bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP187: Subclinical Macro and Microvascular Disease in Stroke-free Subjects With Nonsustained Atrial Fibrillation
Authors: Yetim Ezgi , Arsava Ethem Murat , Canpolat Ugur , Gocmen Rahsan , Oguz Kader K , Ozer Necla , Aytemir Kudret , Topcuoglu Mehmet Akif
Published: June 2021

Introduction:
Prevalence of nonsustained atrial fibrillation (NSAF), described as irregular atrial runs lasting shorter than 30-seconds, is higher in patients with ischemic stroke compared to stroke-free controls. Nonetheless, its role in causality of stroke and future cerebrovascular risk is still not established. Subclinical atherosclerotic burden and vascular stiffness are more prevalent, and have been shown to modify future risk of vascular events in patients with atrial fibrillation (AF). We aimed to determine the relationship between NSAF and subclinical atherosclerosis, vascular dysfunction and cerebral microvascular disease.

Methods:
Sonographic carotid distensibility metrics, carotid intima-media thickness (IMT), carotid plaque burden score (Ten Cate’s), middle cerebral artery (MCA) pulsatility index (PI) and cerebral white matter disease burden (Fazekas’ periventricular and subclinical scores) were studied in 263 stroke-free control subjects. 24-hour Holter monitoring documented NSAF in 27% of study population. Abnormality limits were set as mean±standard deviation.

Results:
Compared to those without NSAF (age 62±8 yr, 43% male), subjects with NSAF (age 67±9 yr, 31% male) had significantly higher total carotid plaque burden score (p=0.009) and significantly lower common carotid artery carotid distensibility (p=0.019). Maximum and averaged IMT, carotid stiffness and elastic modulus, and asymptomatic significant (≥50%) carotid artery stenosis were numerically higher. Patients with NSAF had significantly higher MCA PI (p=0.007) and numerically higher white matter disease scores. Regression analysis models showed that NSAF is one independent predictors of abnormal carotid distensibility (p=0.026) and presence of carotid plaque (p=0.023); but not for carotid plaque burden score (>4), MCA PI (>1.1) and IMT max (>0.966).

Conclusions:
The presence of a significant relationship between NSAF and presence of carotid artery plaque and decreased cervical artery distensibility raises the possibility that NSAF might be a reflection of subclinical atherosclerotic burden. This crosstalk between surrogate markers might explain the higher prevalence of NSAF in ischemic stroke patients.
Abstract WP193: Gum Disease and Ischemic Stroke Risk in the Atherosclerosis Risk in Communities (ARIC) Study
Authors: Sen Souvik , Giamberardino Lauren D , Moss Kevin , Rosamond Wayne , Offenbacher Steven
Published: June 2021

Introduction:
Gum, or periodontal disease (PD) is a risk factor for cardiovascular disease. We assessed the graded association of PD levels with incident ischemic stroke as well as the etiological stroke subtypes in the Atherosclerosis Risk in Communities (ARIC) study.

Methods:
PD was assessed by full-mouth periodontal measurements from 6 sites per tooth, in subjects without prior stroke and categorized into periodontal profile class (PPC). A Latent Class Analysis was used to identify 7 distinct PPCs using the entire cohort that included tooth level periodontal measurements and tooth loss. Stroke diagnoses were based on computer derived diagnosis medical record review and imaging confirmation. Classification required evidence of sudden onset of neurological deficit(s) lasting ≥24 hours. Strokes were classified according to etiology as thrombotic, lacunar, and cardioembolic subtypes.

