bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP83: Ischemic Volume Enlargement and Control of Vital Signs Within First 24 Hours After Admission in Acute Ischemic Stroke
Authors: Chang Hee Jin , Lee Seo Hyun , Jeon Ki Wan , Hyon Yun Kyong , Ha Tae Young , Lee Sukhoon , Kim Jei
Published: June 2021

Background and objectives:
The present study evaluated relationships of volume enlargement with patterns of vital sign control within 24 hours after admission in acute ischemic strokes.

Methods:
We analyzed clinical and radiological data of 130 patients, who were diagnosed as lacunes or branch atheromatous disease occurred in basal ganglia (n=83, 63.8%) or pons (n=47, 36.2%) on initial diffusion weighted image (DWI) within 72 hours of symptom onset and followed-up another DWI within 2 weeks. Ischemic lesion volume on the initial and follow-up DWI images were measured by using a program (ITK-SNAP). Vital signs including systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), respiratory rate (RR), body temperature, and peripheral oxygen saturation were checked every hour to 4 hours for 24 hours after admission for individual patients. Control parameters of each vital sign was evaluated with average, coefficient of variation, t-value of slope of regression line for pattern change, and coefficient of determination for predictability of the t-value of slope of the 24-hour data of the individual vital signs. Then, we evaluated whether the ratio of the follow-up/initial volume relates with not only the control parameters of the 5 vital signs but also known clinical and laboratory cardiovascular risk factors using the regression analysis.

Results:
The ratio of volume enlargement was 2.1 from initial (1300 mm
3
) to follow-up ischemic lesions of DWI (2792 mm
3
). Coefficient of variation (β=19.61, p=0.0033) and t-value (β=0.02, p=0.0052) of SBP, average of HR (β=0.06, p=0.0122) and RR (β=-0.25, p=0.0087), of the parameters for vital sign control, and smoking history (β=1.37, p=0.0384), uric acid (β=0.26, p=0.0483), hemoglobin A1c (β=-0.41, p=0.0054), age (β=-0.03, p=0.0544), and serum glucose (β=0.01, p=0.0966) of the cardiovascular risk factors were shown to be significant in explanation of the change of the volume enlargement ratio.

Conclusion:
The present study showed that the control of blood pressure, heart and respiratory rate of vital signs works together with the known cardiovascular risk to increase the lesion volume factors within 24 hours of admission for acute ischemic stroke patients.
Abstract TP89: Absolute Cerebral Blood Flow Assessment With Novel Low-Dose Whole Brain Dynamic CT Perfusion Technique
Authors: Abbona Pablo , Zhao Yixiao , Hubbard Logan , Malkasian Shant , Flynn Brooklynn , Molloi Sabee
Published: June 2021

Purpose:
Existing CT perfusion (CTP) techniques are limited in accurate assessment of stroke. The purpose of this study is to validate a novel low-dose whole-brain first-pass analysis (FPA) technique as compared with gold standard microsphere measurement in a swine model.

Materials and Methods:
Contrast-enhanced CTP of 5 Yorkshire swine (55 ± 24 kg) was performed over 30 seconds at baseline and following incremental brain embolization. For each acquisition, gold standard fluorescent microspheres, IV contrast, and saline were injected (5 ml/s), followed by dynamic CTP imaging in a 320-slice CT scanner. Scan parameters were 320 x 0.5 mm collimation, 100 kVp, 200 mA, and 350 ms gantry rotation time. On average, 47 contrast-enhanced volume scans were acquired per acquisition to capture the entire time attenuation curve (TAC) of the carotid artery. For each acquisition, only two retrospectively selected volume scans were used to quantify brain perfusion with the low-dose FPA technique. Specifically, the first volume scan was selected at the base, while the second volume scan was selected at the peak of the TAC. Regional low-dose FPA CTP measurements from different lobes were then quantitatively compared to gold standard microsphere perfusion of corresponding tissue samples by using linear regression and Bland-Altman analysis. The CT dose index (CTDI) and dose-length product (DLP) of two-volume FPA technique were also determined.

Results:
Low-dose FPA perfusion measurements (P
FPA
) were related to gold standard microsphere perfusion measurements (P
MICRO
) by P
FPA
= 1.14 P
MICRO
- 0.01 (r = 0.93, p
<
0.01). The CTDI and DLP per two-volume FPA CTP were estimated to be 25.6 mGy and 409.6 mGy, respectively.

Conclusion:
Low dose FPA CTP technique was retrospectively validated in a swine model and has the potential to be used for accurate diagnostic assessment and follow up of patients with stroke and vasospasm.
Abstract TP92: Dynamic Digital Subtraction Angiography With Rotation of Head and Neck May Serve as Critical Imaging Modality and Temporary Use of Cervical Collar in Addition to Anti-Platelet Therapy May Prevent Stroke in Cases of Acute Cervical Vertebral Artery Dissection (CVAD)
Authors: Kim Stanley H , Hernandez Kelsi , De La Torre Yesenia , Dhablania Nathan
Published: June 2021

Introduction:
The AHA/ASA have published a statement on the CVAD in 2014 in which a variety of imaging modalities that are performed with the head in neutral position are discussed and pharmacological and endovascular treatment of CVAD is reviewed. The authors have performed a prospective study of 12 patients with acute spontaneous CVAD from 2012 to 2019 who developed angiographic worsening stenosis or occlusion of the dissected VA associated with rotation of the head and cervical collar was added to the anti-platelet therapy.

Methods:
From 2012 to 2019, we performed a prospective study of 12 consecutive patients with spontaneous acute CVAD. We reviewed initial and follow-up clinical data and dynamic catheter cerebral angiogram with the patient’s head and neck in the straight neutral position and the head turned to the right and left beyond 60 degrees.

