bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 23: Effect Of Intravenous Tirofiban Vs Placebo On First-pass Effect In Endovascular Stroke Thrombectomy: Insights From The Rescue Bt Randomized Clinical Trial
Authors: Yuan Junjie , sang hongfei , An Huijie , kong weilin , Luo Weidong , Song Jiaxing , Huang Jiacheng , Li Fengli , Zi Wenjie , Qiu Zhongming
Published: February 2023

Background:
First-pass effect (FPE) defined as a complete or near-complete reperfusion achieved after a single thrombectomy pass is predictive of favorable outcome in acute ischemic stroke (AIS) patients with large vessel occlusion. It remains uncertain whether intravenous tirofiban is effective to improve the rate of FPE in anterior circulation strokes.

Methods:
RESCUE-BT (A randomized controlled trial of intravenous tirofiban or placebo prior to endovascular thrombectomy for large vessel occlusion stroke) enrolled 948 patients with proximal intracranial large vessel occlusion presenting within 24 hours of time last known well to receive intravenous either tirofiban or placebo before endovascular thrombectomy. Patients who did not treated with endovascular thrombectomy were excluded from this cohort. The endpoint was FPE, which defined by extended thrombolysis in cerebral infarction (eTICI) scale 2b, 2c or 3 after the first pass. A modified Poisson regression analysis was performed to assess the association between intravenous tirofiban treatment and FPE.

Results:
Twenty-two patients were excluded for not treating with endovascular thrombectomy. The remaining 926 patients were included (mean age, 66 years; 380 [41.0%] women), with 450 in the tirofiban and 476 in the placebo group, respectively. Among them, an FPE was achieved in 141 patients (31.3%) of the tirofiban group vs 114 patients (23.9%) of the placebo group. The adjusted risk ratio for FPE with tirofiban vs placebo was 1.24 (95%CI, 1.02-1.52).

Conclusions:
Treatment with intravenous tirofiban before endovascular thrombectomy significantly increased the incidence of FPE in acute ischemic stroke patients with large vessel occlusion presenting within 24 hours of time last known well.
Abstract 26: Low Hematocrit Falsely Elevates P2Y12 Values Leading To More Aggressive Therapy In Carotid Artery Stent Patients
Authors: Kim Hyun Woo , Martinez-Gutierrez Juan Carlos C , Dongarwar Deepa , Tariq Muhammad Bilal B , Ahmad Mohammad Jamil J , Damato Salvatore , Blackburn Spiros , Sheth Sunil , Chen Peng R
Published: February 2023

Introduction:
Plavix resistance is an independent risk factor for thromboembolic complications following carotid artery stent (CAS) placements. The VerifyNow P2Y12 assay is the best studied in gauging for Plavix responsiveness. Its performance is affected when hematocrit (HCT) value is <33%, and the prevalence of anemia in acute stroke patients is 30%. Hence, we studied the effect of low HCT on P2Y12 response units (PRU) in patients with symptomatic carotid artery stenosis who received CAS.

Methods:
We included symptomatic carotid artery patients who suffered ischemic strokes and received CAS during the same hospitalization with PRU measured via VerifyNow assay. Therapeutic PRU is defined as ≤180. Primary outcomes were the comparisons of PRU and the proportion of non-responders between low (<33) and high (≥33) HCT groups. Secondary outcomes evaluated for switch in therapy in non-responders and the rate of major hemorrhages.

Results:
78 of 127 symptomatic carotid artery patients met inclusion criteria. Mean age was 70.5 with 38.5% females. 23 of 78 had HCT < 33. Baseline characteristics between low and high HCT groups were similar except for hemoglobin (9.4 vs. 12.7, p<0.01), HCT (28.2 vs. 37.5, p<0.01), diabetes (69.6 vs. 29.1%, p<0.01), pre-CAS antithrombotic load (Plavix 300mg load, 43.5 vs. 81.8%; Plavix 600mg load, 39.1 vs. 12.7%, p<0.01). Despite more aggressive pre-loading in low group, mean PRU was substantially higher (220.1 vs. 148.3, P<0.01) leading to higher proportion of non-responders (69.6 vs. 38.1%, p<0.01). 34 of 37 non-responders had changes from aspirin and Plavix 75mg to more aggressive therapeutic regimen. Rate of major hemorrhages was higher in non-responder low HCT group vs. the rest without significance (18.8 vs. 3.2%, p=0.15).

Conclusion:
In symptomatic carotid patients receiving CAS, low HCT is associated with increased PRU, resulting in some to be falsely categorized as non-responders receiving more aggressive therapy unnecessarily.
Abstract 27: Effect Of Automated Large Vessel Occlusion Detection On Door-in-door-out Times At Primary Stroke Centers: A Multi-center Prospective Cohort Study
Authors: Chaudhry Mohammad Rauf A , Salazar-Marioni Sergio , Abdelkhaleq Rania , Niktabe Arash , Martinez-Gutierrez Juan Carlos , Ballekere Anjan , Iyyangar Ananya , Dhanjani Saagar , Giancardo Luca , Dongarwar Deepa , Sheth Sunil , Kim Youngran
Published: February 2023

Introduction:
Automated LVO detection and software-based care team integration has been shown to improve door-to-groin time metrics at comprehensive stroke centers (CSCs). The impact of this software on accelerating transfers out of primary stroke centers (PSCs) for LVO AIS patients remains undetermined.

Methods:
We performed a prospective cohort study across 11 stroke centers (7 PSCs and 4 CSCs) in the greater Houston area from January 1st 2021 - February 24th 2022. An automated LVO detection and workflow manager software (Viz.AI) was implemented at all the hospitals. Patients were included if they were diagnosed with LVO AIS based on CT angiogram at a PSC and were transferred to CSC. Patients who presented during a 2-week transition period at the time of LVO detection software activation were excluded. The primary outcome was time from PSC arrival to departure to CSC (door-in-door-out, DIDO) before and after software implementation and was performed using the Wilcoxon rank sum test (STATA v.15).

