bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P507: Clot Ingestion Leads to the Highest First Pass Complete Recanalization Rates in a Human Brain Model of Large Vessel Occlusion Stroke
Authors: Savastano Luis , Liu Yang , Gebrezgiabhier Daniel , Reddy Adithya , Davis Evan , Zheng Yihao , Shih Albert , Arturo Larco Jorge , Pandey Aditya
Published: March 2021

Introduction:
Suction catheters and stent retrievers are based on the classical paradigm of “en bloc” removal of emboli by generation of tensile forces by vacuum or device withdrawal. However, in this process emboli elongate and fracture leading to fragmentation. Fragments can migrate downstream or remain impacted in the arterial wall resulting in a residual occlusion.

Hypothesis:
Clot ingestion is biomechanically superior to “en bloc” removal and leads to higher recanalization rates with less complications.

Methods:
To test this hypothesis, we present a hybrid test bed consisting of pressurized human brains which was developed and validated for large vessel occlusion (LVO) and revascularization. We fabricated 3 types of representative embolus analogs (EAs) (elastic, fragment-prone and stiff) and recreated 105 LVO in twenty-four fresh human brains with the vasculature connected to an hydraulic system to mimic physiological flow and pressures. Recanalization was attempted in 61 LVO cases by Direct Aspiration (DA) using an 068 catheter and in 44 LVO cases combining Stent Retriever with Aspiration (SR+A). Rates of successful recanalization (SR, Grade 2b or higher) and complete recanalization (CR, Grade 2c or higher) were measured. Up to 4 attempts were done before declaring a failure (Grade 2a or lower).

Results:
DA resulted in 90% of SR, 79% of CR, 61% of first pass SR and 49% of first pass CR. SR+A resulted in 34% of SR, 34% of CR, 23% of first pass SR and 14% of first pass CR. Elastic EA were associated with 88% of SR, 85% of CR, 61% of first pass SR and 52% of first pass CR. Stiff EAs were associated with 64% of SR, 64% of CR, 36% of first pass SR and 36% of first pass CR. Fragment-prone EAs were associated with 64% of SR, 40% of CR, 38% of first pass SR and 21% of first pass CR.

Conclusion:
Clot ingestion is biomechanically superior to “en bloc” removal and leads to the highest rates of SR, CR and first pass recanalization. DA achieves higher recanalization rates than SR+A. Elastic clots are associated with the highest rates or recanalization, followed by stiff clots and finally by fragment-prone clots.
Abstract P52: Temporal Progression of Cerebral Small Vessel Disease Lesions on Brain Magnetic Resonance Imaging in Spontaneously Hypertensive Stroke Prone Rats
Authors: Hannawi Yousef , Powell Kimerly A , Bratasz Anna , Ewees Mohamed G , Zweier Jay L
Published: March 2021

Introduction:
Spontaneously Hypertensive Rats- Stroke Prone (SHRSP) are a relevant model for human cerebral small vessel disease (cSVD). However, data are still lacking regarding the neuroimaging correlates of cSVD lesions in SHRSP and their temporal evolution in relationship to histological findings.

Methods:
40 SHRSP and 40 Wistar Kyoto control (WKY) male rats were divided into 4 groups (10 WKY and 10 SHRSP) per group. Systolic blood pressure (SBP) was measured using tail-cuff device, weekly. Select animals of each group had brain MRI at 9.4T machine at 7, 16, 24, and 32 weeks of age. Volumetric analysis was completed using manual segmentation of the total brain, ventricles and bilateral hippocampi. Following MRI, brain histology was completed at the same time points.

Results:
At 6 weeks, SBP was similar (WKY 123.8±0.1 vs SHRSP 130.7±3.2, P=0.09). SHRSP developed hypertension between 9-11 weeks of age and maintained it throughout the experiment (SBP at 31 weeks: WKY 138.1±6 vs SHRSP 169.1±6.7, p=0.0006). At 7 weeks, brain MRI was normal in SHRSP and WKY. Histology was largely unremarkable except for few areas of red blood cell extravasation in couple of SHRSP. At 16 weeks, MRI was normal in WKY and it showed small subcortical hyperintensity on T2 sequences in one SHRSP while histology showed microbleeds (MBs) in 85% of SHRSP. At 24 weeks, brain MRI consistently identified subcortical hyperintensities in SHRSP and H&E showed MBs in all SHRSP in addition to hemosiderin deposition and arteriosclerosis. LFB staining showed areas of demyelination in the corpus callosum. At 32 weeks, SHRSP had hydrocephalus and H&E showed widespread hemosiderin deposition. Volumetric analysis showed larger ventricles in SHRSP (SHRSP 42.3±18.1 ml vs WKY 28.4±7.2 ml, p=0.013) and ventricle size significantly increased with age in SHRSP. Hippocampal and brain volumes were similar in both groups (hippocampal volume: WKY 84.5±8.1 ml vs SHRSP 81.6±2.6 ml, p=0.39; brain volume WKY 2103.4±100.4 ml vs SHRSP 2169.6 ±164.2 ml, p=0.2).

Conclusions:
SHRSP develop cSVD histological changes early in life and brain MRI showed consistent abnormalities at a later time point. These results have implications in defining cSVD phenotypes in SHRSP in future mechanistic studies.
Abstract P526:
PON1
Q192R Alters Clopidogrel Efficacy in Patients With Coiling of Intracranial Aneurysm but Not Carotid Artery Stenting
Authors: Tanaka Koji , Matsumoto Shoji , Ainiding Gulibahaer , Nakahara Ichiro , Ishii Akira , Hatano Taketo , Iinuma Kyoko , Matsushita Takuya , Ishobe Noriko , Yamasaki Ryo , Nagata Izumi , Kira Jun-Ichi
Published: March 2021

Introduction:
The impact of the paraoxonase-1 (
PON1
) polymorphism, Q192R (rs662; c.575A>G or p.Gln192Arg), on platelet inhibition in response to clopidogrel remains controversial. We investigated the impact of
PON1
Q192R on post-clopidogrel platelet reactivity in patients undergoing coil embolization for intracranial aneurysm (IA) and carotid artery stenting (CAS).