Results:
A total of 12 patients (Age 41.8 +/- 9.8; M=8, F=4) presented with acute stroke or TIA due to a total of 12 CVAD at the level of V1 (N=1), V2 (N=2), V3 (N=5), V4 (N= 2), V2-3 (N=2) segments diagnosed by cerebral angiogram. Initial mRS and NIHSS scores on admission were 3 +/-0.5 and 1.5 +/- 1.9, respectively. Dynamic cerebral angiogram performed with the patient’s head in neutral position showed average stenosis of 71.6 % +/- 18.9. Symptomatic occlusion or worsening stenosis of the dissected VA was observed on dynamic cerebral angiogram with rotation of the head to the contra-lateral side in 10 of 12 patients (83%). All patients were treated with daily Aspirin and Plavix for at least 3 months and placed on a cervical collar for 1 month. A follow-up dynamic cerebral angiogram at 1.8 +/- 1.4 months showed resolution of rotational occlusion or worsening stenosis of the VA. Clinical follow-up evaluation at 13.1+/- 10.9 months showed mRS score of 0.9+/- 1.0 and NIHSS score of 0.4 +/- 0.7 with no recurrent stroke.

Conclusion:
Dynamic cerebral angiogram may be critical in diagnosing rotational occlusion or stenosis of the dissected VA in patients with acute CVAD. Traditional imaging of the head and neck in neutral position may fail to diagnose adverse effect of rotation of the head and neck in these patients. Temporary use of cervical collar to prevent rotation of the head in the acute period of CVAD should be considered.
Abstract TP96: Neuroprotective Effects of IGF-1 in Middle-Aged Females Can Be Replicated by Antagomirs to microRNA (miR)-92b and miR-33a
Authors: Bake Shameena , Khosravian Homa , Sohrabji Farida
Published: June 2021

Background:
Our previous studies show that intracerebroventricular (ICV) delivery of Insulin-like growth factor (IGF)-1 reduces MCAo-induced infarction in middle-aged female rats. Analysis of ischemic tissue at 4h showed that IGF1 treatment significantly reduced the expression of a group of miRNAs. To determine if inhibiting these miRNAs could replicate IGF-1-mediated neuroprotection, we examined the effects of antagomirs to miR-33a (A-mir33a) and miR-92b (A-mir92b) in in vivo and in vitro models of ischemia.

Methods:
Middle-aged (12 mo) acyclic female rats were subject to intraluminal MCAo for 90 min followed by reperfusion. Animals received a single tail vein injection of A-miR-33a, A-miR-92b, A-miR-33a+A-miR-92b or scrambled oligos (7ug/kg bwt) after 4h of reperfusion. We evaluated infarct volume (TTC staining) at 2d post stroke and behavioral recovery using neurological scores and adhesive removal test (ART). In parallel, human brain endothelial cell cultures were exposed to oxygen-glucose deprivation (OGD) in the presence of A-mir-33a, A-mir-92b or scrambled oligos. The integrity of the cell monolayer was assessed by tomato-lectin staining and cell death was assayed by LDH.

Results:
Single injection of A-mir92b during the acute stroke phase reduced infarct volume (p<0.04) and improved sensorimotor behavior (p<0.04) while A-mir33a treated animals were not different from scrambled control. However, the combination of A-mir-33a+A-mir-92b resulted in significantly smaller infarct volumes (p<0.04), less motor impairment (neurological score; p<0.02) and sensorimotor deficits (ART; p<0.05). In vitro studies showed that neither of the antagomirs reduced media LDH under OGD. As reported previously, OGD caused cell retraction and A-mir33a notably preserved the cell geometry (continuous lectin staining) to maintain the monolayer integrity and was similar to the normoxic control.

Conclusions:
IGF-1 regulated microRNAs appear to modulate specific aspects of stroke recovery. IV delivery of a combination of miRNA inhibitors may replicate the neuroprotective actions of IGF-1, thus providing a safer alternate to ICV delivery of IGF-1. Supported by R56 NS074895 and RF1 AG04218906
Abstract WMP11: Safety and Efficacy of Mechanical Thrombectomy in Patients With Minor Stroke Due to Large Vessel Occlusion- Insights From the STAR Registry
Authors: Al Kasab Sami , Almallouhi Eyad , Alawieh Ali , Chalhoub Reda M , Psychogios Marios , Arthur Adam , Kim Joon-Tae , De Leacy Reade , Rai Ansaar , Keyrouz Salah , Fargen Kyle M , Dumont Travis , Kan Peter , Starke Robert M , Spiotta Alejandro M
Published: June 2021

Introduction:
Mechanical thrombectomy (MT) is the current standard of care treatment for patients presenting with severe symptoms due to large vessel occlusion (LVO); approximately 30% of patients with LVO however present with mild symptoms (NIHSS < 6). The safety and efficacy of MT in this group has not yet been established. The purpose of this study is to evaluate the safety of MT in patients presenting with mild symptoms due to LVO in a large multicenter registry.

Methods:
STAR registry combined the prospectively maintained databases of 11 thrombectomy-capable stroke centers in the US, Europe and Asia. Patients who underwent MT were included in these analyses. Baseline features, risk factors, location of occlusion, time from symptom onset, tPA receipt, procedural complication rates, symptomatic hemorrhage, and long-term functional outcome were compared between patients with mild symptoms (NIHSS < 6) to those with severe symptoms (NIHSS ≥ 6).

Results:
Total of 2,114 patients were included in this analysis. Of those, 162 patients presented with NIHSS ≥ 6. Baseline features and outcomes are summarized in table 1. There was no difference in age, or sex, tPA receipt, number of attempts, rate of successful revascularization, symptomatic hemorrhage, or length of hospital stay. Median ASPECTS score was 9 in the mild Vs 8 in the severe symptom group (p=< 0.001), there was a higher percentage of patients in the mild symptom group with hypertension, hyperlipidemia, and LVO in the posterior circulation. Conversely there were more patients with atrial fibrillation in the severe symptom group. Excellent outcome (mRS 0-2 at 90 days) was achieved in 69.8% patients in the mild group compared to 38.3% in the severe group, p=<0.001)

Conclusion:
In patients with minor symptoms due to large vessel occlusion, mechanical thrombectomy appears to be safe with low complication rates. Approximately seventy percent of patients achieved excellent functional recovery.

