bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WMP33: Cognitive Outcomes In Patients With A Prior History Of Stroke Participating In Inpatient Rehabilitation
Authors: Contreras Gloria M , Silos Christin , Aggarwal Seema , Hernandez Anna , Savitz Sean I
Published: February 2023

Introduction:
We sought to investigate the impact of prior stroke on cognitive improvement in stroke patients participating in inpatient rehabilitation.

Methods:
This was a retrospective review of clinical data from inpatient stroke rehabilitation (ISR) units collected from 09/2017- 08/2019. Age at onset, stroke type (ischemic or intracerebral hemorrhage (ICH)), therapy days, sex, and past medical history of stroke, diabetes, hypertension (HTN) were extracted as predictors of outcome in ISR. The baseline level of disability upon admission to acute stroke care was accounted for with pre-morbid modified Rankin scale (mRS) score and initial NIH Stroke Scale (NIHSS). The outcome variable of interest was total discharge cognitive functional independence measure (TDC-FIM) from ISR. FIM admission to ISR was controlled for in the model.

Results:
The data of 681 patients were used in a Lasso regression analysis (Figure 1), and of these patients there were 202 patients with a history of prior stroke. Univariate analysis showed a significant difference between prior stroke and first-time stroke groups with respect to pre-morbid mRS (p<0.001), initial NIHSS (p = 0.003), HTN (p=0.004), and stroke type (p=0.023). Lasso regression indicated that patients with diabetes had a 0.58 point decrease in TDC-FIM while those with HTN had a 0.38 point decrease as compared to patients who did not have these vascular risk factors. Patients with ischemic stroke type had a 0.73 point decrease in the TDC-FIM as compared to those who had an ICH. Prior stroke and the patient’s sex had no effect on TDC-FIM. The R-squared of the model was 0.74.

Conclusion:
By controlling for vascular risk factors, our findings show no difference in TDC-FIM with respect to prior stroke. This is different from prior studies that found prior stroke was associated with worse cognitive outcomes at discharge from ISR. Our results indicate that managing HTN and diabetes is imperative for post-stroke cognitive rehabilitation
Abstract WMP50: Lesion-symptom Mapping For Post-stroke Depression
Authors: Sokola Maria , Thoomukuntla Bhaskar , Lapin Brittany , Nakamura Kunio , Jones Stephen , Katzan Irene , Man Shumei
Published: February 2023

Background:
Post-stroke depression poses an important challenge for patients and delays reintegration to societal roles. Earlier identification of patients at higher risk for depression based on clinical imaging would allow a tailored treatment approach.

Methods:
We conducted machine-learning based lesion-symptom mapping (LSM) using a retrospective cohort of 477 patients with first-ever acute ischemic stroke (AIS) presenting to a large cerebrovascular center from 2013-2019 with mild motor impairment defined by mRS 0-2. Patient Health Questionnaire (PHQ-9) depression scale was collected within 60 days of index stroke. The location and volume of AIS lesions on brain MRI were analyzed using a machine-learning based algorithm coupled with the FreeSurfer parcellation package. LSM after random field theory-based multiple comparison correction was conducted to examine the association of AIS location and volume with PHQ-9 scale, adjusting for patient age, sex and NIHSS.

Results:
AIS in the right temporal, parietal, occipital lobes and the right basal ganglia were associated with depressive symptoms (Figure A). Sensitivity analysis excluding those with significant sleep disturbance (n=24) demonstrated that strokes in the right frontal and parietal lobes were associated with severe depression measured by PHQ-9>10 (Figure B).

Conclusions:
This hypothesis generating study was suggestive of a neuroanatomic basis for the development of post-stroke depression. Further studies in a larger dataset are needed to confirm these associations. The methods will help to predict those patients at higher risk for post-stroke depression, allowing for earlier intervention and recovery.
Abstract WMP54: Hyperemia Following Endovascular Therapy For Acute Stroke Is Associated With Ischemic Lesion Growth
Authors: Luby Marie L , Hsia Amie W , Lomahan Carolyn A , Davis Rachel , Burton Shannon P , Kim Yongwoo , Craft Veronica , Uche Victoria , Cabatbat Rainier Michael , Adil Malik , Thomas Leila , De Vis Jill B , Afzal Mariam , McGavern Dorian , Lynch John K , Leigh Richard , Latour Lawrence
Published: February 2023

Introduction:
A substantial proportion of acute stroke patients experience poor outcomes following successful endovascular therapy (EVT) and reperfusion injury to the brain and vasculature may be a contributor. The purpose of this pilot study was to characterize hyperemia following recanalization and test the association of hyperemia with evolution of the ischemic lesion.

Methods:
Acute stroke patients were included with: i) large vessel occlusion of the anterior circulation, ii) successful recanalization, and iii) evaluable MRI early after EVT. Presence of hyperemia on MRI perfusion was assessed by consensus using a modified ASPECTS. Three different approaches were used to quantify relative cerebral blood flow (rCBF) on early post-EVT, 24 hours, and 5 days. Two independent trained readers measured lesion volumes using a semi-automated validated approach.

Results:
Sixty-seven patients with median age of 66 [59-76], 57% female, met inclusion criteria. Hyperemia was present in 35/67 (52%) patients early post-EVT (Figure), in 32/65 (49%) patients at 24 hours, and in 19/48 (40%) patients at 5 days. In comparison to control regions, rCBF was elevated by greater than 50% in hyperemic regions. Patients with hyperemia had larger ischemic lesion volumes and early lesion growth. A strong association (R2=0.81, p<0.001) was found between early post-EVT hyperemia (p=0.027) and lesion growth based on DWI volume at 24 hours, after adjusting for DWI volume at 2 hours (p<0.001) and incomplete reperfusion at 24 hours (p=0.001).

