bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 38: Hemorrhagic Strokes in Patients With Atrial Fibrillation: The Neuro-AFib Study
Authors: Gurol Edip M , Das Alvin S , Daoud Nader , Wohlfahrt Alyssa , Gokcal Elif , Yaghi Shadi , Smith Eric E ,   The Neuro-AFib Study Group
Published: March 2021

Background:
We aimed to compare the clinical features and short-term outcomes of hemorrhagic stroke (HS) to ischemic stroke (IS) in atrial fibrillation (AF) patients using a large contemporary cohort.

Methods:
The Neuro-AFib study is a multicenter effort to elucidate the current causes and consequences of IS and HS in AF patients. The retrospective phase of the study is underway, aimed at obtaining detailed clinical, laboratory and multimodal neuro- and cardiac imaging data from ~9,000 patients with AF admitted to 30 academic stroke centers in the US with an IS or HS between 1/2018-12/2019. Preliminary clinical data from 12 sites are presented in this abstract.

Results:
Of 4764 stroke admissions with AF, 820 (17.2%) had HS and 3944 IS. Patients with HS were younger (74.8
+
12 vs 76.8
+
12), more likely to be male (54% vs 46%) and had lower CHA
2
DS
2
-VASC (3.6
+
1.6 vs 3.9
+
1.6) than IS [all p<0.05]. Patients with HS were more likely to be on AC compared to IS (60% vs 38%, p<0.001). Within the HS cohort, 32% were on direct oral anticoagulant, 28% on warfarin, 16% on antiplatelet, and 24% on no antithrombotic. Patients with HS had worse outcomes than IS in terms of in hospital case fatality (32.4 vs 10.3%, p<0.001) and severe disability (modified Rankin Scale 4-5) at discharge (63.3% vs 53.7%, p=0.002) despite similar rates of severe disability before admission (7% vs 6.2%, p=0.73). All of the reported associations remained significant after adjustment for age, sex and other relevant covariates.

Conclusions:
Preliminary findings from the Neuro-AFib study show significantly worse outcomes for HS compared to IS in AF patients, with triple case fatality and elevated severe disability risks. These results showcase the importance of identifying AF patients at high HS risk. Detailed imaging markers of HS risk including microbleeds, superficial siderosis, leukoaraiosis within the full cohort will be analyzed and discussed during ISC 2021.
Abstract 39: Acute Blood Pressure Dysregulation Increases the Risk of Border Zone Ischemic Lesions in Hypertensive Intracerebral Hemorrhage
Authors: Chen Szu-Ju , Tsai Hsin-Hsi , Tsai Li-Kai , Chen Ya-Fang , Tang Sung-Chun , Jeng Jiann Shing
Published: March 2021

Background:
Intensive blood pressure (BP) reduction is regarded as the gold standard therapy for acute intracerebral hemorrhage (ICH), but its associations to cerebral hypoperfusion and ischemic lesions have been suspected. This study aims to investigate the impact of acute BP reduction on the development of acute ischemic lesions (AILs) at border zone (BZ) areas in patients with hypertensive ICH.

Methods:
We enrolled patients with acute hypertensive ICH (hemorrhagic lesions restricted to deep region [Strictly deep-ICH] or located in mixed lobar and deep areas [Mixed-ICH]) who received brain MRI within 7 days after ICH onset. BZ AILs were defined as lesions locating at BZ areas that were hyperintense on DWI sequence and hypointense on ADC series (figure). Acute SBP change was the difference between the initial SBP and the SBP recorded at 24 hours after ICH onset.

Results:
Of the 274 enrolled patients (62.5 ± 12.7 years old, 65% male), 11 subjects had BZ AILs. Compared to patients without BZ AILs, patients with lesions had wider amount of acute SBP reduction (71.7 ± 33.6 vs. 43.0 ± 32.2 mmHg,
P
= 0.023), more lobar and deep microbleeds (MB) and larger white matter hyperintensity volume (all p < 0.05). Using ROC curve analysis, acute SBP drop at more than 54mmHg was linked to the occurrence of AILs (sensitivity 82%, specificity 64%,
P
= 0.002). In multiple logistic regression model, acute SBP decline at above 54mmHg (OR 11.45, 95%CI 2.06 - 63.49,
P
= 0.005) and higher deep MB burden (
P
= 0.032) raised the risk of AILs after adjustment for age, sex, and image markers of cerebral small vessel disease. In subgroup analysis, larger acute SBP drop remained to be an independent risk factor for development of AILs in patients with Mixed-ICH (
P
= 0.008), but not in patients with strictly deep-ICH (
P
= 0.715).

Conclusion:
Acute SBP change in hypertensive ICH, especially in Mixed-ICH, increases the risk of AILs at BZ areas, showing widespread microangiopathy that is vulnerable to rapid BP dysregulation to ischemia.
Abstract 41: Endovascular Treatment Alone versus Endovascular Treatment With Intravenous Thrombolysis in Patients With Tandem Occlusion: Analysis of the TITAN and ETIS Registries
Authors: Anadani Mohammad , Marnat Gaultier , Arturo Consoli , Panagiotis Papanagiotou , Siddiqui Adnan , Ribo Marc , Spiotta Alejandro M , Bourcier Romain , KYHENG Maeva , Labreuche Julien , Sibon Igor , Dargazanli Cyril , Arquizan Caroline , Anxionnat René , Audibert Gérard , Blanc Raphaël , mazighi mikael , Richard Sébastien , De Havenon Adam H , Gory Benjamin ,   TITAN,   ETIS
Published: March 2021

Introduction:
The benefit of intravenous thrombolysis (IVT) prior to endovascular treatment (EVT) in patients with acute ischemic stroke due to anterior circulation tandem occlusion is not well established. In this study, we aimed to investigate the effect of IVT on the outcome of EVT for anterior circulation tandem occlusions

Methods:
Individual data were pulled from the prospective TITAN and ETIS registries. Patients with anterior circulation tandem occlusion treated with EVT with and without cervical internal carotid artery ( c-ICA) stenting were included. Patents were divided into two groups (IVT+/IVT-) based on IVT treatment. Inverse Probability Treatment Weighting (IPTW) analysis were used to compare the outcomes between the two groups.