Table 1:
Abstract WMP111: Trends in Active Tobacco Smoking Among Stroke Survivors in The United States: An Analysis of the National Health and Nutrition Examination Survey, 1999-2016
Authors: Parikh Neal S , Chatterjee Abhinaba , Merkler Alexander E , Lerario Mackenzie P , Iadecola Costantino , Navi Babak B , Kamel Hooman
Published: June 2021

Background:
Active smoking after stroke is associated with worse outcomes. Since several smoking cessation drugs have become available during the last two decades, we sought to determine whether the rate of active smoking among stroke survivors has decreased.

Methods:
We performed a trends analysis using cross-sectional data from all nine available consecutive cycles of the continuous phase of the National Health and Nutrition Examination Survey from 1999 to 2016. Participants in each cycle were asked about their medical history and health-related behaviors. We included participants 20 years of age and older who answered questions regarding smoking. Patients with prior stroke were identified based on self-report, which has been validated against expert chart review. Active smoking was defined based on self-report. We used multivariable logistic regression methods for survey data to assess for trends in active smoking among all participants and those with prior stroke. Models were adjusted for demographics.

Results:
We included 49,440 participants in our analysis, of whom 1,921 (2.7%) reported a prior stroke. The mean age of stroke survivors was 64.8 (standard error, 0.5) years, and 57% were women. The average prevalence of active smoking over 1999-2016 was 22.2% for the whole sample and 24.3% among stroke survivors. In the overall population, the adjusted prevalence of active smoking decreased over the study period (odds ratio [OR] per cycle, 0.96; 95% confidence interval [CI], 0.94-0.97). The rate did not decrease among stroke survivors (OR, 1.01; 95% CI, 0.93-1.09) (Fig).

Conclusion:
Despite the availability of several effective smoking cessation therapies, the rate of active smoking among stroke survivors has not decreased in the past two decades. Effective strategies for smoking cessation for secondary stroke prevention are needed.
Abstract WMP112: Cilostazol versus Aspirin for Secondary Stroke Prevention: Systematic Review and Meta-Analysis
Authors: Lin Michelle P , Barrett Kevin M , Meschia James F , Eidelman Benjamin H , Huang Josephine F , Brott Thomas G
Published: June 2021

Introduction:
Cilostazol has promise as an alternative to aspirin for secondary stroke prevention given its vasodilatory and anti-inflammatory properties in addition to platelet aggregation inhibition. We conducted a systematic review and meta-analysis to estimate the comparative effectiveness and safety of cilostazol compared to aspirin for stroke prevention in patients with previous stroke or TIA.

Hypothesis:
Cilostazol is more effective than aspirin in preventing recurrent ischemic stroke with lower risk of intracranial hemorrhage and bleeding.

Methods:
We searched PubMed and the Cochrane Central Register of Controlled Trials from inception to 2019. Randomized clinical trials that compared cilostazol vs aspirin and reported the endpoints of ischemic stroke, intracranial hemorrhage and bleeding were included. A random-effects estimate was computed based on Mantel-Haenszel methods. The pooled estimates with 95% confidence intervals were compared between cilostazol and aspirin and displayed as forest plots (Figure).

Results:
The search identified 5 randomized clinical trials comparing cilostazol vs aspirin for secondary stroke prevention that enrolled 7,240 patients from primarily Asian countries (3,615 received cilostazol and 3,625 received aspirin). The pooled results from the random-effects model showed that cilostazol was associated with significantly lower risk of recurrent ischemic stroke (Hazard ratio [HR] 0.70; 95%CI, 0.54-0.89), intracranial hemorrhage (HR 0.41; 95%CI, 0.25-0.65) and bleeding (HR 0.71; 95%CI, 0.55-0.91). See forest plots.

Conclusion:
This meta-analysis suggests cilostazol is more effective than aspirin in the prevention of recurrent ischemic stroke with lower risk of intracranial hemorrhage and bleeding. Confirmatory randomized trials of cilostazol for secondary stroke prevention to be performed in more generalizable populations are needed.
Abstract WMP113: Serial Cognitive Testing Performance by Baseline Fazekas Category in Stroke Survivors: A Secondary Analysis of the SPS-3 Trial
Authors: de Havenon Adam H , Rost Natalia , Prabhakaran Shyam
Published: June 2021

Introduction:
Prior research has shown that an increased burden of white matter hyperintensity (WMH) is an independent risk factor for the development of dementia. However, research has not focused specifically on stroke survivors, who are also predisposed to dementia.

Methods:
This is a secondary analysis of patients in the Secondary Prevention of Small Subcortical Strokes (SPS3) trial, who had a lacunar ischemic stroke within 6 months of enrollment and an MRI at study baseline. The primary outcome is change in the Cognitive Abilities Screening Instrument (CASI) from baseline to a 12 month follow-up. The primary predictor is the Fazekas score on the baseline MRI, with the scores of 0 and 1 collapsed to balance the cohort. We fit regression models to the 12 month CASI and adjusted for baseline CASI, patient age, gender, white race, Barthel Index score at 3 months from enrollment, college education, employment status, diabetes, COPD, and SPS3 randomization arm.

Results:
We included 2,413 patients with a mean (SD) age of 62.8 (10.6) years and 63.7% were male. There were 946 patients in Fazekas 0-1, 1,009 in Fazekas 2, and 458 in Fazekas 3. The mean (SD) CASI score at baseline and 12 months were 85.3 (12.4) and 86.0 (12.4). In the adjusted linear regression model, compared to a baseline Fazekas of 0-1, a baseline Fazekas of 2 was associated with a worse cognitive score (β coef = -0.55, 95% CI -1.01, -0.08, p=0.020), as was Fazekas of 3 (β coef = -0.76, 95% CI -1.36, -0.16, p=0.013).

