bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3713: Possible Role Of Circulating Cellular Microparticles In Progressive Hypertension And Middle Cerebral Artery Remodeling
Authors: Chen Ji , Yuan Bin , Chen Shuzhen , Zhang Liangqing , Zhao Bin , Chen Yanfang
Published: March 2022

Circulating cellular microparticles (MPs) are potential biomarkers for cardiovascular diseases and are also suggested to be involved in the pathogenesis of hypertension and stroke. We assessed the hypothesis that circulating MPs could have implications in influencing mean arterial pressure (MAP) and middle cerebral artery (MCA) remodeling via changes in their levels and contents. Male C57BL/6 mice were fed with normal diet (control) or induced to progressive hypertension by infusion with angiotensin II (ANG II, 42µg/kg/h, osmotic minipump) and fed with high-salt diet (HSD, 8% NaCl) plus L-NAME (120 mg/kg/day, in drinking water) for 2 (for MPs donor) and 4 weeks (for MP infusion study). Circulating MPs isolated from control (cMPs) or hypertensive (hMPs) mice were isolated as we previously described (Chen, et al, AJP, 2011). The levels of circulating endothelial MPs (EMPs) and endothelial progenitor cells-MPs (EPC-MPs) were analyzed using flow cytometry by staining with CD144 (EMPs), CD34 and VEGFR2 (EPC-MPs), respectively. The mRNA levels of CXCR4, endothelial nitric oxide synthase (eNOS), NOX2 and tumor necrosis factor-alpha (TNF-a) in circulating MPs were determined by quantitative real-time RT-PCR. In separate experiment, control or hypertensive mice were treated with infusion of cMPs or hMPs (1x10
5
/100µl) via tail vein once per week for two continuous weeks, and sacrificed at the end of experiment (week four). MAP was measured using radiotelemetric probe. The lumen/wall in the MCA was determined by Hematoxylin and Eosin staining. Results showed (
table
): 1) Mice infused with ANG II and fed with HSD and L-NAME showed progressive hypertension and MCA remodeling. 2) The levels of EMP and EPC-MPs were significantly increased in hypertensive mice. 3) hMPs carried less CXCR4 and eNOS, and higher NOX2 and TNF-a mRNAs when compared with cMPs. 4) Infusion of hMPs increased MAP and MCA remodeling in hypertensive mice, but only induced MCA remodeling in control mice. 5) cMPs decreased MAP and MCA in hypertensive mice, but had no effect on MCA remodeling and MAP in control mice. In conclusion, circulating MPs could be served as biomarkers and used for developing therapeutic avenues for progressive hypertensive and MCA remodeling.
Abstract 3719: Large Vessel Correlates of Cerebral Small Vessel Disease
Authors: Brisset Marion , Tzourio Christophe , Pico Fernando , Boutouyrie Pierre , Alpérovitch Annick , Mazoyer Bernard , Gariépy Jérôme , Zureik Mahmoud , Zhu Yi-Cheng , Dufouil Carole , Laurent Stéphane , Debette Stéphanie
Published: March 2022

Background:
MRI-markers of ischemic cerebral small vessel disease (white matter hyperintensities [WMH] and lacunar infarcts) are common in the general population and are associated with an increased risk of stroke, dementia and mortality. The mechanisms underlying these lesions are poorly understood. Our aim was to investigate the relationship of carotid structure and function with MRI-markers of ischemic cerebral small vessel disease.

Methods:
The study population comprised 1847 community-based participants (mean age 72.5±4.1 years, 60.1% women), from the 3C-Dijon Study, who had undergone both quantitative brain MRI and carotid ultrasound examination. We used multivariable logistic and linear regression models adjusted for age, gender and vascular risk factors.

Results:
Presence of carotid plaques and increasing luminal carotid diameter were associated with a higher prevalence of lacunar infarcts (OR=1.68[95%CI:1.12-2.52], p=0.01 and OR=1.24[1.02-1.52], p=0.03 respectively), and extensive WMH volume (EXT-WMHV, OR=1.37[1.07-1.74], p=0.01 and OR=1.19[1.04-1.36], p=0.01, respectively), independently of vascular risk factors and of each other. There was a graded association of carotid plaques and luminal carotid diameter with increasing severity of ischemic cerebral small vessel disease. Increasing Young’s elastic modulus and carotid circumferential wall stress were associated with EXT-WMHV (OR=1.18[1.02-1.37], p=0.02 and OR=1.20[1.03-1.40], p=0.02 respectively), and there was a significant inverse association of carotid distension with WMH volume (beta±SE: -0.021±0.008, p=0.01), independent of vascular risk factors.

Conclusion:
Our results suggest that, in addition to the established association of carotid plaques with MRI-markers of ischemic brain injury, increasing luminal carotid diameter and markers of carotid stiffness, reflecting large artery arteriosclerosis, are associated with an increased prevalence of ischemic cerebral small vessel disease.
Abstract 3747: Clinical And Imaging Outcomes For Target Aneurysm Retreatment For Remnant Intracranial Aneursym
Authors: Pandya Dhruvil J , Issa Mohammed A , Lazzaro Marc A , Sweis Rochelle , Taqi Muhammad , Abraham Michael , Gheith Ayman , Lynch John R , Zaidat Osama O
Published: March 2022

Introduction:
Aneurysmal subarachnoid hemorrhage (SAH) is a rare but devastating form of stroke. Currently surgical clipping and endovascular embolization are the two therapeutic options for treatment of intracerebral aneurysm. The reported complication rate associated with the initial endovascular treatment is about 2-40%. However, outcome and complications after target aneurysmal retreatment (TAR) is unknown. Our objective is to report clinical and imaging outcomes for TAR.

