bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP10: Incidence, Etiology And Predictors Of Mechanical Thrombectomy Failure
Authors: Lajthia Orgest , Almallouhi Eyad , Ali Hamid , Essibayi Muhammed Amir , Bass Eric , Neyens Ron , Anadani Mohamad , Chalhoub Reda M , Kicielinski Kimberly , Lena Jonathan , Porto Guilherme B , Sattur Mithun , Spiotta Alejandro M , Al Kasab Sami
Published: February 2023

Background:
Despite advances in endovascular techniques, mechanical thrombectomy fails to achieve successful revascularization in approximately 20% of patients. This study evaluates the incidence, and identifies the etiologies and predictors of failed thrombectomy in a contemporary series.

Methods:
A prospectively maintained database of MT between January 2013 and August 2021 was interrogated. We gathered demographic data, clinical presentation, procedural details and etiology of MT failure on adult patients who underwent MT with subsequent failed recanalization. Angiographic images were interpreted by an independent neuro-interventionalist.

Results:
Out of a total of 1010 thrombectomies, 120 (11.9%) were unsuccessful. Mean age was 66.8, 51.5% were male and 61.1% were Caucasian. The most common failure location was intracranially (93.3%) followed by failure at the arch and neck (3.3% each). Of those who failed intracranially, underlying intracranial stenosis (ICAS) was seen in 84 patients (70%). Compared to successful MT, failed MT patients had longer onset to puncture time (444 vs 351 minutes, p=0.012) and longer procedural time (55 vs 23 minutes, p=<0.001). Rescue stenting was more common in the successful MT group (12% vs 5.1%, p=0.024). Multivariate analysis demonstrated that DM (OR 1.82; 95% CI 1.05 - 3.16, p=0.03), more than one pass (OR 4.39; 95% CI 1.96 - 9.80, p<0.001), and longer procedural time (OR 1.06, 95% CI 1.03-1.09, p=<0.001) were independently associated with unsuccessful recanalization.

Conclusion:
Failed MT was encountered in approximately 12% of cases. The most common cause of failed MT was underlying ICAS. Further studies to evaluate better treatment modalities of ICAS related LVO are warranted.
Abstract WP102: Side-to-side Relative Reduction In End-diastolic Velocity Of The Common Carotid Artery For Emergent Discrimination Of Anterior Circulation Large Vessel Occlusion
Authors: Ikenouchi Hajime , Tanaka Kanta , Yamaguchi Eriko , Okada Takashi , Shiozawa Masayuki , Inoue Manabu , Toyoda Kazunori , Ihara Masafumi , Koga Masatoshi
Published: February 2023

Introduction:
Side-to-side relative reduction in end-diastolic velocity (EDV) of the common carotid artery (CCA) may discriminate ipsilateral anterior circulation large vessel occlusion (LVO), which will contribute faster patient triage for reperfusion therapy. We evaluated the discriminative accuracy of this simple sonographic index for anterior circulation LVO in acute stroke population, including intracerebral hemorrhage (ICH).

Methods:
Among patients with acute stroke admitted to our institute between 2016-2018, those who underwent both carotid ultrasonography and head MRA or CTA within 24 hours after last known normal time were reviewed. Relative EDV reduction was calculated as a ratio by dividing the CCA EDV lower side by the EDV higher side. Anterior circulation LVO was defined as occlusion of the internal carotid artery (ICA) or M1 segment of the middle cerebral artery on the lower EDV side. Discriminative performance of relative EDV reduction for anterior circulation LVO was assessed by receiver operating characteristics analysis.

Results:
A total of 688 patients (411 males; median age 77 years; 87 with anterior circulation LVO) were analyzed. When compared to no occlusion, value of relative EDV reduction was remarkably lower in ICA occlusion, followed by that in M1 occlusion (Figure). Area under the curve (AUC) of relative EDV reduction for ICA occlusion was 0.96 (95% confidence interval [CI] 0.94-0.99) with an appropriate cut-off value of 0.50 (sensitivity 94%, specificity 94%). When the discrimination target was set to anterior circulation LVO, the AUC was 0.78 (95% CI 0.72-0.85) with an appropriate cut-off value of 0.67 (sensitivity 69%, specificity 83%). At this cut-point, 51% of patients with M1 occlusion was classified as false negative.

Conclusions:
The discriminative performance of the relative CCA EDV reduction in acute stroke population was excellent for ICA occlusion and acceptable for anterior circulation LVO.
Abstract WP103: Machine Learning Enabled Infarct Core Estimation From CTA Predicts Functional Outcome For Endovascular Stroke Therapy
Authors: Jeevarajan Jerome , Salazar-Marioni Sergio , Tariq Muhammad Bilal , Niktabe Arash , Abdelkhaleq Rania , Giancardo Luca , Sheth Sunil
Published: February 2023

Introduction:
The majority of stroke centers do not have access to advanced imaging when treating acute ischemic stroke (AIS) patients with large vessel occlusion (LVO). We previously demonstrated that a machine learning (ML) algorithm could accurately predict infarct core from CT angiography (CTA). Here, we determine the algorithm's performance to predict clinical outcomes after endovascular therapy (EVT) compared to advanced imaging.

Methods:
From our prospectively maintained multi-center registry, we identified consecutive LVO AIS patients screened with CTA and treated with EVT. A deep neural network ML model was trained and validated to predict infarct core size from CTA, and 24-dimensional vector embedding was extracted for each patient. The primary outcome was performance of predicting 90-day functional independence (mRS 0-3) and was determined by area under the ROC curve for two classifier models (k-nearest neighbors, k=11) that included clinical data (age, gender, NIHSS, TICI) and either the ML embeddings from CTA (KNN-CTA) or CT Perfusion infarct core estimations (RAPID, iSchemaView) (KNN-CTP).