Conclusion:
In patients with recent lacunar stroke, an increased baseline WMH burden is a risk factor for worse performance over a one year period on a validated test of global cognition. Although the absolute difference in score that we found was small (~0.5-0.8 points), this difference is over one year and, over years to decades, could become clinically significant. The implication of this finding is that lacunar ischemic stroke has additive cognitive consequences for patients with an established WMH burden, suggesting that primary stroke prevention in patients with WMH could be an important public health goal to reduce the burden of dementia.
Abstract WMP117: Migraine With Aura as a Risk for Ischemic Stroke (MARS) Risk Score
Authors: Trivedi Tushar , Vezzetti Alexandra , Melikov Petr , Alonso Alvaro , Chen Lin Yee , Soliman Elsayed Z , Magnani Jared W , Gottesman Rebecca F , Rosamond Wayne D , Sen Souvik
Published: June 2021

Introduction:
Migraine with visual aura is associated with an increased risk of ischemic stroke. We developed a model to predict the risk of ischemic stroke in patients with migraine with aura.

Methods:
We prospectively evaluated 429 participants from Atherosclerosis Risk in Communities Cohort (ARIC) with a history of migraine with aura. The association of potential risk factors with ischemic stroke was tested by Cox proportional-hazards analysis and a risk score was created. Assignment of points to risk factors was based on a linear transformation of the corresponding β regression coefficient. The coefficient of each variable was divided by 0.18 (the lowest β value in the model, corresponding to Female Gender).

Results:
Among the 429 participants with a history of migraine with aura at baseline, 31 developed ischemic stroke during a mean follow-up of 20-years. Five independent prognostic factors were identified, and each was assigned a number of points proportional to its regression coefficient: Diabetes Mellitus (7 points), age > 65 years (5 points), heart rate variability (defined as the standard deviation of all normal-to-normal RR intervals) (3 points), hypertension (3 points), and gender (1 point). We calculated risk scores for each patient and defined three risk groups: low risk (0 to 4 points), moderate risk (5 to 10 points), and high risk (11 to 21 points). Hazards ratio for ischemic stroke in high risk (vs. low risk) group was 7.35 (p= 0. 003). Kaplan Meier curves showed significant discrimination of stroke risk among the risk stratification groups (p < 0.001, see Figure).

Conclusions:
Simple risk score was developed to predict stroke risk in those with migraine with aura. These findings can be useful to clinicians for predicting stroke risk in migraineurs and directing preventive therapy. Validation of MARS in an independent population cohort is warranted.
Abstract WMP15: Automated Volumetric Assessment of Infarct Core in Non-Contrast Computed Tomography in Patients With Acute Ischemic Stroke Secondary to Large Vessel Occlusion
Authors: Garcia-Tornel Alvaro , Deck Matias , Ribo Marc , Rodriguez-Luna David , Pagola Jorge , Muchada Marian , Requena Manuel , Olive-Gadea Marta , Boned Sandra , Juega Jesus , Rodriguez-Villatoro Noelia , Piñana Carlos , Hernandez David , Tomasello Alejandro , Ciolli Ludovico , Molina Carlos A , Rubiera Marta
Published: June 2021

Introduction:
Perfusion imaging has emerged as an imaging tool to select patients with acute ischemic stroke (AIS) secondary to large vessel occlusion (LVO) for endovascular treatment (EVT). We aim to compare an automated method to assess the infarct ischemic core (IC) in Non-Contrast Computed Tomography (NCCT) with Computed Tomography Perfusion (CTP) imaging and its ability to predict functional outcome and final infarct volume (FIV).

Methods:
494 patients with anterior circulation stroke treated with EVT were included. Volumetric assessment of IC in NCCT (eA-IC) was calculated using eASPECTS™ (Brainomix, Oxford). CTP was processed using availaible software considering CTP-IC as volume of Cerebral Blood Flow (CBF) <30% comparing with the contralateral hemisphere. FIV was calculated in patients with complete recanalization using a semiautomated method with a NCCT performed 48-72 hours after EVT. Complete recanalization was considered as modified Thrombolysis In Cerebral Ischemia (mTICI) ≥2B after EVT. Good functional outcome was defined as modified Rankin score (mRs) ≤2 at 90 days. Statistical analysis was performed to assess the correlation between EA-IC and CTP-IC and its ability to predict prognosis and FIV.

Results:
Median eA-IC and CTP-IC were 16 (IQR 7-31) and 8 (IQR 0-28), respectively. 419 patients (85%) achieved complete recanalization, and their median FIV was 17.5cc (IQR 5-52). Good functional outcome was achieved in 230 patients (47%). EA-IC and CTP-IC had moderate correlation between them (r=0.52, p<0.01) and similar correlation with FIV (r=0.52 and 0.51, respectively, p<0.01). Using ROC curves, both methods had similar performance in its ability to predict good functional outcome (EA-IC AUC 0.68 p<0.01, CTP-IC AUC 0.66 p<0.01). Multivariate analysis adjusted by confounding factors showed that eA-IC and CTP-IC predicted good functional outcome (for every 10cc and >40cc, OR 1.5, IC1.3-1.8, p<0.01 and OR 1.3, IC1.1-1.5, p<0.01, respectively).

