bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP232: Association Between Myocardial Infarction Size and Location and Cerebral Infarction
Authors: Merkler Alexander E , Alakbarli Javid , Barbar Tarek , Adejumo Oluwayemisi , Kamel Hooman , Kim Jiwon , Okin Peter , Gupta Ajay , Weinsaft Jonathan
Published: June 2021

Introduction:
Myocardial infarction (MI) is associated with cerebral infarction. We assessed whether MI size and location is related to the risk of cerebral infarction.

Methods:
We performed a cross-sectional study of patients evaluated between 2014-2017 at New York-Presbyterian Hospital/Weill Cornell Medicine. We included all adults who underwent both brain MRI and delayed-enhancement cardiac MRI (DE-CMR) within 365 days of each other and had evidence of MI on DE-CMR. We evaluated associations between MI size and any cerebral infarction, apical MI and any cerebral infarction, and between MI size/location and cortical versus subcortical cerebral infarction. We used multiple logistic regression models adjusted for age, sex, race, and the total number of vascular risk factors.

Results:
We identified 234 patients who underwent DE-CMR and brain MRI within 365 days, among whom 76 had evidence of MI on DE-CMR. Of these 76 patients, 51 (67.1%) had evidence of cerebral infarction. There was no association between the size of MI (global MI burden) and any cerebral infarction (OR per 1% increase in MI size, 1.02; 95% CI, 1.0-1.1;
P
= 0.43), but there was an association between MI size and cortical cerebral infarction (OR per 1% increase in MI size, 1.05; 95% CI, 1.0-1.1;
P =
0.047). We found no association between apical MI location and any cerebral infarction (OR 3.2, 95% CI, 0.9-12.2,
P
= 0.08), but there was an association between apical MI location and cortical cerebral infarction (OR, 3.7; 95% CI, 1.2-11.3;
P =
0.02).

Conclusion:
Among patients with MI on cardiac imaging, MI size and apical MI location were associated with cortical cerebral infarction. Our results may help stratify cardioembolic risk and lead to improved antithrombotic treatment algorithms among patients with MI.
Abstract WP233: Unraveling the Profile and Risk Factors of Post-Stroke Cognitive Impairment Among West African Stroke Survivors: Data From the SIREN Study
Authors: Akinyemi Rufus , Ovbiagele Bruce , Akpa Onoja , Sarfo Fred , Akinyemi Joshua , Akpalu Albert , Wahab Kolawole , Obiako Reginald , Owolabi Lukman , Owolabi Mayowa
Published: June 2021

Background:
There is paucity of data on the epidemiology of post-stroke cognitive impairment among African stroke survivors. The aim of this study is to report the profile and risk factors of post- stroke cognitive impairment among stroke survivors participating in the Stroke Investigative Research and Education Network (SIREN) Study.

Methods:
1566 were evaluated with the Montreal Cognitive Assessment (MoCA) tool, the Community Screening Instrument for Dementia (CSID) and the Stick Design Test three months after the index stroke. Domain scores were derived for executive function, language memory and visuo-constructive/visuospatial domains. Cut off scores were derived from normative cognitive data obtained from comparable healthy stroke-free control subjects. We used conditional logistic regression to estimate odds ratios (OR) with 95% CIs.

Results:
Of 1566 stroke survivors [mean age 57.7 (13.4) years] who were assessed 3 months after stroke, 37% were impaired in global cognition and 18-43% were impaired in different domains of cognition (executive, memory, language and visuo-constructive). Stroke severity measured by modified NIHSS score had a strong significant negative association with cognitive function in all domains OR 1.96(1.32-2.91). Older age 1.04 (1.02-2.05), male gender 0.69 (0.50 -0.96), low intake of green leafy vegetables 2.83 (2.03 -3.95) and cardiac disease 1.86 (1.31 -2.75) were associated with poorer cognitive performance in different cognitive domains.

Conclusion:
The frequency of post-stroke cognitive impairment was high among African stroke survivors three months after the ictus. Diet low in green leafy vegetables is a potentially modifiable risk factor for post-stroke cognitive impairment among West Africans.
Abstract WP237: Facilitators and Barriers to Medication Adherence Among Stroke Survivors in India
Authors: SD Shani , Kutty Vr , Varma Rp , VT Jissa , PN Sylaja
Published: June 2021

Background:
Medication nonadherence is a major problem and is an important mediator between the treatment and the outcome. Strict compliance with medication and life style modification are integral to secondary stroke prevention.

Methods:
Cross sectional survey among 240 stroke survivors within a post-stroke period of three months to one year was conducted. Interview based self-reported medication adherence was defined as consumption at least more than 80% of their medication, based on their last prescription. Medication adherence was calculated for five categories of medication; antiplatelets, antihypertensives, antidiabetics, statin and anticoagulants. Overall adherence was defined as adherence to all the categories of medications prescribed. Structured interview using pretested interview schedule was done to collect sociodemographic data, health care seeking behaviour, life style, facilitators and barriers to medication adherence.

Results:
Stroke survivors [n=240; mean age 58.64 ±10.96 years); 25.4% females; post-stroke period of 6.65±3.36 months] were interviewed. Patients with diabetes, hypertension and dyslipidaemia constituted 64.2%, 88.8% and 96.7% and optimal control was achieved in 26%, 36.2% and 72.9% respectively. Overall medication adherence was 43.8% (n=240). Adherence to antiplatelet was 62.24% (n=196). Medication adherence was 34.4% (n=134), 52.6% (n=190) and 56.7% (n=224) for antidiabetics, antihypertensives and statins respectively and was associated with risk factor control (Diabetes: Odds Ratio(OR)=4.85;95% Confidence Interval(CI) 2.12-11.08, Hypertension: OR=3.42; 95% CI 1.83-6.4, Dyslipidaemia: OR=3.88;95% CI 1.96-7.69). Having daily routines (OR=2.82;95% CI 1.52-5.25), perceived need of medication (OR= 2.33;95% CI 1.04-5.2) and perceived poor state of health (OR= 3.09; 95% CI 1.44-6.62) as facilitators. Memory problem (OR 0.32; 95% CI 0.51-0.66), experiencing side effects (OR 0.24; 95% CI 0.11-0.53) and belonging to below poverty line (OR 0.46; 95% CI 0.24-0.91) were barriers to medication adherence.