Results:
Among 119 LVO AIS patients who underwent EVT, median age was 68 [IQR 57-78], 45% were female, median NIHSS was 16 [IQR 13-21], and median ASPECTS was 7 [IQR 6-8]. Average CTP-RAPID core volume was 17.9mL ±27.5 (mean±SD). 94.1% of patients achieved TICI 2b-3 and 52.1% achieved mRS 0-3 at 90 days (Table 1). Point estimates for AUROC were superior for the KNN-CTA classifier compared to the KNN-CTP (0.72 vs 0.63, p=0.025) as shown in Figures 1 and 2.

Conclusion:
A ML model analyzing more widely available CTA images demonstrated superior results compared to industry standard advanced imaging in predicting clinical outcomes for LVO AIS patients after EVT. These findings suggest ML-based approaches may reduce the need for advanced imaging in EVT clinical decision-making.
Abstract WP108: A Novel Multiphase CTA Perfusion Tool Compared To CTP In Patients With Suspected Acute Ischemic Stroke
Authors: Benali Faysal , Zhang Jianhai , Pinky Najratun , Bala Fouzi , Alhabli Ibrahim , Golan Rotem , Duszynski Chris , Qiu Wu , Menon Bijoy
Published: February 2023

Introduction:
We recently published a Machine Learning-based algorithm using mCTA (mCTAp) that generates perfusion maps of the brain, similar to CTP. Here, we aim to validate the clinical utility of mCTAp in detection of ischemia, it’s side, extent and location.

Methods:
One hundred and twenty-one subjects were included in the test dataset. These subjects had completed mCTAp (StrokeSENS) and CTP (4D; GE Healthcare) at baseline. After excluding 2/121 subjects due to poor image quality, a multi-reader-multi-case (n=119) study design was conducted with 3 experienced radiologists, reading post-processed maps (Tmax and rCBF) generated by both mCTAp and CTP. Both reading sessions were separated by a few days. All readers were blinded to modality and clinical information and the reading order was randomized between sessions. Core lab imaging assessments that used NCCT, mCTA and CTP were considered as ground truth. A mixed effect regression model with the reader as random effect variable was used to calculate the AUC, sensitivity, and specificity for both imaging arms regarding ischemia detection, ischemia side, and occlusion site selection (i.e., ICA/M1[considered LVO], M2 or distal, ACA or PCA). The time required for image interpretation was compared between the two modalities.

Results:
The AUCs for detecting ischemia were comparable between mCTAp and CTP (0.85 [95%CI:0.8-0.9] and 0.84 [95%CI:0.8-0.9] respectively; p=0.43), the affected ischemic side (0.94 [0.92-0.97] and 0.96 [0.94-0.98] respectively; p=0.69), detecting a LVO (0.84 [0.8-0.9] and 0.86 [0.8-0.9]; p=0.31) and M2 or distal occlusions (0.8 [0.7-0.8] and 0.9 [0.84-0.92]; p=0.22). The median (IQR) time for interpretation was 62s (46-78) and 59s (42-69) for mCTAp and CTP respectively (p=0.15).

Conclusion:
mCTAp shows similar performances when compared to CTP in assisting readers to detect ischemia, location, and extent by using Tmax and rCBF perfusion maps.
Abstract WP109: CHASM: Comparing Hyperacute Advanced Imaging To Guide Interventional Stroke Management
Authors: Alwood Benjamin T , Meyer Dawn M , Torres Dolores , Poynor Briana , Van Orden Kimberlee , Pham Nhan , Meyer Brett C , Bolar Divya
Published: February 2023

Introduction:
“Stroke AI” platforms discriminate potentially salvageable tissue from infarcted core, to determine embolectomy eligibility. Numerous platforms are in clinical use, but studies comparing their results are limited. Our institution has access to both viz.AI and RAPID for CT perfusion analysis; as such, we assessed whether core and penumbra estimates were statistically different between the two software.

Methods:
We performed a retrospective review of images from 2/18-1/21 of acute stroke patients with symptoms 6-24 hours from onset who had CTP in the setting of large vessel occlusion (IRB#804221). Studies initially processed through RAPID were re-analyzed by Viz.ai; core volume (CBF<30%), penumbra+core (TMax>6s), and mismatch ratio were compared using paired t-test, and for infinite mismatch McNemar statistics.

Results:
A total of 157 cases were identified. 48 were excluded for processing failure or deleted raw data, and 6 research participants were excluded. Viz.ai had larger TMax>6s volumes relative to RAPID (160.13ml,108ml;p=<0.001), but less infinite mismatch (30.1%,40.8%;p=0.04). No significant difference was found for: core volume (16.7ml,18ml;p=0.47), percentage of infarcts >70ml (6.8%,7.8%;p=1.0), and NIR eligibility based on DEFUSE-3 (71.8%,68.9%;p=0.63), with <70ml core(93.1%,92.2%;p=1.0), ≥15ml penumbra (78.6%,76.7%;p=0.79), and mismatch >1.8 (83.1%,81.9%;p=1.0).

Conclusions:
Both Viz.AI and RAPID provided similar core volumes and NIR eligibility, which gives assurance that both algorithms provide similar actionable results. Reasons why Viz.ai showed larger TMax>6s volumes but less infinite mismatch are unclear, though the latter implies that viz.ai identifies a potential core that may or may not be there in more cases. Penumbra estimation is multifactorial and variance may be due to algorithm alterations in voxel selection to account for artifact, scanner and AI protocols as both have different standards for contrast, radiation exposure, and slice #. Understanding if Viz.ai overestimates or RAPID underestimates TMax>6s will require further assessments of imaging and functional outcome variables. Further analysis to assess if results are accounted for by the above factors is ongoing.
Abstract WP11: Outcomes Associated With Iv Tenecteplase And Iv Alteplase For Acute Ischemic Stroke With Or Without Thrombectomy In Real-world Settings In The United States
Authors: Qureshi Adnan I , Baskett William I , Bains Navpreet K , French Brandi R , Siddiq Farhan , Gomez Camilo R , Shyu Chi-Ren
Published: February 2023

Background and Purpose:
Although many stroke centers in United States are using intravenous (IV) tenecteplase (TNK) for acute ischemic stroke patients, there is paucity of comparative data between IV TNK and IV alteplase from real-world settings.