Results:
A total of 602 patients were included of whom 380 (62%) patients received IVT prior to EVT (IVT+). Mean age was 64 and 62 years in IVT+ and IVT - groups, respectively. Median NIHSS was 16 in both groups. Onset to imaging time was shorter in IVT+ group (median 103 vs. 140 minutes). In contrast, imaging to puncture time was longer in IVT+ group (median, 107 vs. 91 minutes). In IPTW analysis, IVT was associated with higher odds of favorable outcome (90-day modified Rankin Scale [mRS] 0-2), excellent outcome (mRS 0-1) and successful reperfusion (modified Treatment in Cerebral Ischemia [mTICI] 2b-3). IVT was also associated with lower odds of any intracranial hemorrhage but not with symptomatic hemorrhage or parenchymal hemorrhage. In secondary analysis of patients treated with cervical internal carotid artery stenting, IVT was associated with higher odds of favorable outcome, and lower odds of mortality.

Conclusion:
Up to our knowledge, this is the first study comparing EVT alone to EVT+IVT in anterior circulation tandem occlusion patients. IVT prior to EVT was associated with better functional outcome and higher odds of successful reperfusion.
Abstract 45: Global Impact of the Covid-19 Pandemic on Stroke Hospitalizations and Mechanical Thrombectomy Volumes: A Society of Vascular and Interventional Neurology Covid-19 International Collaboration
Authors: Nogueira Raul , AbdalKader Mohamad , Qureshi Muhammad Mustafa , Frankel Michael R , Haussen Diogo , Al-bayati Alhamza R , Mohammaden Mahmoud , Nguyen Thanh
Published: March 2021

Introduction:
The COVID-19 pandemic led to profound changes in both the organization of health care systems and the psychosocial behavior of the population worldwide. The extent to which the COVID-19 outbreak disrupted stroke systems of care merits study from a global lens.

Methods:
We conducted a retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The study objectives were to measure the global impact of the pandemic on the volumes for mechanical thrombectomy (MT), stroke and intracranial hemorrhage (ICH) hospitalizations over a 3-month period at the height of the pandemic (March 1 to May 31, 2020) compared with two control 3-month periods prior (immediately preceding and one year prior). A secondary objective was to examine whether these changes in volume were impacted by COVID-19 and baseline hospital center stroke volumes. Third, we evaluated the relationships between stroke and COVID-19 diagnoses.

Results:
There were 26,699 stroke admissions in the 3 months immediately before compared to 21,576 admissions during the pandemic months, representing a 19.2% (95%CI,-19.7 to -18.7) decline. There were 5,191 MT procedures in the 3 months preceding compared to 4,533 procedures during the pandemic, representing a 12.7% (95%CI,-13.6 to -11.8) drop. Significant reductions were also seen in relation to the prior year control period. The decreases were noted across centers with high, intermediate, and low COVID-19 hospitalization burden, and also across high, intermediate, and low volume stroke centers. High-volume COVID-19 centers (-20.5%) had greater declines in MT volumes than mid- (-10.1%) and low-volume (-8.7%) centers. There was a 1.5% stroke rate across 54,366 COVID-19 hospitalizations. SARS-CoV-2 infection was noted in 3.9% (784/20,250) of all stroke admissions.

Conclusions:
The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, MT procedures, ischemic stroke/TIA and ICH admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke and MT volumes. Centers with higher COVID-19 inpatient volumes experienced steeper declines.
Abstract 5: Tenecteplase versus Alteplase Reduces Interfacility (Door-In-Door-Out) Transfer Times
Authors: Miller Samantha , Warach Steven J ,   for Dell Med Sch Ascension Texas Stroke Service
Published: March 2021

Background:
As a single bolus thrombolytic, tenecteplase (TNK) offers the prospect of reduced emergency department workflow times relative to alteplase (ALT), especially for inter-hospital transfers. Our 10 hospital network switched to TNK as the local standard of care thrombolysis in September, 2019 and we compare arrival to transfer times (door-in-door-out) for referrals to a Comphensive Stroke Center with the prior two years’ experience with ALT.

Method:
We hypothesized that patients who received TNK would have a decrease in the time to initiate inter-hospital transfer when compared to patients who received ALT. Comparison data was collected from our registry cohort of all 354 unique patients treated with ALT. To control for transfer time reductions attributable to ongoing process improvements, transfers for endovascular therapy (EVT) who did not receive thrombolysis at the sending hospital will be used for comparison.

Results:
The median door to transfer time (DTT) for ALT patients (n = 60) was 136.5 minutes, with 11.7% within 90 minutes. The median DTT for TNK patients (n = 33) was 113 minutes, with 36.4% within 90 minutes -- TNK was associated with a greater likelihood of DTT < 90 minutes (p=0.007). The median DTT for the subset of ALT patients transferred specifically for evaluation for endovascular therapy (n = 14) was 120.5 minutes, 21.4% within 90 minutes. The median DTT for TNK patients transferred for EVT (n = 20) was 87 minutes, 60.0% within 90 minutes -- TNK was associated with a greater likelihood of DTT < 90 minutes (p=0.038). The median DTT for
non-lytic
patients transferred for evaluation for EVT prior to the switch to TNK (n = 17) was 109 minutes, 35.5% within 90 minutes, and
did not differ
from the median DTT for non-lytic patients (n = 24) after the switch to TNK: 98 minutes, 45.8% within 90 minutes.