Conclusion:
Establishing daily routines, periodic reminders, and financial supports to buy medicines and patient education can enhance medication adherence to prevent future strokes.
Abstract WP238: Atrial Fibrillation is Associated With Severe Basal Ganglia Perivascular Spaces
Authors: Das Alvin S , Gokcal Elif , Regenhardt Robert W , Warren Andrew , Schwab Kristin , Viswanathan Anand , Greenberg Steven M , Rost Natalia S , Rosand Jonathan , Schwamm Lee H , Gurol Edip
Published: June 2021

Introduction:
High burdens of basal ganglia-perivascular spaces (BG-PVS) are often attributed to underlying hypertensive cerebral small vessel disease (HTN-CSVD). Although PVS are thought to arise from decreased perivascular drainage related to changes in arterial pulsatility, the contribution of pulsatility changes from nonvalvular atrial fibrillation (NVAF) has not been studied.

Hypothesis:
We hypothesized that NVAF patients have a higher burden of BG-PVS than HTN-CSVD patients, possibly through hemodynamic factors related to NVAF.

Methods:
Through an observational single-center study of consecutive stroke patients, we compared BG-EPVS severity between 136 patients with NVAF-related ischemic stroke (NVAF-IS) and 107 patients with HTN-CSVD-related intracerebral hemorrhage (HTN-ICH) without NVAF. Within the NVAF cohort, we also built multiple regression models to evaluate independent effects of NVAF-related factors on BG-PVS. All multiple regression models were adjusted for age, hypertension, sex, and neuroimaging markers of CSVD (extent of white matter hyperintensities (WMH), presence of lacunes, and cerebral microbleeds).

Results:
Patients with NVAF-IS were older than patients with HTN-ICH (75
+
12 vs. 64
+
13,
p
< 0.0001); however, there was no difference in sex between groups (
p
= 0.6). Severe BG-PVS (defined as > 20 PVS in the BG) were found in 42.6% of NVAF-IS patients vs. 8.4% of HTN-ICH (
p
< 0.0001). Even after multivariate adjustment, the presence of NVAF remained significantly related to BG-PVS (
p
= 0.001). Within the NVAF cohort, CHA2DS2-VASc was associated with the presence of severe BG-PVS (
p
= 0.003) despite controlling for other covariates. When CHA2DS2-VASc was replaced with its individual components in the same regression model, congestive heart failure (CHF,
p
= 0.017), WMH burden (
p
= 0.009), and age (
p
= 0.02) were found to be predictors of severe BG-PVS.

Conclusions:
Severe BG-PVS were significantly more common in NVAF patients compared to HTN-CSVD patients. NVAF-related features (CHA2DS2-VASc score) and CHF were associated with higher burdens of BG-PVS. These findings suggest that NVAF might play a role in the development of BG-PVS, conceivably through hemodynamic factors.
Abstract WP246: Characteristic of Ischemic Stroke Prior Taking Direct Oral Anticoagulant versus Warfarin Treatment: Results From the PASTA Registry
Authors: Suda Satoshi , Iguchi Yasuyuki , Fujimoto Shigeru , Yagita Yoshiki , Mizunari Takayuki , Yamazaki Mineo , Kono Yu , Kimura Kazumi ,   PASTA investigators
Published: June 2021

Background and Purpose:
The characteristics of patients with stroke prior receiving direct oral anticoagulant (DOAC) have not been fully clarified. We planned to recruit patients prospectively and to investigate the characteristics and outcomes in stroke patients taking DOAC and warfarin treatment prior to the event.

Methods:
The prospective analysis of stroke patients taking anticoagulants (PASTA) registry study is an observational, multicenter, prospective registry of stroke patients receiving OAC. Patient enrollment started in April 2016 at 25 tertiary centers across Japan. We compared clinical characteristics and discharge modified Rankin Scale (mRS) between DOAC-and warfarin-treatment in patients with atrial fibrillation (AF).

Results:
A total of 580 patients (231 women; median age 80 [quartiles 73-84] years) were analyzed (Fig. A). Of these, 365 patients (63%) received prior DOAC treatment and the remaining 215 (37%) received prior warfarin treatment (Fig. B and C). There were significant differences in clinical characteristics and outcome between DOAC-and warfarin-treatment prior to the event regarding initial NIHSS score (median [quartiles]: DOAC, 4 [2-16] vs. warfarin, 9 [3-21];
P
=0.0001), rate of medium-large size of infarct (DOAC, 202/340 [59%] versus warfarin, 152/203 [75%];
P
=0.0003) and the proportion of patients with favorable outcome (mRS, 0-3: DOAC 218/354 [62%] vs. warfarin 108/212 [49%];
P
=0.0036). Subclassification according to DOAC dosing revealed patients with low-dose (259/365; 71%) to be older and to have a higher NIHSS score compared with regular dose (low-dose, 5 [2-17] vs. regular-dose, 3 [1-11];
P
=0.0023) (Fig. D). Type of DOAC agent did not result in relevant differences in clinical characteristics or outcome (Fig. E).