Materials and Methods:
We analyzed the data from 122 healthcare facilities to determine the effect of IV TNK (compared with IV alteplase) on occurrence of two outcomes in acute ischemic stroke patients stratified by use of thrombectomy: non-routine discharge or death, and intracranial hemorrhage after adjusting for potential confounders.

Results:
Among 30,643 acute ischemic stroke patients analyzed, 29,480 (96.2%) and 1,163 (3.8%) patients received IV alteplase and IV TNK, respectively. The proportion of patients who received thrombectomy was significantly higher among patients who received IV TNK compared with those who received IV alteplase (16.7% versus 11.0%, p<0.001). Occurrence of intracranial hemorrhage was higher more common among patients treated with IV TNK among acute ischemic stroke patients who received thrombectomy (20.1% versus 16.8%, p=0.234) or did not receive thrombectomy (7.9% versus 5.1%, p<0.001). In the logistic regression analysis, patients treated with IV TNK who did not receive thrombectomy were at higher risk of intracranial hemorrhage (OR, 1.34, 95% CI 1.05-1.72, p=0.02) after adjusting for potential confounders. There was no difference in the rate of non-routine discharge or death between patients treated with IV TNK and those treated with IV alteplase in the multivariate analyses.

Conclusions:
In an analysis of real-world data, IV TNK was associated with higher rates of intracranial hemorrhage compared with IV alteplase in patients with acute ischemic stroke.
Abstract WP110: Predictors Of False Positive Shunt Detected By Transcranial Doppler: When Is Intracardiac Echocardiogram Beneficial?
Authors: Shahrivari Mahan , Vyas Vedang , Tariq Muhammad Bilal , Ciavarra Bronson , Dhoble Abhijeet , Barreto Andrew D , Sharrief Anjail Z
Published: February 2023

Background and Objective:
Right to left shunts (RLS) found with patent foramen ovale (PFO) are implicated in the pathogenesis of cryptogenic stroke and a risk factor for neurological event. The capability and sensitivity of Transcranial Doppler ultrasound (TCD) to detect a PFO has been established. However, predictors of false positive shunts detected by TCD and benefit of intracardiac echocardiogram (ICE) when studies show conflicting results have not been determined.

Methods:
In this retrospective study, patients who underwent shunt testing with ICE ± endovascular atrial septal defect closure from 2018 till 2022 were included. We abstracted data regarding the type of study used for shunt detection such as transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), ICE and TCD. PFO size and characteristics were evaluated. International consensus criteria were used for TCD PFO detection.

Results:
A total of 184 patients underwent ICE testing, of which 169 (93.4%) had prior TTE, 116 (63%) TEE, and 48 (25%) prior TCD. Among 48 patients with TCD, 24 had negative TTE and 4 had negative TEE. Mean (SD) age was 51.1(14.4). 110(59.8%) were female. Among all patient with ICE 169 (91.8%) had PFO. PFOs were detected in 38 out of 48 (79.1%) patients who had been assessed with both ICE and TCD, whereas 6 patients (12/5%) were found to have a RLS on TCD but no PFO on ICE, p<0.01. Comparing ICE and TCD grading scores for shunt detected, 45.2% had higher grade by TCD compared to ICE, p= 0.17. Among the six false positive cases on TCD, four of them had shower of microembolization and 2 of them had 0-10 HITS microemboli detection.

Conclusion:
Transcranial Doppler ultrasound detection of right to left shunt remains highly sensitive and a non-invasive tool. Considering ICE as gold standard, TCD is associated with false positive shunt detection. Further studies are warranted to assess the shunt characteristics on TCD that are associated with higher predictive value for identifying PFO.
Abstract WP113: Feasibility Of Non-invasive Brain Temperature Measurement In Acute Ischemic Stroke: A Comparison Study Of MR Thermometry Vs. Zero-Heat-Flux Sensors
Authors: Horn MacKenzie , Meulenbroek Nathan , Chu Tak-Ho , Singh Nishita , Tanaka Koji , Menon Bijoy K , Diprose William , Pichardo Samuel , Demchuk Andrew M , Almekhlafi Mohammed
Published: February 2023

Introduction:
Brain-selective hypothermia is a promising neuroprotectant in acute ischemic stroke. However, a non-invasive bedside method to monitor brain temperature during cooling is lacking. We tested the feasibility and accuracy of measuring brain temperature non-invasively using sensors designed to monitor core body temperature.

Methods:
In this prospective single-center study, 20 patients with large or medium vessel occlusion strokes were enrolled. Patients underwent a 3T MR spectroscopy imaging (MRSI, the reference standard) and zero heat flux (ZHF) core temperature sensor measurements (3M
TM
Bair Hugger
TM
) within 12-72 hours from admission. Two ZHF sensors were placed on each side of the forehead on the side of stroke and contralateral side and the temperatures were checked before and after MRSI. A 2x2x2 cm voxel was centered on the infarct and matching contralateral location using diffusion weighted imaging. Brain temperature on MRSI was calculated using the relative chemical shifts of water and N-acetyl aspartate. Temperature measurements of the ZHF sensors were compared to MRSI measurements.

Results:
The brain temperature of stroke and contralateral sides were similar using MRSI or using ZHF sensors when each modality was compared to itself by hemisphere (all p>0.05). However, there was a significant difference for the ipsilateral side: median (SD) temperatures using MRSI was 36.0°C (1.8) vs 36.8°C (0.5) for sensor measurement. Bland-Altman plots showed that 95% of the observations fell within upper and lower limits of agreement of -2.1 to +3.7°C while 61% of observations fell within an agreement limit of +/- 1°C. There was an indication of an overall higher temperature measurements using the ZHF sensors compared to MRSI (Figure 1).

Conclusions:
More studies are needed to validate the use of ZHF thermometry in ischemic stroke including studies implementing hypothermia.