Conclusion:
TNK treatment at a transferring hospital was associated with a greater likelihood of door to transfer time within 90 minutes when compared to ALT treatment, saving approximately 30 minutes in transfer time for EVT. Transfer times without prior thrombolysis did not differ between the thrombolytic drugs.
Abstract 6: The Effect of Vascular Amyloid on White Matter Disease is Mediated by Vascular Dysfunction in Cerebral Amyloid Angiopathy
Authors: Gokcal Elif , Horn Mitchell J , Becker Alex A , Das Alvin S , Schwab Kristin , Rosand Jonathan , Viswanathan Anand , Polimeni Jonathan , Johnson Keith A , Greenberg Steven M , Gurol M. Edip
Published: March 2021

Background:
Cerebral amyloid angiopathy (CAA) is associated with white matter hyperintensities (WMH) but the physiopathological mechanisms remain unclear. We hypothesized that the relationship between vascular amyloid load and WMH is mediated by vascular dysfunction.

Methods:
The study cohort included 38 non-demented probable CAA patients who underwent advanced multimodal structural and functional MRI (fMRI) and amyloid PET scans. White matter hyperintensity volume was quantified using
FreeSurfer
and expressed as a percent of total intracranial volume (pWMHv). Time-to-peak [TTP] of blood oxygen level-dependent [BOLD] response to visual stimulation using fMRI was used as an established measure of vascular dysfunction. Mean cortical Pittsburg Compound B uptake representing amyloid load was calculated. A bootstrapping procedure was used to test the mediation hypothesis adjusting for age, sex, and presence of intracerebral hemorrhage (ICH).

Results:
Of 38 patients with CAA (mean age 70±7.1, 86.8% male), 25 (65.8%) had ICH, while the remaining 13 patients (34.2%) presented with multiple strictly cortical microbleeds. Higher amyloid load correlated with prolonged TTP response (r=0.373, p=0.021) and higher pWMHv (r=0.337, p=0.039), and prolonged TTP response correlated with higher pWMHv (r=0.485, p=0.002). Amyloid load no longer predicted pWMHv (p=0.254) after controlling for TTP. In the bootstrapping model, TTP response had a significant indirect effect (ab=0.977, 95% CI: 0.15-2.42), showing that the association between amyloid load and pWMHv is mediated by TTP.

Discussion:
Our findings confirm the hypothesis that the effect of vascular amyloid load on the extent of white matter disease is mediated by vascular dysfunction in patients with CAA. Amyloid lowering strategies might prevent pathophysiological processes leading to vascular dysfunction, therefore limiting ischemic brain injury.
Abstract 65: Targeted Drug Delivery via Acid-Triggered Release Antioxidant Nanoparticles Improves Efficacy of Na1 for Stroke Treatment
Authors: Zhang Shenqi , Chen Zeming , Deng Gang , Kimberly W T , Simard J Marc , Zhou Jiangbing , Sheth Kevin N
Published: March 2021

Introduction:
Recently, NA1, a peptide designed to protect neurons against NMDA receptor-mediated excitotoxicity, demonstrated promise for acute stroke treatment. Enhanced efficiency of peptide delivery may result in improved efficacy.

Hypothesis:
The bioactive fragment of NA1 is nine amino acids of the carboxyl tail of GluN2B. Delivery of NR2B9c to cells in the brain is achieved through fusion with TAT, a peptide that binds to biological membranes without selectivity. We hypothesize that enhancing targeted delivery of NA1 to the ischemic brain improve the efficacy of NA1.

Methods:
We previously identified betulinic acid (BA) forming nanoparticles (NPs) as a novel formulation of stroke treatment delivery. After intravenous administration, BA NP penetrate the ischemic brain, reduce ischemia-induced infarction as an antioxidant agent, and allow for encapsulation and delivery of drugs. In this study, we engineered BA NPs for improved drug delivery preferentially to the ischemic brain through surface conjugation of AMD3100, and for acid-triggered drug release to selectively in the ischemic region, which is known to be acidic, through chemical modification. The resulting acid responsive, stroke- targeting antioxidant NPs, or ARSTA NPs, were evaluated for stroke treatment in the mouse transient middle cerebral artery occlusion (MCAO) model either alone or in combination with NA1, based on changes of infarct volumes, edema, mortality, and outcomes.

Results:
We found that ARSTA NPs enabled targeted delivery of NA1 preferentially to the ischemic brain and allowed for prompt drug release. We showed that intravenous delivery of 50 ug NA1 (or 1nM/g) encapsulated in 1 mg ARSTAs effectively reduced infarct volumes by 69.8%, edema by 60.3%, mortality (median survival >14 days). In contrast, delivery of ARSTA NPs alone (52.2%, 30.2%, 10) or NA1 (0.7%, 3.3%, 6 days) alone at a comparable dose exhibited significantly less efficacy. Consistently, treatment with NA1-loaded ARSTAs improved neurological outcomes in a degree significantly greater than that by either ARSTA NPs or NA1 alone.

Conclusion:
BA-NP encapsulating NA-1 may represent a novel platform for improved delivery to the ischemic brain. Improved delivery may result in improved efficacy.
Abstract 7: Association Between Incidence, Severity and Recurrence of Ischemic Stroke and Risk of Dementia: The Atherosclerosis Risk in Communities Study
Authors: Koton Silvia , Pike James R , Johansen Michelle C , Knopman David , Lakshminarayan Kamakshi , Mosley Thomas , Patole Shalom , Rosamond Wayne D , Schneider Andrea L , Sharrett A. Richey , Wruck Lisa M , Coresh Josef , Gottesman Rebecca F
Published: March 2021

Background:
Ischemic Stroke (IS) is associated with an increased risk of dementia, but the relative contribution of IS severity or recurrence to cognition is not known. We aimed to determine the risk of dementia after incident IS and how it varies by stroke severity and recurrence in the Atherosclerosis Risk in Communities (ARIC) study.