Results:
At the fourth ARIC visit (1996-1998), a cohort of 6711 subjects (mean age±SD=62.3±5.6, 55% female, 81% white and 19% African-American) were assessed for PD. A total of 299 incident ischemic strokes (47% thrombotic, 26% cardioembolic and 20% lacunar) occurred over a 15-year period. The seven levels of PPC showed a graded association with incident ischemic stroke as noted in the figure. Participants with mild PD (adjusted HR 1.9 95% CI 1.2-3.0), moderate PD group (adjusted HR 2.1 95% CI 1.2-3.5) and severe PD (adjusted HR 2.2 95% CI 1.3-3.8) had an increased risk of incident ischemic stroke, compared with participants without PD after adjustment for confounders (age, race, gender, BMI, hypertension, diabetes, LDL cholesterol, smoking and education). There were class specific associations noted between PD with cardioembolic and thrombotic stroke subtypes.

Conclusions:
A graded association was noted between incident ischemic stroke and increasing levels of PPC. Further, we report class specific associations between PD with cardioembolic and thrombotic stroke subtypes.
Abstract WP199: Outcome of Pregnancies and Deliveries Before and After Ischemic Stroke- A Retrospective Matched Cohort Study
Authors: Aarnio Karoliina , Gissler Mika , Grittner Ulrike , Siegerink Bob , Kaste Markku , Tatlisumak Turgut , Tikkanen Minna , Putaala Jukka
Published: June 2021

Introduction:
Limited data exist on the outcome of pregnancies and deliveries among young women with ischemic stroke.

Hypothesis:
The incidence of pregnancy- and delivery-related complications in women who will suffer or have suffered an ischemic stroke differs from stroke-free controls.

Methods:
We included young female patients admitted for an ischemic stroke to the Department of Neurology, Helsinki University Central Hospital 1994-2007, with pregnancy data before or after stroke recorded in the Medical birth Register (MBR) (n=154), and their stroke-free controls matched with age, parity, year of birth, residential area, and multiple pregnancies (n=616). We obtained data 1987-2014 on pregnancies from the MBR, all-cause hospitalizations from the Hospital Discharge Register, and causes of deaths from Statistics Finland. We used Poisson regression mixed models to compare the incidence of pregnancy- and delivery-related complications over time both before and after stroke.

Results:
Among a total of 1400 singleton pregnancies and deliveries, the incidence rate ratio (IRR) for the composite outcome, including pre-eclampsia, eclampsia, small for gestational age, low birth weight, preterm birth, placental abruption, gestational diabetes, hospital care during pregnancy, death of the mother during pregnancy or puerperium, stillbirth, early neonatal death, Apgar at 1 minute 6 or less, and if the child was not at home at 7 days from the delivery, was 1.29 (95% confidence interval (CI) 1.00-1.65) for the mother with an impending stroke, or a history of stroke, or both, compared with the matched control mother. Similar results were obtained if the data were restricted to those women who became pregnant before or after stroke (IRR 1.25 and IRR 1.34, respectively). When adjusted for smoking and socioeconomic status, the IRR for the composite outcome was 1.31 (95% CI 0.99-1.73).

Conclusions:
There was a slight increase in the incidence of pregnancy- and delivery-related complications over time for mothers with an impending stroke, or a history of stroke, or both, compared with stroke-free mothers.
Abstract WP204: Genetic Variant in VCAM1 Mediates Acute Infarct Size in Ischemic Stroke Patients
Authors: Giese Anne-Katrin , Musolino Patricia , Xu Huichun , Ryan Kathleen , Schirmer Markus D , Dalca Adrian V , Cole John W , McArdle Patrick F , Broderick Joseph P , Jimenez-Conde Jordi , Jern Christina , Kissela Brett M , Kleindorfer Dawn O , Lemmens Robin , Lindgren Arne , Meschia James F , Rundek Tatjana , Sacco Ralph L , Schmidt Reinhold , Sharma Pankaj , Slowik Agnieszka , Thijs Vincent , Woo Daniel , Worrall Bradford B , Golland Polina , Kittner Steven J , Rosand Jonathan , Mitchell Braxton D , Wu Ona , Rost Natalia S
Published: June 2021

Introduction:
Even though neuroinflammation is increasingly recognized as an essential contributor to ischemic brain injury, the exact underlying mechanisms remain unclear. Higher expression of the vascular cell adhesion molecule 1 (VCAM-1) increases leukocyte-brain endothelium interaction and has been associated with larger infarct size following acute ischemic stroke (AIS). The activation of the TGF-β signaling pathways can down-regulate VCAM-1 expression and ameliorate deleterious tissue outcome during neuroinflammation.