Results:
Among 234 patients that met inclusion criteria, median age was 65 [58-76] years, NIHSS 3 [1-8] and 45% were female. Mean time from last known well to PSC arrival was 512 +/- 281 minutes and mean DIDO was 176 +/- 77 min. A total of 156 patients were evaluated in the pre-software implementation period and 78 after. There were no significant differences in the pre- and post-implementation cohorts with respect to age, risk factors (HTN, HLD, Afib, carotid disease, diabetes), although a greater proportion of patients in the pre-implementation phase were female (52% vs. 31%, p<0.01). There was a significant reduction in the median DIDO time with software implementation (163 vs. 130 minutes, p=0.014).

Discussion:
In this multicenter cohort study, implementation of automated LVO detection with coupled care-team communication tool improved PSC transfer performance by over 30 minutes. These findings corroborate the findings for care acceleration at CSCs with similar software implementations.
Abstract 29: Risk Of Early Onset Cerebrovascular Disease After Adverse Pregnancy Outcomes: A Population Based Cohort Study
Authors: Miller Eliza C , Kauko Anni , Tom Sarah , Laivuori Hannele , Niiranen Teemu , Bello Natalie A
Published: February 2023

Background:
Adverse pregnancy outcomes (APO) contribute to a higher risk of maternal cerebrovascular disease, but longitudinal data that include APO and stroke timing are lacking. We hypothesized that APO are associated with younger age at first stroke, with a larger effect in those with recurrent APO (rAPO), defined as >1 pregnancy with APO.

Methods:
We analyzed longitudinal Finnish nationwide health registry data from the FinnGen Study. We included people who gave birth after 1969 when birth and hospital discharge registries were established. We defined APO as a pregnancy affected by gestational hypertension, preeclampsia, eclampsia, preterm birth, small for gestational age infant, or placental abruption. We defined stroke as 1
st
hospital admission for ischemic stroke, non-traumatic intracerebral hemorrhage or subarachnoid hemorrhage, or TIA, excluding stroke during pregnancy or within 1 year postpartum. Stroke and APO diagnoses were validated in the cohort. We created Kaplan Meier survival curves, Cox models, and logistic models to assess the relationship between APO and future stroke, adjusting for demographic and cardiovascular risk factors.

Results:
We included 130,764 individuals with a total of 285,545 births in the analysis sample, of whom 14.9% had 1 pregnancy with APO and 2.8% had rAPO. Those with any APO had higher proportion of obesity, hypertension, hyperlipidemia, heart disease and migraine. Median age at 1
st
stroke was 58.5 years in those with no APO, 54.6 years in those with 1 APO, and 51.3 years in those with rAPO. In adjusted models, age at stroke was younger in those with APO (1 APO: adjusted HR 1.2, 95%CI 1.1-1.3; rAPO: adjusted HR 1.4, 95%CI 1.2-1.6) compared to those with no APO. Those with rAPO had twice the stroke risk before age 45 (adjusted OR 2.1, 95%CI 1.5-2.8), compared to those with no APO.

Conclusion:
People who experience APO have higher risk of early onset cerebrovascular disease, with earliest onset and greatest risk in those with rAPO.
Abstract 34: Liver Fibrosis, Apolipoprotein E, And Hemorrhagic Stroke Risk: A Cohort Analysis
Authors: Parikh Neal S , Zhang Cenai , Murthy Santosh B , Liberman Ava L , Navi Babak B , Iadecola Costantino , Kamel Hooman
Published: February 2023

Introduction:
Cirrhosis is associated with an increased risk of hemorrhagic stroke (HS). Liver fibrosis, typically a silent condition, is antecedent to cirrhosis. We hypothesized that liver fibrosis is associated with an increased risk of HS. Further, because apolipoprotein E2 (ApoE2) and E4 (ApoE4) are associated with HS, and because liver-derived peripheral ApoE4 may disrupt endothelial integrity, we evaluated for effect modification by these isoforms.

Methods:
We performed a cohort analysis using the UK Biobank Study, which prospectively enrolled adults in 2007, with continuous follow-up. We excluded participants with prevalent HS or thrombocytopenia. Liver fibrosis was defined using the validated Fibrosis-4 score. The primary outcome, incident HS (intracerebral or subarachnoid hemorrhage), was captured in UK Biobank based on hospitalization and death registry data. We used Cox proportional hazards models to evaluate the association of liver fibrosis with HS while adjusting for HS risk factors (demographics, systolic blood pressure, hemoglobin A1c, total cholesterol, BMI, tobacco and alcohol use, antithrombotic use). Effect modification by ApoE2 and ApoE4 were evaluated using interaction terms and stratified analyses.

Results:
Among 453,251 included participants, the mean age was 57 years and 54% were women. Approximately 2% had liver fibrosis, 16% used antithrombotic agents, 29% were ApoE4 carriers, and 15% were ApoE2 carriers. In adjusted Cox models, liver fibrosis was associated with an increased risk of HS (HR, 2.17; 95% CI, 1.51-3.12) (Figure). This relationship appeared stronger in ApoE4 homozygotes (HR, 8.27; 95% CI, 2.30-29.73) than in others (HR, 2.18; 95% CI, 1.47-3.24) (P=0.05, interaction). ApoE4 carrier status, ApoE2 carrier status, and ApoE2 homozygosity did not modify this relationship (P>0.20, interactions).