Figure 1. Boxplot of stroke side MRSI compared to zero-heat-flux sensors.
Abstract WP116: Clinical And Diagnostic Features On Cerebrospinal Fluid And Vessel Wall MRI Can Differentiate Primary From Secondary CNS Vasculitis
Authors: Ibrikji Sidonie , Sheth Richa , Shoskes Aaron , Kiczek Matthew , Russman Andrew N , Kharal Abbas G
Published: February 2023

Introduction:
Differentiating primary CNS vasculitis (PCNSV) from secondary CNS vasculitis (SCNSV) can be challenging based on brain imaging and cerebrospinal fluid (CSF) profile alone. Little is known about the diagnostic nuances of differentiating these 2 entities with CSF and vessel wall magnetic resonance imaging (VWMRI) as overlapping features may exist. We aimed to look at clinical features, serum & CSF biomarkers, and VWMRI differences between PCNSV & SCNSV.

Methods:
Patients presenting to our tertiary care center with a diagnosis of PCNSV or SCNSV between January 2015 and January 2021 were extracted from electronic medical record data. We included patients older than 18 years of age with active disease who had CSF studies and VWMRI data available. Demographic, clinical and diagnostic characteristics were reviewed and descriptive statistics were reported for comparison.

Results:
A total of 42 patients (24 with PCNSV and 18 with SCNSV) met study inclusion criteria. The SCNSV group was older (median age 43 years vs 41.5 years), had a higher proportion of male gender (78% vs 54%) and black race (22% vs 4%) compared to PCNSV. Patients with PCNSV more commonly had headache (63% vs 50%) and seizures (21% vs 11%) but less commonly had encephalopathy (42% vs 50%), focal neurological deficits (79% vs 83%) and constitutional symptoms (17% vs 33%). Patients with PCNSV more likely had positive antinuclear antigen levels (25% vs 11%) and elevated sedimentation rate (33% vs 25%) but less likely had elevated C-reactive protein (25% vs 33%) in blood. Comparison of CSF studies showed that the PSCNV group had a lower median CSF white blood cell count (10 cells/mm3 vs 43.5 cells/mm3 , both lymphocytic), lower median CSF protein count (62 mg/dl vs 82 mg/dl) and lower IgG index (33% vs 56%) in comparison to the SCNSV group. On VWMRI, PCNSV group had less diffuse (40 vs 54%) involvement and more anterior multifocal lesions (40 vs 15%) compared to SCNSV group with more large or medium-vessel involvement (70 vs 54%).

Conclusion:
Clinical and diagnostic differences with regards to CSF and VWMRI exist between PCNSV and SCNSV that can aid in differentiating these two entities. This can prove useful especially in undiagnosed systemic vasculitides presenting with CNS vasculitis.
Abstract WP12: The Golden 75 Min And Black 120 Min For Acute Basilar Artery Occlusion Intervention: Effect Of Procedure Time On Outcome
Authors: Guo Changwei , Song Jiaxing , Li Linyu , Yang Jie , Kong Weilin , Huang Jiacheng , Xie Yuqian , Alawieh Ali M , Spiotta Alejandro M , Li Fengli , Zi Wenjie
Published: February 2023

Background and Objectives:
Previous studies have shown the impact of procedure time (PT) on large vessel occlusion (LVO), however, the relationship for patients with acute basilar artery occlusion (ABAO) was not clear. We aimed to characterize the impact of PT and other procedure-related variables on clinical outcomes among patients with ABAO that underwent mechanical thrombectomy (MT).

Methods:
Patients with ABAO that underwent MT with a documented PT in the BASILAR study from January 2014 to May 2019 among 47 comprehensive centers in China were included. Multivariable analysis was performed to reveal the association between PT and 90-day modified Rankin Scale score, mortality, complications, and all-cause death at one year.

Results:
Of the 829 patients from the BASILAR registry, 633 eligible patients were included. A decreased likelihood of favorable outcomes (defined as a modified Rankin Scale score of 0-3 at 90 days) was demonstrated when PT exceeded 60 min (P < 0.001). Additionally, a PT ≤ 75 min independently predicted favorable outcomes (adjusted OR 2.28[95% CI 1.41- 3.68], respectively). The risk of complications and mortality increased by 0.5% and 1.5% with every 10 min increase in PT, respectively (R
2
= 0.64 and R
2
= 0.68, P <0.01). The cumulative rates of favorable outcomes and successful recanalization plateaued after 120 min (2 attempts). Restricted cubic spline regression analysis for the probability of favorable outcomes had an L-shape association (P non-linearity = 0.048) with PT with significant benefit loss before 120 min and then appeared relatively flat.

Discussion:
For ABAO patients, procedures that exceeded 75 min increased the risk of mortality and decreased the likelihood of a favorable outcome. For procedures exceeding 120 min the benefits and costs of continuing the procedure should be carefully considered.

Classification of Evidence:
This study provides Class II evidence for ABAO patients undergoing EVT.
Abstract WP120: Factors And Outcomes Associated With Early And Delayed Gastrostomy In Intracerebral Hemorrhage Patients In The United States
Authors: Chaudhry Mohammad Rauf A , Azher Aidan I , Shahid Muhammad H , Ahmed Rehan , Chaudhry Saqib , Jagolino Amanda , Cruz-Flores Salvador , Qureshi Adnan I
Published: February 2023

Background:
The appropriate timing of gastrostomy in patients with intracerebral hemorrhage who have dysphagia remains unclear.

Objective:
To identify factors and outcomes associated with timing of gastrostomy in patients with after hospitalization in the United States.

Methods:
We analyzed the data from the Nationwide Inpatient Sample (2016-2019), the largest all payer nationally representative dataset. We identified all patients presenting with primary diagnosis of intracerebral hemorrhage who underwent gastrostomy. Early gastrostomy was identified if gastrostomy was performed within 7 days of admission. We performed logistic regression analysis to identify the effect of timing of gastrostomy (early versus late) on none to minimal disability, length of stay, and hospitalization cost after adjusting for variables that were significantly different in univariate analysis.