Hypothesis:
We sought to investigate whether genetic variation in the TGF-beta pathway and adhesion molecule genes is associated with acute stroke lesion size.

Methods:
We completed genome-wide association (GWA) testing and diffusion-weighted imaging lesion volume (DWIv) analysis in a discovery cohort of 532 AIS patients of European ancestry enrolled within 48 hours of symptom onset. An independent European ancestry cohort of 724 AIS patients with GWA data and automated DWIv served as replication cohort. GWA testing per SNP was performed using linear regression modeling of natural log-transformed DWIv adjusted for age, sex and relevant principal components. We selected 42 inflammatory genes in the TGF-beta pathway for a gene-based analysis using VEGAS (Versatile Gene-based -Association Study) software. A pre-specified discovery phase Bonferroni-corrected threshold was set at p<0.001. In the replication phase, 14 SNPs overlapping were tested at the Bonferroni-corrected p-value threshold of p<0.004.

Results:
Of all genes in the TGF-beta pathway, VCAM1 (p=0.0006) was significantly associated with DWIv in the discovery AIS cohort (age: 66 ± 14.9 years, sex: 63.4% male, DWIv: 2.2cm
3
(IQR: 0.6-11.7cm
3
)). A single SNP within the VCAM1 gene boundaries (rs3176876 (BETA=0.2341, p=0.003)) was significantly associated with DWIv in the replication AIS cohort (age: 65 ± 14.1 years, sex: 68.6% male, DWIv: 4cm
3
(IQR: 1.3-17.2cm
3
)).

Conclusion:
The genetic variant rs3176876 in the VCAM1 gene is associated with larger infarct lesion size measured on brain MRI of AIS patients. These findings suggest genetic contribution to the pro-inflammatory mechanisms in acute cerebral ischemia and warrant further investigation.
Abstract WP207: Ethnic Disparities in Hypertensive Heart Disease Among Young Adults with Ischemic Stroke in Hawaii
Authors: Jani Alap R , Ito Cherisse , Seto Todd , Nakagawa Kazuma
Published: June 2021

A recent study showed that Native Hawaiians and Other Pacific Islanders (NHOPI) with ischemic stroke are younger and have a higher burden of cardiovascular risk factors compared to whites and Asians. However, a detailed assessment of the degree of hypertensive heart disease using echocardiogram data among this multi-ethnic young adult population has not been studied. The objective of this study was to assess ethnic differences in the echocardiographic findings of hypertensive heart disease among young adults who were hospitalized for ischemic stroke. We hypothesized that NHOPI young adults with ischemic stroke have a higher prevalence of echocardiographic findings of hypertensive heart disease compared to whites and Asians. We conducted a retrospective study of all young adults (age ≤ 55 years) who were hospitalized at the Queen’s Medical Center in Honolulu, HI between 2008 and 2012 with an admission diagnosis of ischemic stroke. Patients with an ethnicity other than white, Asian, or NHOPI were excluded. Echocardiograms for each patient were reviewed. Left ventricular mass was estimated by the Devereux formula. Early (E) and late (A) transmitral diastolic flow, and mitral medial annulus early diastolic velocities (E’) were recorded; and E/A and E/E’ were calculated as measures of diastolic dysfunction and LV filling pressures. A total of 259 patients (44% NHOPI, 36% Asians, and 19% whites) were included in the study. The overall mean age was 47.1 ± 7.7 years with 34% women. NHOPIs had a higher LV mass (248.9 ± 94.8 g), LV mass index (121.5 ± 41.4 g/m
2
), and mitral E/E’ values (15.5 ± 9.3) compared to whites (218.6 ± 74.6 g, 107.9 ± 34.2 g/m
2
, 11.5 ± 4.6, all
P
<0.05) and Asians (191.3 ± 61.5 g, 106 ± 32.2 g/m
2
, 12.4 ± 5.8, all
P
<0.01). NHOPIs had more severe diastolic dysfunction and relative wall thickness (all
P
<0.05) compared to Asians but not whites. Overall, NHOPIs compared to whites and Asians had 8% compared to 10% and 10.6% with normal geometry, 39% compared to 50% and 47.9% with concentric remodeling, 53% compared to 40% and 41.5% with hypertrophy. Left atrial enlargement was seen in 24% of the total population. In conclusion, this study shows that among young adults with ischemic stroke, NHOPIs have a higher burden of hypertensive heart disease compared to whites and Asians.
Abstract WP219: The Relationship of Low-Density Lipoprotein (LDL) Particle Number (LDL-P) and LDL Particle Size and Incident Stroke Events: The Multi-Ethnic Study of Atherosclerosis
Authors: Kim Yong-Jae , Fan Wenjun , Budoff Matthew J , Mora Samia , Sacco Ralph L. , Tracy Russell , Yeboah Joseph , Wong Nathan D
Published: June 2021