Design/Methods:
We identified patients who underwent TAR from a hospital neurointerventional database. We collected data on demographics, peri-procedural complications, clinical and imaging outcomes at the discharge and last follow-up. Peri-procedural complications were reported as intra operative perforation (IOP), thromboembolic event (TEE), both were considered symptomatic if patient develop new neurological deficit lasting for increase in NIHSS . Length of hospital stay, modified Ranking Scale (mRS), discharge disposition, recurrent SAH, re-treatment of the same aneurysm, and mortality were measured at discharge and follow up appointments. Complete data was available for 115/155 (74%) cases.

Results:
There were total of 155/1169 (13.3%) cases underwent TAR with mean age of 55 ( 3), 98 (63%) were females, and 118 (76%) were Caucasians. One hundred four (67%), had aneurysm located in the anterior circulation, 4/116 (3%) underwent TAR for recurrent acute SAH, 72/116 (62%) required stent and 10/116 (9%) required balloon assist. There were total of 5/115 (4%) IOP, and 8/115 (7%) TEE from which 2/115 (2%), and 1/115 (1%) were symptomatic respectively for a total of 3/115 (2.6%) patients. 117/151 (77%) had complete immediate obliteration of the aneurysm after TAR. Ninety five patients (83%) had mean length of hospital stay with 143/151 (95%) patients discharged home. At discharge 99/114 (87%) patients, had mRS with 0% mortality. Total of 90/155 (58%) patients had average follow up of 14 months with 8/90 (9%) requiring a 2
nd
TAR and 1/90 (1%) requiring 3
rd
TAR for recanalization. There was no re-rupture after the 1
st
TAR for the duration of follow-up period of 14 ( in total of 90 patients).

Conclusions:
In our study the rate of symptomatic events following TAR after initial endovascular therapy is 3/115 (2.6%) with 77% obliteration rate and 0% re-repture rate. TAR after an initial endovascular treatment is safe with an acceptable rate of complications and may be effective, suggested by lower rate of re-rupture.
Abstract 3768: Comparison Of Balloon Remodelled And Stent Assited Coil Embolization Of Cerebral Aneurysms.
Authors: Taqi Muhammad A , Datta Mohit , Lazzaro Marc , Abraham Michael , Pandya Dhruvil J , Issa Mohammad A , Darkhbani Ziad , Zaidat Sam O
Published: March 2022

Background:
Both balloon remodeling and stent placement techniques are used for coil embolization of the large neck aneurysms. Comparison of safety and efficacy of these two endovascular approaches has not been reported in the past. We aimed to compare the risk of thromboembolic event (TEE), intra-operative rupture (IOP)and recanalization rates between the two techniques.

Methods:
A review of a retrospectively collected database was performed, and all aneurysms treated with stent or balloon assistance between 07/2005 to 12/2010 were identified. Cases with a combined use of stent and balloon were excluded. Pearson Chi square 2x2 tables were used to calculate the odds ratio and p-value

Results:
Among 791 aneurysms treated by endovascular cerebral aneurysm embolization (EAE), 81(10.3%) cases used balloon and 275 (35%) cases used stent assistance. Mean age and large neck (> 4 mm ) were not significantly different between the two groups. Balloon remodeling was used more commonly in ruptured aneurysm compare to stent-assistance ( 41% versus 15%; OR 3.7 CI 2.1-6.4; p value 0.0001). Both symptomatic and asymptomatic angiographically proven TEE occurred in 11 (14%) cases treated with a balloon and in 26 (9.5%) cases treated with stent-assistance (OR 1.5 CI 0.7-3.2; p-value 0.3). These TEEs were symptomatic in 2 (2.5%) cases treated with a balloon, and in 2 (0.7%) cases treated with stent-assistance. The rate of symptomatic and asymptomatic intraoperative rupture in balloon-remodeled cases was 1/81(1.2%) compare to 13/275 (4.7%) in stent-assisted cases (OR 4 CI 0.5-30). Symptomatic IOP occurred in 1/81(1.2%) and 1/275 (0.4%) case respectively (OR 3.4 CI 0.2-55). After excluding patient with lack of follow up imaging; 8/66 (12%) of balloon remodeled and 23/201(11.5%) of stent assisted cases had recanalization of the aneurysm defined as any filling of the sac or class 3 per Raymond classification. (OR 1.06 CI 0.4-2.5 p-value 0.8).

Conclusion:
Balloon remodeling was more commonly used in ruptured aneurysm compared to stent assistance. No statistically significant difference was found in the risk of TEE, IOP or recanalization between the two techniques.
Abstract 3788: Mechanical Thrombectomy in a Model System of Cerebrovascular Occlusion: Device-Embolus Interactions, Flow Restoration, and Risk of Distal Embolization
Authors: Chueh Juyu , Wakhloo Ajay K , Gounis Matthew J
Published: March 2022

Background:
Previous clinical studies have shown that the performance of current FDA-cleared mechanical endovascular thrombectomy (MET) devices still can be improved. We hypothesize the efficacy and safety of MET are in part affected by proximal flow arrest, mechanical properties of the embolus, device-embolus interactions, geometry of the vasculature, cerebral hemodynamics, and MET mechanism. To attest our hypothesis, a model system of cerebrovascular occlusion is built for evaluation of different MET technologies.