Conclusions:
Liver fibrosis was associated with an increased risk of HS, possibly more so in ApoE4 homozygous persons.
Abstract 36: Astrocyte-derived Small Extracellular Vesicles Mediate Astrocyte-neuron Communication To Promote Neurite Outgrowth After Stroke In Astrocyte-vesicle Reporter Mice
Authors: Liu Zhongwu , Zhang Yi , xin hongqi , Li Yanfeng , Golembieski William , Lu Mei , Dudley Andrew C , Chopp Michael , Zhang Zheng Gang
Published: February 2023

As an integral part of the neuron-glia system, astrocytes directly contact and communicate to neurons. Small extracellular vesicles (sEVs) are essential mediators of intercellular communication for both physiological and pathological processes. Using astrocyte-sEV reporter mice, we investigated how endogenous astrocyte-derived sEVs communicate to neurons after ischemic stroke. The reporter mice were generated by crossing a CD63-green fluorescent protein (GFP) floxed mouse line with a GFAP-Cre
ERT2
mouse line. Mice were subjected to permanent middle cerebral artery occlusion (n=10). To activate Cre recombinase, tamoxifen was injected daily for 4 days starting 1 day after stroke. Animals were euthanized 14 days after stroke. Coronal brain and spinal cord slices were used for immunofluorescent staining with antibodies against GFAP for astrocytes and SMI32 for neurons. Confocal microscopic imaging analysis showed that ischemia dramatically (p<0.01) increased GFP signal intensity in the brain peri-infarct area (58.4±3.6 A.U.) and in the stroke-impaired gray matter of the spinal cord (42.9±2.8 A.U.), compared to that in normal brain (31.7±1.8 A.U) and spinal cord (34.3±2.7 A.U). Neuronal internalization of astrocyte-sEVs measured as colocalization of GFP with SMI32 neurons in the brain and spinal cord was concomitantly and significantly increased in the stroke mice compared with that in normal mice (stroke brain 0.14±0.01% vs 0.07±0.01% in normal, and spinal cord 0.10±0.01% vs 0.06±0.01% in normal, p<0.05), which was confirmed by electron microscopy. In addition, GFP positive sEVs isolated from ischemic brain of the reporter mice significantly promoted neurite outgrowth of primary cultured mouse embryonic cortical neurons, compared to sEVs isolated from non-ischemic brain (p<0.001). Collectively, our data for the first time provide in vivo evidence that endogenous astrocyte-derived sEVs communicate with neurons under non-ischemic condition, while stroke robustly augments this communication, and thereby promotes neurite remodeling during stroke recovery.
Abstract 37: Acute Hyperglycemia At Stroke Onset Is Associated With Abnormal Red Blood Cells
Authors: Deng Wenjun , Lopez Mary , McMullin David , Heinzelmann Kathleen , Jacobson Jared , Chou Richard , Wang Andrew , Buonanno Ferdinando , Lo Eng H , Ning MingMing
Published: February 2023

Background:
Acute hyperglycemia at stroke onset is a common clinical problem and is an independent predictor of mortality and long-term disability. Abnormal red blood cells (RBCs) have long been recognized as a stroke risk factor and are associated with poor stroke outcome. Recent evidence has shown that short term hyperglycemia exposure can intensify oxidative stress in RBCs and cause hemolysis. We hypothesize that acute hyperglycemia may induce RBC dysfunction in stroke patients, which may be related to the poor outcome in those patients.

Method:
93 stroke patients were consecutively recruited in accordance with IRB protocol. Patients with diabetes, prediabetes or HbA1C ≥ 5.7% were excluded. None of the patients had preexisting anemia. Hyperglycemia was defined as blood glucose > 110 mg/dL at admission. RBC indices were documented for all the patients. Patients with major hemorrhagic events and multiple blood draws were excluded from the study. Clinical outcome was determined by mRankin Scale at 3 month (good: ≤ 2; poor: > 2).

Result:
45 (48.4%) were hyperglycemic and 48 (51.6%) were normoglycemic. Hyperglycemic patients showed gradually decreased RBC counts and hemoglobin content, while RBC distribution width (RDW) was gradually elevated (Fig. A). Subgroup analyses showed that the association of hyperglycemia with RBC alterations was not affected by sex and age, two factors that are known to affect RBC function (Fig. B). More importantly, patients with abnormally low RBC count, low hemoglobin and high RDW were at increased risk of developing poor outcome (Fig. C). These results remained robust after adjusting for other risk factors (Fig. C), suggesting that abnormal RBC parameters are independent predictors of poor stroke outcome.

Conclusion:
Our results revealed that acute hyperglycemia at stroke onset is associated with abnormal RBC indices, which are predictive of poor stroke outcome. Studies in a larger patient cohort with extended time course are still ongoing.
Abstract 38: Admission Hyperglycemia In Stroke Patients Increases Oxidative Stress In Red Blood Cells
Authors: Deng Wenjun , Lopez Mary , McMullin David , Jacobson Jared , Chou Richard , Wang Andrew , Buonanno Ferdinando , Lo Eng H , Ning MingMing
Published: February 2023

Background:
Our recent study has shown that admission hyperglycemia in stroke patients is associated with red blood cell (RBC) dysregulation, however, the underlying mechanism is still unclear. In addition to transporting oxygen via hemoglobin, RBCs also carry a robust antioxidant system to remove the reactive oxygen species (ROS) continuously produced from hemoglobin autoxidation (Fig A). It has been reported that in vitro hyperglycemia can increase oxidative stress in RBCs. We thus hypothesize that acute hyperglycemia in stroke patients may also affect the antioxidant system in RBCs.

Method:
Stroke patients with hyperglycemia and normoglycemia (n=12/group) were prospectively recruited in accordance with IRB protocol. Blood was collected at 2 hr, 24 hr, 72 hr and 3 mon post stroke. RBCs were precipitated from whole blood, and leucocytes were removed with depletion filter. The expression and glycosylation of RBC antioxidants, such as catalase (CAT), superoxide dismutase type 1 (SOD1), glutathione peroxidase 1 (GPX1) and peroxiredoxin 2 (PRX2), were quantified using mass spectrometry-based selected reaction monitoring (SRM) method.

Result:
CAT, SOD1 and GPX1 showed gradually decreased expression in hyperglycemic stroke patients, which may impair the antioxidant capacity of RBCs (Fig B). The glycosylation level of PRX2 was increased in stroke-related hyperglycemia (Fig C), and increased glycosylation was associated with decreased PRX2 activity (Fig D). Consistent with the expression and glycosylation changes in antioxidants, total RBC antioxidant capacity was reduced in hyperglycemic patients, and ROS was significantly accumulated in RBCs (Fig E).