Conclusions:
Our results showed that patients with DOAC treatment before the event showed smaller infarct size, milder initial stroke severity, and favorable outcome compared to patients with warfarin.
Abstract WP248: PFO Shunting is Associated With Increased Long-Term Risk of Dementia
Authors: Deng Wenjun , McMullin David , Buonanno Ferdinando , Lo Eng , Ning MingMing
Published: June 2021

Background:
Right-to-left interatrial shunting through a patent foramen ovale (PFO) has been associated with white matter lesions in literature and in our data. Since white matter lesions, particularly those in the periventricular and subcortical regions, increase the risk of cognitive impairment, we investigate the relationship between PFO shunting and dementia.

Method:
1078 consecutive PFO stroke patients were prospectively recruited in accordance with IRB protocol. No patient had diagnosis of dementia prior to initial stroke. PFO shunt size was evaluated by echocardiography with saline contrast. Cognitive status and recurrent events were followed for up to 11 years.

Result:
27 patients (2.50%) developed vascular cognitive impairment and dementia over 11 years. As expected, dementia patients were older (p<0.001) and were more likely to have hypertension (p<0.001) and hyperlipidemia (p=0.001) (Table 1). Notably, the dementia patients were also more likely to have a large PFO shunt (22.2% vs 8.3%, p=0.023). The association of PFO shunt and dementia remained robust (Odds ratio: 3.07; 95% CI: 1.11~8.55; p=0.031) after adjusting for important traditional risk factors (age, hypertension, hyperlipidemia, diabetes). But PFO risk factors (hypermobile septum, atrial septal aneurysm) that enhance PFO shunting remain significant (Table 2).

Conclusion:
Our study provides support for the hypothesis that the presence of large PFO right-to-left shunting is associated with increased risk of later dementia. We previously reported that PFO shunting enables vasoactive factors to stay elevated in circulation and to contribute to cerebrovascular dysfunction. We hypothesize here that prolonged exposure to PFO shunting may lead to cognitive decline. Further studies assessing PFO shunt size, dementia severity, and other confounders in a non-stroke PFO cohort are ongoing to validate these findings.
Abstract WP25: The Impact of Body Mass Index on Outcomes of Mechanical Thrombectomy for Acute Ischemic Stroke
Authors: Chen Stephanie , McCarthy David , Saini Vasu , Brunet Marie , Peterson Eric , Yavagal Dileep R , Starke Robert
Published: June 2021

Background:
Obesity is an established risk factor for acute ischemic stroke (AIS), but its impact on clinical outcomes and mortality after AIS remains controversial. In this study, we evaluate the association of body mass index (BMI) on outcomes after mechanical thrombectomy (MT) for large vessel occlusion acute ischemic stroke (LVOS).

Methods:
We reviewed our prospective MT database for LVOS between 2015 and 2018. BMI was analyzed as a continuous and categorical variable with underweight BMI <18.5, normal BMI 18.5-24.9, overweight BMI 25-29.9, and obese BMI>30. Multivariate analysis was used to determine predictors of outcome.

Results:
335 patients underwent MT with 7 (2.1%) patients classified as underweight, 107 (31.9%) normal, 141 (42.1%) overweight, and 80 (23.9%) obese. Compared to normal weight (reference), obese patients had higher rates of hypertension and hyperlipidemia, while underweight patients had higher rates of previous stroke and presentation NIHSS. The time from symptom onset to puncture, procedural techniques, and reperfusion success (>TICI 2b) was not significantly different between BMI categories. There was a significant inverse linear correlation between BMI and symptomatic hemorrhagic. In patients with successful reperfusion (>TICI 2b), there was also a significant bell-shaped relationship between BMI and functional independence (mRS < 3) with both low and high BMIs associated with worse outcomes. In patients without post-procedural symptomatic hemorrhage, there was a significant linear correlation between BMI and inpatient mortality.

Conclusion:
In LVOS patients treated with MT, BMI is inversely related with post-procedural symptomatic hemorrhage. Yet in those whom reperfusion is achieved, both lower and higher than normal BMI were associated with worse functional outcomes. Thus, the obesity paradox does not appear to pertain to mechanical thrombectomy, although larger prospective studies are necessary.
Abstract WP252: Secular Trends for Etiologies of Acute Ischemic Stroke in Young Adults
Authors: Molian Vaelan , Shaban Amir , Garg Aayushi , Limaye Kaustubh , Sharma Kanika , Leira Enrique C , Adams Harold P
Published: June 2021

Introduction:
Because acute ischemic stroke (AIS) in young adults is not rare, understanding trends in etiology may help decisions about evaluation and secondary stroke prevention. This study describes probable causes of AIS in a cohort of young adults and identifies changes in etiologies and diagnostic studies compared to 20 years ago.

Methods:
We retrospectively reviewed all patients aged 15-45 admitted to our comprehensive stroke center between 1/2010-11/2016 with AIS. Diagnostic studies and stroke etiologies for each patient were reviewed. We then compared our results to a historic sample of young patients who presented to our center in 1977-1993 using univariate chi-squared comparison for each etiology.

Results:
We identified 333 young adults, 169 (50.8%) were women. The mean age was 36.4±7.1 years. Vessel imaging was performed in 305 (91.3%) cases vs. 68.9% in the historic sample. Of these, 247 (81.0%) had magnetic resonance angiography (MRA). Transthoracic echocardiography (TTE) was performed in 101 (30.3%) and transesophageal echocardiography (TEE) was performed in 171 (51.4%) cases compared to 67.1% who underwent TTE in the historic sample. Etiologic comparisons to the historic sample yielded significant decline in small vessel disease (
P
= .029) and a major increase in stroke of other identified cause (
P
= .024). Other TOAST etiologies illustrated in Figure 1. The most common etiology for stroke in our sample was arterial dissection 84 (25.2%), whereas this was found in only 6.0% of patients in the historic sample (
P<
.001).