Background & Objectives:
The role of lipid and lipoprotein biomarkers in risk prediction of ischemic heart disease is well established, but their value as independent predictors for ischemic stroke is less certain. Certain LDL subclasses based on particle sizes are associated with atherosclerotic risk. However, there is little information available on the relation of LDL particle number (LDL-P, nmol/L), LDL particle size (nm) with stroke. We evaluated associations between LDL-P and LDL particle size with the risk of ischemic stroke (IS) and transient ischemic attack (TIA).

Methods:
We studied US adults aged of 45-84 years not on lipid-lowering medications enrolled in the Multi-Ethnic Study of Atherosclerosis between 2000 and 2002 with follow-up through December 2011. We evaluated associations of LDL-P (total LDL-P, large LDL-P and small LDL-P) and LDL particle size measured by NMR with, (1) composite of incident IS and TIA, and (2) IS alone. Standardized hazard ratios (HRs) were adjusted for age, sex, race (model 1), plus diabetes, hypertension medication, systolic and diastolic blood pressure, family history, smoking, HDL (model 2), and plus LDL concentration (model 3).

Results:
We identified 129 subjects with incident IS, 61 with TIA and 5,328 without any type of stroke during follow-up; mean ages were 67.4, 66.7 and 61.2 years, respectively (p<0.0001). White ethnicity was 37.2%, 42.6% and 37.6%), respectively. For the composite outcome of IS and TIA, while small LDL-P (HR 1.20, 95%CI 1.04 to 1.39) was predictive in model 1, this was attenuated after additional adjustment in models 2 and 3. For the outcome of IS alone, total LDL-P (HR 1.25, 95% CI 1.06 to 1.48) and small LDL-P (HR 1.34, 95% CI 1.13 to 1.60) were associated with incident IS in model 1, but there was no significant association of large LDL-P or LDL size with IS. Only small LDL-P remained predictive of IS in model 2 (HR 1.32, 95% CI 1.05 to 1.65) and in model 3 (HR 1.31, 95% CI 1.03 to 1.67).

Conclusions:
Increased small LDL-P, not particle size, is most closely associated with incident IS and could be useful in risk stratification beyond standard risk factors and lipid measures.
Abstract WP223: Ischemic Stroke After Emergency Department Discharge for Symptoms of Transient Neurological Attack
Authors: Parikh Neal S , Merkler Alexander E , Kummer Benjamin R , Kamel Hooman
Published: June 2021

Introduction:
Compared to transient ischemic attack (TIA), little is known about the risk of ischemic stroke after the nonspecific symptoms of a transient neurological attack (TNA).