Conclusion:
Acute hyperglycemia in stroke patients intensifies RBC oxidative stress by affecting the expression and post-translational modification of RBC antioxidants. Larger studies are underway to verify these findings, and explore how hyperglycemia and RBC oxidative stress influence stroke outcome.
Abstract 39: Targeting Neutrophil-specific Integrin Alpha9 In Obesity-induced Hyperglycemia Mice Improves Stroke Outcome
Authors: Patel Rakeshkumar , Dhanesha Nirav , Sutariya Brijesh , Ghatge Madankumar , Kumskova Mariia , Leira Enrique C , Chauhan Anil K
Published: February 2023

Background:
Obesity-induced hyperglycemia is one of the significant risk factors for stroke. Integrin α9β1 is highly expressed on activated neutrophils and stabilizes adhesion to the endothelium via ligands, including tenascin C. While myeloid deletion of α9 reduces susceptibility to ischemic stroke, it is unclear whether this is mediated by neutrophil-derived α9.
Purpose:
To determine the role of neutrophil-specific α9 in stroke outcome in mice with obesity-induced hyperglycemia.

Methods:
α9
Neu-KO
(α9
fl/fl
MRP8Cre
+
) and littermate control α9
WT
(α9
fl/fl
MRP8 Cre
-
) mice were fed a 60% high fat diet for 20 weeks. Functional outcomes were evaluated up to 28 days after stroke in mice of both sexes using a transient (30 min) middle cerebral artery ischemia. Infarct volume (MRI) and post-reperfusion thrombo-inflammation (thrombi, fibrin, neutrophil, p-NFκB, NETosis, TNFα, and IL1β levels) were measured post 6 or 48 h of reperfusion. Functional outcomes (mNSS, rotarod, corner, and wire-hanging test) were measured at week 1, 2, 3, and 4.

Results:
Stroke upregulated neutrophil α9 expression in obese mice (P<.05 vs. lean mice). Genetic ablation of neutrophil-specific α9 improved functional outcomes up to 4 weeks that was concomitant with reduced infarct size, improved CBF, decreased post-reperfusion thrombo-inflammation, and reduced NETosis (P<.05 vs. α9
WT
obese mice) irrespective of sex. Intravital microscopy revealed that obese α9
Neu-KO
mice were less susceptible to experimental carotid thrombosis (P<.05 vs. α9
WT
obese mice). Infusion of tenascin C increased stroke severity in both α9
Neu-KO
and α9
WT
compared to vehicle, suggesting that neutrophil-specific α9 does not exacerbate stroke via tenascin C. Obese WT mice infused with a blocking anti-integrin α9 IgG exhibited improved functional outcomes up to 4 weeks (P<.05 vs. control IgG). Functional outcomes after stroke were comparable in α9
Neu-KO
mice infused with anti-integrin α9 IgG or control IgG, suggesting no off-target effects of the antibody.

Conclusion:
Both genetic ablation of neutrophil-specific α9 and pharmacological inhibition improve long-term functional outcomes after stroke in mice with obesity-induced hyperglycemia, most likely by limiting thrombo-inflammation and NETosis.
Abstract 40: Gut Dysbiosis Exacerbates Neuroinflammation By Activation Of B Cells In A Mouse Model Of Cerebral Amyloid Angiopathy
Authors: Banerjee Anik , Honarpisheh Parisa , Gorski Damian , Honarpisheh Pedram , McCullough Louise D , Lee Juneyoung
Published: February 2023

Introduction:
Cerebral amyloid angiopathy (CAA) is a debilitating disease that leads to intracerebral hemorrhage, white matter disease, and progressive cognitive decline in patients >50 years of age. Studies investigating the neuroimmune landscape in CAA are sparse. Here, we investigate the role of B cells in CAA.

Methods:
Pre-symptomatic (2 months) and symptomatic (10-13 months) male Tg-SwDI mice (CAA mice) harboring Swedish, Dutch, and Iowa mutations of human amyloid precursor protein (APP) were used as a mouse model of CAA. Single cells isolated from the brain were analyzed using flow cytometry to characterize neuroinflammation and cognitive impairment was assessed using fear conditioning. Fecal microbiota transplantation (FMT) of the microbiome from pre-symptomatic and symptomatic CAA mice into young wild-type (WT) recipient male mice (2 months) was performed to determine if CAA-induced gut dysbiosis contributes to brain B cell activation.

Results:
Cognitive assessment using fear conditioning indicated a significantly lower delta inactive state in symptomatic CAA mice (n=4/grp, *
P
<0.05) compared to pre-symptomatic CAA mice. Symptomatic CAA mice had a significantly lower relative frequency of microglia (CD45
int
CD11b
+
, n=11-13/grp, **
P
<0.01) and significant infiltration of lymphoid (CD45
high
CD11b
-
, n=11-13/grp, ***
P
<0.001) cells in the brain, as compared to pre-symptomatic CAA mice. Symptomatic CAA mice had significantly higher B cells in the brain (n=10-13/grp, *
P
<0.05. Further, activated B cells as assessed by the expression level of CD11b showed that CD11b
+
B cells were significantly higher in the symptomatic CAA brain (n=10-13/grp, *
P
<0.05). Interestingly, this phenotype was recapitulated in young WT recipients reconstituted with pre-symptomatic CAA and CAA microbiome through FMT. Young WT recipients with CAA biome had significantly higher relative frequency of CD11b
+
B cells in the brain compared to young recipients with pre-CAA biome (n=7-9/grp, ***
P
<0.001).