Materials:
The proposed model system was composed of an anatomically representative internal carotid artery/ middle cerebral artery silicone replica, a clinically validated embolus analogue (EA), and physiological hemodynamic conditions. Different MET mechanisms were employed under X-ray guidance, namely, mechanical retrieval, aspiration and ultrasonic cavitation. The self-expanding stents (Solitaire FR and Enterprise stent) were partially deployed to ensnare the EA, followed by EA retrieval. Balloon guide catheter was used to temporarily arrest the antegrade flow when MERCI retriever or Solitaire FR was used. The efficacy endpoints included the amount of blood flow restored and the ability to achieve recanalization. The safety endpoints were an analysis of EA fragments and their size distribution by Coulter principle. A minimum sample size for each device was 5.

Results:
Both the MERCI retriever and self-expanding stents were able to engage the EA after deployment. However, in some cases, it was observed that the EA was not retained in the stent (or retriever) during retrieval. The composite flow restoration (recanalization rate × flow restoration rate x 100%) was: MERCI retriever 67%, Solitaire FR 92%, Penumbra aspiration system 77%, Enterprise stent 15%, and the ultrasound waveguide 0%. More large (>200μ m) EA fragments were generated during Penumbra aspiration. No EA fragments had dimension greater than 1000μ m, and mean size of the small and large EA fragments were between 23 to 37 and 215 to 285 μ m, respectively.

Conclusion:
The model system of cerebrovascular occlusion allows visualization of device-EA interactions and quantitative measurement of flow restoration. It also offers a reproducible testing environment to evaluate the existing devices and/or newly developed prototypes. The recanalization rate of the retriever device is related to the ability of the device to capture the EA and temporary blockage of antegrade flow during device removal. The tortuosity of the cerebrovasculature may impede the ultrasonic wave propagation and in part accounts for the failure to restore flow. The risk of the embolic shower is influenced by the mechanism of action for the MET device.
Abstract 3789: Adiposity, Leanness and 4-year Mortality in Stable Latin American Outpatients with Established Cerebrovascular Disease: Challenging the Concept of Obesity Paradox
Authors: Chiquete Erwin , CantÚ-Brito Carlos , Ruiz-Sandoval José L , Steg Gabriel , Bhatt Deepak L
Published: March 2022

Background.
The lean weight index (LWI) is a new body composition measure recently described by our group that indicates better the fat-free mass content, as compared with other anthropometric measures such as body mass index (BMI). BMI reflects both fat and lean mass, and therefore, it is not the ideal body composition index for assessing obesity. This in part may be responsible for the apparently paradoxical protective effect of a high BMI (sometimes interpreted as “protective obesity”) in reducing the risk of long-term death in some chronic diseases. We aimed to assess both BMI and LWI as predictors of long-term death in stable outpatients with cerebrovascular disease (CVD).Methods. We analyzed 582 Latin American outpatients with CVD (56.7% men, mean age 68.9 years), pertaining to the Reduction of Atherothrombosis for Continued Health (REACH) registry. LWI [LWI = BMI / waist-to-height ratio (WHtR)] and BMI were included in adjusted multivariate analyses on 4-year all-cause mortality. A LWI 30 as a cut-off indicating obesity.

Results.
At baseline, 22.3% patients had BMI >30, and 12.2% had LWI 30, and 22.5% with LWI 30, and 14.1% with LWI <40), respectively. In multivariate analysis adjusted for multiple confounders, 4-year all-cause mortality was directly associated with a baseline LWI <40 [hazard ratio (HR): 2.00, 95% confidence interval (CI): 1.09-3.64], congestive heart failure (HR: 2.64, 95% CI: 1.35-5.18) and coronary artery disease (HR: 2.31, 95% CI: 1.35-3.95), and inversely associated with statin use (HR: 0.40, 95% CI: 0.23-0.69).

Conclusion.
As shown by our results, it is possible that a certain lean mass, as reflected by LWI, may be necessary to reduce the risk of long-term mortality. The obesity paradox, as examined by the BMI, is not confirmed here when LWI is included in the multivariate analyses.
Abstract 3792: The Modified Graeb-scale Evaluates Extent Of Ventricular Hemorrhage And Independently Predicts Functional Outcome After Intracerebral Hemorrhage In A Population-based Cohort
Authors: Hansen Bjorn M , Morgan Timothy C , Sundgren Pia C , Norrving Bo , Hanley Daniel F , Lindgren Arne
Published: March 2022

Introduction:
Presence of intraventricular hemorrhage (IVH) reduces survival probability after intracerebral hemorrhage (ICH). A new semi-quantitative method, describing the extent of IVH, the modified-Graeb-scale (mGraeb), has been developed for clinical trial use (e.g. CLEAR IVH). It ranges from 0 when no IVH is present, to 32 when all ventricles are filled and also expanded by blood. We analyzed the predictive value of mGraeb in a population-based ICH cohort.

Method:
We included 256 consecutive first-ever stroke patients with ICH from Lund Stroke Register. Baseline CT scans (< 7 days after ICH) were analysed by two independent readers evaluating mGraeb, ICH-location (deep, lobar, mixed, infra-tentorial) and ICH-volume. Baseline Glasgow Coma Scale (GCS) and modified Rankin Scale (mRS) at 3 months were estimated from patient files. Cox proportional hazards models were used to identify predictive factors (age, sex, GCS and ICH-volume in all models; IVH / mGraeb and supratentorial ICH / all ICH in different models) for unfavourable outcome defined as mRS>3 or death at 3 months.