Methods:
Using administrative claims data, we identified patients discharged from emergency departments (ED) in New York State between 2006 and 2012 with a primary discharge diagnosis of a TNA symptom, defined as in prior work as altered mental status, generalized weakness, and sensory changes. The primary outcome of ischemic stroke was identified using validated
ICD-9-CM
diagnosis codes. We used Kaplan-Meier survival statistics to calculate cumulative rates, and Cox regression to compare stroke risk after TNA versus after TIA (positive control) or renal colic (negative control) while adjusting for demographics and vascular risk factors. We performed subgroup analyses stratified by age. In sensitivity analyses, TNA was limited to cases of altered mental status or sensory changes, as these were more commonly associated with stroke in prior work, or limited to discharges without neuroimaging, to assess whether limited evaluation was associated with increased risk.

Results:
Of 499,369 patients diagnosed with a TNA symptom and discharged from the ED, 7,756 were hospitalized for ischemic stroke over 4.7 (±1.9) years. At 90 days, the cumulative stroke rate was 0.29% (95% confidence interval [CI], 0.28-0.31%) after TNA symptoms versus 2.08% (95% CI, 1.89-2.28%) after TIA and 0.03% (95% CI, 0.02-0.04%) after renal colic. The hazard of stroke was higher after TNA than after renal colic (hazard ratio [HR], 2.13; 95% CI, 1.90-2.40). However, the risk was lower than after TIA (HR, 0.47; 95% CI, 0.44-0.50). Compared to TIA, TNA was less strongly associated with stroke among patients under 60 years of age (HR, 0.22; 95% CI, 0.19-0.25) than in those over 60 years of age (HR, 0.50; 95% CI, 0.47-0.53) (
P
<0.001 for interaction). Our results were unchanged in sensitivity analyses limiting TNA diagnoses to patients with altered mental status or sensory changes or to those who did not undergo neuroimaging.

Conclusions:
Patients discharged from the ED with TNA symptoms faced a higher risk of ischemic stroke than low risk controls, but the magnitude of stroke risk was low, particularly in comparison to TIA.
Abstract WP224: Impact of Stroke Risk Factors on Ethnic Stroke Disparities Among Midlife Mexican Americans and Non-hispanic Whites
Authors: Patel Rajiv C , Sanchez Brisa , Morgenstern Lewis , Li Chengwei , Lisabeth Lynda
Published: June 2021

Introduction:
Overall ischemic stroke (IS) incidence has declined in the US, but has remained stable among midlife (age 45-59) adults and is higher in midlife Mexican Americans (MAs). We examined the contribution of stroke risk factors to ethnic differences in IS rates among midlife MAs and non-Hispanic Whites (NHWs) in a population-based study.

Methods:
Incident IS (N=823) counts and corresponding risk factors were identified from the BASIC Project, Nueces County, Texas (2000-2010). US Census data (2000) for Nueces County was used to estimate the population at-risk for stroke, and the Texas Behavioral Risk Factor Surveillance System for Public Health Region 11(2000-2010) was used to estimate prevalence of risk factors in the stroke free population. Poisson regressions were run combining stroke counts (numerator) and population at-risk counts (denominator) classified by ethnicity and risk factor status to estimate unadjusted and risk factor adjusted associations between ethnicity and IS rates. Separate models were run for each risk factor (diabetes, hypertension, coronary heart disease, high cholesterol, education < high school, no health insurance, current smoking, BMI>30), and extended to include an interaction term between ethnicity and risk factor.

Results:
The crude ethnic IS rate ratio (RR) comparing MAs with NHWs was 2.13 (95% CI: 1.84-2.47). The ethnic RR was lower in models that adjusted for diabetes (RR:1.54; 95% CI: 1.31-1.78), hypertension (RR: 1.92; 95% CI: 1.65-2.22), and education < high school (RR: 2.02; 95% CI: 1.72-2.38) compared to the crude association. Ethnicity significantly modified associations between diabetes, smoking, health insurance, education and IS rates. Associations between diabetes and IS rates was greater among MAs (RR: 6.82, 95% CI: 5.76-8.07) compared with NHWs (RR: 4.40, 95% CI: 3.33-5.81), while smoking associations were greater in NHWs (MA RR: 2.61, 95% CI: 2.20-3.10; NHW RR: 3.49, 95% CI: 2.73-4.46). Socioeconomic variables increased IS risk in NHWs but were insignificant or protective in MAs.