Methods:
15,405 ARIC participants free of stroke and dementia at baseline (1987-9) were followed for IS and dementia through 2019. Incident and recurrent IS were classified by expert review of hospital records, with stroke severity by the National Institutes of Health Stroke Scale (NIHSS) classified as NIHSS≤5, 6-10, 11-15, ≥16. Dementia cases were adjudicated through expert review of in-person evaluations, informant interviews, phone assessments, hospitalization code or death certificates. Poisson regression models with robust error variance were used to estimate dementia incidence in participants with and without IS, and associations between time-dependent IS incidence (excluding dementia in the first year after stroke), frequency and severity, and dementia were studied with Cox proportional hazards models, adjusting for demographics,
APOE
ε4 and vascular risk factors
.

Results:
1151 IS (970 incident) and 2807 dementia cases were identified. NIHSS was available for 877 IS (76%). Adjusted incidence rates (95% CI) of dementia per 100 person-years were 0.45 (0.42-0.49) in participants without IS vs. 1.33 (1.15-1.55) in those with IS. Compared to no IS, risk of dementia (adjusted HR, 95% CI) increased with IS number and severity from 1.71 (1.47-1.99) for participants with one IS to 6.68 (3.58-12.46) for those with ≥3 events, and from 1.64 (1.36-1.98) for NIHSS≤5 to 4.43 (1.84-10.68) for NIHSS≥16 (
Table
).

Conclusion:
Risk of dementia is significantly increased after stroke, independent of vascular risk factors. These data suggest a dose-response relationship between number of stroke events and stroke severity, and risk of dementia.
Abstract MP14: White Matter Hyperintensity Progression, Macroalbuminuria, and Intensive Glycemic Control in Diabetics
Authors: Muddasani Varsha , Sheibani Nazanin , Wong Ka-ho , De Havenon Adam H
Published: March 2021

Introduction:
White matter hyperintensity (WMH) is associated with a higher risk of stroke, dementia, and depression. Prior research has suggested that renal impairment and diabetes may predispose to the development of WMH. Here, we evaluated the association between WMH volume (WMHv), macroalbuminuria, and glycemic control in a cohort of diabetic patients.

Methods:
This is a secondary analysis of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) dataset. The primary outcome is WMH progression in mL, evaluated by fitting linear regression to WMHv on the month 40 MRI and including the WMHv on the baseline MRI in the model. The primary predictors were incident macroalbuminuria, defined as new onset urinary albumin >300mg/day, and the ACCORD glucose randomization arm.

Results:
We included 502 patients. The mean (SD) WMHv at baseline was 2.1 (3.9) mL and at month 40 was 3.6 (5.7) mL. Twenty-three patients (4.6%) developed macroalbuminuria during the study period, who had a higher mean WMH progression (2.9 vs. 1.4 mL, p=0.012). In a linear regression model adjusted for mean systolic blood pressure during follow-up, macroalbuminuria was a significant predictor of WMH progression (Beta 1.20, 95% CI 0.17-2.22, p=0.022). In the same model, the interaction term between glucose randomization arm and macroalbuminuria was highly significant (Beta 3.38, 95% CI 1.20-5.57, p=0.003). The predicted follow-up WMHv for the interaction term are in Figure 1, showing that macroalbuminuria with intensive glycated hemoglobin reduction (goal A1c<6%) was associated with the most WMH progression.

Conclusion:
In diabetic patients, the development of macroalbuminuria was associated with WMH progression over 40 months, although only in patients assigned to intensive glycemic control. This finding is consistent with the adverse events seen in ACCORD with intensive glycemic control.
Abstract MP16: Excessive White Matter Hyperintensity Burden and Functional Outcomes After Acute Ischemic Stroke
Authors: Hong Sungmin , Giese Anne-katrin , Schirmer Markus D , Dalca Adrian V , Bonkhoff Anna , Bretzner Martin , Donahue Kathleen , Jern Christina , Lindgren Arne , Maguire Jane , Rost Natalia S ,   MRI-GENIE and GISCOME Investigators,   International Stroke Genetics Consortium
Published: March 2021

Objective:
Ability of the brain to recover after an acute ischemic stroke (AIS) is linked to the pre-stroke burden of white matter hyperintensity (WMH), a radiographic marker of brain health. We sought to determine the excessive WMH burden in an AIS population and investigate its association with 3-month stroke outcomes.

Data:
We used 2,435 subjects from the MRI-GENIE study. Three-month functional outcomes of 872 subjects among those subjects were measured by 90-day modified Ranking Scale (mRS).

Methods:
We automatically quantified WMH volume (WMHv) on FLAIR images and adjusted for a brain volume. We modeled a trend using the factor analysis (FA) log-linear regression using age, sex, atrial fibrillation, diabetes, hypertension, coronary artery disease and smoking as input variables. We categorized three WMH burden groups based on the conditional probability given by the model (LOW: lower 33%, MED: middle 34%, and HIGH: upper 33%). The subgroups were compared with respect to mRS (median and dichotomized odds ratio (OR) (good/poor: mRS 0-2/3-6)).

Results:
Five FA components out of seven with significant relationship to WMHv (p<0.001) were used for the regression modeling (R
2
=0.359). The HIGH group showed higher median (median=2, IQR=2) mRS score than LOW (median=1, IQR=1) and MED (median=1, IQR=1). The odds (OR) of good AIS outcome for LOW and MED were 1.8 (p=0.0001) and 1.6 (p=0.006) times higher than HIGH, respectively.