Results:
Of 22,530 patients with intracerebral hemorrhage who underwent gastrostomy during hospitalization, 5765 (25.6%) underwent early gastrostomy. Patients who underwent early gastrostomy were more likely to be older (P <0.001), women (p=0.02), white patients (p<0.001), and admitted to non-teaching hospitals (P = 01). Among intracerebral hemorrhage patients who survived, patients who underwent early gastrostomy were more likely discharged with none to minimal disability odds ratio [OR] 1.51, 95% confidence interval [CI] 1.16-1.97) compared with those in the delayed gastrostomy group after adjusting for potential confounders. Early gastrostomy was associated with both lower length of stay (P <0.001) and hospitalization cost (P <0.001) in the multivariate analyses.

Conclusion:
Patients with intracerebral hemorrhage who undergo early gastrostomy are more likely to be discharged with none to minimal disability. Furthermore, early gastrostomy is associated with both reduction in hospital cost and length of stay.
Abstract WP122: Effect Of Prior Exposure To Statin Therapy On Clinical And Radiological Features Of Intracerebral Hemorrhage: A Post-hoc Analysis Of The I-def Trial
Authors: Lee Kun , Carvalho Filipa , Lioutas Vasileios , Das Alvin S , Heistand Elizabeth , Marchina Sarah , Selim Magdy H
Published: February 2023

Background:
Conflicting data exist regarding the relationship between prior statin use and perihematomal edema (PHE) in patients with intracerebral hemorrhage (ICH). We performed a post-hoc analysis of the ICH Deferoxamine (i-DEF) trial to examine whether there is an association between statin use prior to the onset of ICH and baseline PHE volume and its growth on 72-96 hour follow-up scans.

Methods:
Statin use prior to the study enrollment was assessed, and CT scans were performed at presentation and after 24 hours after the completion of a 3-day infusion of either saline or deferoxamine (DFO). ICH volumes and various PHE parameters were measured semi-quantititavely using Analyze imaging software. Multivariable logistic regression model was created, adjusting for the variables that were significantly different on univariable analyses, to assess for any associations between prior statin use and measures of ICH and PHE. Bonferroni correction was applied for multiple testing.

Results:
Seventy-four (25.4%) of 291 participants in i-DEF used statin prior to ICH onset. On univariable analyses, those with prior statin use had higher prevalences of hypertension, diabetes, and prior ischemic stroke, as well as concomitant antihypertensive and antiplatelet uses. Patients with prior statin use had smaller baseline ICH volume, absolute PHE (aPHE) volume, and edema extension distance (EED). Greater hematoma volume growth, baseline relative PHE (rPHE) volume, and reduction in rPHE volume from baseline to follow-up scans were also seen in those with prior statin use. On multivariable analysis, none of the measures of ICH and PHE was significantly associated with prior statin use, after adjusting for multiple testing.

Conclusion:
In this post-hoc analysis of a randomized controlled trial with standardized imaging and functional assessments, we did not find significant associations between pre-ICH statin use and measures of ICH or PHE volumes and their growth.
Abstract WP123: Machine Learning To Predict High Risk Adverse Events In Treatment Trials For Intracerebral Hemorrhage
Authors: Tariq Muhammad Bilal , Ling Yaobin , Savitz Sean I , Fann Yang C , Jiang Xiaoqian , Kim Yejin
Published: February 2023

Background:
ICH clinical trials have shown that aggressive blood pressure (BP) lowering can lead to adverse events (AEs) such as renal failure (RF) or new stroke. These studies focused on whether the study intervention causes AEs on average. By combining trials, we estimate each individual’s risk of developing AEs with BP lowering.

Methods:
We augmented data from ATACH2 by adding patients from the observational ERICH study and performed
propensity score matching
with a radius (radius=0.4, ratio=1). We estimated the individualized counterfactual outcome of renal AEs using augmented ATACH2. ERICH had 127 patients (out of 1,706) with new onset of RF during hospital stay. ATACH2 had 68 patients (out of 1000) with renal AEs (recorded by MedDRA) within 7d. We built the counterfactual prediction model using a neural network model (FlexTENet). We extracted feature importance score using Shap Deep Explainer.

Results:
We borrowed 1,706 patients to augment ATACH2. The augmented cohort had 2706 patients in total. FlexTENet captured the heterogeneity fairly. For factual outcome prediction accuracy, the FlexTENet achieved the best area under precision-recall curve (0.203) and the area under receiver operating curve (0.703). High diastolic BP at admission and low platelets increased the counterfactual effect of BP reduction on occurrence of renal AEs. In addition, high systolic BP and high glucose decreased the counterfactual effect on the occurrence of renal AEs.

Conclusions:
Identifying treatment-related AEs at an individual level has rarely been studied. Our counterfactual machine learning shows potential to predict individual patient’s risk of treatment-related adverse events.
Abstract WP126: Predictors Of Intracranial Hemorrhage Volume Expansion In Patients Receiving Factor Xa Inhibitors In The Annexa-4 Trial
Authors: Concha Mauricio , Hu Lizhen , Horn MacKenzie , Ohara Tomoyuki , Nakamya Juliet , Beyer- Jan , Shoamanesh Askan , Cohen Alexander T , Ladenvall Per , Connolly Stuart J , Demchuk Andrew M
Published: February 2023

Introduction:
Andexanet, a specific reversal agent for FXa inhibitors, showed an effective hemostasis in 82% of patients with major bleeding in the ANNEXA-4 trial. However, little is known about the predictors associated with hematoma expansion in patients with FXa inhibitor-associated intracranial hemorrhage (ICrH) receiving andexanet.

Methods:
ANNEXA-4 was a prospective, single-arm, open-label study of andexanet in patients with acute major bleeding within 18h after taking a FXa inhibitor. Hematoma volumes at baseline and 12h after andexanet treatment were measured utilizing a computerized-assisted volumetric method. Univariate and multivariate logistic regression analyses of baseline clinical and non-clinical parameters were performed to identify factors predictive of different volumes of hematoma expansion.