Conclusions:
These results suggest that the aberrant activation of B cells in the brain may be influenced by CAA-induced gut dysbiosis. Further investigations upon the functional role of CD11b
+
B cells in the vascular deposition of Aβ are warranted.
Abstract 41: Synthesis And Pharmacological Validation Of Novel Neuroprotective Purinergic Receptor P2X4 Antagonists For The Treatment Of Ischemic Stroke
Authors: Verma Rajkumar , Toti Kiran S , Gamiotea Turro Daylin , Wen Zhiwei , Lewicki Sarah , Jacobson Kenneth , Liang Bruce T
Published: February 2023

Background and Purpose:
Identification of a novel treatment for ischemic stroke is urgently needed. We previously showed that genetic deletion as well as short term pharmacological inhibition of P2X4R, a purinergic receptor for adenosine triphosphate ATP, provides acute neuroprotection and thus can be potential drug targets to treat ischemic stroke. Here we synthesized and pharmacologically validated those experimental drugs for the treatment of ischemic stroke.

Methods:
We first performed the P2X4 receptor structure activity (SAR) relationship based on known heterocyclic antagonist P2X4 antagonists including NP-1815-PX Following extensive modification of the reported synthetic route, we synthesized several analogues that maintained or enhanced antagonist affinity. We used [Ca
2+
]
i
influx assay in P2X4R overexpressing human HEK cells to identify potent and specific P2X4R antagonist. Two most potent leads (MRS4719 and 4596 given subcutaneously for 3 days post stroke) were then tested for their neuroprotective activity using middle cerebral artery occlusion (MCAo) model of ischemic stroke (60 min MCAo followed by 3 days of reperfusion) using both sexes of young and aged mice. MRS4719 was also tested in human primary monocyte derived macrophage obtained from the blood of de-identified aged healthy subjects (55±10 years).

Results:
Analogues MRS 4719 and MRS4596 were most potent at human (h) P2X4R (IC
50
0.503 and 1.38 μM, respectively), and were highly selective versus hP2X1R, hP2X2/3R, hP2X3R). Both MRS 4719 and MRS 4596 showed neuroprotective effects after 3 days of ischemic stroke in a dose dependent manner in young mice (8-12 weeks old). Optimal dose of MRS4719 (1.5 mg/kg/day) also significantly reduced infarct volume (59.6±5.3 vs. 27.47±10.23 mm
3
; p<0.05) in middle-aged mice (11-12 months). MRS 4719 showed learning and memory enhancing activity when measured after 4 weeks of stroke. MRS 4719 inhibited ATP-induced [Ca
2+
]
i
influx in primary human monocyte-derived macrophages, consistent with its blocking effect at endogenously expressed P2X4R.

Conclusions:
This study indicates MRS4719 is a potent P2X4R antagonist and has translational potential for the treating of ischemic stroke across the age.
Abstract 42: Von Willebrand Factor (vwf) Is Required For Outward Remodeling Of Leptomeningeal Collateral Arterioles Following Stroke.
Authors: WU TING , Ahn John , Doan Andrea , Harmon Elisabeth , Andersohn Alexander , Cruz Miguel A , Yee Andrew , Kim Gab , Marrelli Sean P
Published: February 2023

Introduction:
VWF is an endothelial glycoprotein with known roles in vascular hemostasis and thrombosis. We previously showed increased expression of VWF in leptomeningeal collateral arterioles (LMCs) that underwent outward remodeling in the post-stroke brain. Interestingly, recent studies indicate that VWF may act as a novel smooth muscle mitogen and contribute to smooth muscle proliferation. The present study tested the hypothesis that VWF is required for LMC outward remodeling in the post-stroke brain.

Methods:
Permanent distal middle cerebral artery occlusion (pdMCAO) was performed in C57BL6 WT mice (cohort 1; 4 mos, males) or VWF KO and WT mice (cohort 2; 10 mos, males). At 3 days after pdMCAO, the intact leptomeningeal vasculature was “planed off” for VWF immunofluorescence and morphometric analyses of LMCs and distalmost arterioles (DMAs) from the ipsilateral (ischemic) and contralateral hemispheres. VWF density in LMCs was normalized to the connected DMAs and presented as a fold difference. In a subset of samples, VWF location in LMCs was imaged by super-resolution microscopy (STED imaging, Nikon).

Results:
At 3 days post-stroke, WT mice of cohort 1 demonstrated significantly increased VWF expression in ipsilateral LMCs (5.34 ipsi LMC vs 1.89 contra LMCs; p<0.01, 35-50 vessels from 7 mice). Cohort 2 was used to evaluate the effect of VWF expression on LMC remodeling. Mean diameter of DMAs were similar between VWF KO and WT mice at 3 days post-stroke (32.6 ± 1.1 μm vs 33.3 ± 0.8 μm, p=NS). The LMC diameter was significantly increased in the WT mice (39.7 ± 1.7 μm), however, it was not significantly altered in VWF KO mice (35.1 ± 1.4 μm). Lastly, super-resolution imaging demonstrated increased VWF in the endothelial layer as well as in the smooth muscle layers of remodeled LMCs. Notably, VWF in the smooth muscle layer was evident as long “pillars” running perpendicular to the vessel lumen and extending several microns into the smooth muscle layer.

Conclusions:
Our study revealed novel evidence for the essential role of VWF in the outward remodeling of LMCs in the post-stroke brain. Our findings also provide direct evidence for VWF within the smooth muscle layer, supporting the potential role of VWF as a critical smooth muscle mitogen in LMC remodeling.
Abstract 5: Malignant Venous Outflow Profile Predicts Futile Recanalization After Endovascular Thrombectomy.
Authors: Li Siyuan , Hong Lan , Zhang Yiran , Liu Xinyu , Cheng Xin
Published: February 2023

Objective:
To explore the association of baseline venous outflow from the occluded cerebral territory and futile recanalization (FR) in patients with acute ischemic stroke due to large vessel occlusion (LVO) in the anterior circulation.

Methods:
Consecutive patients from a prospectively maintained stroke database were included in this study if they presented with a multimodal CT-confirmed LVO in the anterior circulation and underwent thrombectomy within 24 hours after stroke onset. Excellent recanalization of the occluded artery, defined as final mTICI 2c-3 on digital subtraction angiography, was considered to be futile if patients fail to achieve functional independence (modified Rankin Scale of 0-2) at 90 days. Baseline venous outflow profile was determined by a 7-point semi-quantitative scoring system which assessed ipsilateral venous opacification of the vein of Labbe, Trolard and superficial middle cerebral vein on single-phase CTA source images. Hypoperfusion intensity ratio (HIR, defined as delay time >6 seconds/delay time >3 seconds) was applied to evaluate tissue-level collateral status.