Conclusions:
Using the TOAST classification, the most common subtype in young adults was stroke of other identified cause; a rate that reflects a marked increase in the diagnosis of dissection. Despite advancement in diagnostic studies, cryptogenic stroke remains a common category in young adults.
Abstract WP261: The Left Atrial Septal Pouch: A New Stroke Risk Factor?
Authors: Kapoor Ruchi , Wadi Lara , Becerra Brian , Eskander Michael , Razmara Ali , Lombardo Dawn , Paganini-Hill Annlia , Kim Jin K , Fisher Mark
Published: June 2021

Background:
The left atrial septal pouch (LASP) is a common anatomic variant produced by the incomplete fusion of septa primum and secondum at the inter-atrial septum, thus creating a potential embolic source from an open flap or blind pouch in the left atrium. Our prior work demonstrated increased prevalence of LASP in cryptogenic strokes (Frontiers Neurology 3-24-15). The aim of the current study was to examine the prevalence of LASP in a separate, more recent group of stroke patients and control subjects who underwent transesophageal echocardiography (TEE).

Methods:
We examined consecutive TEE studies performed between July, 2011 and December, 2018 at UC Irvine Medical Center. Prevalence of LASP was determined in TEE studies referred for ischemic stroke or TIA (“stroke subjects”), and compared to LASP prevalence in patients undergoing TEE for other reasons (“control subjects”). Stroke subtyping was performed using TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria.

Results:
TEE studies were performed on 221 cerebrovascular cases and 164 control subjects. Age and sex were 57±1 years (mean±SE) and 53% male for stroke subjects, and 56±1 years and 62% male for control subjects. Prevalence of LASP was 24% (40/164) in control subjects, 17% (24/138) in non-cryptogenic stroke subjects, and 36% (30/83) in cryptogenic stroke subjects. LASP prevalence was significantly higher for cryptogenics compared to the other groups (p=0.007). There was no significant difference between LASP prevalence in controls vs non-cryptogenic stroke. Elimination from analysis of subjects with other inter-atrial septal abnormalities (ie, patent foramen ovale or atrial septal defect) did not significantly change results.

Conclusions:
These findings demonstrate an increased prevalence of LASP in cryptogenic stroke, confirming our prior published findings. Given the plausibility of LASP acting as a thromboembolic nidus, additional studies are needed to determine the generalizability of these findings and their therapeutic implications.
Abstract WP266: Microembolic Signals and Association With Stroke Etiology in Ischemic Stroke
Authors: Chen Michael M , Mahinrad Simin , Srivastava Arth K , Liotta Eric , Bernstein Richard A , Gorelick Philip B , Sorond Farzaneh A
Published: June 2021

Background:
Microembolic signals (MES) detected by the transcranial Doppler ultrasound (TCD) have established prognostic value for stroke recurrence in patients with carotid stenosis. However, the frequency of MES in the context of other stroke etiologies remains unknown.

Methods:
All stroke admissions to Northwestern Memorial hospital between 2016-2018 who underwent TCD within the first 48 hours of admission were reviewed. Final stroke diagnosis was extracted from chart review. Presence or absence of MES was extracted from clinical TCD reports. Frequency of stroke etiology among MES groups were compared using chi-squared test.

Results:
A total of 789 patient charts were reviewed (mean age 62±17 years, 55% male). MES were present in 95 patients. Demographics and medical history of patients were not different among those with and without MES. Compared to patients without MES, those with MES were more frequently diagnosed with cardioembolic stroke (36.4% vs 21%,
p
=0.001) and less frequently with small vessel disease stroke (5.7% vs 24%,
p
<0.001). However, there was no difference in the frequency of cryptogenic strokes between patients with and without MES (
p
=0.844). Among patients with MES, the most frequent etiologies of stroke were cardioembolic (36.4%), cryptogenic (19.3%), large vessel disease (17.1%), and small vessel disease (5.7%).

Conclusion:
TCD detection of MES is seen across all stroke subtypes and may provide additional information for risk stratification in secondary stroke prevention. We are currently reviewing the prognostic utility of MES for stroke recurrence in this cohort.
Abstract WP268: Von Willebrand Factor Expression in Various Subtypes of Acute Ischemic Stroke
Authors: Mereuta Oana M , Fitzgerald Sean , Abbasi Mehdi , Dai Daying , Kadirvel Ramanathan , Kallmes David F , Doyle Karen M , Brinjikji Waleed
Published: June 2021

Introduction:
Von Willebrand factor (VWF) is a key component of acute ischemic stroke (AIS) thrombi. The aim of our prospective study was to investigate the immunohistochemical expression of VWF in clots and to evaluate whether VWF is associated with certain subtypes of AIS.

Methods:
VWF immunostaining was performed on 79 thrombi collected as part of the multi-center Stroke Thromboembolism Registry of Imaging and Pathology (STRIP) registry. The cases were classified according to TOAST criteria. The VWF expression was quantified using Orbit Image Analysis (www.Orbit.bio) machine learning software. IBM SPSS statistics 25 was used to assess the relationship between the VWF levels and different etiology subtypes.

Results:
A cardioembolic stroke was defined in 39 cases (49.4%) whereas an atherosclerotic origin was identified in 13 patients (16.5%). Other causes accounted for 12 cases (15.1%). Unknown etiology was reported in 15 cases (19%). The mean VWF content in the clots was 12.8%. According to the Mann-Whitney U-test, the level of VWF was significantly higher in the cases with unknown etiology compared to cardioembolic origin (p=0.044). We found also that patients with unknown etiology of stroke had higher VWF expression as compared to the other two subtypes, although this difference was not statistically significant.