Conclusions:
Hyperemia is frequently observed after successful EVT and is associated with lesion growth at 24 hours. Evidence of hyperemia may identify patients that may benefit from adjunctive therapy to prevent reperfusion injury, edema, and lesion growth.
Abstract WMP57: Brain Frailty Mediates The Relationship Between Age And 90-day Functional Outcome After Endovascular Therapy: Analysis Of The Escape-na1 Trial
Authors: Benali Faysal , Singh Nishita , Fladt Joachim , Tanaporn Jaroenngarmsamer , Bala Fouzi , Tymianski Michael , Hill Michael D , Goyal Mayank , Ganesh Aravind
Published: February 2023

Introduction:
Age is a predictor of functional outcome after acute ischemic stroke (AIS). Frailty increases with age and comorbidities, and imaging markers of brain-frailty (e.g. atrophy, small-vessel-disease) are associated with outcomes. However, the extent to which the association of age and 90-day outcome is mediated by brain-frailty is unknown. We explored this mediation in AIS patients receiving endovascular therapy (EVT), with a particular interest in neuroimaging.

Methods:
In this post-hoc analysis of the ESCAPE-NA1 trial, in which all patients underwent EVT, we assessed brain atrophy (subcortical/cortical), white-matter disease (periventricular/deep) and the number of lacunes and chronic infarctions. Structural equation modelling (SEM) was used to create 3 latent variables: “imaging-frailty” (above-mentioned markers), “clinical-frailty” (e.g. pre-stroke mRS, cardiovascular risk factors, cancer) and “total-frailty” (imaging + clinical markers). We created 3 models (
figure1)
including each latent variable as a potential mediator of the association of age and 90-day outcome, adjusting for baseline ASPECTS, NIHSS, onset-to-puncture-time, nerinetide and alteplase.

Results:
Among 1,092 patients, the indirect effect of age on 90-day outcome, mediated by imaging-frailty, contributed 96% of the total effect(β=0.047;p=0.02), while the indirect effect through clinical-frailty accounted for only 21%(β=0.01;p=0.001) of the total effect. When including both frailty constructs, the indirect pathway accounted for 86% of the total effect(β=0.06;p<0.01). These proportions were similar when imaging features were assessed on MRI.

Conclusions:
Brian frailty mediates the association of age and 90-day outcome after EVT, with most of the effect mediated by imaging as opposed to clinical markers of frailty. This work underscores the importance of considering brain-frailty, as opposed to chronological age alone, in predicting post-stroke outcomes.
Abstract WMP58: Scaling Behaviors Of Deep Learning And Linear Algorithms For The Prediction Of Stroke Severity
Authors: Bourached Anthony P , Bonkhoff Anna K , Schirmer Markus D , Regenhardt Robert W , Hong Sungmin , Bretzner Martin , Wu Ona , Jern Christina , Lindgren Arne G , Maguire Jane , Rhee John , Kimchi Eyal , Rost Natalia S
Published: February 2023

Introduction:
Deep learning (DL) has allowed for substantial progress in many, often machine vision-focused medical scenarios. Since DL models typically require 10
5
-10
7
examples, it is currently unknown whether DL can also enhance predictions of outcomes post-stroke in real-world samples of stroke patients that are several magnitudes smaller. We here compared the capacities of linear and DL algorithms regarding their prediction of stroke severity.

Methods:
Our analyses relied on a total of 1435 patients assembled from the MRI-GENIE study and a Massachusetts General Hospital-based study. The primary outcome was acute NIHSS-based stroke severity, which we predicted by means of lesion location. We automatically derived lesion segmentations from DWI scans, performed spatial normalization and principal component analysis (PCA), retaining 95% of the variance of the original data. We then separated a train, validation, and test set, of sizes 918, 230, and 287 respectively. We downsampled the train set to 100, 300, and 900 and learned to predict the NIHSS score for each sample size with regularized linear regression and an 8-layered neural network. We selected hyperparameters on the validation set and conducted 500 dataset splits. We here report explained variance (R-squared) in the test set.

Results:
While linear regression performed favorably for a sample size of 100 patients (R-squared=0.28), DL started to significantly outperform linear regression when trained on 900 patients (R-squared=0.34,
Figure 1
). Average prediction performance improved by ~20% when increasing the sample size 9x.

Conclusions:
For sample sizes of ~1000 patients, DL showed a more convincing prediction performance for stroke severity than typically employed linear methods. Our findings suggest the existence of non-linear relationships between lesion location and outcome post-stroke that can be utilized for an improved prediction performance once samples are reasonably large.
Abstract WMP60: Eliminating False Positive Detections Of Intracranial Hemorrhage (ICH) Using RAPID ICH 3
Authors: Sreekrishnan Anirudh , Giurgiutiu Dan-Victor , Kitamura Felipe , Martinelli Carlos , Haerian Hafez , Dehkharghani Seena , Heit Jeremy J
Published: February 2023

Introduction:
Prompt detection of intracranial hemorrhage (ICH) on a non-contrast head CT (NCCT) is critical to initial patient triage. Several ICH detection and notification programs now exist, but none presently generate locations or segmentations of suspected ICH, and false-positive notifications are not easily identified. We investigated an enhanced ICH detection tool with heightened immunity to false-positive diagnosis.

Methods:
NCCT scans from 3 large databases were evaluated for the presence of an ICH (IPH, IVH, SAH or SDH) of >0.4 ml by the automated RAPID ICH 3.0 software module and compared to a consensus detection from 3 neuroradiology experts. Scans were excluded for (1) severe CT acquisition artifacts, (2) prior neurosurgical procedures or (3) intravenous contrast administration. ICH detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by RAPID ICH 3 were determined.

Results:
A total of 790 studies were included. RAPID ICH 3.0 correctly identified 399/411 ICH-positive cases and 378/379 ICH-negative cases, resulting in a sensitivity of 98.08% and specificity 99.74%, positive predictive value 99.75%, and negative predictive value 96.92% for ICH detection. The positive and negative likelihood ratios for ICH detection were similarly favorable at 367.93 and 0.03 respectively. Mean processing time was <40 seconds.