Results:
145 patients met the inclusion criteria. Multivariable logistic regression analysis showed that malignant venous outflow (OR 4.30 [95% CI 1.41-14.57]; p =0.013) was independently associated with functional dependence regardless of age, glucose, HIR, early neurologic deterioration, hemorrhagic transformation and final infarct volume. FR was observed in 24/52 (46%) recanalized patients. Stepwise logistic regression revealed a poor venous outflow profile at presentation as an independent predictor of FR (OR 7.04 [95% CI 1.29-50.16]; p =0.03) adjusted for baseline NIH Stroke Scale score, HIR and presence of hemorrhagic transformation.

Conclusion:
A malignant venous outflow profile at baseline is associated with FR in patients with LVO. The mechanism by which poor venous outflow from the occluded territory hinders clinical recovery despite prompt successful thrombectomy remains to be determined.
Abstract 55: Intensive Blood Pressure Treatment Remodels Brain Perivascular Spaces: A Secondary Analysis Of The SPRINT MIND Trial
Authors: Kern Kyle C , Nasrallah Ilya M , Wright Clinton B
Published: February 2023

Introduction:
Perivascular spaces (PVS) contribute to brain waste clearance pathways, possibly via arterial pulsatility, and are implicated in neurodegenerative disease. Aging, hypertension, and small vessel disease are associated with enlarged PVS, but the effect of intensive blood pressure (BP) control on PVS structure is unknown.

Methods:
This is a secondary analysis of the SPRINT-MIND MRI substudy, in which participants with cardiovascular risk but without clinical stroke were randomized to intensive BP control (systolic <120) or standard control (<140) and underwent MRI brain at baseline and 4 years. An established spatial filtering algorithm was applied to T2 images to automatically segment PVS within the supratentorial white matter and basal ganglia. PVS volumes were calculated as a percentage of the tissue volume analyzed. We tested for an effect of intensive BP treatment over time on PVS volume fraction using mixed-effects linear models, including random effects for subject and site, and fixed effects for treatment, timepoint, treatment-by-time interaction, age, and sex.

Results:
At randomization 658 participants had useable images (mean age = 67 years, 60% female), and PVS volume fraction was associated with age (Beta=0.0043; CI:0.0012 - 0.0076; p=0.007), white matter hyperintensity volume (B=0.18; 0.13 - 0.23; p<0.0001) and brain parenchymal fraction (B=0.011; 0.004 - 0.018; p=0.003). At mean follow-up of 3.9 years, 243 in the intensive treatment arm and 199 in the standard treatment arm had evaluable pre and post scans. PVS volume fractions were similar at randomization between treatment groups (1.38% vs 1.39%) but decreased with intensive treatment to 1.35% (p=0.022) while remaining stable with standard treatment (interaction p=0.040).

Discussion:
Intensive BP treatment reduces the volume of perivascular spaces. These changes may reflect remodeling of waste clearance pathways and/or volume status.
Abstract 63: Age-related Changes In Gray Matter Cerebral Metabolism And Vascular Reactivity In Children
Authors: Lewis Josiah B , Mirro Amy , Rutlin Jerrel , Binkley Michael M , Fellah Slim , Chen Yasheng , Ford Andria L , An Hongyu , Fields Melanie E , Lee Jin-moo , Shimony Joshua , Guilliams Kristin P
Published: February 2023

Introduction:
Metabolic demand changes throughout childhood as the brain develops, peaking in the 2
nd
decade of life. Cerebral blood flow (CBF) is dynamic throughout childhood, likely in response to the increased metabolic demand of brain development. Cerebrovascular reactivity (CVR) reflects the ability to further increase CBF in response to a stimulus, such as carbon dioxide (CO
2
). We hypothesized that gray matter oxygen metabolism (GM CMRO
2
) is increased in younger children, corresponding to higher GM CBF and lower GM CVR.

Methods:
CVR was calculated as the proportional change of a subject’s MRI-measured blood oxygen level dependent signal in response to an increase in end-tidal CO
2
administered by the RespirAct® RA-MR™ device. GM CMRO
2
was calculated voxel-by-voxel as the product of GM CBF (arterial spin labeling), GM oxygen extraction fraction (asymmetric spin echo), and arterial oxygen content (= Hb х (oxygen saturation)х1.34). Univariate relationships were tested using Spearman’s correlation coefficient, and corrected for multiple comparisons.

Results:
GM CVR, CBF, and CMRO
2
were calculated for 15 healthy participants (ages 8-19, 7 male). GM CMRO
2
was highest in young children and decreased with age (ρ=-0.68, P=0.005), as did CBF (ρ =-0.67, P=0.006). CVR was lower in young children, increasing with age (ρ=0.58, P=0.02). However, while GM CVR correlated with CBF (ρ=-0.64, P=0.01) it did not significantly associate with CMRO
2
(ρ=-0.43, P=0.114).

Conclusion:
Although GM CMRO
2
and CVR both have age-related changes, CVR does not directly correlate with CMRO
2
. Rather, their relationship may be moderated through other influences on CBF, as further study will investigate.

Figure: Linear fits and 95% confidence intervals of subject data, including age, GM CBF, and GM CMRO
2
, versus GM CVR. P-values are from Spearman’s test for monotonic correlation.
Abstract 66: Diffusion Imaging Demonstrates White Matter Alterations In Children With Moyamoya In Watershed Tracts
Authors: Ahtam Banu , Feldman Henry A , Solti Marina , Doo Justin , O'Donnell Lauren , Zhang Fan , Vyas Rutvi , Rathi Yogesh , Orbach Darren , See Alfred P , Smith Edward R , Grant P E , Lehman Laura L
Published: February 2023

Introduction:
Moyamoya is a progressive cerebrovascular disease leading to stenosis of arteries located in the circle of Willis which increases risk of hypoperfusion in specific areas of the brain called watershed regions. Using diffusion weighted magnetic resonance imaging (dMRI), adults with moyamoya have significantly lower fractional anisotropy (FA) and higher mean diffusivity (MD) and radial diffusivity (RD) in their white matter compared to controls. These areas of white matter alterations have been associated with cognitive deficits as well. To our knowledge the examination of combined white matter tracts in the watershed regions of the brain in children with moyamoya has not been previously examined.