Conclusions:
Among the patients with ischemic stroke included in this study, the VWF expression was significantly increased in those with unknown etiology compared to the group with cardioembolic stroke. Our finding provides new insights into clot composition in cryptogenic stroke and may influence the treatment and secondary prevention in these cases.
Abstract WP270: Etiopathologies of Symptomatic and Asymptomatic Intracranial Large Arterial Disease: The Results of HR-MRI and Genetic Studies
Authors: Kim Hyung Jun , Bang Oh Young , Baek In-Young , Lee Mee So , Kim Ingyeong , Kim Jae-Hwan , Kim Ye Sel , Kim Gyeong-Moon
Published: June 2021

Introduction:
Intracranial large arterial disease (ILAD) is common, especially in Asians. We compared clinical, genetic, and imaging features between symptomatic and asymptomatic ILAD.

Methods:
We conducted a prospective study of patients with acute symptomatic ILAD and subjects with asymptomatic ILAD diagnosed during medical checkups. Patients who had steno-occlusive lesions on the middle cerebral artery and/or distal internal carotid artery underwent high-resolution MRI (HR-MRI) and
RNF213
(p.Arg4810Lys variant) gene studies. We excluded patients who had proximal embolic sources in ipsilateral carotid and heart. A presumptive etiology of ILAD was made based on HR-MRI and
RNF213
gene studies. Patients were classified into intracranial atherosclerosis (ICAS) when relevant plaques existed on HR-MRI; moyamoya disease (MMD) when patients had
RNF213
variant and HR-MRI showed no plaque but characteristic features of MMD (negative remodeling and basal collaterals); and intracranial arterial dissection (ICAD) when pathognomic features (intimal flap/double lumen or mural hematoma) exist on HR-MRI.

Results:
Among 224 patients analyzed, 124 were symptomatic and 100 were asymptomatic. ICAS-type was more common in symptomatic ILAD than in asymptomatic ILAD (61.4% vs. 45.0%, p=0.009). The
RNF213
variant was observed in one third of ICAS-type ILAD (37.0% in asymptomatic and 38.6% in symptomatic). Similarly, the proportion of MMD-type was similar between asymptomatic (33, 21.3%) and symptomatic (32, 19.0%) ILAD. Multivariate testing showed that symptomatic ILAD was associated with the presence of intracranial plaque on HR-MRI, regardless of the presence of the
RNF213
variant, site of ILAD, and number of tandem stenosis.

Conclusions:
While various etiopathologies can cause ILAD, ICAS is an important pathology of symptomatic ILAD and should be target for medical management.
Abstract WP272: Automatic Detection and Measurement of Atherosclerotic Plaques in Carotid Ultrasound Using Deep Learning
Authors: Yeo Leonard L , Engin Melih , Lange Robin , Tang David K , Monajemi Sadaf , Mohammadzadeh Milad , Goh Chin Kong , Tu Tian Ming , Sharma Vijay K
Published: June 2021

Purpose:
B-Mode ultrasound imaging is commonly used for detection and measurement of atherosclerotic carotid plaques, which are an important cause of ischemic stroke. However, accurate interpretation of ultrasound can be difficult and subjective. Artificial Intelligence (AI) models can assist in image interpretation, reducing subjectivity, and speeding up the process of detection and measurement of carotid plaques. We evaluated the accuracy of a deep learning model for automatic detection of carotid plaques in b-mode ultrasound compared against expert interpretation of the images.

Methods:
We propose an automated method using convolutional neural networks to detect atherosclerotic plaques and measure intima-media thickness (IMT) in B-Mode carotid images. In contrast to most of the existing methods, our goal was to not only measure IMT in healthy subjects (max IMT below 1.2 mm) but also to provide accurate detection of plaques and other vessel wall pathology. Given the B-mode longitudinal image as the input, the neural network first finds a region of interest (ROI) surrounding the artery and then segments both near wall and far wall of the artery. The network was trained and tested on two separate datasets obtained retrospectively from 3 stroke centers and 4 different ultrasound machine manufacturers. The training dataset was comprised of 1021 images.

Results:
The performance of the method was assessed on an independent dataset not used for model development to prevent bias, consisting of 205 images, where 54% (111 out of 205) of the images had pathology. The ground truth was determined by an expert reader interpreting images, and Pearson coefficient (IMT correlation) and Bland-Altman analysis were used to assess the performance of the method. The obtained correlation coefficient was 0.93 and r-squared was 0.87, showing a strong correlation. There was no significant over or under estimation of IMT (bias = -0.002 mm, lower limit of agreement (LOA) = -0.246 mm, upper LOA = 0.242 mm).

Conclusion:
The results show that the proposed deep learning method can be used for accurate analysis and interpretation of carotid ultrasound scans in a clinical setting and potentially reduce the reporting time while increasing objectivity of the reports.
Abstract WP277: The Los Angeles Motor Scale is an Effective Tool for Triaging Patients in the Prehospital Setting
Authors: Stead Tej , Ganti Latha , Banerjee Paul
Published: June 2021

Introduction:
The Los Angeles Motor Scale (LAMS) is a 3-item scale to identify motor deficits. This can identify severe strokes in the field so that patients can be transported appropriately.

Methods:
Prospective observational cohort study based in a county EMS system. Patients transported for stroke had a LAMS administered in the field. Outcome data from individual receiving hospitals collected within 45 days of the event.

Results:
Our cohort (n=2374) had a median age of 72 and was 51% female. 19% had LAMS 0, 14% LAMS 1, 13% LAMS 2, 17% LAMS 3, 16% LAMS 4, and 21% had LAMS 5.