Conclusions:
In this large data set of nearly 800 patients, the RAPID ICH 3.0 automated software maintained a high sensitivity for detection of ICH, while essentially eliminating false positive identifications, leading to very high positive predictive value.
Abstract WMP61: Vulnerable And Stabilized States After Cerebral Ischemic Events: Implications Of Kinetic Modeling In The POINT, SOCRATES, And THALES Trials
Authors: Brorson James R , Prabhakaran Shyam , Johnston S Claiborne , Giurcanu Mihai
Published: February 2023

Background:
Trials of acute secondary prevention following initial minor stroke or TIA, such as POINT, SOCRATES, and THALES, demonstrate a high rate of initial recurrence of ischemic stroke, quickly dropping to a sustained lower rate. For the POINT trial, this was shown to support a two-state kinetic model, in which after the index event subjects are initially in a vulnerable state, with a high rate of stroke recurrence, and then transition to a stabilized state at lower risk for stroke recurrence. This allows for estimation of the distinct kinetic rates characterizing these events. We aimed to extend such a kinetic analysis to the SOCRATES and THALES trials, and to compare estimates of kinetic rates across these trials.

Methods:
Kaplan-Meier estimates of survival curves in POINT, THALES, and SOCRATES trials were constructed and fitted by a non-linear two-state model, producing estimates of kinetic parameters, using nonparametric bootstrap with repetitive resampling to estimate standard errors.

Results:
The two-state model closely fit survival curves in all the trials, with similar kinetic parameters across trials. Estimated kinetic rates for stroke recurrence in the vulnerable state were about 100-fold higher than rates in the stabilized state for subjects in the control groups. The transition rates from the vulnerable to stabilized state were still more rapid. Active treatment groups showed similar kinetics, with reduced rates of stroke in the vulnerable state.

Conclusion:
Across multiple trials of acute secondary stroke prevention following minor stroke or TIA, in both control and active treatment groups, recurrence of stroke is well-described by a two-state kinetic model postulating separate vulnerable and stabilized states. The distinct kinetic states may be revealing distinct pathobiologies with implications about differential impact of therapies delivered immediately or in a delayed fashion.
Abstract WMP63: Race/ethnicity And Ischemic Stroke Severity In The United States
Authors: de Havenon Adam , Skolarus Lesli , Johnston Karen C , Sharma Richa , Bangad Aaron , Abbasi Mehdi , Wong Ka-Ho , Yaghi Shadi , Sheth Kevin N
Published: February 2023

Background:
Although prior research has investigated the association of race/ethnicity with stroke severity, the cohorts were not nationally representative or stroke severity was put into categories (i.e, mild to severe).

Methods:
We performed an analysis of adult hospital discharges in the National Inpatient Sample 2016-2019 with a primary diagnosis of ischemic stroke (I63*) and an admission NIH Stroke Scale (NIHSS). We treat NIHSS as an interval variable because the 43 levels (0-42) approximate an interval variable and prior simulations have demonstrated that it does not inflate the type I error. We fit linear regression models to NIHSS with the predictor or self-reported race/ethnicity (White, Black, Hispanic, other). Model 1 is unadjusted, model 2 is adjusted for age and sex, model 3 is further adjusted for atrial fibrillation, diabetes, congestive heart failure, and hypertension, and model 4 is further adjusted for income quartile by zip code and primary payor.

Results:
We included 138,680 stroke discharges with a mean NIHSS of 6.7±7.3. The cohort was 68.8% White, 17.2% Black, 8.0% Hispanic, and 6.0% other. In unadjusted analysis, White discharges have a significantly lower NIHSS than other race/ethnicity (Figure 1). After sequential adjustments, Black discharges consistently have the most severe stroke severity, which is ~1 NIHSS point higher than White discharges (p<0.001, Figure 1), although the difference is similar for Hispanic and other discharges.

Conclusion:
In a large, contemporary, and nationally representative sample of acute ischemic stroke patients, we show an association between non-White race/ethnicity and higher stroke severity. These results require further validation, but are concerning for a potentially underappreciated health disparity in ischemic stroke.
Abstract WMP78: Predictors Of Memory And Carotid Intervention-related Memory Changes
Authors: Succar Bahaa , Chou Ying-hui , Hsu Chiu-hsieh , Rapcsak Steven , Trouard Theodore , Zhou Wei
Published: February 2023

Introduction:
Carotid atherosclerosis is the culprit of stroke and dementia. It has been linked to cognitive impairment in cerebrovascular diseases . A bulk of evidence suggests that carotid interventions improve cognitive functions in appropriately selected patients. We aim to investigate the factors that modulate changes in episodic memory following carotid recanalization procedures.

Methods:
A total of 170 subjects undergoing carotid revascularization procedures were recruited prospectively. Neuropsychometric testing was performed preoperatively, and at 1-,6-, and 12-month postoperatively. Rey Auditory Verbal Learning Test (RAVLT) was used to assess episodic memory. Changes in RAVLT sum scores at individual time points were compared to the baseline. Linear and logistic regression models were fitted to predict RAVLT sum baseline score, and postop changes at each time point compared to preop, respectively. Univariate and multivariate analyses (after adjusting for risk factors and patient demographics) were performed and variables with p <0.25 were included in the multivariable analysis.

Results:
At baseline, having a prior stroke, and being older than 80 years of age were independent predictors of a low preop RAVLT sum score (p=0.001 and p=0.001 respectively). Interestingly, a low preop RAVLT sum score is the only independent predictor of post-intervention cognitive improvement at all three time points compared to preop (P<0.01). CEA and Age <80 years predicted short-term improvement at 1 and 6 months postop. Conversely, carotid artery stenting (CAS) is an independent predictor of verbal memory decline at 1-month post-intervention (p=0.039), while being older than 80 years of age predicted the decline at 1-month (p= 0.046) and 6-month (p= 0.043) postoperatively.