Conclusion:
Traditional stroke risk factors may contribute to midlife ethnic stroke disparities; particularly diabetes, given its high prevalence and stronger association with IS among midlife MAs as compared with NHWs.
Abstract WP226: Isolated Aphasia in the Emergency Department: Prevalence and Characteristics of Isolated Aphasia Due to Stroke Within a Population
Authors: Coleman Elisheva R , Khoury Jane C , Moomaw Charles J , Alwell Kathleen , Kissela Brett M , Woo Daniel , Flaherty Matthew L , Opeolu Adeoye , Khatri Pooja , Martini Sharyl , Ferioli Simona , Mackey Jason , De Los Rios La Rosa Felipe , Kleindorfer Dawn O
Published: June 2021

Background:
Aphasia is a disabling consequence of ischemic stroke (IS), usually caused by strokes in the territory of the left middle cerebral artery. It is often seen as part of a larger syndrome with right hemiparesis and other left hemisphere signs. Isolated aphasia may be difficult to recognize given the lack of motor symptoms, potentially delaying treatment. Our study seeks to determine the prevalence of isolated aphasia, the rate at which these patients call 911, and the rate and speed of treatment with rt-PA compared with the general IS population.

Methods:
Adult IS patients in 2005 and 2010 in the Greater Cincinnati/Northern KY region (pop. 1.3 million) were ascertained from all local hospitals via ICD-9 codes 430-436, using retrospective chart review. We limited analysis to acute IS cases that presented to an ED. Isolated aphasia was defined by a score >0 on item 9 of the initial rNIHSS (indicating language deficit) and scores of 0 on all other items except 1b and 1c. We compared rates of EMS use and rt-PA administration and median times to presentation and treatment for those with isolated aphasia versus not, using chi-square, Fisher’s exact test, t-test, or Wilcoxon rank-sum test.

Results:
In 2005 and 2010, 3814 IS cases presented to EDs in the region; 22% were black, 56% were female, and the mean (SD) age was 70 (15) years. Of these, 120 (3.2%) presented with isolated aphasia. Characteristics of the isolated aphasia group are compared with all other IS in Table 1. Isolated aphasia patients showed a trend toward later arrival and lower rate of treatment with rt-PA.

Discussion:
The trend toward later arrival in patients with isolated aphasia, though not statistically significant, suggests a need to better educate the public on recognizing this stroke syndrome. Isolated aphasia was significantly associated with atrial fibrillation and was associated with decreased small vessel and increased cardioembolic and undetermined stroke subtypes, a finding that merits further study.
Abstract WP23: Comparison of Suction Thrombectomy, Stentriever, and Combined Approach: Thrombus Size, Fragmentation, and Outcome - A Single Center Analysis
Authors: Leesch Wolfgang , Ramakrishnan Pankajavalli , Kostov Dean , Gossage O’Brien , Sanderson Frank
Published: June 2021

Introduction:
Few reports have compared the commonly used technical approaches of stentriever, suction thrombectomy, and combined technique, particularly with emphasis on thrombus volume, fragmentation, distal embolization, and clinical outcome.

Methods:
Medical records and radiographic images of patients undergoing endovascular stroke therapy at our institution between 2014 and 2015 were reviewed for the following data points: Patient age, sex, NIH stroke scale (NIHSS) at presentation, number of passes, presence of distal embolization on angiography, TICI score, and Modified Rankin Scale (MRS) at discharge. When available, photographic images of the retrieved thrombus were analyzed for number of fragments and size of the largest fragment. Parameters were compared for the three thrombectomy techniques of suction (ADAPT technique), stentriever, and the combined approach.