Results:
A total of 305 patients with both baseline and follow-up imaging were included (mean age 80 years; 60.2% with intracerebral hemorrhage; 55.4% taking apixaban; 32.5% taking rivaroxaban). Overall median baseline hematoma volume was 10.4 mls (IQR 2.7-28.1) and time from symptom onset to baseline CT was 3.3h (1.5-6.8). Mean baseline anti-FXa activity levels were 148 ng/mL (SD 107.5). In follow up scans, 48 cases (15.7%) showed evidence of ICrH expansion ≥6 mls. Utilizing a four category ICrH Expansion Scale as the dependent variable, ordinal logistic regression identified Glasgow Coma Scale (GCS) score (OR 0.79; 95% CI 0.64-0.97), baseline ICrH volume (OR 1.02; 95% CI 1.01-1.04) and time from symptom onset to CT (OR 0.73 (0.53-0.99) as significant predictors of ICrH expansion. Baseline anti-FXA activity (OR 1.54; 95% CI 0.95-2.51; p value 0.08) and multiple compartment ICrH (OR 2.32; 95% CI 0.98-5.51; p value 0.06) showed trend as predictors of ICrH expansion. ICrH expansion dichotomized by ≥6 mls or <6 mls as dependent variable, identified similar predictors of ICrH expansion.

Conclusions:
Shorter time from onset of symptoms to CT, lower GCS score and larger hematoma volumes at presentation increased the probability of ICrH expansion in FXa-associated ICrH treated with andexanet. These findings can inform the eligibility criteria of clinical trials targeting hemostatic efficacy in patients with FXa-associated ICrH.
Abstract WP130: Intracerebral Hemorrhage Outcomes And Trends During The Covid-19 Pandemic. An Observational Study Of 61,417 Cases.
Authors: Renedo Daniela , Leasure Audrey C , Acosta Julian , Young Rebecca T , Alhanti Brooke , Mac Grory Brian , Spudich Serena , Messe Steven , Reeves Mathew , Hassan Ameer E , Schwamm Lee H , Matouk Charles , Sheth Kevin N , Falcone Guido J
Published: February 2023

Background:
Patients with ischemic stroke have worse outcome if there is concomitant coronavirus 2019 (COVID-19) infection. We hypothesize that patients with intracerebral hemorrhage (ICH) during the pandemic era had worse outcomes than ICH patients during the pre-pandemic period, and that concomitant COVID-19 in ICH patients is associated with worse outcome.

Methods:
We analyzed data from Get With The Guidelines® Stroke. We implemented a two-stage design: first, we compared outcomes for ICH patients pre-pandemic (admitted between March 2019 and February 2020) with outcomes for ICH patients admitted during the pandemic (from March 2020 to February 2021); second, we compared outcomes of ICH patients with and without COVID-19 infection admitted during the pandemic (from March 2020 to February 2021). We used multivariable logistic regression adjusted by age, sex, race/ethnicity, and clinical covariates for in-hospital mortality and poor functional outcome using the modified Rankin Scale (mRS) at discharge (mRS >= 4) and a for length of stay (LOS).

Results:
The first stage included 62,743 pre-pandemic and 64,681 intra-pandemic ICH cases 64,681. ICH patients during the pandemic had worse outcomes, including higher modified rankin scale (mRS) (OR 1.10, CI 1.06-1.14) and higher mortality (OR 1.04, CI 1.01-1.07). The second stage included 60,091 COVID-19-negative and 1,326 COVID-19-positive ICH patients. Patients with concomitant COVID-19 infection had worse outcomes, including higher LOS (RR 1.32, CI 1.25-1.39), high mRS (OR 1.68, CI 1.40-2.01), and increased mortality (OR 1.50, CI 1.33-1.71).
(Table).

Conclusion:
When comparing pre- and intra-pandemic cases of ICH, critically ill stroke patients admitted during the pandemic had worse outcomes. When comparing COVID-19 positive and negative ICH cases that happened during the pandemic, those with the infection had worse clinical outcomes. COVID-19 infection is an independent risk factor for poor outcomes in ICH.
Abstract WP132: Cerebral Amyloid Angiopathy And Risk Of Ischemic And Hemorrhagic Stroke
Authors: Bruce Samuel S , Zhang Cenai , Parikh Neal S , Merkler Alexander E , Navi Babak , Kamel Hooman , Murthy Santosh
Published: February 2023

Introduction:
Cerebral amyloid angiopathy (CAA), a condition characterized by beta amyloid deposition in the cerebral vasculature, is a common cause of intracerebral hemorrhage (ICH) in elderly patients. Radiographic features of CAA such as white matter hyperintensities and cerebral microbleeds are also associated with an increased risk of ischemic stroke. However, there are limited population-based data regarding the risk of incident ischemic and hemorrhagic stroke associated with clinically diagnosed CAA.

Methods:
We performed a retrospective cohort study using inpatient and outpatient claims from 2016 to 2018 from a nationally representative 5% sample of Medicare beneficiaries. The study exposure was a diagnosis of CAA identified using ICD-10-CM code I68.0. Participants with prevalent stroke were excluded. The primary outcome was any stroke (ischemic or hemorrhagic), and secondary outcomes were ICH, subarachnoid hemorrhage (SAH), and ischemic stroke, assessed separately. These outcomes were identified using validated ICD-10-CM diagnosis codes. Cox proportional hazards regression was used to determine the association between CAA and outcomes after adjustment for demographics and vascular comorbidities.

Results:
Of the 1.3 million Medicare beneficiaries included, 436 had clinically documented CAA without a prior or concurrent stroke. During a median follow-up of 3.0 years (IQR, 2.3-3.0), incident ischemic stroke occurred in 29,545 patients (2.28%), SAH in 3,340 (0.26%), and ICH in 4,338 (0.34%). In adjusted Cox models, CAA was significantly associated with an increased risk of any stroke (HR, 3.4; 95% CI, 2.5-4.7), ICH (HR, 17.1; 95% CI, 11.1-26.3), and SAH (HR, 6.2; 95% CI, 2.7-13.9). There was a nonsignificant association with ischemic stroke (HR, 1.4; 95% CI, 0.8-2.4).