Conclusion:
Younger patients with severe atherosclerotic carotid disease and low baseline episodic memory scores benefit most from carotid intervention, specifically CEA, whereas age ≥80 years predicts poor baseline memory score and worse intervention-related memory change. Further studies with larger sample sizes are necessary to confirm the characteristics of patients with carotid occlusive disease who could benefit from revascularization procedures.
Abstract WMP85: Mobile Stroke Unit: Direct To Angio Or Some Stops Along The Way?
Authors: Martucci Maria , Toth Gabor , Buletko Andrew , KHAWAJA Zeshaun , Russman Andrew N , Hussain Muhammad S
Published: February 2023

Introduction:
Reducing the time from last known well to recanalization are associated with better functional outcomes and lower mortality in ischemic stroke. Recent data suggests that a “direct to angio” approach might improve the outcome of stroke patients with suspected emergent large vessel occlusion (ELVO). In this study, we aim to describe our direct-to-angiography vs those taken for additional imaging-first experience in our mobile stroke unit (MSU).

Methods:
Retrospective chart review from 2014 until 2022 was done. Patients with acute ischemic stroke due to ELVO arriving via MSU to our tertiary care comprehensive stroke center were included. We compared outcomes of those who went directly to the angiography suite versus those who underwent additional imaging studies first.

Results:
14 patients with ELVO went directly to angio (DTA group) compared to 52 patients who underwent additional imaging (CTA group). There were no differences in age, gender, pre-morbid vascular risk factors or presenting symptoms. The DTA group had a higher median initial NIHSS and a higher interquartile range when compared to the CTA group but not significant. The DTA group received more thrombolytic therapy compared to the CTA group (p = 0.03). The DTA group had better door-to-groin times (median 39 minutes) compared to the CTA group (median 51.5 minutes) (p = 0.02). TICI 0 - 2a was more frequently seen in the DTA group (35.7%) compared to the CTA group (9.6%) (p = 0.03). Mortality was significantly higher in the DTA group compared to the CTA group (35% vs. 9%; p = 0.028) but there was no difference in functional outcomes amongst groups (mRS 0 - 2 28% vs 17%; p = 0.45). There was a non-significantly higher incidence of tandem occlusions in the DTA group (28.5%) compared to the CTA group (28.5% vs. 15%; p = 0.43).

Conclusions:
In our analysis, those going direct to angiography from the MSU had less successful recanalization and increased mortality. These findings could also be related to the higher rate of tandem occlusions in the DTA group. Due to head only scanning being available on MSU, additional information from in-hospital scanning may offer other information which may influence selection of patients for the procedure. Further analysis of these paradigms, particularly on MSUs, are warranted.
Abstract WMP86: Risk Of Hemorrhagic Transformation Is Related To Severity Of Hba1c Elevation In Patients Undergoing Mechanical Thrombectomy
Authors: Baker David , Hussain Muhammad , Toth Gabor
Published: February 2023

Introduction:
While prior studies have demonstrated hyperglycemia as an independent predictor of hemorrhagic transformation and poor clinical outcome following Mechanical Thrombectomy (MT), it is less clear to what extent HbA1c impacts these relationships. The objective of this study was to assess the association between severity of poor glycemic control, functional independence and hemorrhagic transformation.

Methods:
A retrospective analysis was performed on patients who underwent MT for large vessel occlusion (LVO) at a single comprehensive stroke center between January 2016 and January 2022. Primary safety and efficacy outcomes included the presence of hemorrhagic transformation and good 90-day functional outcome defined as modified Rankin scale (mRS) of 0-2. Good glycemic control was described as HbA1c <6.4 mg/dl. Fisher’s Exact Probability Test was used to compare cohorts to those with good glycemic control and calculate odds ratios for given outcomes.

Results:
657 patients were included in the analysis. Among these, the observed HbA1c value was <6.5 (n=535), 6.5-8.0 (n=72), or >8.0 (n=50). There were no significant differences between cohorts in terms of age, gender, ethnicity, initial NIH stroke scale, level of occlusion, or medical comorbidities. Patients with HbA1c ≥6.5 had a 17.0% lower incidence of good functional outcome vs those with good glycemic control (OR 0.47, CI: 0.32-0.88). An HbA1c threshold of ≥6.5 did not correlate with significant differences in HT incidence (OR 1.08, CI: 0.76-1.79). However, patients with HbA1c > 8.0 had a 14.8% higher incidence of HT vs those with good glycemic control (OR 1.81, CI: 1.15-4.35).

Conclusions:
While suboptimal glucose control and diabetes (HbA1c ≥6.5) is associated with worse outcomes following MT for acute ischemic stroke, its effect on hemorrhagic transformation risk was only seen in those with poor glycemic control (HbA1c >8.0) in our single center analysis.
Abstract WMP87: Primary Results From The CLEAR Study Of The Safety And Effectiveness Of The Neva Stent Retriever For Large Vessel Thrombectomy
Authors: Yoo Albert J , Geyik Serdar , Froehler Michael , Maurer Christoph , Kass-Hout Tareq , Zaidat Osama , Nogueira Raul G , Hanel Ricardo , Pierot Laurent , Spelle Laurent , Lopes Demetrius , Hassan Ameer E , Sirvinskas Audrius , Lin Eugene , Ribo Marc , Blasco Jordi , Taqi Muhammad , Badruddin Aamir , Siddiqui Adnan H , Miller Timothy R , Hussain Muhammad , Haussen Diogo C , Woodward Keith , Groden Christoph , Consoli Arturo , Chaudry Imran , Ramsey Christian , Maud Alberto , Bentley Joshua , Brinjikji Waleed , Bajrami Arsida , Sahnoun Maher , Fiehler Jens , Gupta Rishi
Published: February 2023