Conclusion:
Once accounted for clinical covariates, the excessive WMHv was associated with worse 3-month stroke outcomes. These data suggest that a life-time of injury to the white matter reflected in WMH is an important factor for stroke recovery and an indicator of the brain health.
Abstract MP18: Covid-19 Susceptibility and Mortality Among Individuals With Mild Cognitive Impairment, Alzheimer’s Disease and Related Dementias
Authors: Pan Alan , Meeks Jennifer , Potter Thomas , Khan Osman , Seshadri Sudha , Masdeu Joseph , Vahidy Farhaan S
Published: March 2021

Introduction:
We evaluated the burden of SARS-CoV-2 susceptibility and COVID-19 mortality associated with Mild Cognitive Impairment (MCI) or Dementia (MCID).

Methods:
We analyzed data from COVID-19 Outcomes Registry (CURATOR) at Houston Methodist; a tertiary healthcare system in greater Houston. All adult (≥ 18 years) patients tested for SARS-CoV-2 RNA in nasopharyngeal swabs were included. Utilizing validated ICD-10 codes (MCI, Alzheimer’s Disease, Vascular and Other Dementias) and use of MCID specific medications, we flagged patients with preexisting MCID. Logistic regression models were fitted to evaluate the odds of SARS-CoV-2 susceptibility and COVID-19 mortality associated with preexisting MCID. Odds ratios (OR) and 95% Confidence Intervals (CI) are reported.

Results:
Between March 3 and August 10, 2020; 86,614 individuals were tested, of whom 14,233 (16.4%) tested positive, with 4,473 (31.4%) hospitalizations, and 431 (9.6%) deaths. Overall 3,069 individuals had preexisting MCID; among whom 518 (16.9%) tested positive. Among all SARS-CoV-2 positive cases, MCID patients (vs. non MCID group) were older (79.9 vs. 47.3 years) and had higher overall comorbidity burden (median Charlson Comorbidity Index: 6 vs. 0), with higher proportion (%) of hypertension (90.3 vs. 39.0), heart failure (37.8 vs. 7.5), diabetes (69.3 vs. 28.2), and cancer (14.5 vs. 4.8). Mortality among MCID patients (vs. non MCID) was 22.3% vs. 8.6%. In fully adjusted models (demographics, comorbidities, clinical / laboratory parameters, complications, treatment and ICU admission), pre-existing MCID was independently associated with higher SARS-CoV-2 susceptibility, OR (CI) 1.62 (1.46-1.80) and in-hospital mortality OR (CI): 1.79 (1.23-2.61) among COVID-19 patients (graphic).

Conclusions:
Regardless of age, MCID is a potential risk factor for SARS-CoV-2 infection and COVID-19 mortality. Targeted prevention and management strategies are warranted for this high-risk group.
Abstract MP2: An Older Thrombus Delays Reperfusion in Mechanical Thrombectomy for Ischemic Stroke
Authors: Kitano Takaya , Hori Yumiko , Shimada Yuki , Iwamoto Takanori , Okazaki Shuhei , Nakamura Hajime , Kanki Hideaki , Sasaki Tsutomu , Beck Goichi , Kishima Haruhiko , Murayama Shigeo , Morii Eiichi , Sakaguchi Manabu , Yagita Yoshiki , Mochizuki Hideki , Todo Kenichi
Published: March 2021

Background:
Thrombus formation is a dynamic process and the structure of thrombus changes with time. We examined the effect of thrombus age on the quality of reperfusion and prognosis in mechanical thrombectomy for acute ischemic stroke.

Methods:
We examined 185 patients who underwent mechanical thrombectomy in 3 stroke centers between January 2015 and December 2019, and pathologically evaluated their retrieved thrombi. Thrombi were classified according to histologically accepted definitions as: fresh, with intact granulocytes; and older, with organization or lytic changes characterized by areas of colliquation necrosis and karyorrhexis of granulocytes. The extent of neutrophil extracellular trap formation (NETosis) in thrombi was assessed on the basis of the density of citrullinated histone H3 positive particles. Baseline characteristics, time to successful reperfusion (eTICI 2b or more), thrombus feature, and functional outcome were compared between the patients with fresh and older thrombi.

Results:
Fresh thrombi were obtained from 43 patients (23%), and older thrombi, from 142 patients (77%). The stroke subtypes and onset-to-puncture time did not significantly differ between the two groups. The erythrocyte content was higher, whereas the density of macrophages and extent of NETosis were lower in the fresh thrombi. Fresh thrombi were associated with shorter time from puncture to recanalization (median, 48 vs. 62 min, P = 0.004; Figure), and fewer passes before reperfusion (median, 1 vs. 2; P < 0.001). In the multivariate analysis, favorable outcome (mRS ≤ 2) was observed more often in patients with fresh thrombi (adjusted OR, 2.76; 95% CI, 1.20-6.32).

Conclusions:
An older thrombus necessitated longer procedure time and more device passes, which deteriorate the functional outcome of patients with acute ischemic stroke. Thrombus maturation may contribute to resistance to mechanical thrombectomy.
Abstract MP22: Sex Differences in the Delivery of Acute Telestroke Care
Authors: Morton Johanna L , Didwania Suraj , Anderson Eric , Hallock Jason
Published: March 2021

Background:
Sex differences are encountered in many aspects of ischemic stroke, including risk factors, presenting symptoms, stroke mechanism, acute interventions and functional outcomes. As telestroke services continue to expand, many patients utilize telestroke for the evaluation and treatment of suspected stroke symptoms. To date, the existence of such differences between sexes has not been identified in the patient population having utilized telestroke for acute stroke care.

Methods:
A retrospective observational study of the experience of a single teleneurology practice serving 340 hospitals from April 2018 to June 2020 was performed. Patients seen in the emergency department (ED) with a diagnosis of suspected stroke were included. Data from the acute stroke encounter was reported through the current medical record platform.