Results:
IVH was detected in 116 (45%) of 256 patients, with a mean mGraeb of 11.2 (range 1-28). At 3 months, the 161 (63%) patients who were still alive had a mean mRS of 2.7. In the primary Cox analysis of patients with supratentorial ICH (n=206), the presence of IVH more than doubled the hazard for poor outcome (HR 2.20; 95% CI 1.42-3.40; p<0.001). In the secondary Cox analysis, each unit increase in mGraeb increased the hazard by 6% (HR 1.06; 95% CI 1.03-1.09; p<0.001). Age (HR 1.03; 95% CI 1.02-1.05; p<0.001), GCS (HR 1.42; 95% CI 1.23-1.65; p<0.001) and ICH-volume (HR 1.07; 95% CI 1.03-1.11; p=0.001) were also related to poor outcome. Sex and ICH-location did not independently influence the outcome in the secondary Cox analysis. Results where similar when the endpoint was changed to death at 3 months and also when cases with infratentorial ICH (n=50) were included in a tertiary Cox analysis.

Conclusion:
The mGraeb, is an independent predictor for outcome after ICH. Compared with the dichotomous variable IVH (yes/no), it gives more detailed information regarding prognosis. The mGraeb can be considered for routine evaluation of ICH patient prognosis.
Abstract 3798: Correlation Between Recanalization Rate and Good Clinical Outcome in Acute Ischemic stroke, A Meta-Analysis.
Authors: Nourollahzadeh Emad , Kass-Hout Omar , Mokin Maxim , Aliotta Rachel , Snyder Kenneth , Siddiqui Adnan , Levy Elad , Kass-Hout Tareq
Published: March 2022

Correlation Between Recanalization Rate and Good Clinical Outcome in Acute Ischemic stroke, A Meta-Analysis.
Emad Nourollahzadeh, Omar Kass-Hout, Maxim Mokin, Rachel Aliotta, Kenneth Snyder, Adnan Siddiqui, Elad Levy, Tareq Kass-Hout

Background:
Early recanalization is strongly associated with improved functional outcomes and reduced mortality in acute ischemic stroke (AIS). This is the rationale that stands behind the use of intravenous (IV) or intra-arterial (IA) thrombolytics and the growing list of mechanical thrombectomy devices. There has been multiple small sized studies that have reported this positive association, however, we are lacking a recent review compilation demonstrating this.

Methods:
Data were collected through Medline search. We analyzed all articles published between the years 2002-2011 comparing various clinical outcomes including modified Rankin Scale (mRS) at 90 days, symptomatic intracranial hemorrhage (sICH), and mortality rate between non-revascularized and revascularized groups in the setting of AIS therapy. Search key words included recanalization, reperfusion, thrombolysis, thrombectomy, modified rankin scale, in combination with ischemic stroke and cerebral ischemia.

Results:
Seventy three studies reporting recanalization rate on 4,390 patients were analyzed. Recanalization rate through various intervention approaches were extracted (IV thrombolytic 32%, IA 58%, mechanical thrombectomy 89%, and combined thrombolytic/Mechanical 91%). Correlation between clinical outcomes and different revascularization therapies, location of the occlusion and the time from symptom onset to revascularization was only stratified in 68 studies. Patients with successful revascularization defined as Thrombolysis In Myocardial Infarction (TIMI) of 2-3 had a better functional clinical outcome compared to non-revascularized group (Pooled odds ratio 6.01; 95% CI 4.87 to 7.18). Mortality rate was reduced in patients that were revascularized (Pooled odds ratio 0.32; 95% CI 0.18 to 0.41). Symptomatic intracranial hemorrhage rate were reduced for the non-revascularized group, however it was not significant (
P
= 0.31).

Conclusion:
This meta-analysis further supports the positive correlation between revascularization rate and good functional outcome and reduced mortality rate in AIS.
Abstract 3804: Regression of DWI Lesion is Frequent and is Associated with Outcome after Endovascular Therapy for Acute Ischemic Stroke
Authors: Tateishi Yohei , Toth Gabor , Aoki Junya , Jin Yonming , Hussain Muhammad S , Gebel James , Uchino Ken
Published: March 2022

Background:
Hyperintensity on diffusion weighted imaging (DWI) on MRI obtained ultra-early is hypothesized to represent core ischemic lesion in patients with acute ischemic stroke. However, resolution of a part of DWI lesion is well known. We evaluated the evolution of the hyperintensity on DWI among acute stroke patients who underwent endovascular recanalization therapy.

Methods:
We reviewed prospective database of early MRI imaging in screening for endovascular therapy in acute stroke from May 2010 to July 2011. We included patients who had both pre-treatment and follow-up MRI. We assessed the change in DWI lesion volumes among these patients. Patients were divided into 2 groups: “growth group” (patients showing more than 10 % increase in lesion volumes), “non-growth group” (patients showing less than 10 % increase or decrease in lesion volumes). Stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS) score at arrival and discharge. We compared patient’s backgrounds, imaging findings, endovascular therapy, and Thrombolysis in Myocardial Infarct (TIMI) flow grade following endovascular therapy between “growth” and “non-growth” group.

Results:
Fifty four patients underwent acute endovascular therapy. Of these, 30 patients (56 %) had both pre-treatment and follow-up MRI. The median time between stroke onset to initial MRI was 257 minutes, and follow-up MRI were performed at median 2.5 days after endovascular therapy. Decrease of DWI lesion volume was seen in 5 patients (17 %) with median volume decrease of 15 ml among the 5 patients. Total of seven patients had decrease or <10% growth of DWI lesion. There were no differences in pre-treatment NIHSS score or DWI lesion volume between the “non-growth” and “growth” groups. The “non-growth” group had a lower NIHSS score at discharge (median, 3 versus 14, p = 0.013) compared to that of growth group. TIMI recanalization grade 2 or 3 (88 % versus 87%, p = 1.000), or TIMI recanalization grade 3 (14 % versus 26 %, p = 1.000) were not different between the two groups.