Despite the proven benefit of stent retrievers, challenges to rapid revascularization of large vessel occlusions (LVO) persist. Current stent retrievers have limited effectiveness for removing organized thrombi. The NeVa device is a novel stent retriever designed with openings in the basket cell structure (“drop zones”) intended to capture organized thrombi within the central scaffold during retrieval. Prospective, multicenter, open label, single arm, FDA-regulated IDE study to evaluate the performance of the NeVa device for recanalizing occluded intracranial vessels including ICA, M1/M2 MCA, and vertebrobasilar arteries, within 8 hours of onset. Primary endpoint was rate of eTICI 2b-3 within 3 NeVa passes, tested for non-inferiority against a performance goal of 72% with a margin of -10%. Additional efficacy endpoints included first pass effect to eTICI 2b-3 (FPE) and 90-day mRS 0-2. Primary safety endpoint was 90-day mortality. (ClinicalTrials.gov NCT04514562) (Site-adjudicated revascularization results are reported here. Final core lab results will be presented at the conference.) From April 1, 2021 to April 28, 2022, 139 subjects were enrolled at 25 centers in the US and Europe. Mean age was 67 ± 13 years; 47% were female. Median NIHSS score was 16 (IQR: 12-20). Occlusions were 14 (10%) ICA, 85 (61%) M1, 38 (27%) M2, 1 (1%) Basilar and 1 (1%) PCA. Mean time to first pass was 19 ± 12 minutes. eTICI 2b-3 within 3 NeVa passes occurred in 87.8% (122/139; CI 81.1%,92.7%; non-inferiority p<0.0001; post hoc superiority p=0.002, tested against performance goal of 72%). FPE (to eTICI 2b-3) was observed in 67.6% (94/139), with first pass to eTICI 2b67-3 in 61.2% (85/139) and to eTICI 2c-3 in 43.9% (61/139). Median number of passes was 1 (IQR 1-2). Final eTICI 2b-3 rate was 94.2% (131/139); final eTICI 2c-3 rate was 65.5% (91/139). Good outcome (90-day mRS 0-2) was seen in 62.6% (87/139) and was 74.4% in patients with FPE (70/94 vs. 17/45 (37.8%) without FPE; p<0.0001). Mortality was 9.4% (13/139) with sICH in 8 (5.8%) subjects. The NeVa device is effective and safe for revascularization of LVO strokes and demonstrates high first pass success in this international multicenter study. First pass reperfusion (eTICI 2b-3) was strongly associated with functional independence.
Abstract WMP9: Favorable Mechanical Thrombectomy Outcomes From The Latin American Stroke Registry (lase) And Resilient Trial Compared To A 90-day Functional And Mortality Predictive Model.
Authors: Torrealba-Acosta Gabriel , Barboza Miguel A , Arauz Antonio , Amaya Pablo F , Ameriso Sebastian F , Cano Vanessa , Flores Alan F , Lavados Pablo M , Pujol Lereis Virginia A , Serrano Fabiola , Kent Thomas A , Mandava Pitchaiah
Published: February 2023

Introduction:
Except for RESILIENT, there is a paucity of randomized controlled trials (RCTs) for stroke from Latin America (LA), home to growing stroke burden. Comparison between stroke population typically suffers from baseline factor imbalances. Here, we developed outcome models from RCTs to compare Latin American Stroke Registry (LASE) with similar baselines.

Methods:
LASE is a registry of patients receiving tPA and thrombectomy from 17 centers in 9 countries. A systematic review identified RCTs that provided median NIHSS, mean age, percentage of patients receiving tPA, time-to-randomization, 90d mRS0-2, and mortality. Akaike Information Criterion (AIC), an information theory construct, was used to select the best model amongst 15 combinations of 4 variables. 90d outcomes of LASE and RESILIENT were compared at the baseline values against the selected model.

Results:
34 RCTs with ~8300 subjects were identified. Models based on NIHSS and the percentage of tPA were considered the most optimum in terms of AIC. In the 3D models (Fig1), the middle surface defines the function and the bounding surfaces the ±90% intervals. The LASE registry has 950 patients that received tPA alone, 127 that received tPA & mechanical thrombectomy (MT), and 101 that received MT alone. LASE & RESILIENT outcomes were plotted onto the models at their baseline values. LASE tPA alone group was on the middle surface for mRS 0-2 (Fig1-A), indicating that outcomes were in line with the RCT-informed model. MT alone (0% tPA) and MT + tPA (100%), and the RESILIENT MT arm (68.5% tPA) were above the +90% surface, indicating superior efficacy compared to no-MT. The RESILIENT control arm (71.8% tPA) had > expected mortality, suggesting harm, while mortality of all other arms was within the ±90% intervals (Fig1-B).

Conclusion:
Functional outcomes and mortality of patients from the LASE that received MT and MT+tPA compared favorably to a 90-day functional and mortality predictive model.
Abstract WMP92: Presentation Blood Glucose Is Associated With CTP Core Volume Overestimations In Acute Ischemic Stroke Patients With Large Vessel Occlusion
Authors: Niktabe Arash , Martinez-Gutierrez Juan Carlos C , Kim Youngran , Abdelkhaleq Rania , Rodriguez Quintero Juan Carlos , Salazar-Marioni Sergio , Jeevarajan Jerome , Tariq Muhammad B , McCullough Louise D , Sheth Sunil
Published: February 2023

Background:
CT Perfusion (CTP) predictions of infarct core play a large role in determination of treatment eligibility in large vessel occlusion (LVO) acute ischemic stroke (AIS). Prior studies have demonstrated that glucose can affect cerebral blood flow (CBF). Here we evaluate the influence of acute and chronic glucose levels on CTP over-estimation (OE) of infract core, leading to potential undertreatment.