Results:
Within the queried period, there were 11,454 male and 11,794 female patients identified as having received ED telestroke evaluation for suspected acute stroke. Males were younger than females (67 vs 70,
P
<0.01). Males had higher rates of prior stroke, hypertension, diabetes, hyperlipidemia, and coronary disease than females (
P
<0.01), while females had higher rates of atrial fibrillation (
P
=0.03) and TIA (
P
<0.01). Rates of antiplatelet and anticoagulants were higher in males (
P
<0.01) than females. There were no differences in time to ED presentation, time to request consult or make a thrombolysis decision, or length of consult. Females had higher stroke severity (
P
<0.01) and door-to-needle times (
P
<0.01), but lower alteplase rates (
P
=0.02) compared to males.

Conclusion:
This review of a national heterogeneous telestroke patient population is indicative of sex differences in multiple aspects of acute ischemic stroke, most notably in thrombolysis delivered via telestroke. Further investigation into the etiology of such differences is warranted, as well as a survey of functional outcomes. As telemedicine continues to expand in the era of the COVID-19 pandemic, it is imperative that the reasons behind this disparity are investigated.
Abstract MP24: Pitfalls of Mobile Stroke Treatment Unit - A Single Center Review
Authors: Gopal Mangala , Powers Ciaran , Nimjee Shahid M , Heaton Sharon , Lee Vivien
Published: March 2021

Introduction:
Although Mobile Stroke Treatment Units (MSTU) can reduce time to intravenous thrombolysis (IVtPA), limitations in MSTU care have not been well described.

Methods:
We retrospectively reviewed consecutive patients transported by MSTU to our academic comprehensive stroke center (CSC) from May 2019 to August 2020 for suspected stroke to assess for potential limitations of care. The Columbus MSTU is owned by a separate health system, but represents a collaborative venture with 3 CSCs and the Columbus Division of Fire, operating daily from 7am-7pm. Data was abstracted on demographics, clinical presentation, last known normal (LKN) time, initial National Institutes of Health Stroke Scale (NIHSS), neuroimaging, and IVtPA administration.

Results:
Among 93 patients transported to our CSC by MSTU, the mean age was 65 years (range, 21-93) and 61 (66%) were female. The mean initial NIHSS was 7.1 (range, 0 to 33) and 52 (55.9%) had a final diagnosis of stroke (4 hemorrhagic, 48 ischemic). IVtPA was administered in 15 (16.1%) with a mean LKN to IVtPA time of 120 minutes (range, 41 to 243). Among 15 patients treated with IVtPA, 10 received IVtPA in MSTU and 5 in CSC ED. In 7 patients who underwent thrombectomy, mean door to groin time was 57 minutes (range, 28 to 88). Among the overall group, 9 (9.7%) cases were identified with limitations in MSTU care, including 2 patients who received IVtPA by MSTU that were more than 10% off from ideal dosing (underdosed by 9mg and overdosed by 21mg), 1 warfarin-associated hemorrhage requiring intubation who did not receive reversal in MSTU but did upon arrival to CSC ED, and 5 patients who received IVtPA after arrival to CSC ED. The reasons for withholding IVtPA included inability to confirm LKN, patient declination, lack of translator, incorrect LKN, and seizure requiring intubation. The LKN to IVtPA time was significantly longer in the ED compared to MSTU (197 vs 82 minutes, p <0.0001).

Conclusion:
In our series of suspected stroke patients evaluated by MSTU, gaps identified within MSTU acute stroke care were related to limitations of resources and included errors in weight-based IVtPA dosing, inability to administer IVtPA, or reversal for anti-coagulation related hemorrhage. Clinicians need to be aware of potential pitfalls of MSTU evaluation.
Abstract MP26: Medicaid Expansion Did Not Reduce Stroke Readmissions After One Year
Authors: McGee Blake T , Kim Seiyoun
Published: March 2021

Introduction:
Up to 21% of stroke survivors are re-hospitalized within 30 days. Health insurance promotes access to follow-up care that can mitigate the risk of readmission, but 12 states do not participate in the Affordable Care Act’s Medicaid expansion.

Hypothesis:
The probability of 30-day hospital readmission after acute ischemic stroke was lower in Medicaid expansion states than in non-expansion states.

Methods:
A retrospective, quasi-experimental study using six inpatient databases from AHRQ’s Healthcare Cost and Utilization Project: four from expansion states (AR, MD, NM and WA) and two non-expansion (FL and GA). The sample comprised all patients hospitalized in 2012-14 with a principal diagnosis of ischemic stroke (ICD-9-CM 433.x1, 434.x1 or 436) who were aged 19-64; resided in the state where admitted; had a primary payer of Medicaid, self-pay or no charge; and were discharged alive (
N
=18,766). Mixed effects logit models with a time-by-treatment interaction were built to test if the probability of readmission changed differentially between expansion and non-expansion states from 2012-13 (before expansion) to 2014. Any in-state hospitalization within 30 days of discharge (except for rehabilitation, psychiatry, or cancer treatment) was considered a readmission. A secondary analysis of unplanned, potentially preventable readmissions (adapted from the AHRQ Prevention Quality Indicators) was also conducted. Models included race, sex, age, number of diagnoses, median household income quartile of patient ZIP code, and metropolitan residence as fixed effects, with random intercepts for hospital and state.

Results:
In 2012-13, 8.9% of the expansion state patients were readmitted compared to 9.0% in non-expansion states; in 2014, 11.1% were readmitted in expansion states versus 10.5% in non-expansion states. In multivariable models, the time-by-treatment interaction was not statistically significant: β=0.072,
p=
.541, for all readmissions, β=0.168,
p
=.683, for unplanned, potentially preventable readmissions.