We generated three receiver operating characteristic curves for the interventions of mechanical intervention, tPA, and CTA perfusion imaging, with C statistics of .706, .632, and .668 respectively. All three models were significant using the likelihood ratio test, p < .0001. In all three models, the cut point was a LAMS of 4. Accordingly, a high LAMS was defined as 4 or 5, whereas a low LAMS was defined as <4. In the following table, all associations were significant with p < .0001 using the likelihood ratio test. The median NIHSS at hospital arrival was 6, IQR 2-13. For low LAMS it was 4 (IQR 1-8), and for high LAMS it was significantly greater at 13, IQR 7-21, p <.0001 using Wilcoxon’s rank-sum test. At hospital discharge, median NIHSS was 2, IQR 0-7. For low LAMS it was 1 (IQR 0-5), for high LAMS it was significantly greater at 5 (IQR 1-14.75), p < .0001 using Wilcoxon’s rank-sum test. Median NIHSS improvement was 2 points, p < .0001 (Wilcoxon signed-rank test). The differences were significant with p < .0001 for both low LAMS and high LAMS patients individually (Wilcoxon signed-rank test). Low LAMS patients had a median improvement of 1.5 points. High LAMS patients had a significantly greater median improvement of 4 points (p < .0001 using Wilcoxon rank-sum test), likely because they generally started out in worse condition.

Conclusion:
The LAMS is a powerful prehospital predictor of intervention and outcomes after acute stroke.
Abstract WP278: Air versus Ground Transportation During Inter-Hospital Transfer of Patients for Endovascular Thrombectomy Evaluation
Authors: Reddy Sujan Teegala , Wu Tzu-Ching , Zhang Xu , Vahidy Farhaan , Ankrom Christy , Savitz Sean
Published: June 2021

Introduction:
Mode of transport utilized during inter-hospital transfers can influence delays in patients with suspected large vessel occlusion (LVO). We hypothesized that air transport is advantageous over ground in this patient population.

Method:
Suspected LVO patients transferred to our hub from 13 spoke hospitals within our tele-stroke network at UT-Houston, from September 2015 to April 2018 were retrospectively analyzed. Patients were dichotomized into air vs. ground transport. Travel time was calculated as time from transfer center activation to arrival at hub. For each spoke, average air miles/hour and ground miles/hour indices were calculated for comparison. Air transport was considered advantageous if the difference in indices was positive. Results were stratified by time of the day [diurnal (6a-6p) vs. nocturnal (6p-6a)].

Results:
In a total of 339 patients, 290 (86%) used air transport, while 49 (14%) used ground. Baseline age, gender, race, use of IV-tPA, mRS in the 2 groups were similar, except air group had higher NIHSS [median 15 vs. 12, p = 0.048]. Overall, mean ground indices were smaller compared to air indices (21.35 ± 10.76 vs. 25.77 ± 14.33, p = 0.006). The advantage of air transport was maintained when stratified by time of the day but more notable during nocturnal hours [air 25.12 ± 14.93 vs. ground 19.85 ± 10.14, p = 0.021)] compared to diurnal hours [(air 28.82 ± 13.68 vs. ground 25.00 ± 10.80, p = 0.17)]. Difference between air and ground indices (y axis) was positively correlated with ground distance (x axis) (Pearson rho = 0.80, 95% CI 0.42 to 0.93, p<0.001) indicating efficiency of air transport becomes more profound as distance increases (Figure 1). Ground transport was faster for distances <20 miles.

Conclusion:
Irrespective of time of the day, air transport is faster mode of transporting patients during inter hospital transfers and should be utilized particularly for spokes situated farther away (over 20 miles) from hub and during nocturnal hours.
Abstract WP284: National Trends in Utilization and Outcomes of Thrombolytic Use by Drip and Ship Paradigm in Acute Ischemic Stroke Patients in United States
Authors: Chaudhry Saqib A , Chaudhry Mohammad Rauf A , Gill Mohsain , Akhtar Iqra N , Qureshi Adnan I
Published: June 2021

Background and Purpose:
The drip and ship paradigm has rapidly expanded in the last decade allowing higher thrombolytic utilization and endovascular treatment. We performed this analysis to evaluate trends in utilization of drip and ship paradigm in United States and associated outcomes.

Methods:
We analyzed data for patients admitted with primary diagnosis of ischemic stroke in the United States from Nationwide Inpatient Sample, the largest nationally representative data, for the years 2009 to 2015. We studied changes in utilization of drip-and-ship paradigm and subsequent performance of endovascular treatment, and rates of discharge with none to minimal disability and moderate to severe disability.

Results:
Of the 3,043,190 patients admitted with ischemic stroke, 56,449 (1.85%) patients received thrombolytic treatment through drip-and-ship paradigm over a 7 year period. Of all patients who received thrombolytic treatment (n=243,824), 56,449 (23.15%) received using drip and ship paradigm. There was almost 3 fold increase in drip and ship paradigm (in 0.98% 2009 to 2.80% in 2015 (test for trend= p < 0.001). Among the patients who underwent drip and ship paradigm, 5,061 (8.97%) underwent endovascular treatment. The rate of endovascular treatment increased from 6.62% to 12.39% among patients treated with drip and ship paradigm (test for trend= p < 0.001). The rate of none minimal disability at discharge increased from 39.93% to 47.08%, (test for trend p < 0.001) while moderate to severe disability decreased 51.22% to 47.08%, (test for trend p < 0.001) in ischemic stroke patients treated using drip-and-ship paradigm. Similar trends were observed for hospital outcomes in multivariate logistic regression model, adjusted for age, gender, medical comorbidities and secondary intracranial hemorrhages.