Methods:
From our prospectively collected multicenter observational cohort, we identified AIS LVO patients evaluated with non-contrast CT, CTA and concurrent CTP who underwent endovascular therapy with substantial reperfusion (TICI2b-3), and also had MRI 48-72 hours post-treatment. OE was defined as a difference of at least 20 mL between CTP-RAPID (IschemaView, Stanford CA) predicted infarct core and DWI final infarct volume (FIV). The primary outcome was the association of glucose and HgbA1c on OE and was measured using multivariable logistic regression to control for other patient level factors.

Results:
Among 256 patients meeting inclusion criteria, median age was 67 [IQR 57-77] and 51.6% were female. Median CTP-predicted core was 6 mL [IQR 0-30], median DWI FIV was 14 mL [IQR 6-43] with median difference of 12 mL [IQR 5-35]. 28 patients (10.9%) had OE, with median difference in infarct size of 40 mL [24-56]. In univariable analysis, early time window (<6 hours from last known well), absence of diabetes, normal HgbA1c, and normal admission glucose were associated with OE. In multivariate analysis, early time window (aOR 2.87, p=0.025) and lower/normal glucose (aOR 3.01, p=0.02) were independent predictors of OE. Among 65 patients with higher HgbA1c and blood glucose levels (>6.5, >126), 27 patients (42%) had CTP core under-estimation (UE).

Conclusions:
Acute and chronic changes in glycemic state affect automated CTP interpretations. These findings may be related to previously described effects on cerebral blood flow.
Abstract WMP95: External Validation Of Acute Atherosclerotic Ischemic Stroke Radiological Markers
Authors: Barnes Vincent A , Henry Alayna N , Ume Kiddy L , Rajah Gary , Dandapat Sudeepta , Ortega-Gutierrez Santiago , Siddiqui Fazeel M
Published: February 2023

Introduction:
Intracranial atherosclerosis-related acute large vessel occlusion (ICAS-LVO) is the dominant cause of acute middle cerebral artery (MCA) occlusions that can be passed with wire or microcatheter but cannot be completely opened (5-15% of all middle cerebral artery (MCA) infarcts). The major challenge of ICAS-LVO is the tendency of reocclusion or cause a residual, fixed severe stenosis rendering the vessel with suboptimal revascularization. These patients carry a poor functional outcome and high mortality despite mechanical thrombectomy (MT). We aimed to externally validate three preidentified markers of ICAS-LVO on early non-contrast computed tomography (NCCT) and CT Angiogram (absent hyperdense MCA sign (HMCAS), Hounsfield measurements (HU ratio≤1.1 and Delta HU<6) and CTA truncal occlusion).

Methods:
We conducted a retrospective analysis of 77 consecutive patients presenting with acute M1 occlusions undergoing MT. Based on our previous observational experiences, NCCT and CTA patterns that had been associated with ICAS-LVO included the absent HMCAS, HU ratio and Delta HU between site of occlusion and contralateral MCA and CTA truncal occlusion. ICAS-LVO was identified if an occlusion was difficult to cross, had tendency to reocclude after successful recanalization or demonstrated residual fixed severe stenosis. These markers were also compared with reperfusion rates and functional outcomes at 3 months.

Results:
Out of 77 patients, 13 (16%) had suspected ICAS-LVO. Absent HMCAS had a sensitivity of 91% and specificity of 90% (AUC 0.91), HU ratio ≤1.1 and delta HU <6 had sensitivity of 100% and specificity of 98% (AUC 0.992) and CTA truncal occlusion had sensitivity of 91% and specificity of 97% (AUC 0.943), in predicting ICAS-LVO. These radiological markers were also significantly associated with unsuccessful reperfusion (TICI 0-2a) and poor functional outcomes (mRS>2) at 3 months.

Conclusion:
Initial non-contrast CT and CTA markers are highly sensitive and specific in predicting atherosclerotic M1 occlusions and significantly associated with failed reperfusion, and poor functional outcomes after mechanical thrombectomy.
Abstract WMP98: Associations Between Long-term Co, No
2
, O
3
, Pm
2.5
, And So
2
Exposure And 30-day All-cause Hospital Readmission Among Stroke Patients In The Us: 2014-2015
Authors: Tran Phoebe , Leifheit Erica C , Warren Joshua , Goldstein Larry B , Lichtman Judith H
Published: February 2023

Objective:
There are known associations between long-term air pollution exposure and greater stroke incidence, morbidity, and mortality; however, there is little research on the association of pollutant exposure with poststroke hospital readmission.

Methods:
We assessed associations of average annual CO, NO
2
, O
3
, PM
2.5
, and SO
2
exposure with 30-day all-cause hospital readmission in US fee-for-service Medicare beneficiaries age ≥65 years hospitalized for ischemic stroke in 2014-2015. We fit Cox models to assess 30-day readmission as a function of these pollutants, adjusted for patient and hospital factors and temperature. We repeated the models stratified by performance of the treating hospital on the Centers for Medicare & Medicaid Services (CMS) risk-standardized 30-day all-cause readmission for stroke measure to determine if the results were independent of performance: Low (CMS rate for hospital <25th percentile of national rate), High (>75
th
percentile), and Middle (all others).

Results:
There were 448148 patients discharged with stroke in 2014-2015 of whom 12.5% were readmitted. Average 2-year CO, O
3
, PM
2.5
, and SO
2
values during the study were below national standards. In adjusted analyses, each 1 standard deviation increase in average annual NO
2
and SO
2
exposure was associated with a 3.6% (95% CI 2.9%-4.4%) and a 2.0% (95% CI 1.1%-3.0%) increased readmission risk within 30-days, respectively (
Table
). Associations between long-term air pollution exposure and increased readmissions persisted across performance categories.