Conclusion:
Patients without growth of DWI lesion may have good outcome. Decrease of DWI hyperintense lesion was observed in about one-fifth of patients who underwent endovascular therapy. However, that was not associated with the degree of recanalization.
Abstract 3830: Wnt/ beta-catenin Signaling is Upregulated Early Post-stroke and Exogenous Activation of the Pathway Promotes Neurogenesis, Enhances Functional Recovery and has Potential Neuroprotective Effects
Authors: Iordanova Ilina , Loya Joshua , Dargie Andrew , Anderson Matthew , Sun Guo Hua , Steinberg Gary
Published: March 2022

Introduction and Objectives:
Wnt/ beta-catenin signaling has been identified as an essential component of adult neurogenesis within the hippocampus. Its role within the adult Subventricular Zone, SVZ, is less well understood, as is its role in the context of post-stroke neurogenesis. With this work we aim to 1) compare the levels of Wnt/ beta-catenin signaling at the neurogenic subventricular zone, SVZ, at 1, 3, 5 and 7 day post-stroke or SHAM surgery 2) to determine the cell types that upregulate the Wnt/ beta-catenin signaling pathway post-stroke 3) to determine the effect on neurogenesis and post-stroke recovery following 3.1 an intraparenchymal injection of a Wnt-3a liposomes able to activate the pathway and 3.2 ablation of the pathway through a conditional knock-out model.

Methods and Results:
- Wnt/ beta-catenin signaling is upregulated within the adult neurogenic subventricular zone, SVZ, at 1 and 3 days post 30 min MCAO but is unchanged compared to SHAM operated animals at 5 and 7 days post-stroke. Strokes were performed on adult male Axin2 +/- animals, reporter for Wnt/ beta-catenin signaling. - Doublecortin, DCX, positive immature neurons both at the SVZ and migrating towards the injury site were positive for the pathway, as were reactive astrocytes, expressing GFAP, and mature NeuN expressing neurons in both the cortex and striatum - Intraparenchymal injections of Wnt-3a liposomes, able to activate the Wnt/ beta-catenin pathway both in vivo and in vitro, significantly increased the levels of neurogenesis at the SVZ post-stroke, when compared to PBS liposomes (p<0.001, t-test). Wnt-3a or PBS liposomes were injected at 3, 5 and 7 days post-stroke and animals were sacrificed at the 2 week time point for histology and 6 weeks post-stroke for infarct size analyses. A trend in reduced infract size, as measured by MRI and silver staining, and a significant score improvement on the ladder test at 4 weeks post-stroke were also observed (p<0.01, t-test). - Conditional ablation of the Wnt/ beta-catenin pathway using the GLAST/ beta-catenin knock out mice, generated in collaboration with Dr. Magdalena Goetz laboratory at Heidelberg, resulted in a trend of larger stroke sizes, which is being reconfirmed.

Conclusions:
We have demonstrated that the Wnt/ beta-catenin signaling pathway is upregulated early post-stroke and is present within immature neurons, reactive astrocytes and mature neurons. Exogenous activation of the pathway post-stroke promotes neurogenesis and has beneficial effects on functional recovery as well as potential neuroprotective effects.
Abstract 3875: Quantifying The Contribution Of Risk Factors For Ischaemic Stroke In Patients With A History Of TIA
Authors: Ramsey Duncan C , Burnett Mark G , Cowperthwaite Matthew C
Published: March 2022

Background:
The risk of stroke is significantly greater in patients with a history of transient ischaemic attack (TIA). Here, we present a model that comprehensively quantifies individual risk for an ischaemic stroke within 30-days after a TIA.

Methods:
We conducted a retrospective analysis of 57,585 TIA admissions to 155 United States hospitals. For each admission, we gathered demographic data, diagnostic and procedural codes, and length of stay; we collected the zip code and primary stroke center (PSC) certification status of each hospital. We used this information to build hierarchal regression models to study the risk of stroke readmission in TIA patients.

Results:
The prevalence of 30-day ischaemic stroke readmissions was 11 per 1,000 TIA admissions, however most (53.2%) occurred within one week. The regression model revealed peripheral vascular disease (Odds-Ratio: 1.83), hypertensive chronic kidney disease (OR: 1.69), history of myocardial infarction (OR: 1.33), essential hypertension (OR: 1.14) and diabetes mellitus (OR: 1.2) as significant comorbid predictors that contributed to individual risk. Cerebrovascular disease was the primary readmission reason in the TIA patient population (19% of readmissions). The risk-adjusted stroke-readmission rates showed little variation among hospitals (c
v
= 0.06). PSC status was not significantly associated with the observed differences in stroke readmission rates among hospitals (Fisher exact,
p
= 0.30).

Conclusions:
Cardiovascular comorbidities and diabetes mellitus are associated with significantly greater risk for a stroke readmission within 30-days of a TIA. Our results highlight the need for identifying at-risk individuals based on the profile of their comorbidities when assigning care.
Abstract 3896: Positive Deviance of Acute Ischemic Stroke Care: Time
Truly
is Brain at Best Practice Hospitals
Authors: Hudak Marissa L , Cumbler Ethan
Published: March 2022

Objectives
As of July 31, 2011, only 133 national stroke centers have been recognized on the AHA Target: Stroke Honor Roll. At these hospitals, at least 50% of treated ischemic stroke patients receive IV thrombolysis within an hour of arrival. Utilizing positive deviance methodology, successful strategies and institutional culture were identified among a selection of these hospitals.

Methods
Structured phone interviews were conducted with Stroke Program Coordinators of 12 Honor Roll centers. Detailed descriptions of evaluation and treatment process and methodology were elicited. Emphasis was placed on changes instituted, barriers, and delays. Each hospital was asked which elements were critical to their success. Common themes were identified. Utilization of the 10 AHA Target: Stroke best practice strategies was assessed.