Results:
Of 63 patients receiving endovascular stroke therapy, 47 (75%) underwent mechanical thrombectomy: Stentriever 17 (36%), Suction 18 (38%), and combined 12 (26%). Average age and presenting NIH stroke scales were similar in the groups. A single pass thrombectomy was more common in the suction group (72%) than in the stentriever (29%) and combined groups (8%). There were more thrombus fragments in the stentriever (2.3) and combined groups (3.4) than in the suction group (1.4), correlating to more frequent distal embolization (suction 22%, stentriever 70%, combined 50%). The retrieved thrombus was largest in the suction group (12.9 mm; stentriever 6.6 mm; combined 10.4 mm). Overall outcome at discharge was better in the suction group (61% MRS 0-2) than in the stentriever (35%) and combined groups (17%).

Conclusions:
In our patient sample suction thrombectomy outperformed the stentriever and combined techniques in the categories of achieved reperfusion grade, single pass, retrieved thrombus size, number of fragments, distal embolization and clinical outcome. While stent retriever and suction thrombetomy were used as primary approaches, the combined technique was commonly utilized as a rescue attempt once the primary approach had failed, constituting a potential limitation of the analysis in this category.
Abstract WP230: Real-life Detection Rate of Insertable Cardiac Monitors in Patients with ESUS
Authors: Pallesen Lars-Peder M , Mayer Julia , Barlinn Kristian , Barlinn Jessica , Prakapenia Alexandra , Siepmann Timo , Winzer Simon , Piorkowski Christopher , Puetz Volker
Published: June 2021

Introduction:
It has recently been shown that insertable cardiac monitors (ICM) reveal intermittent atrial fibrillation (AF) in up to 12.4% of patients with embolic stroke of undetermined source (ESUS) at 1 year follow-up. We sought to analyze the detection rate of intermittent AF with ICM in real-life clinical practice.

Methods:
We prospectively studied consecutive patients with ESUS who received an ICM (NeuroLinq®) from 01/2014 to 06/2015). Baseline characteristics, treatment modalities and AF detection rate in the first year following ICM placement was assessed.

Results:
We enrolled 75 ESUS patients (64% men, median age 61 years) who underwent ICM placement. Two patients were excluded due to diagnosis of prion disease and Churg-Strauss syndrome after placement of ICM. Sixty-nine of 73 (95%) patients complied with the eligibility criteria adopted by the CRYSTAL-AF study. Intermittent AF was detected in 14 (19%) patients with a median time from ICM placement to diagnosis of 57 (range, 312) days.

Conclusions:
Our data suggest that the real-life detection rate of intermittent AF with ICM placed in patients with ESUS is comparable to that one observed under clinical trial conditions.
Abstract WP240: Association Between Mitral and Annular Calcification or Aortic Valve Calcification and Complex Aortic Atheroma in Ischemic Stroke Patients
Authors: Ishizuka Kentaro , Hoshino Takao , Ashihara Kyomi , Kitagawa Kazuo
Published: June 2021

Background and aims:
The aim of this study was to investigate the prevalence of mitral annular calcification (MAC) and aortic valve calcification (AVC) according to the presence or absence of complex aortic atheroma (CAA), using transesophageal echocardiography (TEE) data.

Methods:
This study included 130 (mean age 59.5 years; male 68.5%) consecutive patients who admitted in our hospital with acute ischemic stroke and underwent transesophageal echocardiography (TEE) for determination of stroke etiology during hospitalization. Stroke subtypes were classified with TOAST criteria. Embolic stroke with undetermined source (ESUS) was defined on the basis of the Cryptogenic Stroke/ESUS International Working Group criteria. MAC and AVC were defined as focal areas of high echogenicity of mitral valve annulus and aortic leaflet, respectively. CAA was assessed by TTE and defined as ≥4 mm and/or ulceration and/or mobile plaques. Comparisons were made between patients with and without CAA (CAA and non-CAA group, respectively) with regard to clinical and echocardiological findings.