Methods:
Between May 2010 and September 2015, 567 patients undergoing elective neurointervention with dual antiplatelet therapy were registered. On-treatment platelet reactivity was measured using a VerifyNow P2Y12 assay in P2Y12 reaction units (PRUs). High platelet reactivity (HPR) was defined as a PRU of ≥208. Genotype testing was performed for
PON1
Q192R and
CYP2C19*2
and
*3
(loss of function alleles), and
*17
. Consequently, 473 patients were eligible for further analysis. For patients undergoing coil embolization for IA or CAS, associations between ≥1
PON1
192R allele and HPR were investigated.

Results:
HPR was observed in 59.4% of 276 patients undergoing coil embolization for IA (78 male; median age, 62 years) and 47.7% of 197 patients undergoing CAS (153 male; median age, 72 years). Among patients undergoing coil embolization for IA, carriers of ≥1
PON1
192R allele demonstrated HPR more frequently compared with non-carriers (92.1% vs. 83.0%, respectively;
P
= 0.021). Carrying ≥1
PON1
192R allele was associated with HPR (adjusted odds ratio [aOR] 3.43, 95% confidence interval [CI] 1.45-8.42). In contrast, among patients undergoing CAS, the frequency of HPR was similar between carriers of ≥1
PON1
192R allele compared with non-carriers (90.4% vs. 87.4%, respectively;
P
= 0.652). Carrying ≥1
PON1
192R allele was not associated with HPR (aOR 0.95, 95% CI 0.34-2.60).

Conclusions:
PON1
Q192R is associated with HPR of clopidogrel in patients undergoing coil embolization for IA but not in patients undergoing CAS. PON1 metabolizes clopidogrel into the inactive endo isomer. By contrast, PON1 protects against low-density lipoprotein oxidation. High PON1 activity may cancel the disadvantage in clopidogrel metabolism through its antioxidant and atheroprotective effects in patients carrying ≥1
PON1
192R allele with carotid artery stenosis representing advanced systemic atherosclerosis.
Abstract P536: Impact of the Covid-19 Pandemic on the Volumes and Outcomes of Acute Ischemic Stroke and Myocardial Infarction
Authors: Nogueira Raul , Etter Katherine , Nguyen Thanh , Ikeme Shelly , Frankel Michael R , Haussen Diogo C , Del Rio Carlos , McDaniel Michael C , Sachdeva Rajesh , Devireddy Chandan , Al-bayati Alhamza R , Mohammaden Mahmoud , Liberato Bernardo , Dinesh Dinesh , Bhatt Nirav , Khanna Rahul
Published: March 2021

Introduction:
The COVID-19 pandemic has wreaked havoc on the presentation, care and outcomes of patients with acute cerebrovascular and cardiovascular conditions. We sought to measure the national impact of COVID-19 on the care for acute ischemic stroke (AIS) and acute myocardial infarction (AMI).

Methods:
In this retrospective, observational study, we used the Premier Healthcare Database to evaluate the changes in the volume of care and hospital outcomes for AIS and AMI in relation to the pandemic. The pandemic months were defined from March 1, 2020- April 30, 2020 and compared to the same period in the year prior. Outcome measures were volumes of hospitalization and reperfusion treatment for AIS and AMI (including intravenous thrombolysis [IVT] and/or mechanical thrombectomy [MT] for AIS and percutaneous coronary interventions [PCI] for AMI) as well as in-hospital mortality, hospital length of stay (LOS) and hospitalization costs were compared across a 2-month period at the height of the pandemic versus the corresponding period in the prior year.

Results:
There were 95,453 AIS patients across 145 hospitals and 19,744 AMI patients across 126 hospitals. There was a significant nation-wide decline in the absolute number of hospitalizations for AIS (-38.94%;95%CI,-34.75% to -40.71%) and AMI (-38.90%;95%CI,-37.03% to -40.81%) as well as IVT (-30.32%;95%CI,-27.02% to -33.83%), MT (-23.54%;95%CI,-19.84% to -27.70%), and PCI (-35.05%;95%CI,-33.04% to -37.12%) during the first two months of the pandemic. This occurred across low-, mid-, and high-volume centers and in all geographic regions. Higher in-hospital mortality was observed in AIS patients (5.7% vs.4.2%, p=0.0037;OR 1.41,95%CI 1.1-1.8) but not

AMI patients. A shift towards an increase in the proportion of admitted AIS and AMI patients receiving reperfusion therapies suggests a greater clinical severity among patients that were hospitalized for these conditions during the pandemic. A shorter length of stay (AIS: -17%, AMI: -20%), and decreased hospitalization costs (AIS: -12%, AMI: -19%) were observed.

Conclusions:
Our findings shed light on the combined health outcomes and economic impact the COVID-19 pandemic has had on acute stroke and cardiac emergency care.
Abstract P538: A Detailed Analysis of Intracranial Hemorrhage After Endovascular Treatment in Acute Ischemic Stroke Due to Large Vessel Occlusion in the Escape-NA1 Trial
Authors: Ospel Johanna , Hill Michael D , Kashani Nima , Mayank Arnuv , Singh Nishita , Cimflova Petra , Marko Martha , Nogueira Raul G , McTaggart Ryan A , Demchuk Andrew M , Poppe Alexandre Y , MENON Bijoy K , Tymianski Michael , Goyal Mayank
Published: March 2021

Purpose:
We investigated the prevalence and prognostic impact on outcome of any intracranial hemorrhage, hemorrhage morphology, type and volume in acute ischemic stroke patients undergoing mechanical thrombectomy.

Methods:
Prevalence of intracranial hemorrhage, hemorrhage type, morphology and volume was determined on 24h follow-up imaging (non contrast head CT or gradient-echo/susceptibility-weighted MRI). Proportions of good outcome (mRS 0-2 at 90 days) were reported for patients with vs. without any intracranial hemorrhage. Multivariable logistic regression with adjustment for key minimization variables and total infarct volume was performed to obtain adjusted effect size estimates for hemorrhage type and volume on good outcome.