Findings
Seven of ten AHA best practice strategies were employed by 100% of the interviewed hospitals: “Advance Hospital Notification by EMS”, “Rapid Triage Protocol and Stroke Team Notification”, “Rapid Acquisition and Interpretation of Brain Imaging”, “Rapid Laboratory Testing (Including point of Care Testing if indicated)”, “Rapid Access to Intravenous rt-PA, Team-Based Approach”, and “Prompt Data Feedback”. 58% of the hospitals utilized “Single Call Activation System”. “Stroke Tools” and “Mix rt-PA Medication Ahead of Time” were implemented by 50% of the hospitals. Additional strategies identified included: active time monitoring, allowing t-PA ordering with lab results pending, utilization of non-Neurologist staff as lead in stroke alerts, required NIHSS training for all ED staff, and visual feedback of performance to staff. Common themes of institutional culture included strong stroke champions in multiple departments, empowering staff to find department-specific solutions to solve the common challenge, and setting progressively more ambitious targets. A unifying theme throughout all hospitals was an extreme sense of urgency and utmost priority on time to stroke treatment.

Conclusion
Positive deviance methodology examines a common challenge and identifies successful outliers. Although the majority of the AHA strategies were supported by the interviewed hospitals, many centers modified methods to achieve the goal of Target: Stroke. For rapid treatment of ischemic stroke the positive deviance lies in institutional culture of urgency and continuous improvement. Best practice hospitals create a healthy competition amongst staff, solidify interdepartmental partnerships, instill an equal sense of accountability, open communication, and an atmosphere of teamwork. A great deal of variation was discovered in roles and processes employed by the hospitals, though all identified the essential goal of fostering a culture of motivation and urgency.
Abstract 3906: Comparative Effectiveness of Long-Term Outcomes of Treatment of Unruptured Intracranial Aneurysms
Authors: Torner James C , Zhang Jie , Piepgras David , Huston John , Meissner Irene , Brown Robert ,   ISUIA Investigators
Published: March 2022

Introduction:
The long term effectiveness of preventive intracranial treatment of unruptured aneurysms for hemorrhage and aneurysm-related morbidity and mortality has been hypothesized. No randomized trial has been done. Propensity adjusted comparison within The International Study of Unruptured Intracranial Aneurysms was undertaken to compare long-term effectiveness.

Hypothesis:
The purpose of this analysis was to compare the long-term outcome in the treatment cohorts (surgery and endovascular) with those of the untreated subgroup.

Methods:
Patients were subdivided into the initial treatment and untreated cohorts based upon observation or treatment practices in 61 centers from 1991-1998. 1691 patients were in the observational cohort, 471 were in the endovascular cohort and 1917 patients were in the surgical cohort. The cohorts were followed for a median follow-up of 9.2 years. Outcomes were determined prospectively and with central review. The data were grouped together and analyzed to determine treatment decisions. Comparison of outcomes was done using covariate adjustment and using propensity analysis where equivalent probability groups were constructed. Similar main predictors of treatment and outcome were observed. Analysis of hemorrhage, mortality and short-term and long-term morbidity and mortality were assessed. Risk-benefit ratios were also calculated.

Results:
Significant differences in baseline variables between treatment and observed patients were aneurysm size, symptoms, age, prior SAH or not group, geographical region, family history, hypertension and myocardial infarction history. The results show comparability of groups using the patient propensity-based score subset. Using the propensity score method, the results showed a benefit in prevention of hemorrhage by surgery and endovascular treatment versus observation (p<.01). No difference was found between endovascular versus surgery. However when procedure-related outcomes are included, no significant difference at 1 year, 5 years or 10 years in the combined aneurysm or procedure related endpoint was evident between cohorts.

Conclusions:
Propensity score matching to achieve comparability resulted in balanced groups. Comparison of long-term results showed that intervention demonstrated a benefit in reducing hemorrhage risk. However, peri-procedural risk negates any short-term benefit for 10 years.
Abstract 3930: Differences in Admitting Hospital Characteristics for African American and White Patients with Acute Ischemic Stroke Patients in United States
Authors: Hassan Ameer , Chaudhry Saqib , Suri Fareed , Qureshi Adnan
Published: March 2022

Background_
Racial disparities in acute ischemic stroke treatment may be due to differences in characteristics of admitting hospitals. Recent studies have found a significantly lower rate of admission for African-American patients with acute myocardial infarction to revascularization centers.

Objective_
To ascertain if there are racial disparities in admitting hospital characteristics in regards to hospital based outcomes and availability of revascularization among patients with ischemic stroke.

Methods_
We identified African-American and white acute ischemic stroke patients from the Nationwide Inpatient Sample-2009. We categorized hospitals based on availability of intravenous thrombolysis (>10 patients per year) and/or endovascular treatment (>1 patient per year). We assessed hospital’s quality using a score based on in-hospital stroke mortality. Hospitals with a score in the top 20% were categorized as high quality, and those in the lowest 20% as low quality. The odds of admission to high or low quality hospitals for white and African American patients was determined after adjusting for risk factors in multivariate analysis.

Results-
Of the 110,511 patients admitted with ischemic stroke including 16,334 (14.8%) African-American patients. African-American patients lower mean age (64.7 versus 72.7 years), higher percentage of females (56.5% versus 52.5%) and increased incidence of hypertension (86.6% versus 77.7%) p<0.0001.

African American patients were relatively less likely (
P
<0.001) to be admitted to a high-quality hospitals (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.84 to 0.95) and more likely (
P
<0.001) to be admitted to low-quality hospitals (OR, 1.16; 95% CI, 1.05 to 1.28). There was no difference in the rates of admission to hospitals with availability of revascularization according to race (OR, 1.026; 95% CI, 0.978 to 1.077).