Conclusion:
Long-term air pollution exposure was associated with increased 30-day readmissions after stroke at pollutant levels below national standards across hospital performance categories. Additional research is needed to determine whether improvements in air quality lead to reductions in poststroke hospital readmissions.
Abstract WMP99: Effect Of Intensive Glycemic Control And Microvascular Complications On White Matter Hyperintensity Progression
Authors: Goldstein Eric D , Yaghi Shadi , De Havenon Adam H
Published: February 2023

Background:
Individuals with diabetes mellitus are prone to neurologic complications from prolonged hyperglycemia. While the effects of hyperglycemia are well documented, aggressive correction of systemic glucose levels may have deleterious effects. We aimed to identify whether diabetic treatment goals influenced the progression of white matter hyperintensities (WMH) burden in a meaningful way in a cohort of known diabetics. We hypothesized that more aggressive treatment would yield less WMH progression.

Methods:
We included individuals enrolled in the ACCORD-MIND trial who had a baseline and 40-month follow-up MRI with volumetric quantification of WMH in mL. The primary outcome was WMH progression, defined as the baseline adjusted difference in WMH between the two scans. The exposure was the interaction between a microvascular outcome (ACCORD composite of photocoagulation or vitrectomy for retinopathy, acute renal failure, ESRD/dialysis, or serum creatinine ≥3.3 mg/dL) and glucose treatment arm (standard therapy with target A1c 7-7.9 or intensive therapy with target A1c 6-6.9). We fit a linear regression model adjusted for baseline age, sex, race/ethnicity, history of cardiovascular disease including stroke, Hgb A1c, and mean systolic blood pressure between the MRIs.

Results:
We included 502 individuals (mean age 62.7±5.7 years, 46.2% female, 67.9% White), of which 29 had a microvascular outcome and 229 were randomized to the intensive glucose arm. The interaction between microvascular outcome*glucose arm was highly significant (p=0.009). In individuals without a microvascular outcome, WMH progression was not significantly different in the intensive vs. standard glucose arm (difference of 0.3 mL, 95% CI -0.2, 0.7; p=0.299), but in those with a microvascular outcome there was 2.6 mL more WMH progression in the intensive than standard glucose arm (95% CI 0.9-4.4; p=0.003).

Conclusion:
Although hypothesis-generating, these results suggest that in diabetic individuals with microvascular disease, intensive glucose lowering may have a harmful effect on WMH progression. Our data is similar to other findings amongst the ACCORD trial suggesting intensive glucose control may not be benign in all diabetics.
Abstract WP106: Hemispheric Comparison Of Magnetic Susceptibility 24-72 Hours After Reperfusion
Authors: Kataike Victoria Mercy , Ng Felix , Desmond Patricia , Steward Chris , Thijs Vincent , Campbell Bruce , Venkatraman Vijay
Published: February 2023

Introduction:
Magnetic susceptibility is a radiological contrast mechanism that may provide a measure of oxygenation and contribute to an understanding the pathophysiology of stroke. Currently, there are few studies that have explored magnetic susceptibility in ischemic tissue as a marker of tissue injury. Our study assesses day one ischemic tissue post-reperfusion for changes in magnetic susceptibility and evaluates its relationship with radiological markers of ischemic injury - apparent diffusion coefficient (ADC).

Methods:
In a prospective observational study, thirty-five ischemic stroke patients who underwent endovascular thrombectomy were scanned with MRI (24 – 72 hours after reperfusion) to obtain multi-echo Gradient Echo and DWI images. An experienced neuroradiologist manually delineated ischemic tissue ROIs (region of interest) on DWI images. Contralateral ROIs were obtained using an automated method. The cerebrospinal fluid and regions of haemorrhagic transformation were excluded from the ROIs. A Morphology Enabled Dipole Inversion (MEDI) pipeline was employed to generate Quantitative Susceptibility Mapping (QSM) images, and these were used to quantify magnetic susceptibility. Mean magnetic susceptibility and mean ADC values were measured in these ROIs, and these values were then correlated.

Results:
Mean magnetic susceptibility of the ischemic ROI was significantly higher than that of the contralateral ROI (0.71±11.72 ppb, -5.59±7.30 ppb; p = 0.003). Mean ADC values of the ROI in the ischemic hemisphere were significantly lower than those in the contralateral hemisphere (0.65±0.09 х 10
-3
mm
2
/s, 0.81±0.05 х 10
-3
mm
2
/s; p = 1.31 х 10
-11
). No significant correlation between susceptibility and ADC was found (ρ = -0.278, p = 0.106).

Conclusion:
Magnetic susceptibility in the ischemic tissue is measurable and is elevated when compared to the normal tissue. This may be attributed to the increased oxygen extraction fraction in the ischemic tissue. Further voxel wise analysis and larger longitudinal multi-parametric analysis correlating magnetic susceptibility with other imaging measures of tissue injury over time will help characterise the significance of lesional magnetic susceptibility changes in ischemic tissue.
Abstract WP111: Reduced Left Atrial Strain Is More Common In Embolic Stroke Of Undetermined Source Compared To Non Cardioembolic Stroke
Authors: Chen Edward W , Bashir Zubair , Wang Shuyuan , Shu Liqi , Goldstein Eric , Rana Maheen , Kala Narendra , Dai Xing , Mandel Daniel , Yaghi Shadi , Has Phinnara , Xie Mingxing , Wang Tao , Simmons James , Song Christopher , Haines Philip
Published: February 2023