Conclusions:
Medicaid expansion did not reduce 30-day readmissions after stroke in the first year of implementation in four diverse states. Stroke readmissions among non-elderly adults require more targeted interventions.
Abstract MP36: Blood Pressure Reductions in the Hyperacute Phase of Large Vessel Occlusion Ischemic Stroke Are Associated With Infarct Progression and Poor Functional Outcome
Authors: Peshwe Krithika Umesh , Nguyen Cindy Khanh , Kodali Sreeja , Kobsa Jessica , Prasad Ayush , Soto Alexandria , Wira Charles R , Matouk Charles , Sheth Kevin N , Petersen Nils H
Published: March 2021

Introduction:
Decreases in blood pressure (BP) during endovascular therapy (EVT) have been associated with infarct progression and worse outcome after large vessel occlusion (LVO) stroke. However, BP trajectories in the hyperacute phase prior to EVT have not been well characterized. We used high-frequency BP and hemodynamic monitoring to study the timing of BP reductions during the hyperacute period of stroke and evaluated their relation to infarct progression and functional outcome.

Methods:
We prospectively enrolled patients with anterior circulation LVO stroke undergoing EVT. BP and cardiac hemodynamic variables were recorded every 20 seconds from ER admission until the end of EVT using non-invasive finger plethysmography. Patients underwent initial CT perfusion imaging and a follow-up MRI at 24 hours to calculate infarct growth. The following hemodynamic parameters were defined as exposure variables: the difference between admission MAP and lowest MAP (ΔMAP), MAP drop> 20% from admission, MAP<70 mmHg, and SBP<140 mmHg. Functional outcome was measured with the modified Rankin Scale (mRS) at 90 days. Core associations between BP reductions and outcomes were studied using linear regression and logistic regression models.

Results:
45 patients underwent continuous BP monitoring (age 72±17; 58% female; NIHSS 13±6). Aggregated time series data revealed a marked BP reduction around the time of imaging from which patients recovered (mean SBP 33 mmHg, duration 18 min). A sustained decrease in BP was observed after groin puncture without return to baseline BP levels. A linear regression analysis revealed a 13ml infarct growth for every 10 mmHg reduction in ΔMAP (p=0.054). Patients were divided into two groups based on median ΔMAP = 29. Those with ΔMAP ≤29 had better functional outcome at 90 days (34.78% vs. 9.09%, p = 0.038).

Conclusion:
Marked and frequently iatrogenic BP reductions occur around the time of initial imaging and may present a potential target for therapeutic intervention. Decrease in blood pressure before reperfusion may increase the risk of infarct progression and poor functional outcome. Changes in cardiac hemodynamic variables throughout the acute stroke period suggest a potential role for fluid resuscitation for hemodynamic optimization.
Abstract MP37: Race/Ethnicity Differences in Response to Intensive Blood Pressure Treatment After Intracerebral Hemorrhage: Analysis of the Atach-2 Trial
Authors: Anadani Mohammad , De Havenon Adam H
Published: March 2021

Background:
The main analysis of the ATACH-2 (Antihypertensive Treatment in Intracerebral Hemorrhage-2) trial suggested no benefit from intensive blood pressure lowering (BPL) treatment after intracerebral hemorrhage (ICH). However, whether outcome and response to treatment differs according to race was not sufficiently studied.

Methods:
This is a post-hoc analysis of the ATACH-2 trial. The primary outcome was death or disability (90-day modified Rankin Scale [mRS] 4-6). Patients were divided according to race/ethnicity. Logistic regression was fit to assess the association between race and the primary outcome. In addition, we assessed the interaction between intensive BPL treatment and race.

Results:
A total of 939 patients (White=206, Asian=549, Black=111, Hispanic=73) were included. Death and disability occurred more frequently in White patients than other races (Figure). However, after adjusting for patient age, sex, baseline Glasgow Coma Scale, intracranial hemorrhage volume in mL, presence of intraventricular hemorrhage, deep vs. lobar, left vs. right hemisphere, intubation and ATACH treatment arm, Black patients had higher odds of the primary outcome (OR=1.98, P=0.02) compared to White patients. In contrast, Asian and Hispanic patients had non-statistically significant lower odds of the primary outcome (OR=0.68, P=0.09; OR= 0.97; P=0.95, respectively) compared to White patients. We did not observe treatment-by-race interaction. the p values for the interaction of intensive BPL treatment vs. standard BPL were 0.508 in Blacks, 0.336 in Hispanics and 0.190 in Asians, with Whites as the reference group.

Conclusion:
Black patients had higher odds of death or disability after non-traumatic supratentorial intracerebral hemorrhage compared to White patients.
Abstract MP38: Intracerebral Hemorrhage Across the United States: Incidence and Mortality Trends From 1990 to 2017
Authors: DeLago Augustin , Singh Harpreet , Rupal Arashdeep , Jani Chinmay , Parvez Arshi , Shalhoub Joseph , Marshall Dominic , Salciccioli Justin , AbdelRazek Mahmoud
Published: March 2021

Background:
Intracerebral Hemorrhage (ICH) accounts for 10% of strokes annually in the United States (US). Up-to-date trends in disease burden and regional variation remain unknown; especially after a dramatic increase in the use of direct oral anticoagulants (DOACs) since 2010. Our study reports updated incidence, mortality and mortality to incidence ratio (MIR) data related to ICH across the US.

Methods:
This observational study utilized the Global Burden of Disease database to determine age-standardized incidence (ASIR), death (ASDR) and MIR rates for ICH overall and for each state in the US from 1990-2017. All analyses were stratified by sex. Trends were analyzed using Joinpoint regression analysis, with presentation of estimated annual percentage changes (EAPCs) in ASIRs, ASDRs and MIRs over the observation period.