Hypothesis:
We hypothesize that children with moyamoya will have higher FA and lower MD and RD in the combined white matter tracts that are in the watershed region compared to control children.

Methods:
We compared a cohort of 15 children with moyamoya with 24 affected hemispheres without stroke to 25 children controls. We analyzed dMRI data using an unscented Kalman filter (UKF) tractography method and extracted major white matter pathways with a fiber clustering method. We compared the FA, MD, axial diffusivity (AD), and RD of the combined watershed white matter tracts using co-variate adjusted ANOVA.

Results:
Age and sex were not significantly different between children with moyamoya and controls. For the combined watershed white matter tracts, children with moyamoya had significantly lower FA and higher MD and RD. AD was also higher but not significant compared to control children (Table 1).

Conclusion:
Lower FA with higher MD and RD is consistent with alterations in white matter tracts concerning for unrecognized white matter injury from hypoperfusion. These dMRI findings could be used as a biomarker for children with moyamoya at risk for cognitive deficits due to hypoperfusion.
Abstract 78: Neighborhood Socioeconomic Deprivation Is Associated With Increased 30-day Mortality After Stroke: Results From A Nationwide Study Of 755,899 Medicare Patients
Authors: Lusk Jay , Hoffman Molly N , Clark Amy G , Mac Grory Brian C , Luedke Matthew W , Xian Ying , Bae Jonathan , Hammill Bradley G
Published: February 2023

Introduction:
The relationship between neighborhood socioeconomic deprivation- a reflection of the general economic and environmental conditions of a neighborhood- and outcomes after stroke is not known.

Methods:
We performed a retrospective study of 100% nationwide Medicare inpatient claims from 2017-2019. We categorized admissions for cerebrovascular diseases using principal ICD-10-CM codes as follows: Ischemic Stroke (I63), Subarachnoid Hemorrhage (I60), Intracerebral Hemorrhage other than SAH (I61 and I62); Transient Ischemic Attack (G45); Precranial stenosis without ischemia (I65). The primary outcomes of interest were 30-day mortality and 30-day unplanned readmission (per CMS definition). The exposure of interest was the Area Deprivation Index (ADI), calculated at the census block group level. Adjustment covariates included beneficiary demographics (age, sex, and race), Medicaid-dual eligibility status (as a proxy for individual SES), end-stage renal disease status, discharge year, and the 29 Elixhauser index comorbid conditions. Generalized estimating equation methods were used to estimate logistic regression models.

Results:
A total of 755,899 patients were included (mean age 79.4 years (SD 8.3), 47.1% male, 18.9% dually eligible for both Medicare and Medicaid) and the median Elixhauser comorbidity index was 17.0 (SD 14.1). After multivariable adjustment, a strong, dose-dependent association was observed between neighborhood deprivation and 30-day mortality for all conditions studied (Figure). No adjusted association was observed between ADI and 30-day unplanned readmission.

Conclusions:
For the first time, we show that neighborhood socioeconomic deprivation is associated with increased 30-day mortality for patients admitted with common cerebrovascular disorders, potentially in a dose-dependent fashion, after adjusting for age, sex, race, comorbidity burden and individual socioeconomic status.
Abstract 82: Sex Differences In Recurrent Stroke: Twenty-Year Trends From A Population-Based Study
Authors: Chen Chen , He Kevin , Reeves Mathew J , Morgenstern Lewis B , Farris Karen B , Lisabeth Lynda D
Published: February 2023

The growing number of stroke survivors in the US, especially among women, makes understanding sex-specific trends in recurrent strokes crucial. Yet, such data are rare. We estimated 20-year sex-specific trends in recurrence in a population-based stroke study.

Methods:
We included first-ever ischemic strokes (IS) ascertained between January 1, 2000 and December 31, 2019 from the Brain Attack Surveillance in Corpus Christi (BASIC) Project in South Texas. Time to recurrence was calculated from first-ever IS to recurrence, death, or December 31, 2019, whichever came first. We estimated the cumulative incidence function (CIF) of recurrence by a multivariable Fine-Gray subdistribution hazard model, which accounted for the competing risk of death. An interaction term between calendar year and sex was used to generate 1-year and 5-year sex-specific trends in risks of recurrence between 2000-2019 from the fitted CIF.

Results:
Among the 5,752 IS (median age 69, 49.9% women), 786 (13.7%) had recurrences over a median of 7.6 years of follow-up and 2,653 (46.1%) died over a median of 3.7 years of follow-up. Women had significantly higher adjusted 1-year and 5-year risks of recurrence than men in 2000 (Figure). One-year and 5-year risk of recurrence declined in both sexes over time but women experienced larger declines such that the risks were similar between both sexes around 2009 but higher among men after that. The largest sex difference in recurrence was in the 5-year risk in 2000 with women having 5.0% (1.5%-8.4%) higher risk.

Conclusions:
The welcoming trends in recurrent strokes suggest successful secondary stroke prevention, especially in women, where greater declines were noted.
Abstract 83: Racial Disparities In Gluconic Acid, A Lifestyle-related Biomarker Associated With Stroke In REGARDS
Authors: Kijpaisalratana Naruchorn , Ament Zsuzsanna , Patki Amit , Bhave Varun M , Garcia Guarniz Ana-Lucia , Judd Suzanne E , Cushman Mary , Long Leann , Irvin Marguerite M , Kimberly W T
Published: February 2023

Introduction:
In the United States, the risk of stroke is greater among Black compared to White adults. Furthermore, hypertension has a greater impact on stroke risk among Black adults. We hypothesized that race-specific metabolites may account for some of this observed disparity.

