular event, a composite of stroke recurrence, myocardial infarction and vascular death; and secondary outcome measures were stroke recurrence and all-cause death. We performed frailty model analysis to estimate hazard ratios (HRs) of statin therapy on outcomes accounting for variation in quality of care among centers. Stabilized inverse probability of treatment weighting method with propensity scores was used to remove baseline imbalances between statin users and non-users.

Results:
Of the 6124 CES patients, 2987 patients (male, 52%; mean age, 73±12 years) met the eligibility criteria; and 2125 (71%) of 2987 patients were on statin at discharge. Compared to the non-users, the statin users were more likely to arrive at hospitals later, have milder neurologic deficits at presentation, be on stain prior to index stroke and have hyperlipidemia and were less likely to have atrial fibrillation and occlusion of relevant cerebral arteries. During the median follow-up of 364 days, major vascular events were observed in 118 patients (5.6%) among the statin users and 177 patients (20.5%) among the non-users, respectively (p<0.001 on log rank test); the adjusted HR of statin therapy was 0.35 (95% confidence interval, 0.27-0.46). The adjusted HRs of statin therapy were 0.71 (0.49-1.04) for stroke recurrence and 0.55 (0.46-0.66) for all-cause death, respectively.

Conclusion:
This study suggests that statin therapy may reduce major vascular events and all-cause death in cardioembolic stroke patients without definite indications for statin.
Abstract 195: Sulforaphane Protects Against Subarachnoid Hemorrhage and Alters the Expression of Inflammatory and Extracellular Matrix Remodeling Genes in a Mouse Model of Intracranial Aneurysm
Authors: Pascale Crissey L , Sawyer David M , Pace Lauren A , O’Neill Brannan E , O’Donnell Devon , Dumont Aaron S
Published: June 2021

Introduction:
Oxidative stress has been shown to play an important role in the pathogenesis of intracranial aneurysm (IA). Sulforaphane is an isothiocyanate that exhibits antioxidant properties via the Nrf2 transcription factor. We tested whether sulforaphane would protect against IA formation and subarachnoid hemorrhage (SAH) in a mouse model.

Methods:
C57BL/6 mice were treated intraperitoneally with either 0.5mg/kg/day of sulforaphane (treatment group, n = 32) or a vehicle solution (control group, n = 26) prior to being subjected to a well-established IA induction protocol involving unilateral nephrectomy, mineralocorticoid administration, and intracranial injection of elastase. Sulforaphane/vehicle treatments were begun seven days prior to elastase injection, and continued daily for the duration of the experiment. Animals were followed for 14 days until sacrifice, with measurement of the number of aneurysms formed and ruptured in each animal. Intracranial vessel tissue was collected, pooled, and analyzed using real-time PCR (RT-PCR) with experiments performed in triplicate (n = 3).

Results:
There was a lower incidence of IA in the treatment group (1.06 +/- 0.24 per animal) than in the control group (1.54 +/- 0.33), but this trend did not reach significance. The incidence of SAH in the treatment group (0.53 +/- 0.09 per animal) was approximately 50% lower than in the control group (1.08 +/- 0.21, p = 0.012). RT-PCR showed significant (p < 0.05) differences in the expression of interferon gamma, matrix metalloproteinase 9, collagen Ia2, interleukin-6, myosin heavy chain, and SM22 between the treatment and control groups.

Conclusions:
Treatment with sulforaphane resulted in a significantly lower incidence of SAH in a mouse model of IA. The expression of genes involved in inflammation and extracellular matrix remodeling were altered by sulforaphane administration.
Abstract 197: Roles of Neutrophil Extracellular Trap in the Rupture of Intracranial Aneurysm
Authors: Korai Masaaki , Furukawa Hajime , Kamio Yoshinobu , Mitsui Kazuha , Nagahiro Shinji , Hashimoto Tomoki
Published: June 2021

Introduction:
Neutrophil extracellular traps (NETs) are originally described as proinflammatory, antimicrobial structures consisting of extracellular chromatin decorated with granular and cytoplasmic proteins. The formation of NETs requires peptidylarginine deiminase (PAD) 4. Recent studies revealed that NETs can play an important role in promoting inflammation in vascular diseases. Inflammation is emerging as a key component of the pathophysiology of intracranial aneurysm. In both human and mouse studies, activated neutrophils were shown to be associated with formation and rupture of intracranial aneurysms. Therefore, we hypothesized that the formation of NETs by PAD4 promotes the development of aneurysm rupture. We tested this hypothesis utilizing both pharmacological and genetic approaches in mice.