Conclusion:
Automated volumetric assessment of infarct core in NCCT has similar performance predicting prognosis and final infarct volume than CTP. Prospective studies should evaluate a NCCT-core / vessel occlusion penumbra missmatch as an alternative method to select patients for EVT.
Abstract WMP18: Global White Matter Microstructural Injury Predicts Poor Outcomes After Ischemic Stroke
Authors: Etherton Mark R , Wu Ona , Rost Natalia
Published: June 2021

Background:
Early outcome prediction after acute ischemic stroke (AIS) is critical to guide care and rehabilitation strategies. Pre-existing chronic structural injury to cerebral white matter (WM), including ischemic WM hyperintensity (WMH) and microstructural changes within the normal-appearing WM (NAWM), is known to impede post-stroke recovery. Quantitative assessment of total pre-existing WM injury may therefore improve prognostication of functional stroke outcomes. Peak width of skeletonized mean diffusivity (PSMD) is an automated marker of cerebral small vessel disease and global WM injury. In a cohort of AIS patients, we measured PSMD in the hemisphere contralateral to the acute infarct and characterized its association with 90-day functional outcomes.

Methods:
Brain MRI with diffusion tensor imaging sequences was acquired within 48 hours of AIS admission. WMH volume (WMHv) was measured in a semi-automated manner. NAWM masks were constructed by subtracting the WMH and chronic infarct masks from a probabilistic WM atlas. NAWM mean diffusivity (MD) was then measured in the NAWM mask. PSMD was extracted by skeletonizing the WM tracts in the MD image using the Fractional Anisotropy image and the FSL Tract-Based Spatial Statistics pipeline with a mask for the contralesional hemisphere. Excellent outcome was defined as a modified Rankin scale score < 2 at 3-6 months post-stroke. Logistic regression analysis was performed to evaluate predictors of excellent outcome.

Results:
In 292 AIS patients, increasing PSMD and NAWM MD, but not WMHv, were associated with decreased likelihood of excellent outcome in univariable analysis. Increasing age, admission NIHSS score, DWI volume, and female sex were also negatively associated with excellent outcome. In backward stepwise logistic regression, including all significant variables from the univariable step, increasing age (β = -0.03;
P
= 0.01), NIHSS (β = -0.1;
P
= 0.0005), DWI volume (β = -0.02;
P
= 0.0004), PSMD (β = -0.08;
P
= 0.03), and female sex (β = -0.7;
P
= 0.01) were associated with decreased likelihood of excellent outcome.

Conclusion:
In AIS patients, automated determination of contralesional PSMD, as a marker of chronic, global white matter injury, is an independent predictor of functional outcomes.
Abstract WMP20: Effect of Leukoaraiosis on Outcomes of Mechanical Thrombectomy and Proposed New Leukoaraiosis-Aspects Score
Authors: Brinjikji Waleed , Benson John , Rabinstein Alejandro A , Kallmes David F
Published: June 2021

Background and Purpose:
Leukoaraiosis is a poor prognostic marker for patients with acute ischemic stroke (AIS). This study sought to assess if severity of leukoaraiosis is associated with outcome in patients with AIS following endovascular thrombectomy, and to propose a leukoaraiosis-related modification to the ASPECTS score to improve its predictive value for good outcome.

Methods:
We analyzed consecutive patients with AIS that underwent mechanical thrombectomy for anterior circulation large vessel occlusion at our comprehensive stroke center. Leukoaraiosis burden was graded using the Fazekas scale (combined scores from two locations categorically divided into no leukoaraiosis (score = 0), mild (1-2), moderate (3-4) and severe (5-6)). The primary outcome measure was 90-day mRS. A proposed Leukoaraiosis-ASPECTS (“L-ASPECTS”) was calculated by subtracting values from the traditional ASPECT based on leukoaraiosis severity (1 point subtracted if mild, 2 if moderate, 3 if severe).

Results:
Of 174 included patients, 89 (51.2%) were female; average age was 68.0±9.1. 28 (16.1%) had no leukoaraiosis, 66 (37.9%) had mild, 62 (35.6%) had moderate, and 18 (10.3%) had severe. Leukoaraiosis severity was associated with worse 90-day mRS among all patients (p=0.0005) as well as those that were successfully revascularized (p=0.0002). A multivariate analysis confirmed that leukoaraiosis burden was associated with worse 90-day mRS among all patients (mild: p=0.006; moderate: p=0.002; severe: p=0.03), as well as those that underwent successful thrombectomies (p=0.005). Both L-ASPECTS and ASPECTS were associated with poor outcomes, but the association was stronger with L-ASPECTS (p<0.0001 and AUC=0.7 for L-ASPECTS; p=0.04 and AUC=0.59 for ASPECTS).

Conclusion:
Leukoaraiosis severity on pre-mechanical thrombectomy NCCT is associated with worse 90-day outcome in patients with AIS following endovascular recanalization, and is an independent risk factor for worse outcomes. A proposed L-ASPECTS score had stronger association with outcome than the traditional ASPECTS score.
Abstract WMP21: Machine Learning Identification of Large Vessel Occlusion (LVO) on Non-Contrast Computed Tomography (NCCT) Images
Authors: Ribó Marc , Crespo Carlos , Granés Cristina , Hernández-Pérez María , Perez de la Ossa Natalia , Laredo Carlos , Urra Xabier , Soler Juan Carlos , Soler Alexandre , Puyalto Paloma , Cuadras Patricia , Martí Cristian
Published: June 2021

Purpose:
To validate a Machine Learning algorithm able to identify LVO on NCCT.

Methods:
Patients with suspected acute stroke who underwent NCCT+CT Angiography (CTA) from two comprehensive stroke centers were included. Patients with intracranial haemorrhage were excluded. Two experienced radiologists identified the presence of LVO on CTA (NR-CTA) tagging the clot location and manually segmenting the clot. Acute ischemia and clot signs on NCCT were also depicted with assistance of the CTA clot location. With this information a deep learning system was used to create an algorithm (Deepstroke) to identify and locate the presence/absence of acute ischaemia and clot signs in NCCT. Deepstroke image output was used to train a binary classifier to determine LVO on NCCT. Cross-validation was performed in a stratified 5-fold of the data, including deep learning training. We also studied the effect on Deepstroke accuracy when adding the patients NIHSS and time from onset to the model (Deepstroke+).