Conclusions:
In a nationally representative cohort of Medicare beneficiaries, CAA was associated with a significantly increased risk of future ICH and SAH, but was not significantly associated with an increased risk of future ischemic stroke.
Abstract WP136: Cerebral Blood Flow Correlates Of Brain Arterial Dilatation
Authors: Gutierrez Jose , Spagnolo-Allende Antonio , Liu Minghua , Marshall Randolph , Du Xinjian , Charbel Fady , Amin-Hanjani Sepideh
Published: February 2023

Introduction:
Based on the Poiseuille’s law (blood flow= [pressure gradient* [Pi*radius
4
]]/[8*blood viscosity*length]) larger brain arterial diameter should associate with a proportional increase in cerebral blood flow. We have reported that larger brain arterial diameters are associated with higher risk of dementia and cerebrovascular disease, but the flow correlates of larger brain arterial diameters have not been studied.

Methods:
We leveraged an existing data repository of 325 unselected volunteers recruited to validate phase contrast quantitative magnetic resonance angiography (QMRA). Imaging was performed in a 3.0 Tesla MRI Scanner (Signa VHi to HDx, General Electric Medical Systems, later GE Healthcare, Milwaukee, WI, USA) using either a four-channel or eight-channel neurovascular coil. The volume flow rate measurements were acquired with the Noninvasive Optimal Vessel Analysis software (VasSol,Chicago, IL, USA). Brain arterial diameters of the circle of Willis were measured using LKEB Automated Vessel Analysis (LAVA) software. Adjusted models by age, sex, race/ethnicity and height were built to explore the association between blood flow and the diameters of the basilar, middle, and anterior cerebral arteries.

Results:
We include 325 participants (mean age 48 ± 15 years, 52% female, 64% non-Hispanic white). As expected, arterial luminal diameters are associated with proportionally higher cerebral blood flow. Among people with the largest diameters in this sample, however, the corresponding cerebral blood flow was lower than predicted[MRS1] and this non-linear association was significant in three out of the five arteries studied (Figure 1).

Conclusions:
In a sample of relatively healthy individuals, those with the largest diameters had lower-than-expected cerebral blood flow. Further studies are needed to better understand the physiopathology by which larger brain arterial diameters relate to cerebrovascular disease.
Abstract WP14: A Patient-level Data Euclidean-matched Analysis Of Reperfusion Therapies In Acute Ischemic Stroke From The Latin American Stroke Registry (lase)
Authors: Barboza Miguel A , Torrealba-Acosta Gabriel , Valdez Hector , Arauz Antonio , Abanto Carlos , Amaya Pablo F , Ameriso Sebastian F , Bonardo Pablo , Cano Vanessa , Diaz-Escobar Luis , Ecos Rosa Lizbeth , Fernández Morales Huberth , Gómez-Schneider Maia , Gongora - Rivera Fernando F , Huamani Charles , Lavados Pablo M , Marquez-Romero Juan M , Martins Sheila , NAVIA GONZALEZ VICTOR HUGO , Pujol Lereis Virginia A , Roa Wandurraga Luis F , Ruiz-Franco Angelica , Serrano Fabiola , Vences Miguel A. , Zurru Maria , Kent Thomas A , Mandava Pitchaiah
Published: February 2023

Introduction:
As acute stroke therapies expand to less well-resourced regions, it is imperative to study real-world data to assess outcomes and the quality of stroke care. The present study analyzes clinical, and imaging outcomes after acute IV thrombolysis (IV-tPA) compared to mechanical thrombectomy (MT) or combined therapy in the LASE.

Methods:
A retrospective analysis of consecutive acute ischemic stroke cases in 17 centers from 9 Latin American (LA) countries since 2012 was performed using weighted Euclidean matching of nearest neighbors in 3-D space of baseline NIHSS, age, and glucose.

Results:
950 patients receiving only IV-tPA were matched to 127 treated with MT+IV-tPA. Matching resulted in 97 pairs well balanced for age (69.1 vs. 69.3), baseline NIHSS (17 vs. 17), and glucose (124.3 vs. 124.5), all p>0.2. 3-month mRS 0-1 (38.3% vs 29.8%, p=0.23) and mRS 0-2 (46.8% vs 41.5%, p=0.54) were non-significantly higher in the MT+IV-tPA group, with higher hemorrhage (26.6% vs 15.5%, p=0.05) and trends for higher death (15.1% vs 9.5%, p=0.40) and symptomatic hemorrhage (7.4% vs 6.2%, p=1.0). One hundred one patients receiving only MT were matched to 127 patients with MT+IV-tPA, resulting in 61 pairs; MT+IV-tPA showed trends for higher rates of 3-month mRS 0-1 (45.0% vs 35.6%, p=0.31), mRS 0-2 (48.3% vs 42.4%, p=0.54); with trends for lower rates of death (16.9% vs 20.0%, p=1.0) and symptomatic hemorrhage (8.3% vs 11.1%, p=0.75).

Conclusions:
In this real-world LA sample, trends for better functional outcomes were demonstrated with MT+IV-tPA compared to either treatment alone, as in non-LA populations. A trend for higher adverse events in the combined group requires further investigation.
Abstract WP140: Coma As A Presentation For Large Vessel Occlusion Stroke
Authors: Young Michael J , Awad Amine , Andreev Alexander , Bonkhoff Anna , Schirmer Markus D , Rabinov James D , Stapleton Christopher J , Das Alvin S , Singhal Aneesh , Rost Natalia S , Patel Aman B , Regenhardt Robert W
Published: February 2023

Introduction:
Coma is an unresponsive state of disordered consciousness characterized by impaired arousal and awareness. While coma has been studied in the context of traumatic brain injury, the epidemiology and pathophysiology of coma in ischemic stroke has been underexplored. We sought to characterize the incidence and clinical features of coma as a presentation of large vessel occlusion (LVO) stroke.

Methods:
Individuals who presented with LVO were identified from July 2018 to December 2020. Coma was defined as an unresponsive state of impaired arousal and awareness, operationalized as a score of 3 on NIHSS item 1a: responds only with reflex motor or autonomic effects or totally unresponsive, flaccid, and areflexic.