Results:
Hemorrhage on follow up-imaging was seen in 372/1097 (33.9%) patients, among them 126 (33.9%) with hemorrhagic infarction (HI) type 1, 108 (29.0%) with HI-2, 72 /19.4%) with parenchymal hematoma (PH) type 1, 37 (10.0) with PH2, 8 (2.2%) with remote PH and 21 (5.7%) with extra-parenchymal/intraventricular hemorrhage. Good outcomes were less often achieved by patients with hemorrhage on follow-up imaging (164/369 [44.4%] vs. 500/720 [69.4%]). Any type of intracranial hemorrhage was strongly associated with decreased chances of good outcome (
adj
OR 0.62 [CI
95
0.44 - 0.87]). The effect of hemorrhage was driven by both PH hemorrhage sub-type [PH-1 (
adj
OR 0.39 [CI
95
0.21 - 0.72]), PH-2 (
adj
OR 0.15 [CI
95
0.05 - 0.50])] and extra-parenchymal/intraventricular hemorrhage (
adj
OR 0.60 (0.20-1.78) Petechial hemorrhages (HI-1 and HI-2) were not associated with poorer outcomes. Hemorrhage volume (
adj
OR 0.97 [CI
95
0.05 - 0.99] per ml increase) was significantly associated with decreased chances of good outcome.

Conclusion:
Presence of any hemorrhage on follow-up imaging was seen in one third of patients and strongly associated with decreased chances of good outcome.
Abstract P542: Management and Outcome of Stroke Patients With Tandem Carotid Occlusion in the ESCAPE NA1-Trial
Authors: Marko Martha , Cimflova Petra , Singh Nishita , Ospel Johanna , Kashani Nima , Mayank Arnuv , Nogueira Raul G , McTaggart Ryan A , Demchuk Andrew M , Poppe Alexandre Y , Hill Michael D , Menon Bijoy K , Goyal Mayank , Almekhlafi Mohammed A ,   on behalf of the ESCAPE NA1-Investigators
Published: March 2021

Background:
The optimal treatment for stroke patients with tandem cervical carotid occlusion is debated. We analyzed the treatment strategies and outcomes of tandem occlusion patients in the ESCAPE NA1 trial.

Methods:
ESCAPE NA1 was a multicenter international randomized trial of nerinetide vs. placebo in patients with acute ischemic stroke who underwent EVT. We defined tandem occlusions as complete occlusion of the cervical ICA on catheter angiography. The influence of tandem occlusions on outcome was analyzed using regression modeling with adjustment for age, sex, baseline NIHSS and ASPECTS, occlusion location, thrombolysis and treatment allocation.

Results:
115 of 1105 patients (10.4%) had tandem occlusions. 73/115 tandem patients (66.0%) received treatment for the cervical occlusion: 21.9% were stented before thrombectomy, 68.5% were stented after thrombectomy, and 8.2% had angioplasty alone. Successful reperfusion was significantly higher in patients who had thrombectomy first followed by carotid treatment (eTICI 2b-3: 40/40 (100.0%)) or carotid angioplasty before and cervical stent after intracranial thrombectomy (9/10 (90.0%)) compared to carotid intervention before intracranial thrombectomy: (19/23 (82.1%), p=0.016). 90-day mRS 0-2 was achieved in 82/115 patients (71.3%) with tandem occlusions (treated occlusions: 74.0%, untreated: 66.7%) compared to 579/981 (59.5%) patients without tandem occlusions. In adjusted analysis, tandem occlusion was not predictive of outcome. In the subgroup of tandem patients, cervical stent-treatment was nominally associated with better outcomes (OR 2.2, 95% CI 0.5 - 9.2).

Conclusion:
Cervical carotid stenting may improve outcomes for EVT patients with tandem occlusions, but these results are limited by the sample size and non-randomized selection of patients for stenting.
Abstract P544: Automated Artificial Intelligence Based Detection and Location Specification of Large Vessel Occlusion on CT Angiography in Stroke
Authors: Bruggeman Agnetha A , Koopman Miou , Soomro Jazba , Yoo Albert J , Marquering Henk A , Emmer Bart J , Majoie Charles B
Published: March 2021

Introduction:
Fast and accurate detection of large vessel occlusions (LVOs) is crucial in selection of patients for endovascular treatment. We assessed the diagnostic performance and speed of an Artifical Intelligence algorithm for automated LVO detection with a novel feature that specifies the exact level of occlusion.

Methods:
All Computed Tomography Angiography (CTA) imaging data were analyzed by an automated algorithm for anterior circulation LVOs (internal carotid artery (ICA), M1 or M2 segments of the middle cerebral artery) (StrokeViewer, Nico.lab). Ground truth was established by consensus of two independent neuroradiologist readings. Diagnostic performance was assessed by calculating sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). Performance of the LVO localization feature was assessed by calculating interrater agreement (Cohen’s Kappa) between the algorithm and the expert panel.

Results:
CTAs from 297 patients referred or directly admitted to a comprehensive stroke center in the United States (mean age 67 years, SD 15; 145 males) were analyzed. One-hundred and fifty-six patients had an anterior circulation LVO. Location of the occlusions was ICA (n=43 [28%]), M1 (n=79 [51%]) and M2 (n=34 [22%]). Sensitivity and specificity for LVO detection were respectively 92% (95% CI, 86.2%-95.5%) and 85% (95% CI, 78.1%-90.5%). NPV and PPV were 90% and 87% respectively. Interrater agreement between the algorithm and the expert observers for LVO location was 0.92 (95% CI, 0.86-0.98). Median upload-to-notification time for all cases was 3 minutes, 34 seconds (minimal 2:28 minutes; maximal 5:03 minutes).