Conclusions_
There appears to be higher odds for African-American stroke patients to be admitted to low quality hospitals in United States warranting a better understanding of associated factors.
Abstract 3932: High Rate Of Radiographic Stroke Recurrence In Cryptogenic TIA And Minor Stroke Patients: A Prospective Imaging Study
Authors: Bal Simerpreet S , Patel Shiel K , Almekhlafi Mohammed , Modi Jayesh , Demchuk Andrew M , Coutts Shelagh B
Published: March 2022

Introduction:
Cryptogenic stroke (CS) mechanism in patients with TIA/Minor stroke has a recurrent stroke risk of 1-6% within 3 months. There is some evidence to suggest that an occult embolic phenomenon would be a likely cause of stroke in many patients with CS. It is likely that radiographic event rates are higher than clinical event rates which may potentially be a therapeutic target for proof of concept prevention trials. We sought to determine clinical and radiographic event rates in patients with cryptogenic mechanisms in a TIA/minor stroke population.

Methods:
Patients with TIA/Minor stroke (NIH Stroke Scale ≤ 3) were prospectively enrolled and imaged within 24 hours of symptom onset as part of two prospective imaging cohorts. [VISION (V) and CATCH (C)]. Patients were included if their baseline modified Rankin scale (mRS) was ≤1. All patients were followed clinically for 3 months to document any clinical recurrence and had a repeat MRI either at day 30 (V) or at day 90 (C). Stroke mechanisms were categorized as per TOAST criteria after parenchymal and vascular imaging and cardiac investigations. Patients were labelled as cryptogenic only after standard etiological workup for ischemic stroke including at least vascular imaging, transthoracic echocardiogram and holter monitoring was completed. Follow up imaging was assessed for any new lesions in comparison to baseline imaging.

Results:
Among patients enrolled in both prospective studies 380/844(45%) had cryptogenic stroke mechanisms. Of these, 215 patients had follow up imaging. There were 132 (61%) males. Intracranial occlusions was seen in 23/215 (10.6%) with baseline DWI abnormality documented in 66/215 (30.6%). In the VISION dataset, 5/76 (6.6%, 95%CI 2.2-15%) patients had new lesions on follow-up MRI at day 30. In the CATCH dataset 19/131 (14.5%: 9-22%) of patients had new lesions on follow-up MRI at day 90. Baseline DWI abnormalities was a significant predictor of new radiological lesions on follow-up imaging [p=0.003 OR 4.75 95% CI: 1.67-13.2]. Overall clinical recurrence was seen in 10/215 (4.6%: 2.2-8.4%) of patients. Baseline DWI abnormality was not a significant predictor of clinical recurrence (p=0.96).

Conclusion:
TIA/Minor stroke patients with cryptogenic mechanism show evidence of silent radiological accumulation of disease on follow up imaging at a higher rate than clinical recurrence. Repeat brain imaging at 3 months or potentially later may be a useful surrogate marker for disease activity in treatment trials in this population. There is a need for randomized controlled trials using novel anticoagulants with follow-up imaging as a surrogate marker of disease activity to improve treatment of cryptogenic minor stroke/TIA.
Abstract 3940: Perihematomal Leukocytes Peak 3 Days After Intracerebral Hemorrhage
Authors: Hammond Matthew D , Alander Cynthia B , Sansing Lauren H
Published: March 2022

Background:
Intracerebral hemorrhage (ICH) is followed by a robust inflammatory response in the brain. Therapies inhibiting leukocyte migration to the brain have been developed, but their potential application to ICH relies on detailed understanding of the invading inflammatory cells after injury. Our objective was to quantify the various leukocyte populations between 1 and 7 days after ICH using a mouse model.

Methods:
Using the autologous blood injection model in WT (C3H/HeOuJ) mice, we injected 15μ l of blood into the basal ganglia 2.5mm right of bregma. At 24h, 72h, and 7 days following surgery, we isolated the brain and dissociated each hemisphere into a single cell suspension using collagenase, dispase, and mechanical digestions prior to staining with CD45, CD3, CD11b, Ly6G, CD11c, Gr-1, and NK1.1 antibodies. Immune cell populations were quantified by flow cytometry (see
figure
for gating) and the numbers of excess ipsilateral cells were calculated. Additionally, at 72 hours after ICH or sham surgery, we isolated the ipsilateral hemisphere for quantification of chemokine production by ELISA.

Results:
There was a significant increase in blood-derived leukocytes (CD45hi) between 24hr and 72hr, mostly accounted for by inflammatory monocytes and dendritic cells (
Figure
). We then saw a significant decrease between 72 hours and 7 days in the inflammatory monocyte population as well as a trend towards a decrease in the dendritic cell population. Natural killer cells accounted for less than 0.3% of all leukocytes detected. The monocyte-recruiting chemokine CCL2 (MCP-1) was increased in the brains at 72 hours after ICH (ICH 260.8 ± 31.1 pg/g brain vs sham 148.8 ± 12.4, p<0.05) consistent with the peak of inflammatory monocyte recruitment.