Conclusion:
There has been a significant increase in the proportion of acute ischemic stroke patients treated using drip-and-ship paradigm (out of proportion to overall thrombolytic use) with increase in subsequent endovascular treatment in United States. The in hospital outcomes of patients have improved perhaps due to higher utilization of endovascular treatment.
Abstract WP29: National Patterns of Stroke Mechanical Thrombectomy Before and After the 2015 American Stroke Association Focused Update Endovascular Treatment Guidelines
Authors: Atchaneeyasakul Kunakorn , Liaw Nicholas , Lee Rex , Liebeskind David , Saver Jeffrey
Published: June 2021

Introduction:
Positive pivotal trials followed by guideline endorsement can be a major driver of change in US national medical practice patterns. We therefore analyzed national trends in the use and outcomes of mechanical thrombectomy (MT) for acute ischemic stroke (IS) due to large vessel occlusion before and after the 2015 publication of pivotal trials and the US guideline update.

Methods:
We analyzed the National Inpatient Sample from 2012-2016. IS and MT patients were identified using ICD-9 and ICD-10. The primary efficacy outcome measure was discharge to home, which strongly correlates with mild disability at discharge. Safety outcomes include in-hospital mortality and in-hospital medical complications.

Results:
Between 2012-2016, 2,394,550 discharges had diagnosis of IS, 39,150 (1.6%) underwent MT. The number and proportion of IS patients undergoing MT rose from 4,910/452,905 (1.1%) in 2012 to 11,860/509,215 (2.3%) in 2016. The largest increase occurred between 2014, when 6,460 stroke patients were treated with MT, and 10,280 in 2015. Comparing the pre (Q1 2012-Q4 2014) and post (Q4 2015 - Q4 2016) RCT/Guideline epochs, in addition to increased MT rates, the proportion of MT patients who received IV-tPA decreased (46% to 24%, p<0.001). Rates of mild disability outcome increased from 17% to 20% (p=0.04), while mortality decreased from 17.7% to 15% (p=0.03). The odds of pulmonary embolism, urinary tract infection, and pneumonia reduced, while intracranial hemorrhage, sepsis, deep venous thrombosis, shock, and cardiac arrest were unchanged.

Conclusion:
In US, thrombectomy treatment for acute ischemic stroke increased rapidly and substantially in frequency following publication of positive clinical trials and a US guideline update in 2015, accompanied by improved functional outcomes and reduced peri-procedural mortality.
Abstract WP293: Simplified Prehospital Prediction Models to Estimate the Likelihood of 4 Types of Stroke: 7-Item Japan Urgent Stroke Triage (Just-7) Score
Authors: Uchida Kazutaka , Yoshimura Shinichi , Sakakibara Fumihiro , Kinjo Norito , Araki Hayato , Morimoto Takeshi ,   JUST Score Investigators
Published: June 2021

Background and Purpose:
Prehospital prediction models to estimate the likelihood of several types of stroke (large vessel occlusion [LVO], intracranial hemorrhage [ICH], and subarachnoid hemorrhage [SAH], and other strokes) should be useful to transfer those with suspected stroke to appropriate facilities. Japan Urgent Stroke Triage score with 21 items had excellent predictive abilities, but we tried to simplify the score with parsimonious items and comparable predictive abilities.

Methods:
We conducted historical and prospective multicenter cohort studies from June 2015 to July 2017. We developed the prediction rule with select variables from JUST score for LVO, ICH, SAH and other strokes using historical cohort study with 2236 patients and validated the developed score using prospective cohort study with 964 patients. We used multivariable logistic regression models to develop the prediction models using the same variables for each stroke type.

Result:
In the historical cohort, there were 1150 stroke, including 235 LVO, 352 ICH, 107 SAH and 456 other stroke. We developed the score with 7 items (high blood pressure, arrhythmia, conjugate deviation, headache, dysarthria, disturbance of consciousness, paralysis of upper limbs) which showed area under the receiver operating curve (AUC) of 0.84 for any type of stroke, 0.89 for LVO, 0.79 for ICH, and 0.90 for SAH in the historical cohort. The score was validated with good predictive ability in the prospective cohort (AUC of 0.76 for any type of stroke; 0.81 for LVO, 0.73 for ICH, and 0.85 for SAH).

Conclusions:
The simplified 7-item JUST (JUST-7) score had good predictive ability and can help paramedics or primary care physicians to estimate the likelihood of different type of stroke and decide the referral hospital.
Abstract WP294: In Search of Greater Efficiencies: Implementation of Computed Tomography Angiography in a Telestroke Network Improves Triage for Both Primary and Comprehensive Stroke Centers
Authors: Yu Andrew T , Regenhardt Robert W , Whitney Cynthia , Schwamm Lee , Viswanathan Anand , Patel Aman , Lev Michael , Leslie-Mazwi Thabele
Published: June 2021

Introduction:
Telestroke (TS) networks provide an important function in community hospitals by supporting thrombolytic use and screening for patients with large vessel occlusion (LVO) who may be eligible for endovascular thrombectomy (EVT). The expansion of treatment to 24 hours from last known well has dramatically increased the pool of patients to screen. Idealized triage processes within TS networks remain uncertain. We sought to characterize the impact of the implementation of a routine spoke hospital (SH) CTA protocol in our integrated TS network.

Methods:
We introduced protocol-driven CTA process at 25 SH in November 2017. We retrospectively identified patients who presented to a SH with an NIHSS ≥ 6 between 3/1/2016-3/1/2017 (pre-CTA) and 3/1/2018-3/1/2019 (post-CTA). We characterized baseline demographics, transfer patterns, and rates of CTA utilization, LVO, and EVT. Differences were assessed using Wilcoxon rank-sum for continuous variables and χ2 tests for categorical variables.