Conclusions:
Anterior circulation LVOs can be rapidly and accurately detected by an automated LVO detection algorithm with reliable localization of the involved vessel segment. Therefore, the algorithm presented in this study is a suitable screening tool to support diagnosis of LVOs.
Abstract P550: Incidence, Predictors and Impact of Emboli in New Territory in Escape NA1 Trial
Authors: Singh Nishita , Cimflova Petra , Marko Martha , Ospel Johanna , Kashani Nima , Mayank Arnuv , Nogueira Raul G , Mctaggart Ryan A , Demchuk Andrew M , Poppe Alexandre Y , Hill Michael D , MENON Bijoy K , GOYAL MAYANK , Almekhlafi Mohammed
Published: March 2021

Introduction:
Emboli in new territory (ENT) are known potential complication of endovascular thrombectomy. We explored their incidence and predictors in ESCAPE-NA-1 trial.

Methods:
We included patients from the ESCAPE-NA1: a multicenter, international randomized study that assessed the efficacy of intravenous nerinetide in patients with acute ischemic stroke who underwent EVT within 12 hours from onset. All the imaging was reassessed, and ENT was defined as angiographic evidence of emboli in vascular territories other than the MCA, which was not present in the initial CT angiogram. We collected details of management and its influence on outcomes.

Results:
We analyzed 1095 patients from the ESCAPE NA1. ENT occurred in 40 patients (3.6%, mean age 69.5 years, 50% females). There were no significant differences at baseline in groups with and without ENT. Most common ENT site was ACA (38,95%). Thrombolysis, use of balloon guide catheter, nerinetide treatment, and initial occlusion site did not predict ENT. Seven ENTs (17.5%) were pursued with endovascular therapy: retrievable stents in 6 patients and intra-arterial thrombolysis in 1 patient. Patients with ENT had longer total arterial puncture to first reperfusion times (65 vs 40.5 minutes, P<0.001), and a higher final median infarct volume compared to those without ENT (77.9 vs 24.2, P<0.001). On multivariable analysis, presence of ENT was a negative predictor of clinical outcome (mRS 0-2) after adjustment for age, sex, NIHSS, ASPECTS and successful reperfusion (OR 0.26, 95%CI 0.13-0.55).

Conclusion:
The incidence of ENT was low in ESCAPE NA1 trial but associated with poorer clinical outcomes.
Abstract P552: Characteristics of Acute Stroke Intervention Therapies During Covid-19
Authors: Kolikonda Murali K , given Curtis , Ramsey Christian , Newman Ben
Published: March 2021

Background and Purpose:
We aimed to investigate the characteristics of acute stroke intervention therapies during coronavirus disease 2019 (COVID-19) pandemic.

Methods:
The data were obtained from a comprehensive stroke center in the central region of the state of Kentucky in the United States. Pre-COVID period, which is before the first confirmed case in Kentucky, from January 1 to March 5 , 2020, was compared with the COVID period from March 6 to May 9, 2020. The variables included were total number of stroke alerts, final diagnosis of stroke, stroke severity scale, thrombolysis including intravenous and intra-arterial tissue plasminogen activator administration and mechanical thrombectomy. The 2 time periods were compared using nonparametric statistics.

Results:
Total thrombectomies were increased from median, 3( Interquartile range, 1-7) during pre-COVID period to median of 7( Interquartile range, 2-17, p=0.01) during COVID period. Intravenous thrombolysis and adjunct therapy with intra-arterial thrombolysis did not differ between two time periods.

Conclusions:
We observed an increase in acute stroke intervention therapies during the surge of COVID-19 cases in Kentucky. This observation could be attributed to the increased association of COVID-19 and acute ischemic stroke.
Abstract P56: Diffusion Tensor Imaging at the Time of Stroke is Associated With Cognitive Performance 4 Months Later
Authors: Kern Kyle C , Wright Clinton B , Leigh Richard
Published: March 2021

Introduction:
Cognitive impairment after stroke is associated with stroke severity and baseline brain health. We hypothesized that acute diffusion tensor imaging (DTI) metrics would identify patients at risk for post-stroke cognitive impairment.

Methods:
Patients were enrolled prospectively in an observational study that involves serial MRI and cognitive testing in patients with recent stroke and moderate white matter disease on MRI but without dementia. DTI was performed at the time of stroke; cognitive testing with the MOCA and the Telephone Interview for Cognitive Status (TICS) were performed 3 months later. DTI was used to calculate Peak Skeletonized Mean Diffusivity (PSMD), a measure of global white matter microstructural integrity previously validated in cerebral small vessel disease. Fractional anisotropy maps were skeletonized (figure panel A) and a histogram of the corresponding MD values was used to calculate the peak width in the non-stroke hemisphere (panel B). Linear regression was used to test whether acute PSMD in the non-stroke hemisphere, acute stroke volume, or baseline NIHSS predicted cognitive performance 3 months later.

Results:
Fourteen patients followed-up at a median of 123 days. Patients had a median age of 73 years, mean baseline NIHSS of 1.2 (IQR 0-1.75), mean infarct volume of 4cc (range 0-16cc), mean MOCA of 25 (range 19-30), mean TICS of 33 (range 23-41), and 50% were women. Using multivariable linear regression, only acute PSMD predicted follow-up MOCA (std beta= -0.64, adj R
2
= 0.37, p= 0.013) while compared to baseline NIHSS, PSMD showed a stronger association with follow-up TICS score (std beta= -0.57 vs -0.44, p= 0.017; model adj R
2
= 0.476, p= 0.011)(Panel C).

Conclusions:
In this cohort of patients with small strokes we found that acute contralateral PSMD provided a measure of brain health that appears to predict cognitive performance at 3 months better than stroke size or severity. These are preliminary findings from an ongoing study.
Abstract P567: Postoperative Cerebrovascular Accident Following Symptomatic Carotid Endarterectomy (OSTIUM) A Retrospective Case-Control Study
Authors: Hood Jack , Das Abhijit , Makar Ragai , Sekhar Alakendu , Khallaf Andrew I , HEYWORTH Joanna , FARRAG Georgia , Selvarajah Bhavana , KARUNAKARAN Parthasarathy , Pulupula Kumar , Chatterjee Kausik
Published: March 2021

Introduction:
Despite considered being a safe and efficacious procedure in patients with moderate to severe symptomatic carotid artery stenosis, carotid endarterectomy (CEA) carries a risk of postoperative cerebrovascular accident (POCVA). There is currently a lack of evidence pertaining to the relationship between cranial vascular integrity and its interaction with intraoperative haemodynamic fluctuations and risk of POCVA.