Results:
A total of 28/638 (4.4%) patients with large vessel occlusion stroke were identified as presenting with coma. The median age was 65 (IQR 48-78), and 57% were female. The median NIHSS was 32 (IQR 29-34). Occlusion locations included basilar (10), vertebral (2), P1 posterior cerebral (2), internal carotid (4), M1 middle cerebral (6), and M2 middle cerebral arteries (4). In all 14 patients with anterior LVO, the acute LVO was unilateral. Of these 14, 6 had evidence of acute or chronic stroke involving the contralateral hemisphere; 1 experienced seizure; 1 experienced cardiac arrest; and 1 had chronic occlusion of the contralateral ICA. Overall, 20/28 died during the admission. Of those who died, 9 presented with anterior LVO and 11 with posterior LVO. Eight patients were treated with EVT. For those not treated, reasons included established infarct with ASPECTS <6 (11), delayed presentation (2), pre-stroke disability and goals of care (3), and absence of intracranial proximal occlusion on repeat imaging (2).

Conclusions:
It is not uncommon for patients with LVO stroke to present with coma, and 65% of patients not treated with EVT had delayed presentations or large established infarcts, emphasizing the need for maintaining a high index of suspicion. While more commonly thought to result from posterior LVO, coma in our cohort was similarly likely to result from anterior LVO. Further study of these patients may shed light on the pathophysiology of coma. Efforts to improve early diagnosis and care are crucial given their poor outcomes.
Abstract WP144: Inflammation After Intracerebral Hemorrhage Is Locally Mediated
Authors: Yager Brock , Kondrasov Sasha , Zhidan Xiang , Wolfe Stacey , Jestus Jack , Diz Debra I
Published: February 2023

Introduction:
Secondary injury due to neuroinflammation poses a target in ICH research. We have demonstrated elevated serum IL-12 levels in rodents with cardiometabolic syndrome with hypertension compared with normotensive rodents. As hypertension is a risk factor in ICH, it is critical to understand whether there are also local cerebral changes in pro-inflammatory cytokines to explore targets for therapeutics.

Methods:
A pilot study of autologous-injection ICH was induced in (mREN2)27 (n=7) and control Hanover Sprague-Dawley (SD) (n=7) rats. Animals underwent tail-cuff blood pressure measurement, pre- and post-ICH neurobehavioral testing, and serum cytokine measurements. Sacrifice with brain harvest was performed at 24h and 7h post-ICH. Homogenization of the brain with quantitative measurement of hemoglobin and IL-12 concentrations was performed.

Results:
IL-12 peaked in the ipsilateral hemisphere in both SD and mREN rats at 24h post-ICH. There was a significant difference in local IL-12 levels between the ipsilateral and contralateral hemispheres at 72h, with minimal IL-12 elevation in the contralateral hemisphere (p=0.05) (Figure 1). Additionally, there was high correlation between hematoma size and IL-12 local expression. While there was no difference in cerebral IL-12 levels between strains, there was a significant elevation in baseline IL-12 serum levels in mREN compared to SD rats, and a trend towards serum elevation at 72h post-ICH.

Conclusions:
Cerebral IL-12 levels ipsilateral to ICH are significantly elevated compared to contralateral levels and peak 24h post-ICH. While serum IL-12 levels are elevated in rats with cardiometabolic syndrome, this is not seen in brain tissue following ICH. With the high correlation between hematoma size and IL-12 expression, these findings implicate macrophage recruitment from the hematoma as a driver of neuroinflammation and potential therapeutic target to augment surgical interventions for ICH.
Abstract WP15: Short-Term Functional Outcomes Of Patients With Large Vessel Occlusions Transported By Mobile Stroke Unit Compared To Conventional Transport.
Authors: Ferra Pradas Katherine , Mathew Jason , Khan Arham , Reinsel Ruth , Fiorella David
Published: February 2023

Background:
A major limiting factor of favorable outcomes among patients with emergent large vessel occlusions (ELVO) is delay in transfer to a comprehensive stroke center (CSC). Stony Brook University Hospital (SBUH) is one of two CSCs in Suffolk County, serving approximately 1.5 million patients over 912 square miles. In 2019, SBUH implemented 2 mobile stroke units in strategic locations within Suffolk County to facilitate rapid delivery of acute stroke treatments. With the capability of performing computed tomography angiography (CTA) in addition to non-contrasted head CT, SBUH MSU offers an opportunity to rapidly triage patients to necessary CSCs. We sought to compare functional outcomes of patients receiving thrombectomies following transport by MSU versus conventional EMS and hospital transfers.

Methods:
A retrospective study was conducted that included patients eligible to receive mechanical thrombectomy from 2017 to 2020. Patients who had pre-morbid modified Rankin scale (mRs) greater than 0, transient ischemic events, subarachnoid hemorrhage, intraparenchymal hemorrhage, or strokes post-hospital arrival were excluded. A total of 77 patients were included, 37 of whom received care by MSU and 40 by EMS or transfers. Time interval from Door-to-Needle time was measured. T-test for independent samples was used to measure differences in time among both groups. Functional outcomes were measured using mRS at discharge. Patients were trichotomized into three outcome groups, mRS 0-1, 2-4, and 5-6. Chi square was used to analyze differences among the outcome groups

Results:
MSU patients had a significantly shorter Door-to-Needle time than the EMS patients: (69± 64 min vs. 115 ± 65 min respectively, t=3.319, 78.155df, P<0.001). At discharge in MSU group, 37.8% (14) had favorable mRS 0-1 compared to the control group 26.4% (14). The MSU group had 56.8% (21) moderate mRS 2-4 compared to the control group 47.2% (25) with mRS of 2-4. The MSU group had 5.4% (2) severe mRS 5-6 compared to the control group 26.4% (14). X
2
=7.716, 2df, p<.01

Conclusions:
CTA can be performed on MSUs to detect ELVOs in the field and achieve prompt triage of these patients to CSCs, thereby reducing time to thrombectomy and improving short-term functional outcomes.