Results:
The data cohort included 1354 patients, 724 (53%) with LVO by NR-CTA. The accuracy of Deepstroke to identify LVO had an AUC of 0.81 (sensitivity 0.85; specificity 0.49, PPV 0.66, NPV 0.74), and improved combined with NIHSS and time from symptom onset to AUC 0.88 (sensitivity 0.87, specificity 0.68, PPV 0.76, NPV 0.82). Deepstroke performed better on larger occlusions (Table). Among patients identified as LVO by Deepstroke+ only 19% showed no findings on NR-CTA. The agreement in LVO detection between NR-CTA and Deepstroke+ was 0.78 (Deepstroke was 0.68). Process time per patient was below 120s.

Conclusions:
In patients with suspected acute stroke, Deepstroke identified LVO in NCCT with a high correlation with radiologist readings of CTAs. Deepstroke could reduce the need to perform CTA, generate alarms and increase the efficiency of patients transfers in the acute management in stroke networks. Deepstroke accuracy will improve as more cases are added to the training set.
Abstract WMP32: Osteoprotegerin Attenuates the Growth of Intracranial Aneurysms Activating Collagen Biosynthesis and Vascular Smooth Muscle Cell Proliferation via Transforming Growth Factor-Beta1 Signaling
Authors: Miyata Takeshi , Minami Manabu , Kataoka Hiroharu , Hayashi Kosuke , Yokode Masayuki , Miyamoto Susumu
Published: June 2021

Introduction:
The pathogenesis of intracranial aneurysms (IAs) are characterized by reduced extracellular matrix and decreased number of vascular smooth muscle cells (VSMCs) in cerebral vascular walls. It is previously reported that osteoprotegerin (OPG) increase collagen content and activate VSMCs proliferation via transforming growth factor-beta1 (TGF-beta1). We investigated whether to attenuate IAs growth through the effect of OPG on collagen expression and VSMCs proliferation in IAs model rats.

Materials and Methods:
IAs were surgically induced in 7-week-old male Sprague Dawley rats. 1 week after the operation, mouse recombinant OPG at 125 μg/mL or vehicle was continuously infused into the lateral ventricle via an osmotic pump. 5 weeks after the first operation, aneurysmal size, media thickness of IAs were measured in the both groups. The expression of type-I and type-III collagen, TGF-beta1 and phosphorylated Smad2/3 in IA walls were examined by immunohistochemistry and RT-PCR. Primary cell culture of mouse VSMCs were analyzed by RT-PCR and the cell proliferation assay with SB431542 (a selective TGF-β receptor I inhibitor).

Results:
In the OPG treatment group, size and media thickness ratio of IAs were significantly smaller (control vs. OPG: 42 ± 6.5 μm vs 66 ± 6.1 μm;
P
< 0.05) and higher (control vs. OPG: 55 ± 7 % vs 34 ± 3 %;
P
< 0.05) than in the vehicle-control group. In the immunohistochemistry, collagen and phosphorylated Smad2/3 were upregulated in IA walls in the OPG group. In the RT-PCR study, OPG treatment significantly upregulated expression of collagen and TGF-beta1 genes (
P
< 0.05). In mouse VSMC cultures, OPG administration enhanced the expression of collagen and TGF-β1 genes. The cell proliferation assay revealed the OPG administration promoted VSMCs proliferation and SB431542 canceled this effect (
P
< 0.05).

Conclusions:
Our results demonstrate that OPG has a suppressive effect on IAs growth through the activation of collagen biosynthesis and VSMC proliferation via TGF-beta1 signaling in IA walls. OPG may represent a novel therapeutic target of the medical treatment for IAs.
Abstract WMP41: The Value of Arterial Spin-Labeling Imaging in the Cerebral Collateral Circulation Evaluation of Carotid Occlusive Disease; Correlation Study With Acetazolamide-Stress Single Photon Emission Computed Tomography
Authors: Kang Hyunkoo , Kim Yoone
Published: June 2021

Introduction:
We investigated the relationship between the level of cerebral collateral circulation on arterial spin-labeling (ASL) magnetic resonance imaging (MRI) and cerebrovascular reserve (CVR) on acetazolamide (ACZ)-stress single photon emission computed tomography (SPECT) brain scans in internal carotid artery (ICA) stenosis.

Methods:
This study enrolled 129 patients with severe ICA stenosis (>70%). Collateral circulation was assessed in pulsed ASL images based on the presence of arterial transit artifact (ATA) that late-arriving flow appears as serpiginous high ASL signal within cortical vessels. CVR based on rest-SPECT and ACZ-stress SPECT with Tc-99m-ECD was calculated. The ASL CBF maps were independently assessed by two neuroradiologists blinded to clinical information. The two neuroradiologists graded on two slices of ASL images corresponding to Alberta Stroke Program Early Computed Tomography Score (ASPECTS) location using a 4-point scale for ASL intensity.

Results:
With ACZ-stress SPECT, the 88/129 (68%) patients showed normal CVR and 41/129 (32%) patients showed decreased CVR. In 73/88 (82%) of the normal CVR group patients, ASL showed ATA in ipsilateral to the stenosis. In 19/41 (46%) of the decreased CVR group patients, ASL showed no evidence of ATA in ipsilateral to the stenosis. Significant positive relationship was observed between the normal CVR group and the ATA showing group in ICA stenosis patients (p = 0.001, chi-square test). The ASL-based ASPECTS scores of brain in the ipsilateral side was lower than the scores in the contralateral side to the ICA stenosis (p < 0.0001, Wilcoxon signed rank test). The ASL-based ASPECTS scores of brain ipsilateral side to the ICA stenosis was lower in the reduced CVR group than normal CVR group (p = 0.005).