Atrial fibrosis, a determinant of atrial cardiopathy, is seen more commonly in ESUS as compared to non-cardioembolic stroke patients and precedes changes in atrial dimension. We utilized speckle tracking echocardiography (STE) to identify atrial cardiopathy and to investigate the association between LA strain and ESUS compared to NCE stroke. Hospitalized patients with ESUS and NCE stroke subtypes who underwent in-hospital STE were included. Three phases of LA strain (reservoir, conduit, and contractile) were retrospectively calculated. Binary logistic regression analyses using LA strain as a continuous variable and as tertiles were performed to determine the association between different phases of LA strain and stroke subtypes (ESUS vs NCE). Among 680 total stroke patients, 355 were classified as NCE and 325 as ESUS. LA reservoir strain (36.3 ± 18.3 vs. 31.5 ± 17.8), LA contractile strain (17.4 ± 11.1 vs. 15.4 ± 10.4), and LA conduit strain (19.0 ± 11.9 vs. 16.7 ± 11.7) differed significantly between NCE and ESUS stroke subtypes. The fully adjusted binary logistic regression revealed that the lowest tertile of LA reservoir (OR 2.378, 95% CI 1.538-3.676), contractile (OR 1.555, 95% CI 1.032-2.342), and conduit strain (OR 2.009, 95% CI 1.293-3.124) was more likely to be associated with ESUS compared to NCE stroke. When using strain as continuous variables, LA reservoir (OR 0.987, 95% CI 0.977-0.997) and conduit strain (OR 0.980, 95% CI 0.965-0.996) were significantly reduced in ESUS compared to NCE. Our study demonstrates that reduced LA strain is more strongly associated with ESUS compared to NCE stroke subtype. We believe that atrial cardiopathy carries mechanistic significance and measuring LA strain may become a critical imaging biomarker in ESUS stroke prognostication.
Abstract WP112: Iodine-123-iomazenil Spect Revealed Recovery Of Neuronal Viability In Association With Improvement Of Cognitive Dysfunction After Revascularization In Moyamoya Disease
Authors: Yoshioka Hideyuki , Wakai Takuma , Hashimoto Koji , Tateoka Toru , Fukuda Norito , Kanemaru Kazuya , Kinouchi Hiroyuki
Published: February 2023

Background:
Recent studies indicate 123I-iomazenil (123I-IMZ) SPECT could demonstrate a neuronal viability. Although cognitive dysfunction has been recognized as an important issue in adult moyamoya disease (MMD), standard neuroradiological methods to define such condition are not established.

Aim:
Relationship between cognitive function and 123I-IMZ SPECT before and after revascularization in MMD was firstly examined.

Method:
Fifteen patients whose cerebrovascular reactivities (CVRs) were decreased only on the treatment sides were studied. Cognitive function was examined using mini-mental scale examination (MMSE, cutoff 27) and frontal assessment battery (FAB, cutoff 16) before and 6 months after surgery. 123I-IMZ and 123I-iodoamphetamine SPECT with acetazolamide challenge were performed at the same timings. Radioreactivities of 123I-IMZ SPECT at the regions with decreased CVR were investigated using affected-to-contralateral side ratio (ACR).

Results:
Eleven patients showed normal cognitive dysfunction before surgery (MMSE 29.5, FAB 18). In their preoperative 123I-IMZ SPECT, there were no regions with decreased uptakes (ACR 0.97). The cognitive functions and 123I-IMZ SPECT were not worsened after surgery (MMSE 29.9, FAB 18, ACR 0.99). By contrast, preoperative images of four patients with cognitive dysfunction (MMSE 23.8, FAB 14) showed decrease of 123I-IMZ uptakes, and the preoperative ACRs (0.82) were significantly lower than those of the normal group. Cognitive functions and 123I-IMZ uptakes of these four patients tended to ameliorate after revascularization (MMSE 27.5, FAB 15.5, ACR 0.92).

Conclusion:
Cognitive functions of MMD patients were associated with 123I-IMZ uptakes, and could improve after surgery with recoveries of neuronal viabilities.
Abstract WP115: DWI/FLAIR Mismatch Is Common In Late Window Patients With Target Perfusion Mismatch
Authors: Slawski Diana , Albers Greg
Published: February 2023

Introduction:
The presence of a DWI/FLAIR mismatch has been suggested as a method to identify patients within 4.5 hours from stroke symptom onset. We studied patients from DEFUSE 2 and 3 with the target perfusion mismatch profile to evaluate the rates of DWI/FLAIR mismatch in patients with who have favorable collaterals in early and late time windows. We hypothesize that the persistence of DWI/FLAIR mismatch in late window patients may reflect good collateral circulation.

Methods:
We identified 58 eligible patients in D2 and 30 patients from D3. Imaging was reviewed by two neuroradiologists and one neurologist who rated the presence of DWI-FLAIR mismatch.

Results:
The inter-rater agreement for the presence of DWI/FLAIR mismatch was 88.3%. There were 32 patients who were < 6 hours from last known well (LKW) or symptom onset, 17 patients who were ≥ 6 hours from symptom onset, and 26 patients who were ≥ 6 hours from LKW with an unknown time of symptom onset. These are categorized as early, late, and suspected late window, respectively. The rate of DWI/FLAIR mismatch was 56% in the early window group, 41% in the late window group, and 35% in the suspected late window group. The overall rate of DWI/FLAIR mismatch did not differ significantly between these three groups (56% vs. 41% vs. 35%, p=0.239). Of the early window patients, the rate of DWI-FLAIR mismatch was higher in those with the target perfusion mismatch profile (67%) compared to those without (36%). All but one the known onset late window patients had the target perfusion mismatch profile, and the rate of DWI-FLAIR mismatch in this group was 35%. Forthcoming analyses will include predictors of DWI-FLAIR mismatch such as hypoperfusion intensity ratio, time from symptom onset, and NIHSS score.

Conclusions:
More than one-third of patients presenting >6 hours from symptom onset with a target perfusion mismatch profile have DWI/FLAIR mismatch. This could reflect the presence of good collateral circulation that may delay the appearance of a FLAIR lesion. The rate of DWI/FLAIR mismatch did not differ among early, late, and expected late window patients. This suggests that, among patients with favorable collaterals, DWI/FLAIR mismatch does not reliably identify early window patients.