Methods:
This was a case-cohort study nested in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Incident ischemic stroke cases (n=1,075) were compared with a random cohort sample (n=968). Metabolites were measured by liquid chromatography-tandem mass spectrometry. Weighted logistic regression and Cox proportional hazard model were used to identify race-specific metabolites in association with prevalent hypertension and incident stroke respectively. Candidate metabolites were assessed for mediation between hypertension and incident ischemic stroke. Linear regression was used to explore the association of metabolites with lifestyle factors.

Results:
A total of 162 plasma metabolites were quantified. Of these, gluconic acid was associated with prevalent hypertension in Black adults (OR=1.86, 95% CI=1.39-2.47,
P
=2.58x10
-5
) but not in White adults (OR=1.00, 95% CI=0.80-1.24,
P
=0.97;
P
for interaction=4.57x10
-4
). Gluconic acid was also associated with incident ischemic stroke among Black adults (HR=1.53, 95% CI=1.28-1.81,
P
=1.76x10
-6
) but not White adults (HR=1.16, 95% CI=1.00-1.34,
P
=0.057;
P
for interaction=0.019). Gluconic acid mediated 25.4% (95% CI=4.1%-46.8%,
P
=0.02) of the association between hypertension and ischemic stroke among Black adults. Specific lifestyle factors were linked to elevated gluconic acid level among Black adults in multivariable analysis, including a Southern diet (β=0.18, 95% CI=0.08-0.28,
P
<0.001), lower educational attainment (β=0.45, 95% CI=0.19-0.72,
P
=0.001), and lack of exercise (β=0.26, 95% CI=0.01-0.51,
P
=0.045).

Conclusions:
Gluconic acid is a lifestyle-related biomarker that is associated with prevalent hypertension, incident ischemic stroke, and mediates the relationship between hypertension and ischemic stroke in Black adults. Key factors linked to gluconic acid include Southern diet, low educational attainment, and low physical activity.
Abstract 87: Area Deprivation And Race Synergistically Contribute To Undiagnosed Hypertension Leading To Acute Ischemic Stroke
Authors: Rivier Cyprien , Acosta Julian , Renedo Daniela , Sheth Kevin N , Falcone Guido J
Published: February 2023

Background:
Area deprivation is one of the leading social determinants of health and is associated with lower access to clinical care. We hypothesize that undiagnosed hypertension is more prevalent in highly deprived areas as well as in people from black race and that undiagnosed hypertension is associated with a higher risk of incident stroke.

Methods:
We conducted an observational study analyzing participants from the All of Us study (AoU). We identified people who meet the criteria for hypertension based on blood pressure measurements at the time of enrollment but were not known to have the condition according to EHR or survey data. We evaluated area deprivation using the Deprivation Index (DI), an aggregate variable derived from six metrics of the American Community Survey. We used multivariable logistic regression to test for interaction between tertiles of DI and race in a model predicting undiagnosed hypertension adjusting for age, sex, income, and education.

Results:
Out of 372,397 participants enrolled in AoU, 269,063 had data for area deprivation and blood pressure, including 6,690 (2.5%) who sustained a stroke. Compared to low area deprivation, intermediate and high deprivation were associated with 3.4% (OR 1.034, 95%CI 1.00-1.07) and 17.4% (OR 1.174, 95%CI 1.14-1.21) higher risk of undiagnosed hypertension (test-for-trend p<0.0001). Compared to White participants, Black participants had a 67.4% (OR 1.674, 95%CI 1.62-1.73, p<0.0001) higher risk of undiagnosed hypertension. There was significant synergy between DI and race (interaction p<0.0001): compared to White participants living in areas of low deprivation, Black participants living in areas of high deprivation had 106% (OR 2.06, 95%CI 1.96-2.16, p<0.0001) higher risk of undiagnosed hypertension. In the whole cohort, undiagnosed hypertension was associated with a 34% (OR 1.34, 95%CI 1.12-1.62, p=0.002) higher risk of incident stroke when adjusting for prevalent hypertension and the remaining socioeconomic factors.

Conclusion:
High area deprivation and Black race are associated with a higher risk of undiagnosed hypertension. Undiagnosed hypertension is associated with a higher risk of ischemic stroke after accounting for prevalent hypertension diagnosis.
Abstract 91: Early Stroke Recurrence Is Not Reduced By Early Statin Initiation In The Point Trial Population
Authors: Azizi Elham , Prabhakaran Shyam , Brorson James R
Published: February 2023

Objective:
To discern effects of early statin treatment on early stroke recurrence in the POINT trial.

Background:
Benefits of statin therapy in reducing risk of ischemic stroke over the long-term are well-established, but the immediate effects of statin therapy on early stroke recurrence after an initial ischemic event are less clear.

Design/Methods:
In secondary analysis of the data of the Platelet Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial, we evaluated the effects of statins on early stroke recurrence within 7 days of randomization using Cox proportional hazard regression analysis. We separately compared the effects in subgroups of subjects on and not on statins prior to the index event.

Results:
In the POINT trial, most recurrences of ischemic stroke were early, with 175 occurring within 7 days of trial entry, and only 105 occurring over the remainder of the 90 day trial. Overall, 39% were on statin treatment at time of enrollment which increased to 79% by 7 days post-index event. In Cox proportional hazard analysis for stroke recurrence over the 7 day period after index stroke or TIA, statin administration showed no significant effect in subjects not on statin at baseline (Adjusted p=0.34). In contrast, statin use prior to enrollment was associated with decreased hazard of early stroke recurrence (Adjusted H.R. 0.31, p=0.001).

Conclusion:
In the POINT trial population of patients with minor ischemic stroke or TIA, prior treatment with statins was associated with decreased risk of early stroke recurrence within 7 days following index stroke or TIA. There was no effect of initiating statin treatment in reducing risk of early stroke recurrence.