Methods:
We used 8- to 10-week-old male C57BL/6J mice, global PAD4 knock out (KO) and granulocyte-specific PAD4 KO mice. Aneurysm was induced by a combination of elastase injection and hypertension as we previously describes. We used deoxycorticosterone acetate (DOCA)-salt hypertension. A single dose of elastase was injected into the cerebrospinal fluid using a stereotaxic approach.

Results:
Cl-amidine, an inhibitor for PAD4, significantly decreased the rupture rates (92 vs 36%, P < 0.01). At the same time, Cl-amidine decreased the number of neutrophils and the formation of NETs analyzed by Ly-6G staining and citrullinated histone H3 staining, respectively. In the inhibitor treated mice, the messenger ribonucleic acid (RNA) level of ICAM-1, MCP-1 and TNFα in the cerebral arteries were lower than that of vehicle control treated mice. Furthermore, the rupture rates were decreased in the global PAD4 KO mice and the granulocyte-specific PAD4 KO mice than in the corresponding wild type mice groups. Finally, inhibition of the formation of NETs by DNase treatment also reduced the rupture rates.

Conclusions:
Our data indicate that the formation of NETs by granulocyte PAD4 promotes the development of aneurysm rupture. NETs may be represented a potential therapeutic target for the prevention of aneurysm rupture.
Abstract 198: Endovascular Biopsy:
in vivo
Brain Aneurysm Endothelial Cell Sampling and Gene Expression Analysis
Authors: Cooke Daniel L , Halbach Van , Hetts Steven , Amans Matthew , Dowd Christopher , Higashida Randall , Lawson Devon , Nelson Jeffrey , McCoy David , Kim Helen , Hashimoto Tomoki , Werb Zena , Su Hua , Sun Zhengda
Published: June 2021

Introduction:
Cerebral aneurysms affect 1-6% of the population and their rupture carries significant mortality and morbidity. The paucity of data related to histopathological features of aneurysms stems largely from the risks associated with aneurysm tissue collection. We set out to establish a feasible technique to isolate viable endothelial cells (EC) and to characterize the differences in genetic expression (GE) between iliac arterial cells vs. aneurysm cells and non-ruptured vs. ruptured aneurysm cells.

Methods:
10 patients (5 non-ruptured and 5 ruptured) undergoing aneurysm treatment were enrolled under IRB approval. ECs from aneurysms and iliac arteries were sampled using an appropriately sized coil and a 0.035 “J” wire respectively. Coils and wires were processed via FACS and single cell qPCR to quantify expression of 48 genes implicated in EC function and aneurysm pathogenesis. Mixed models were performed using each GE level as the outcome with multiple predictors. Unsupervised cluster analysis including: hierarchical heat-map clustering, K-medoids, principle components, cART, and self-organizing maps (SOM) were used to find cell clusters based on coordinately expressed GE.

Results:
437 FACS-sorted cells were collected and 319 demonstrated CD31, CD34 and CD105 triple-positive expression. Of these, 94 were aneurysmal cells. The average number of extracted aneurysm cells per patient was 9.4 (1-24, median 6.5) with a trend for higher cell yields from ruptured aneurysms (p = 0.116). Mixed model analyses revealed a history of smoking showed the strongest associations with GE (median p-value 0.104 with 11/48 analyses p < 0.05); 5 genes significantly predicted rupture status (median p-value 0.363 with 5/48 analyses p < 0.05); and one gene significantly differentiated cell type (median p-value 0.557, with 1/48 analyses p < 0.05). SOM analysis revealed clustered GE profiles suggestive of distinct functional EC sub-populations.

Conclusion:
Cerebral endovascular sampling is a safe and reliable means for targeted cell collection for genetic analysis. Smoking was strongly associated with GE levels. Our analysis provides evidence that GE levels may be associated with cell type and rupture status.
Abstract 2: Tolerability and Medication Requirements of Aggressive Medical Management in SAMMPRIS
Authors: Al Kasab Sami , Banerjee Chirantan , Lynn Michael , Cotsonis George A , Nizam Azhar , Derdeyn Colin P , Fiorella David , Chimowitz Marc I , Turan Tanya N
Published: June 2021

Introduction:
SAMMPRIS was the first secondary stroke prevention trial to employ multi-modal protocol-driven aggressive medical management (AMM). Achievement of target SBP, LDL and physical activity were predictors of lower vascular event rates. We sought to determine the tolerability and medication requirements related to AMM.

Methods:
Medications and adverse events (AEs) in all 451 SAMMPRIS patients were recorded by sites at baseline, 30 days, 4 monthly visits, and closeout. Start and stop dates were recorded for each medication and AE, with AEs classified by the site as possibly, probably, definitely, or unrelated to risk factor treatment. AEs were adjudicated centrally by consensus of 3 neurologists after the trial ended. Standard descriptive statistics were used.