Results:
There were 167 patients pre-CTA and 207 post-CTA. The rate of CTA at SHs increased from 13% to 70% (p<0.001). Despite increased screening of patients >4.5 hr from last known well time, the rates of transfer out of SHs did not increase (56% vs 54%, p=0.83). The rate of transfer to our CSC for EVT increased non-significantly (26% vs 35%, p=0.12) but the proportion of patients transferred >4.5 hr increased ~5-fold (7% vs 34%, p<0.001) with a decrease in need for repeat imaging at our CSC (94% vs 66%, p<0.001). The overall rate of EVT performed on patients transferred for possible EVT more than doubled (22% to 47%, p=0.011).

Conclusions:
Implementation of a CTA protocol at SHs in our TS network was feasible, and effective in improving the efficiency of interhospital triage of candidates for EVT. In the era of late-window EVT, introducing CTA into PSC enhances the stroke system of care and keeps care local whenever possible. Replication of these findings in other TS networks is needed.
Abstract WP295: Factors Influencing Ems Transport Time for Patients After Stroke in San Diego County
Authors: Kenner-Brininger Amelia , Olson-Mack Lindsay , Calzone Lorraine , Koenig Kristi L , Hemmen Thomas L
Published: June 2021

Background:
Emergency Medical Services (EMS) play an important role as initial providers to stroke patients. Data of on scene and transport times for stroke patients with unbiased populations are rare. We explored the range of times for stroke patients to receive care on scene and transport to a stroke receiving center (SRC) in a region with 3.3 million residents, 18 SRCs and 19 ground transport advanced life support EMS agencies. This will inform researchers on prehospital stroke invervention and policy makers deliberating triage and stroke center designation.

Methods:
We included all patients with final hospital diagnosis of AIS, ICH, SAH, or TIA transported by EMS to a San Diego County SRC between July 2017 and December 2018 with computer automated dispatch record and base hospital record. Records were linked on EMS incident number, reviewed for accuracy. We analyzed scene and transport time, weekday vs. weekend, last known normal (LKN) to EMS enroute < 6 hours (approximation of LKN to 911 call), EMS recognition of stroke, and final hospital diagnosis.

Results:
In total, 2,376 patients with final stroke diagnosis were transported between July 2017 and December 2018. In 1,514 (63.7%) cases, EMS recognized stroke. In these cases mean (±SD) scene time was 12.0 (±4.6) minutes and transport time 12.4 (±7.2). In stroke patients without EMS stroke recognition the mean (±SD) scene time was 14.8 (±5.7) (p=.0001) and transport time of 16.2 (±8.1) (p=.0001). Scene time (p=.002), EMS stroke recognition (p=.00001), weekend vs. weekday (p=.013), LKN to enroute < 6 hours (p=.00001) were all correlated with shorter transport time; hospital stroke diagnosis (p=.56) was not. Linear regression indicated LKN to enroute < 6 hours (p=.001) and EMS stroke recognition (p=.00001) were significant in determining shorter transport time.

Conclusion:
EMS transport time of stroke patients varies across our system. However, when EMS providers recognize a stroke patient, scene time decreases by nearly 3 minutes and transport time decreases by nearly 4 minutes compared with patients with stroke undetected until after hospital arrival. Additionally, patients with a shorter LKN to EMS enroute time have a shorter transport time, which may be clinically important for this time-sensitive condition.
Abstract WP307: Molecular Mechanisms, Temporal and Spatial Dynamics of Inflammasome Activation in Ischemic Stroke
Authors: Cai Wei , Hu Mengyan , Lu Zhengqi
Published: June 2021

Background:
Multiple sensors, executors and products are involved in inflammasome activation. Inflammasome activation has been found in several immune cells after stroke. However, the molecular mechanisms, the temporal and spatial dynamics of inflammasome activation in stroke remain elusive. Therapeutic value of modifying inflammasome activation in stroke is still debatable.

Methods:
Inflammasome markers of NLRP3 and IL-1β in stroke patients and healthy control were evaluated with flow cytometry. Correlation of NLRP3/IL-1β expression with stroke outcomes of patients was assessed. Ischemic stroke was induced in mice with transient middle cerebral artery occlusion (tMCAO, 1h). Expression dynamics of inflammasome components, location and cellular target of inflammasome activation in tMCAO models were analyzed. Therapeutic effects of inhibiting inflammasome activation on stroke outcomes were evaluated.

Results:
Rapid increase of inflammasome markers NLRP3 and IL-1β was detected at 1d after disease onset in stroke patients, which was positively correlated with patients’ infarct volume and NIHSS score. The sensors of NLRP3 and NLRC4 were involved in post stroke inflammasome activation, which increased at 1-3d after stroke and peaked at 3-5d in tMCAO models. Similar dynamics of the executors cleaved Caspase-1/11, as well as the products IL-1β, IL-18 and GSDMD were detected. AIM2 and Caspase-8 seemed not to take any part in post-stroke inflammasome activation. Macrophage was demonstrated as the main cell in which inflammasome was formed in both patients and mice, while microglia, dendritic cells and neutrophil also had inflammasome formation. Inflammasome activation of macrophage was mostly detected in stroke lesion. The executors of Caspase-1 and -11 were the key factors in inflammasome activation in stroke. Preventing inflammasome activation by inhibiting Caspase-1/11 signalings showed promising therapeutic efficacy.

Conclusion:
The impact of inflammasome activation is detrimental to ischemic stroke. Inhibiting Caspase-1/11 signalings is a promising therapeutic strategy for stroke.