Methods:
In this retrospective case-control study, we utilised data collected from patients undergoing CEA for symptomatic carotid artery disease between Dec’05 and Oct’19 in the South Mersey Arterial Centre, UK. Patients with three-dimensional CT angiogram (3D-CTA) and evidence of POCVA were considered as cases, matched with those without such evidence that were considered as controls. 3D-CTAs were analysed following a structured proforma, and haemodynamic changes were obtained from operative notes.

Results:
Out of 951 patients, a total of 21 cases and 55 matched controls were identified. Presence of atherosclerotic disease in the vertebral arteries (VA) in either side, intracranial atherosclerosis (ICAS) (81% vs 40% and 57% vs 27%; <0.01, p<0.05 respectively), and drop in the systolic blood pressure (mean
+
SD 61
+
23 mmHg vs. 44
+
20 mmHg, p<0.01) were significantly different between the cases and the controls (fig 1). A multivariate logistic regression model showed that odds of stroke were increased with VA stenosis on either side (OR 6·5, 95% CI 1·7-24·6, p=0.006) and intraoperative systolic blood pressure drop greater than 44 mmHg (OR 6·6, 95% CI 1·6-27·6, p=0.01).

Conclusions:
These findings highlight the importance of routinely identifying posterior circulation abnormalities during the preoperative assessment, and judicious blood pressure management during the intraoperative period, both of which have the potential to help to develop a personalised risk stratification pre-CEA and greater intraoperative monitoring during CEA.
Abstract P571: Effects of Renal Insufficiency on Congestive Heart Failure and Coronary Artery Disease Burden in Patients Undergoing Elective Percutaneous Coronary Intervention
Authors: Doshi Kajol , Harutyunyan Misak , Yager Neil , Schulman-marcus Joshua , Torosoff Mikhail
Published: March 2021

Background:
We investigated coronary artery disease (CAD) burden and rates of death and stroke in stable patients with renal insufficiency undergoing elective percutaneous coronary intervention (PCI).

Methods:
Data from 2015 NY state Angioplasty registry was utilized. There were 33,508 PCI recipients (65+/-11 years old; 32% females, 40% with diabetes, 6.4% with COPD, 6.9% with history of CHF, and 8.25% with peripheral artery disease) without history of recent myocardial infarction (MI in less than 24 hours), shock, or prior coronary artery bypass surgery. Patients were divided according to the glomerular filtration rate (GFR) status consistent with the National Kidney Foundation classification: 24% had a GFR more than 90 ml/min (group G1) , 49% GFR of 60-89 (G2), 15% GFR of 45-49 (G3a), 6.9% GFR 30-44 (G3b), 2% GFR of 15-29 (G4), and 4% with GFR of less than 15 ml/min (G5).

Results:
With decline in GFR, prevalence of CHF increased significantly. CHF was present in 3.6% of G1 patients undergoing elective PCI, 4.49% of G2, 10.20% of G3a, 17% of G3b, 22.26% of G4 and 22.20% of G5 patients (P<0.0001). With decline in GFR, CAD burden was also significantly increased. Left main or three vessel CAD was present in 19.39% of G1 patients undergoing elective PCI, 19.13% of G2, 22.62% of G3a, 25.83% of G3b, 29% of G4 and 27.8% of G5 patients (p<0.001). Furthermore, advanced kidney disease was associated with increased rates of post elective PCI stroke and death. Specifically, post PCI stroke occurred in 0.11% of G1 patients, 0.13% of G2, 0.33% of G3a, 0.27% of G3b, 0.7% of G4, and 0.6% of G5 patients (p<0.001). Similarly, post elective PCI mortality occurred in 0.16% in G1 patients, 0.19% in G2, 0.41% in G3a, 1.04% in G3b, 1.22% in G4 and 1.49% in G5 patients (p<0.0001). After adjustment for co-morbidities such as diabetes, CVD, and COPD, risk of post PCI stroke and death was significantly increased by 3.528 (95%CI 1.866-6.671, p<0.0001) in patients with GFR less than 15 ml/min.

Conclusion:
In patients undergoing elective PCI, renal insufficiency is associated with increased rates of post-procedural death and stroke as well as increased prevalence of CHF. Additional research is needed to decrease risk of elective interventions in this vulnerable group of CAD patients.
Abstract P572: Cerebral Hemodynamics Underlying Artery-To-Artery Embolism in Symptomatic Intracranial Atherosclerotic Disease
Authors: Leng Xinyi , Feng Xueyan , Chan Ka Lung , Fang Hui , Lan Linfang , Abrigo Jill , Ip Hing Lung , Soo Yannie O , Xu Yuming , Leung Thomas W
Published: March 2021

Background:
Artery-to-artery embolism (AAE) is a common stroke mechanism in patients with symptomatic intracranial atherosclerotic disease (ICAD), which might be associated with a higher risk of recurrent stroke than other stroke mechanisms. We aimed to investigate cerebral hemodynamic features associated with AAE in symptomatic ICAD patients.