Results:
As Table 1 shows, most subjects were on statins and BP medications at baseline. The use of rosuvastatin, which was donated for the trial, increased during follow-up. ACE inhibitors were the most commonly used BP medication. AEs related to BP medications (e.g. standing BP drop > 15mm Hg or postural hypotension) occurred in 240 (53.2%) patients at any point in the trial (including baseline), of which 123 (27.3%) were symptomatic. Syncope occurred in 11 patients, with 3 considered probably or definitely related to study treatment. AEs related to lipid lowering medications occurred in 18.8% patients, 16.6% of which were myopathy symptoms and 1.3% were AST/ALT > 3 times normal, and there were no reported cases of rhabdomyolysis. AEs related to other risk factor treatments occurred in 17.5% patients (e.g. hypoglycemia secondary to glipizide).

Conclusion:
In the SAMMPRIS trial, AMM required the use of multiple risk factor medications and was well tolerated by most patients, with AE rates similar to SPS3 and SPARCL.
Abstract 204: Regional Hypoperfusion is Associated with Cortical Thinning in Asymptomatic Carotid Artery Disease
Authors: Marshall Randolph S , Asllani Iris , Pavol MaryKay , Slattery Pamelia , Lazar Ronald
Published: June 2021

Objective:
Cortical thinning has been reported in patients with cerebrovascular disease and degenerative dementia, but the direct impact of regional hypoperfusion on cortical pathology has been difficult to establish. We examined the association between regional cerebral blood flow (rCBF) and regional cortical thickness (rCT) in a cohort of patients with unilateral high-grade internal carotid artery (ICA) disease without history of stroke.

Methods:
Twenty-seven patients age 73±10yrs, 11F with unilateral ICA stenosis ≥80% or occlusion but no stroke underwent MRI, including high resolution T1 (MPRAGE) and tissue specific pseudocontinuous arterial spin labeling (ts-pCASL) to assess cortical thickness and gray matter resting CBF. Cortical thickness was measured in each hemisphere in the primary motor cortex (M1--Brodmann Area 4) by a blinded investigator using Freesurfer software (
http://surfer.nmr.mgh.harvard.edu/
), and in visual cortex (V1, Brodmann area 17) as a control for nonspecific effects in the posterior circulation. Paired t-tests were used to assess hemispheral asymmetry for rCBF and for rCT in M1 on the occluded vs unoccluded side. Linear regression was used to predict the effect of rCBF on rCT in M1 on the occluded side.

Results:
Cortex was 0.08mm thinner on the side of ICA occlusion in M1 (95%CI=0.04-0.11, p=0.0003). There was no rCT asymmetry in V1 (p=.276). rCBF was 9.3 ml/100gm*min
-1
lower in M1 of the occluded hemisphere (95%CI=5.1-13.5, p<.0001). Cortical blood flow in M1 was a significant predictor of cortical thickness in M1 on the side of the occluded ICA (adj R
2
=.128, p=.038).

Conclusion:
Cortical thinning occurred in M1 on the side of carotid occlusion in the absence of stroke, and correlated with lower rCBF. Brodmann area 4 was chosen to represent the distal field of the carotid artery. Our finding demonstrates an important effect of chronically reduced blood flow on brain pathology, and suggests that a broader definition of “symptomatic” carotid artery disease may be needed.
Abstract 21: Can Telemedicine Replace an On-board Vascular Neurologist in Deciding about Tissue Plasminogen Activator Treatment? A Pre-Specified Substudy of the BEST-MSU Study
Authors: Wu Tzu-Ching , Parker Stephanie A , Jagolino Amanda L , Yu Amy , Yamal Jose-Miguel , Bowry Ritvij , Thomas Abraham , Jackson Kamilah , Grotta James C
Published: June 2021

Background:
Faster treatment with tPA may be achieved by optimizing prehospital triage with mobile stroke units (MSUs). The Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit (BEST-MSU) study is a prospective comparative effectiveness trial of outcomes in patients randomized to MSU or standard management (SM).

Purpose:
To evaluate the inter-rater agreement for tPA eligibility between a telemedicine vascular neurologist (TM-VN) and the onboard vascular neurologist (OB-VN) in acute stroke patients seen on the MSU.

Methods:
Cluster randomization of MSU and SM weeks started on August 18, 2014. On scene, both the TM-VN and OB-VN evaluated the patient and independently documented their tPA treatment decision, NIHSS and CT interpretation. Agreement was determined using Cohen’s kappa (K) statistic. TM related technical failures that impeded remote assessment were recorded.