Conclusion:
This study demonstrated the statistically significant positive correlation between good collaterals on ASL MRI and intact CVR in patients with ICA stenosis.
Abstract WMP50: Age-Specific Female-Male Disparities in Endovascular Thrombectomy Use for Acute Ischemic Stroke in the United States
Authors: Saber Hamidreza , Towfighi Amytis , Liebeskind David S , Saver Jeffrey L
Published: June 2021

Introduction:
Studies have suggested sex-related and age-related variations in frequency of reperfusion therapy, but have been limited by constrained geographic scope, data from before the modern thrombectomy era, and incomplete exploration of sex-related differences in discrete age ranges. We therefore analyzed sex-, age-, and sex-age interaction in the frequency of endovascular thrombectomy (EVT) for acute ischemic stroke in the US National Inpatient Sample.

Methods:
In the National Inpatient Sample , we identified all adult ischemic stroke EVT hospitalizations from 2010-2016, using
ICD-9-CM
and
ICD-10-CM
codes. Patient age was categorized as: <50y, 50-59y, 60-69y, 70-79y and ≥80ys. Rates of use of EVT were assessed standardized to the 2010 US Census population.

Results:
Among 50,573 EVT hospitalizations, 50.1% were female. The number of EVTs increased from 4091 in 2010 to 12,875 in 2016. Over the entire 7y time period, a sex-age interaction was noted: 49% in <50y; 37% in 50-59y; 35% in 60-69y; 53% in 70-79y; and 66% in ≥80y. This sex-age interaction was present as well for EVT rates per 100,000 individuals in the population, with the total ratio of female to male rate of EVT per 100,000: 0.93 for in <50y; 0.52 in 50-59y; 0.58 in 60-69y; 0.91 in 70-79y; and 1.1 in ≥80y. EVT utilization rates increased substantially over time in both men and women in all age groups. However, the ratio of women to men per 100,000 receiving EVT changed for only one age range, decreasing among <50y from 0.98 in 2010 to 0.79 in 2016 (P<0.05).

Conclusion:
While half of all endovascular thrombectomies in the US are performed in women, there are major age-related sex-specific variations in EVT rates, with rates of EVT much lower among women than men in 50-70 age group. Determinants of these age-specific female-male disparities in EVT treatment merit detailed investigation.

Figure:
Age- and sex-specific female to male thrombectomy utilization rates.
Abstract WMP60: Temporal Trends in Incidence, Prevalence and Epidemiological Characteristics of Cerebral Venous Thrombosis in the United States
Authors: Otite Fadar , Patel Smit , Sharma Richa , Khandwala Pushti , Desai Devashish , Latorre Julius , Izzy Saef , Akano Emmanuel , Anikpezie Nnabuchi , Malik Amer , Khandelwal Priyank , Yavagal Dileep , Chaturvedi Seemant
Published: June 2021

Background:
The primary aim of this study is to describe current trends in racial-, age- and sex-specific incidence, clinical characteristics and burden of cerebral venous thrombosis (CVT) in the United States (US).

Methods:
Validated International Classification of Disease codes were used to identify all adult new cases of CVT (n=5,567) in the State Inpatients Database of New York and Florida (2006-2016) and all cases of CVT in the entire US from the National Inpatient Sample 2005-2016 (weighted n=57,315). Incident CVT counts were combined with annual US Census data to compute age and sex-specific incidence of CVT. Joinpoint regression was used to evaluate trends in incidence over time.

Results:
From 2005-2016, 0.47%-0.80% of all strokes in the US were CVTs but this proportion increased by 70.4% over time. Of all CVTs over this period, 66.7% were in females but this proportion declined over time (p<0.001). Pregnancy/puerperium (27.4%) and cancer (11.8%) were the most common risk factors in women, while cancer (19.5%) and central nervous trauma (11.3) were the most common in men. Whereas the prevalence of pregnancy/puerperium declined significantly over time in women, that of cancer, inflammatory conditions and trauma increased over time in both sexes. Annual age and sex-standardized incidence of CVT in cases/million population ranged from 13.9-20.2, but incidence varied significantly by sex (women: 20.3-26.9; men 6.8-16.8) and by age/sex (women 18-44yo: 24.0-32.6%; men: 18-44yo: 5.3-12.8). Age and sex-standardized incidence also differed by race (Blacks:18.6-27.2; whites: 14.3-18.5; Asians: 5.1-13.8). On joinpoint regression, incidence increased across 2006-2016 but most of this increase was driven by increase in all age groups of men (combined annualized percentage change (APC) 9.2%, p-value <0.001), women 45-64 yo (APC 7.8%, p-value <0.001) and women ≥65 yo (APC 7.4%, p-value <0.001). Incidence in women 18-44 yo remained unchanged over time .

Conclusion:
The epidemiological characteristics of CVT patients in the US is changing. Incidence increased significantly over the last decade. Further studies are needed to determine whether this increase represents a true increase from changing risk factors or artefactual increase from improved detection.
Abstract WMP62: High Linfocytes B Cells In Intracranial Thrombi Represent A Biomarker Of Atherothrombotic Stroke
Authors: Juega Jesus , Pagola Jorge , Palacio Carlos , David Rodriguez-Luna , Alvaro Garcia-Tornel , Manuel Requena , Noelia Rodriguez-Villatoro , Matias Deck , Olive Marta , Sanjuan Estela , Muchada Marian , boned sandra , Rubiera Marta , Ribo Marc , Piñana Carlos , Hernandez David , Camacho Jessica , Cardona Pedro , Quesada Helena , Laura Dorado , Hernandez Maria , De la Torre Carolina , Jose alvarez , tomasello Alejandro , Ramon y Cajal Santiago , Molina Carlos
Published: June 2021

Approximately 30% of strokes are cryptogenic despite an exhaustive in-hospital work-up Analysis of clot composition following endovascular treatment could provide insight into stroke etiology.

Objective:
To evaluate different population of lymphocytes in the clot analyses obtained in the hyper acute phase of stroke, as an early marker of etiology of ischemic stroke.