Methods:
Patients with acute, anterior-circulation ischemic stroke attributed to ICAD (50-99% stenosis) confirmed in CT angiography (CTA) were recruited from two teaching hospitals. We classified probable stroke mechanisms as isolated parent artery atherosclerosis occluding penetrating artery (PAO), AAE, hypoperfusion, and mixed mechanisms, based on infarct topography in MRI and ICAD lesion features. CTA-based computational fluid dynamics (CFD) models were built to simulate blood flow across culprit ICAD lesions. Translesional pressure ratio (PR=Pressure

post-stenotic

/Pressure

pre-stenotic

) and translesional wall shear stress ratio (WSSR=WSS

stenotic-throat

/WSS

pre-stenotic

) were calculated, to reflect the relative change of the two hemodynamic metrics across an ICAD lesion. PR ≤ median was defined as low PR, indicating a larger pressure gradient across the lesion; and WSSR ≥ 4
th
quartile as high WSSR, indicating elevated WSS upon the lesion. We associated PR and WSSR with presence of AAE as a probable stroke mechanism.

Results:
Among 99 symptomatic ICAD patients, 44 had AAE as a probable stroke mechanism, 13 with AAE alone and 31 with coexisting hypoperfusion; the remaining patients respectively had isolated PAO (n=18) and isolated hypoperfusion (n=37) as the probable stroke mechanisms. High WSSR was independently associated with AAE (adjusted OR 4.21; 95% CI 1.33-13.26; p=0.014). The significant, positive relationship between high WSSR and higher risk of AAE remained in those with a low PR (adjusted OR 4.01; 95% CI 1.03-15.46; p=0.044), but not in those with a normal PR (p=0.621).

Conclusions:
High WSS upon ICAD lesions may increase plaque vulnerability and lead to distal embolism, while sustained antegrade flow across the ICAD lesion (normal PR) may help clear the emboli. In secondary prevention of symptomatic ICAD with AAE, impaired cerebral perfusion may be a therapeutic target.
Abstract P577: An Association Between CHADS-VASc Score Morbidities, Coronary Artery Disease Severity, and Post-Elective Percutaneous Coronary Intervention Stroke and Death
Authors: Harutyunyan Misak , Torosoff Mikhail , Yager Neil
Published: March 2021

Background:
The CHADS-VASc score is a clinical prediction tool used to assess stroke risk in patients with atrial fibrillation or flutter. An association between CHADS-VASc score morbidities and outcomes of elective percutaneous coronary intervention (PCI) has not been well studied.

Methods:
This cohort study utilized 2015 NY State Angioplasty Registry data and included 33,568 consecutive patients. Patients with prior CABG, shock, or acute coronary syndrome (ACS) within 24-hours of PCI placement were excluded. CHADS-VASc score was calculated by adding 1 point each for positive history of congestive heart failure (CHF), diabetes mellitus (DM), vascular disease, age 65-75 years old, female sex, and 2 points each for age >75 years old and history of stroke. As the Registry does not record history of hypertension, the calculated score used 0 for hypertension in all patients.

Results:
In the studied cohort, 68.4% were males, mean age 65.5 +/- 11.5 years old. Increased burden of CHADS-VASc morbidities was associated with more advanced CAD, including 3 vessel and left-main (LM) CAD. Of patients with CHADS-VASc score of 0, 16.3% had 3 vessel disease and 0.7% had LM disease, score of 3 had 20% 3 vessel disease and 2.3% LM disease, and score of 6 and/or 7 had 31.2% 3 vessel disease and 5.7% LM disease (p<0.0001). Increased burden of CHADS-VASc morbidities was also associated with increasing incidence of post-elective PCI stroke and mortality. Stroke was observed in 0.03% of cases with score of 0, 0.3% of cases with score of 3, and 1.4% of cases with score of 6 and/or 7 (p<0.0001). Mortality rate was 0.05% in patients with score of 0, 0.7% with score of 3, and 1.4% in patients with score of 6 and/or 7 (p<0.0001).

Conclusions:
This pilot study indicates that increased burden of CHADS-VASc morbidities is associated with more advanced CAD and increased incidence of post-elective PCI stroke and mortality. These data suggest that the simple CHADS-VASc calculation may be useful in identifying patients at greater risk of post-elective PCI complications, aid in estimating patient prognosis, and provide a reference point for clinicians contemplating PCI in stable CAD patients.
Abstract P579: Fluid Attenuated Inversion Recovery Correlates With Time of Onset of Arterial Ischemic Stroke in Childhood
Authors: Shaw Dennis , Barry Dwight , Abraham Michael G , Cummings Dana D , MacKay Mark T , Rivkin Michael J , Amlie-lefond Catherine
Published: March 2021

Background:
In adults, time since stroke onset correlates with efficacy and risk of recanalization therapies; beyond this temporal window there is increased risk of adverse events in particular hemorrhage with thrombolysis and decreased benefit of recanalization due to irreversible tissue injury. In adults the appearance of fluid attenuated inversion recovery (FLAIR) signal is a proxy for time, and is typically present by 6 hours. The time to FLAIR signal hyperintensity in childhood stroke is unknown but is of interest with potential utility due to the often greater uncertainty as to timing symptom onset.

Methods:
Time to FLAIR signal hyperintensity on brain MRI performed on children within 24 hours of stroke onset was studied with logistic regression.

Results:
A total of 68 MRIs with FLAIR imaging were available from 54 children (27 female), age 0.8 to 17.9 years, median 12.0 years. Seventy-four percent (40/54) of children and 72% (49/68) of scans had anterior circulation stroke. Interquartile range for time to FLAIR presence was 7.8 to 19.1 hours. The 90% probability of FLAIR change was reached at 11.2 hours for all strokes (Figure, dotted line; 80% highest density interval (HDI): 1.2-11.2 hours), and 9.3 hours for anterior circulation only strokes (Figure, solid line; 80% HDI: 3.3-9.3 hours), though nearly all had FLAIR change by 6 hours. FLAIR change was absent in 4 children after 6 hours, two with anterior circulation stroke (16 year-old at 6.1 hours, 10 year-old at 7.0 hours) and 2 with posterior circulation stroke (15 year-old at 7.3 hours, 9 month-old at 18.2 hours).