Results:
The remote TM-VN evaluated 173 patients. In 4 (2%) cases the TM-VN was not able to make a decision about tPA because of technical difficulties ( 1 case due to TM camera failure and 3 cases due to poor connectivity). The TM-VN agreed with the OB-VN on 88% of evaluations, with a K of 0.73 representing substantial agreement. Baseline NIHSS correlation between the TM-VN and OB-VN was 0.88. Agreement about ICH on CTH was a near-perfect K of 0.97.

Conclusions:
We conclude from these results that remote VN assessment of stroke patients in the MSU via TM is clinically and technologically feasible, reliable and accurate. TM assessment of CTH and NIHSS was also comparable to the OB evaluation. These findings will allow either OB-VN or TM-VN assessment for the remainder of the study.
Abstract 213: Hematoma-infiltrating Macrophages Transition From Inflammatory to Reparative Programs in Patients After Intracerebral Hemorrhage
Authors: Askenase Michael H , Goods Brittany A , Steinschneider Arthur F , Raddassi Khadir , Beatty Hannah , Hafler David A , Love J. Christopher , Sansing Lauren H
Published: June 2021

Intracerebral hemorrhage (ICH) causes rapid recruitment of circulating leukocytes to the injury; however, the roles of these cells in disease progression and repair in the brain are poorly understood. Findings from animal models have failed to translate into effective therapies for ICH, emphasizing the importance of studying the ICH immune response in the patient population. To gain insight into the inflammatory response in patient hematomas, we are utilizing mass cytometry, flow cytometry, and RNA-seq to characterize hematoma-infiltrating leukocytes isolated from ICH patients over a 5 day period, in conjunction with the ongoing MISTIE III trial for surgical evacuation of ICH. We have found that the hematoma immune infiltrate is predominantly composed of neutrophils and macrophages recruited from the circulation, rather than CNS-resident microglia. We have observed that hematoma macrophages have acquired a distinct phenotype differing from phagocyte populations in the peripheral blood, suggesting that their gene expression is controlled by local signals in the hematoma. Preliminary transcriptional analysis of hematoma macrophages 24-50 hours post-ICH has revealed an inflammatory profile characterized by increased expression of antigen presentation, TLR signaling, glycolytic metabolism, and prostaglandin production pathways (Figure 1). Intriguingly, by 100 hours post-ICH, macrophages downregulated these pathways and engaged a wound healing program characterized by TGF-beta signaling, fatty acid metabolism, and collagen deposition (Figure 1). These findings, in agreement with our previous results in animal models of ICH, suggest that recruited macrophages may contribute not only to initial inflammatory damage, but also to clearance of the hematoma and resolution of inflammation, making them potentially ideal targets for therapeutic intervention.
Abstract 219: Early-onset Cerebrovascular Disease and Smooth Muscle Dysfunction Associated with a Novel
Mylk1
Mutation
Authors: Malta de Sá Matheus , Fullerton Heather J , Shapiro Kevin A
Published: June 2021

Introduction:
Genetic arteriopathies are an important cause of early-onset cerebrovascular disease. We report a novel mutation in the gene for myosin light chain kinase 1 (
Mylk1
), a protein essential for smooth muscle contractility, leading to vascular smooth muscle dysfunction and stroke. Our patient presented with signs of systemic smooth muscle dysfunction at birth, and developed left hemiparesis due to right MCA stroke at 8 months of age. Cerebral angiogram showed tortuous intracranial vessels with right M1 occlusion and extensive proliferative ICA collaterals.

Methods:
Whole exome sequencing showed a
de novo
mutation in
Mylk1
leading to a P1588L substitution in the ATP binding site. To understand the effect of this substitution on protein function, we built a homology model of MYLK1 based on the resolved crystal structure of MYLK4. We then investigated conformational changes in the secondary structure using Molecular Dynamics Simulation. The protein was solvated in TIP3P water and simulated at 310K, at 1 bar, in 150 mmol/L of NaCl. The integrity of the model was verified by Ramachandran plot, with 99.6% of the amino acids in allowed regions.

Results:
The P1588L substitution alters the loop-helix structure of the ATP binding domain, which is integral for the catalytic activity of MYLK1. The substitution also affects the polarity and the flexibility of the ATP binding site, which is likely to affect the docking and binding of ATP.

Conclusions:
Using
in silico
modeling, we demonstrated that a novel mutation in
Mylk1
alters protein structure, likely interfering with systemic and vascular smooth muscle contractility and resulting in a clinical phenotype of stroke in childhood.