Material and Methods:
Consecutively, intracranial clots were obtained in the hyper acute phase of stroke in endovascular treatment with solitaire device and analyzed by flow cytometry quantifying the relative proportion ( RP ) of main leukocyte, monocyte, granulocyte and total lymphocyte populations and lymphocyte sub populations of B line (CD19), T line (CD3, CD4, CD8), Cytotoxic and Natural Killer. The results were expressed as percentages (%). All patients included were studied with complete diagnostic work up that included at least complete arteriography , aortic Angio CT , complete cardiac holter monitoring until one month form hospital discharge and transthoracic echocardiography , The etiology of stroke was categorized: cardiomebolic ( major structural heart disease and Atrial Fibrillation) atherosclerotic ( AT) (severe symptomatic arterial stenosis or complicated aortic atheromatosis ulceration confirmed by trans esophageal echocardiography ) ,infrequent causes or unknown etiology .

Results:
80 patients were included. 22, 5% AT (n = 18) strokes were associated with higher RP lymphocytes PR (16.55 % vs. 5. 37 % p < 0,001), CD4 RP (5.74% vs. 2.03 % p = 0.001) and RP CD 19 (2.26 % vs. 0.37 % p< 0,001) in clot cytometry Analysis than rest of of strokes etiologies (n= 72). Multivariate logistic regression analysis showed that RP CD 19 (OR 3.51; 95% CI, 1, 81-6.81) was an independent predictor of atherosclerotic stroke .The ROC curve showed AUC (0.83) (95% CI, 0.72-0.95) for RP CD 19 for diagnosis of atherosclerotic strokes with flow cytometry of the clot ,obtained in emergent endovascular treatment.

Conclusion:
High expression of lymphocytes B in intracranial thrombi is a marker of atherosclerotic etiology.
Abstract WMP65: Prospective Validation of Predictive Features of Paroxysmal Atrial Fibrillation (PROPhecy): An Interim Analysis
Authors: Field Thalia S , Kuzmuk Leah , King-Azote Princess , Yip Samuel , Andrade Jason
Published: June 2021

Background:
Atrial fibrillation (AF) has a distinct antithrombotic regimen for secondary stroke prevention. While 30-day cardiac monitoring has a greater detection rate for AF than 24-hour Holter, it is not widely accessible. Risk stratification may identify patients who could benefit most from prolonged monitoring. PROPhecy aims to prospectively validate predictive features for detection of AF found in EMBRACE, a trial using 30-day monitoring in individuals with an embolic stroke of undetermined source (ESUS).

Methods:
Participants were
>
55 years and within six months of ESUS, without evidence of AF/flutter on 24-hour Holter. All were given an event-triggered external loop recorder for 30 days. Primary outcome was detection of sustained (
>
30 sec) or non-sustained AF/flutter on 30-day monitoring.

Results:
150 of a planned 250 participants have completed long-term monitoring to date. Baseline characteristics are compared to EMBRACE (Table 1). Any AF/flutter was detected in 19.3% (EMBRACE, 16.1%). Burden of atrial premature beats in PROPhecy was low in comparison to EMBRACE and did not predict presence of AF on monitoring (Table 2). Left atrial volume index was a significant predictor of AF in both univariable and multivariable regression adjusted for age and sex (OR1.04 per mL/m
2
, 95% 1.01-1.08, p=0.02).

Conclusion:
Recruitment is ongoing. AF was detected in ~1/5 participants. The burden of atrial ectopy in our cohort is much lower than in EMBRACE despite similar patient characteristics and AF burden. Further work is required to assess the nature of these differences. Left atrial volume index may be helpful for risk stratification.
Abstract WMP70: Increased Left Atrial Appendage Density on Computerized Tomography is Associated With Cardioembolic Stroke
Authors: Chang Andrew D , Ignacio Gian , Akiki Ronald , Mac Grory Brian , Cutting Shawna S , Burton Tina , Jayaraman Mahesh , Merkler Alexander , Song Christopher , Poppas Athena , Kamel Hooman , Elkind Mitchell S , Furie Karen , Yaghi Shadi
Published: June 2021

Background and Purpose:
While studies have stratified cardioembolic (CE) stroke risk by qualitative left atrial appendage (LAA) morphology and biomarkers of atrial dysfunction, the quantitative properties that underlie these observations are not well established. Accordingly, we hypothesized that LAA volume and contrast density (attenuation) on computerized tomography (CT) may capture the structural and hemodynamic processes that underlie CE stroke risk.

Methods:
Data were collected from a single center prospective ischemic stroke database over 18 months and included all patients with ischemic stroke who previously underwent routine, non-gated, contrast enhanced thin-slice (≤2.5 mm) chest CT. Stroke subtype was determined based on the inpatient diagnostic evaluation. LAA volume and attenuation were determined from CT studies performed for various clinically appropriate indications. Univariate and multivariable analyses were performed to determine factors associated with ischemic stroke subtype, including known risk factors and biomarkers, as well as LAA density and morphologic measures.

Results:
We identified 311 patients with a qualifying chest CT (119 CE subtype, 109 ESUS, and 83 non-CE). In unadjusted models, there was an association between CE (vs. non-CE) stroke subtype and LAA volume (OR per mL increase 1.15, 95% CI 1.07-1.24, p<0.001) and LAA density (4
th
quartile vs. 1
st
quartile; OR 2.95, 95% CI 1.28-6.80, p=0.011), but not with ESUS (vs. non-CE) subtype. In adjusted models, only the association between LAA density and CE stroke subtype persisted (adjusted OR 3.71, 95% CI 1.37-10.08, p=0.010).

Conclusion:
The LAA volume and density values on chest CT are associated with CE stroke subtype but not ESUS subtype. Patients with ESUS and increased LAA volume or attenuation may be a subgroup where the mechanism is cardioembolic and anticoagulation can be tested for secondary stroke prevention.