Conclusion:
Similar to adults, FLAIR hyperintensity can be used to estimate time since stroke ictus in childhood stroke. Children may have somewhat delayed time to FLAIR signal change compared with adults, suggesting that they may have a longer window for effective recanalization therapies.
Abstract P586: Care and Outcomes of Pediatric Community vs. In-Hospital Stroke
Authors: Ortolani Elissa , Cummings Dana
Published: March 2021

Introduction:
In-hospital stroke refers to stroke occurring during an acute care hospitalization. Unlike stroke occurring in the community, there is a potential for rapid diagnosis and treatment given access to resources. Existing research in adults however suggest higher rates of morbidity and mortality compared to community onset stroke patients. Worse outcomes may be multifactorial, including risk factors inherent to the inpatient status and relative contraindication for acute therapy . However, little is known of the care and outcomes of in hospital stroke in pediatric patients.

Objectives:
Our goal was to evaluate the stroke care and outcome of pediatric patients with in-hospital and community onset stroke. Our primary outcome was the time from stroke symptoms to the first neuroimaging procedure( less than 4.5 hours, 4.5 to 12 hours, 12 hours to 24 hours or greater than 24 hours). Secondary outcomes include type neuroimaging preformed, stroke risk factors, clinical stroke presentation, length of stay, and discharge destination.

Methods:
Retrospective chart review of children > 28 days and less than or equal to 18 years with diagnosis of acute stroke by clinical and radiographic criteria admitted between January 2009 and September 2019.

Results:
We screened a total of 779 patients, and identified 63 patients with in hospital strokes and 109 patients with community strokes. The largest percentage of in-hospital strokes had imaging obtained between 4.5 to 12 hours from last known well vs. over 24 hours in the community stroke group. CT was the most common imaging obtained in both groups. The major stroke risk factor was cardiac disease in the in-hospital stroke group versus infection in the community group. Clinical presentation was more common to be focal in the community group, versus non-focal in the in-hospital group. Length of stay was longer in the in-hospital stroke group and discharge destination was more commonly rehab in the in-hospital group vs. home in the community group .Mortality was higher in the in-hospital population.

Conclusion:
Patients with in-hospital stroke have more rapid diagnosis, but have increase rates of mortality . Presentations in this group are more commonly non-focal, and the largest stroke risk factor is cardiac disease.
Abstract P593: Association Between Troponin and Ischemic Stroke Recurrence in the Greater Cincinnati/Northern Kentucky Stroke Study
Authors: Merkler Alexander E , Sucharew Heidi , Alwell Kathleen S , Haverbusch Mary , Rothenberg Florence , Kissela Brett , Ferioli Simona , Mackey Jason , Woo Daniel , De Los Rios La Rosa Felipe , Demel Stacie L , Star Michael , Coleman Elisheva R , Walsh Kyle B , Slavin Sabreena , Jasne Adam , Mistry Eva , Kamel Hooman , Kleindorfer Dawn
Published: March 2021

Introduction:
Elevations in troponin (cTn) are common in patients with acute ischemic stroke, yet their significance remains uncertain.

Hypothesis:
Elevated cTn at the time of acute ischemic stroke is associated with ischemic stroke recurrence.

Methods:
We included all adult patients with acute ischemic stroke who were residents of the Greater Cincinnati/Northern Kentucky region and who presented to an emergency department (ED) in 2015 and who had a cTn measured within 24 hours of ED arrival. Our exposure variable was an elevated cTn, defined as a value exceeding the laboratory’s 99
th
percentile. Our primary outcome was ischemic stroke recurrence, defined as a new ischemic stroke with radiographic confirmation in the 3 years following the index ischemic stroke event. Cox proportional hazards model was used to evaluate the association between elevated cTn and ischemic stroke recurrence while adjusting for demographics, vascular risk factors, and stroke severity. In a secondary analysis, we excluded patients with a concomitant adjudicated myocardial infarction (MI) at the time of the index ischemic stroke.

Results:
Among 2,334 patients with acute ischemic stroke, 1,992 (85%) had a cTn assay within 24 hours of ED arrival and were included in the analysis. 402 (20%) patients had an elevated cTn and 259 (13%) patients had a recurrent ischemic stroke. 66 (3%) patients had an elevated cTn and a concomitant acute MI and 336 (17%) patients had an elevated cTn without a concomitant acute MI. After adjustment for demographics, vascular risk factors, and stroke severity, we found

an association between elevated cTn and recurrent ischemic stroke (hazards ratio [HR], 1.5; 95% CI, 1.1-2.0). Our results were unchanged after excluding patients with a concomitant adjudicated MI (HR 1.4; 95% CI, 1.03-2.0).

Conclusions:
Among patients with acute ischemic stroke, elevated cTn even in the absence of concomitant adjudicated MI, was associated with ischemic stroke recurrence. Further mechanistic studies are necessary to explore the underlying etiology of hypertroponinemia among patients with acute ischemic stroke in order to guide targeted therapies to reduce stroke recurrence.
Abstract P6: Impact of Ethnicity on the Outcomes of Mechanical Thrombectomy- Insights From Star
Authors: Almallouhi Eyad , Al Kasab Sami , Alawieh Ali , Chen Stephanie , BURKS JOSHUA , Wolfe Stacey , Jabbour Pascal M , Levitt Michael , Arthur Adam S , De Leacy Reade A , Grossberg Jonathan A , Ogilvy Christopher S , Park Min S , Raper Daniel , Polifka Adam , Crowley R. Webster , Dumont Travis , Osbun Joshua , Crossa Roberto , Maier Ilko , Kim Joon-Tae , Casagrande Walter , Rai Ansaar , Chowdhry Shakeel , Mokin Maxim , Matouk Charles , Fragata Isabel , Williamson Richard , Yoo Albert J , Mascitelli Justin , Kan Peter , Psychogios Marios , Fargen Kyle , Starke Robert , Spiotta Alejandro M
Published: March 2021

Introduction:
Previous studies have reported that Hispanic stroke patients have limited access to mechanical thrombectomy (MT) compared to other ethnic groups. This has resulted in worse stroke outcomes in this group. However, limited data is available about the outcomes of MT in Hispanic patients.