Conclusion:
Leukocytes peak in the brain at 72 hours after ICH and are almost completely absent by 7 days. Inflammatory monocytes and dendritic cells account for the greatest numbers of leukocytes at 72 hours. CCL2 levels are elevated when inflammatory monocyte populations peak. Therapies inhibiting the CCL2-dependent migration of inflammatory monocytes across the blood-brain barrier should be investigated to determine if these cells contribute to injury.
Abstract 3968: Eloquence Of Region And Extent Of Brain Ischemia Detected By DWI Predicts Degree Of 24h Nihss Score Improvement After Arterial Recanalization In Ischemic Stroke
Authors: Bal Simerpreet S , Aaron Sanjith , Menon Bijoy K , Goyal Mayank , Cho Kyung Hee , Smith Eric E , Demchuk Andrew M , Sohn Sung IL
Published: March 2022

Introduction
Improvement in NIHSS score at 24 hrs or delta NIHSS change (ΔNIHSS) is an early measure of response to recanalization treatment and has been associated with good outcome. We hypothesized that ΔNIHSS achieved with arterial recanalization may be influenced by eloquence of region involved within a vascular territory on baseline imaging.

Methods
Patients from prospectively collected Keimyung University stroke database, [2005-2009] were analyzed. Patients with proximal anterior circulation occlusions (ICA, MCA M1, proximal M2) who recanalized after IV tPA/IV tPA+endovascular therapy (TIMI 2/3) on DSA / MRA were included for final analysis.Detailed clinical and biochemical data collected prospectively was analyzed. Imaging analysis was done in University of Calgary. Two readers evaluated baseline DWI imaging and graded ischemic infarcts in16 anatomical regions(cortical MCA-M1,M2,M3,M4,M5,M6, insula; subcortical MCA- corona radiata -C1,C2,C3, basal ganglia; posterior limb of internal capsule; ACA- A1,A2 and PCA-P1,P2). Depending on the number of infarct regions involved, patients were categorized into three groups: mild - (0-3 infarct regions), moderate-(4-6), large and extensive (7-16). Improvement of 10 point in NIHSS score was labeled as treatment responders. ΔNIHSS change per point was the primary outcome.

Results
Among 265 patients in database, 101 patients who recanalized (TIMI2/3,) were analyzed. ΔNIHSS ≥10 was seen in 24 (24%) of subjects. There were 56% males. The mean age of patients was 65+-11.2yrs, Baseline median NIHSS was: 14 (IQR -11-16) and 24 hrs median NIHSS was 7 (IQR 6-9). There was no neurological improvement (ΔNIHSS) in patients with greater than 6 areas of involvement (p<0.001).Glucose was significantly higher in patients without ΔNIHSS compared to patients with ΔNIHSS (p=0.01). The most eloquent regions as measured by absence of delta NIHSS>10 despite recanalization were basal ganglia (OR 0.03 95%CI 0.004-0.25, p=0.001),posterior limb of internal capsule (OR 0.10 95%CI 0.01-0.85, p<0.001) ,M2 ( OR 0.06 95%CI 0.01-0.25, p<0.001)and C2 (core of corona radiata)(OR 0.12 95%CI 0.04-0.35 p<0.001).

Conclusions
ΔNIHSS at 24 hours after recanalization is high in a situation when more anatomical regions are involved. Patients with more than six infarcted regions had no improvement in ΔNIHSS. Patients with baseline involvement (ischemic core) of the corona radiata (C2), M2 (temporal lobe), basal ganglia and internal capsule have the least chance for significant ΔNIHSS improvement.
Abstract 3998: Anterior Choroidal Artery Involvement Is Predictor Of Poor Neurological Outcomes In Distal Carotid Occlusions
Authors: Bal Simerpeet , Menon Bijoy , Almekhlafi Mohammed , Goyal Mayank , Hill Michael , Bhatia Rohit , Sohn Sung-Il , Demchuk Andrew
Published: March 2022

Introduction
Distal internal carotid (ICA) occlusions with ischemic stroke has been shown to have poor outcomes despite successful endovascular treatment related recanalization. Anterior choroidal artery (AchA) infarcts are commonly seen with distal ICA occlusion. We hypothesized that anterior choroidal artery territory involvement may be a key factor responsible for poor neurological outcomes in these patients and evaluated this hypothesis in two independent imaging databases of endovascular treated patients with distal ICA occlusion.

Methods
The computed tomography angiography (CTA) database of the Calgary stroke programme and Keimyung University MR databases were reviewed. All patients with acute ischemic stroke with distal ICA occlusions were identified. Patients with endovascular intervention with or without thrombolytic therapy were analyzed. CT or MRI done from day 1 - 7 after the procedure was evaluated for involvement of areas supplied by AchA. Patients from Keimyung University, Daegu South Korea had MR imaging with acute protocol before endovascular intervention. Patients with partial and complete involvement of anterior choroidal artery were categorized in the same group. MRS ≤2 at 3 months was used as good outcome. Recanalization was defined as TIMI 2-3 flow on angiography.

Results
Among 1454 patients from Calgary CTA database, 90 patients were identified to have distal ICA occlusions (
Figure
). Overall, involvement of anterior choroidal artery on followup imaging was a strong predictor of poor neurological outcomes (p=0.003, RR 4.3, 95% CI 1.57-11.75). Among 265 patients from Keimyung MR database, 55 patients were identified with distal ICA occlusions, of which 48 underwent endovascular treatment. Good Overall, involvement of anterior choroidal artery on baseline imaging was a strong predictor of poor neurological outcomes (p=0.003, RR 4.3, 95% CI 1.57-11.75). Overall, involvement of anterior choroidal artery on follow-up imaging was also a strong predictor of poor neurological outcomes (p=0.003, RR 4.3, 95% CI 1.57-11.75).

Conclusion
There is significant proportion of patients having AchA infarcts with distal ICA occlusion. Sparing of AchA territory is associated with good outcome whendistal ICA occlusions are successfully recanalized. Baseline AchA infarcts in a setting of distal ICA occlusion tend to have poor outcomes irrespective of whether recanalization is achieved.