Results:
We observed an overall decrease in ASIRs, ASDRs and MIRs in both genders from 1990-2017, apart from female ASIRs and ASDRs in West Virginia and Kentucky. In 2017, the mean ASIR per 100,000 population for men was 25.67 and 19.17 for women. The 2017 mean ASDRs per 100,000 population for men and women were 13.96 and 11.35, respectively. The District of Columbia had the greatest decreases in ASIR EAPCs for males at -41.25% and females at -40.58%, and the greatest decreases in ASDR EAPCs for both males and females at -55.38% and -48.51%, respectively. The overall MIR during the study period decreased in males by -12.12% and females by -7.43%. However, MIR increased in males from 2014-2017 (EAPC +2.2% [95% CI +0.9%-+3.5%]) and in females from 2011-2017 (EAPC +1.0% [CI +0.7%-+1.4%]).

Conclusion:
This report reveals overall decreasing trends in incidence, mortality and MIR from 1990-2017. Notably, no significant change in mortality was found in the last 6 years of the study period, and MIR worsened in males from 2014-2017 and in females from 2011-2017, suggesting decreased ICH related survival lately. The substitution of vitamin K antagonists with DOACs is one possible explanation for a downtrend in incidence despite an aging population and increased use of anticoagulants. Limited access to reversal agents for DOACs is a potential reason for increase in MIR, however concrete deductions cannot be made owing to the observational nature of the study.
Abstract MP42: Arterial Spin Labeling Imaging Assessment of Cerebrovascular Reactivity in Hypertensive Small Vessel Disease
Authors: Tsai Hsin-Hsi C , Lee Bo-Ching , Huang Abel Po-Hao , Tsai Li-Kai , Chen Ya-Fang , Wu Wen-Chau
Published: March 2021

Objective:
Cerebrovascular reactivity (CVR) represents the phenomenon that cerebral vessels dilate or constrict in response to vasoactive stimuli, and CVR impairment may contribute to the brain injury caused by cerebral small vessel disease (SVD). We aim to determine the CVR in hypertensive intracerebral hemorrhage (ICH) and to identify its vascular dysfunction.

Methods:
21 patients with spontaneous hypertensive ICH (strictly deep or mixed deep and lobar hemorrhages, mean age 62.5 ± 11.3 years) and 10 control subjects (mean age 66.1 ± 6.0) were enrolled for CVR measurement. Each participant received a brain MRI study, and CVR was calculated as cerebral blood flow (CBF) change using arterial spin labeling (ASL) sequence at baseline and 10 minutes after intravenous dipyridamole injection (0.57mg/Kg). Traditional MRI markers for SVD including cerebral microbleed, white matter hyperintensity, lacune and MRI-visible enlarged perivascular space were also evaluated to determine the total small vessel disease score.

Results:
Hypertensive ICH patients showed reduced CVR in the basal ganglia (CBF change 22.4 ± 22.7% vs. 41.7 ± 18.3, p=0.026), the frontal (15.1 ± 11.9 vs. 26.6 ± 9.9, p=0.013) and the temporal lobes (14.7 ± 11.1 vs. 26.2 ± 10.0, p=0.010) compared to control subjects (Figure). These differences remained significant in multivariable models after adjusting for age, sex, hypertension, diabetes, and hyperlipidemia. Within ICH groups, the CBF change in basal ganglia was significantly correlated with total small vessel disease score (R=-0.58, p=0.006), but not with individual MRI markers.

Conclusion:
Patients with advanced HTN-SVD demonstrated impaired vasoconstriction after dipyridamole challenge in basal ganglia, frontal and temporal lobes. Our findings provide safe approaches for whole brain CVR mapping in small vessel disease, and identify the potential physiological basis of vascular dysfunction in HTN-SVD.
Abstract MP51: Association Between Cervical Artery Dissection and the Risk of Aortic Dissection
Authors: Witsch Jens , Mir Saad , Parikh Neal S , Murthy Santosh , Kamel Hooman , Navi Babak , Segal Alan Z , Buchman Stephanie , Zhang Cenai , Merkler Alexander E
Published: March 2021

Background:
Cervical artery dissection (CAD) often affects young, otherwise healthy people. Few data exist on whether patients with CAD face an increased vulnerability to aortic dissection. Herein we tested the hypothesis that CAD is associated with an increased risk of aortic dissection.

Methods:
We performed a retrospective cohort study using statewide administrative claims data from all Emergency Department visits and admissions at nonfederal hospitals in Florida from 2005 to 2015 and New York from 2006 to 2015. We used previously validated International Classification of Disease, Ninth Revision, Clinical Modification codes (ICD-9-CM) to identify patients with CAD and aortic dissection. Patients with prevalent aortic dissection were excluded. Our exposure variable was CAD and the outcome was incident aortic dissection after discharge from CAD hospitalization. Survival statistics were used to calculate incidence rates and Cox proportional hazards analysis was used to determine the association between CAD and aortic dissection while adjusting for demographics and vascular risk factors. In a secondary analysis, we excluded patients who had a traumatic CAD, defined as having concomitant ICD-9-CM codes for head or neck trauma at the time of CAD.

Results:
Among 19,715,114 patients, 4,537 (0.02%) had a CAD. The mean age of patients with CAD was 52.3±16.4 years. During 4.2±3.1 years of follow up, 16,571 patients were diagnosed with an aortic dissection (0.08%). The incidence of aortic dissection was 2.5 (95% CI, 1.7-3.7) per 1,000 patients per year in those with CAD versus 0.2 (95% CI, 0.2-0.2) per 1,000 patients per year in those without CAD. After adjustment for demographics and vascular risk factors, we found that CAD was associated with subsequent aortic dissection (HR 3.0, 95% CI, 2.1-4.5). Our results were similar in a secondary analysis excluding patients with traumatic CAD (HR 3.3, 95% CI, 2.2-4.8).

Conclusions:
In a large population-based cohort, we found that CAD was associated with a 3-fold increased risk of aortic dissection. Future studies should evaluate the utility of performing screening aortic imaging in patients with CAD.