Methods:
We used data from the Stroke Thrombectomy and Aneurysm Registry (STAR) that combined the prospectively maintained databases of 28 thrombectomy-capable stroke centers in the US, Europe, and Asia. Consecutive patients who underwent MT were included in these analyses and patients were divided into 2 groups (Hispanics vs. non-Hispanics). Baseline features, time from symptom onset, thrombolysis receipt, final thrombolysis in cerebral infarction (TICI) score, symptomatic hemorrhage, and 90-day functional outcomes (measured by modified Rankin scale-mRS) were compared between Hispanic and non-Hispanics patients. A generalized linear model with logit link was used to assess the relationship between ethnicity and favorable outcomes at 90-day (mRS 0-2) controlling for confounders.

Results:
We included 2015 patients in these analyses. Of those, 285 (14.1%) were Hispanic. As shown in table 1, Hispanic patients were older (72 vs. 70, p=0.007), more likely to have diabetes (41.1% vs. 26.5%, p<0.001), and more likely to have hypertension (81.8% vs. 73.7%, p=0.004). Importantly, Hispanics had a shorter procedure duration with a similar rate of successful recanalization (TICI≥2B). On multivariable analysis, Hispanic ethnicity was associated with a lower probability of favorable 90-day outcome (aOR 0.659, 95% CI 0.494-0.879, P=0.005) after controlling for age, stroke risk factors and location of occlusion.

Conclusion:
Hispanic patients receiving MT have higher rate of stroke risk factors including diabetes and hypertension. Moreover, Hispanic ethnicity was independently associated with lower probability of favorable 90-day outcome.
Abstract P603: Atrial Cardiopathy and Brain Infarction in Multiple Vascular Territories in the ARCADIA Trial
Authors: Kamel Hooman ,   ARCADIA Investigators
Published: March 2021

Introduction:
Some embolic strokes of undetermined source (ESUS) are likely caused by occult cardiac embolism. One potential cardioembolic source is atrial cardiopathy without atrial fibrillation (AF). Patients with cardiac embolism more often have brain infarcts in multiple vascular territories than those with stroke mechanisms not involving a central embolic source.

Hypothesis:
In patients with ESUS, atrial cardiopathy is associated with brain infarction in multiple vascular territories.

Methods:
The ARCADIA trial is enrolling ESUS patients, screening them for atrial cardiopathy, and randomly assigning those with atrial cardiopathy to aspirin or apixaban. In the trial, atrial cardiopathy is defined as ≥1 of the following: P-wave terminal force >5,000 μV*ms in ECG lead V
1
, serum NT-proBNP >250 pg/mL, and left atrial diameter index ≥3 cm/m
2
on echocardiogram. Site investigators report whether the index CT or MRI showed brain infarction in the left carotid, right carotid, or posterior circulation, or some combination. In this analysis, our primary outcome was brain infarction in more than one of these three vascular territories. Our secondary outcome was infarction in both the left and right carotid territories.

Results:
Among 1,707 ESUS patients enrolled in ARCADIA, 679 (39.8%) met the trial’s randomization criteria for atrial cardiopathy and 213 (12.5%) had multi-territorial brain infarcts. The prevalence of brain infarction in more than one vascular territory was 14.0% in those with atrial cardiopathy versus 11.5% in those without (prevalence ratio, 1.22; 95% CI, 0.95-1.57). The prevalence of brain infarction in both the left and right carotid territories was 9.1% in those with atrial cardiopathy versus 7.4% in those without (prevalence ratio, 1.24; 95% CI, 0.90-1.70).

Conclusions:
These preliminary analyses from ARCADIA suggest a possible association between atrial cardiopathy and brain infarction in multiple vascular territories, but further analysis of a larger sample is needed to conclusively test whether our atrial cardiopathy definition is associated with the classic neuroimaging profile of cardiac embolism.
Abstract P608: Risk of Cancer Following an Ischemic Stroke: A Retrospective Cohort Study From the Canadian Longitudinal Study on Aging
Authors: Rioux Bastien , Gioia Laura C , Keezer Mark R
Published: March 2021

Background:
Cancer promotes thromboembolism through inflammation and hypercoagulability, and an ischemic stroke may be the first sign of an occult malignancy. Stroke survivors may be at higher risk of incident cancer diagnosis, although the magnitude and the period at risk remain unclear. We conducted a retrospective cohort study to compare the risk of cancer in stroke survivors to that of the general population.

Methods:
The Canadian Longitudinal Study on Aging (CLSA) is a large, national population-based cohort of Canadian women and men aged 45-85 years when recruited between 2011 and 2015. Participants provided information on socio-demographics and prior diagnoses. We used data from the comprehensive sub-group (n=30,097) to build a retrospective cohort of participants with and without prior stroke by exact matching for age (1:4 ratio). We used log-binomial regression models to estimate the risk of cancer in people with versus without ischemic stroke while adjusting for shared risk factors.

Results:
We included 920 individuals in the stroke group and 3,680 individuals in the control group, respectively followed for a median of 10 (interquartile range [IQR]: 4, 17) and 11 years (IQR: 5, 19). Most inclusion events in the stroke group were minor strokes or transient ischemic attacks (n=614, 66.7%). We observed a higher incidence of cancer in the first year after stroke that declined thereafter (p=0.030). The risk of new cancer diagnosis after stroke was significantly increased (relative risk: 2.38; 95% confidence interval: 1.18, 4.63; p-value=0.012) after adjustments. The most frequent primary cancers in the first year after stroke were prostate (n=8, 57.1%) and melanoma (n=2, 14.3%).

Conclusions:
The risk of new cancer diagnosis in the first year after an ischemic stroke is about 2.4 times higher as compared to age-matched individuals from the general population without stroke after adjustments. Surveillance bias may explain a portion of post-stroke cancer diagnoses in the stroke group although a CLSA tendency to recruit healthier participants likely led to an underestimation of post-stroke cancer risk. Prospective experimental trials are needed to quantify the potentially pressing need to screen for post-stroke cancer.