Results:
Of the 130 patients, 26 (20.0%) had CAA. The patients in the CAA and non-CAA groups showed significant differences in age (mean, 69.5 vs. 57.0,
P
< 0.001), hypertension (88.5% vs. 44.2%,
P
< 0.001), chronic kidney disease (46.2% vs. 22.1%,
P
= 0.013), diabetes mellitus (61.5% vs. 23.1%,
P
< 0.001), hyperlipidemia (69.2% vs. 37.5%,
P
= 0.004), MAC (23.1% vs. 2.9%,
P
< 0.001), AVC (19.2% vs. 5.8%,
P
= 0.022), and MAC or/and AVC (34.6% vs. 7.7%,
P
< 0.001). When restricted to ESUS patients, there were significant differences in age (mean, 65.0 vs. 53.3,
P
= 0.042), hypertension (mean, 80.0% vs. 43.6%,
P
= 0.040), history of coronary artery disease (40.0% vs. 2.6%,
P
< 0.001), diabetes mellitus (60.0% vs. 12.8%,
P
= 0.001), hyperlipidemia (80.0% vs. 30.8%,
P
= 0.004), AVC (37.5% vs. 6.8%,
P
= 0.012), and MAC or/and AVC (34.6% vs. 7.7%,
P
= 0.030) between the 2 groups, whereas the prevalence of MAC was not different between CAA and non-CCA groups (12.5% vs. 2.3%,
P
= 0.16).

Conclusions:
Stroke patients with CAA frequently have concurrent MAC and/or AVC, which may prompt an effort to detect CAA for patients with MAC and /or AVC in transthoracic echocardiography.
Abstract WP241: The Yield of Transthoracic Echocardiogram in Diagnosis and Management of Small Singular Subcortical Infarcts
Authors: Celaj Stela , Corado Carlos , Prabhakaran Shyam
Published: June 2021

Introduction:
Lacunar strokes are single, small, subcortical (SSS) infarcts caused by small cerebral vessel blockage. The diagnosis of lacunar strokes relies on presence of risk factors, typical lacunar syndromes, and radiographic confirmation. Though non-lacunar causes such as large artery atherosclerosis (LAA) and cardiac embolism occasionally result in subcortical infarcts, the added utility of transthoracic echocardiogram (TTE) in clinical management of SSS infarcts has not been reported. We hypothesized that TTE would identify potential cardioembolic causes, subsequently changing management in patients with SSS infarcts.

Methods:
We performed a retrospective study of a prospective cohort of ischemic stroke patients from August 2012-July 2014 in whom brain MRI and TTE were completed during index stroke admission. We assessed infarct topography and TTE results blinded to stroke subtype and treatment. We defined SSS infarcts as lesions in the corona radiata, basal ganglia, thalamus, or brainstem measuring <1.5 cm. We assessed prevalence of TTE findings: dilated left atrium, patient foramen ovale (PFO), atrial septal aneurysm (ASA), low ejection fraction (EF <35%), and thrombus.

Results:
Among 908 patients, 75 (8.3%) met inclusion criteria (mean age 65.46, 53% female, 57% white). Of these patients, 4 had atrial fibrillation by EKG and 5 had symptomatic LAA by vessel imaging. TTE revealed cardiac abnormalities in nearly half of the 66 remaining patients. The most common finding was dilated left atrium (33%), followed by PFO (15%) and ASA (7.5%); 1 patient had thrombus, 1 had atrial myxoma, and another had EF <35%. Anticoagulants were prescribed on the basis of TTE findings in 4.5% (95% CI [1.6-12.5]) of patients. The final stroke subtype was: 72% lacunar; 8% cardioembolic, 6.7% LAA, 2.7% other determined cause and 10.6% undetermined cause.

Conclusion:
TTE findings revealed potential cardioembolic sources in roughly half of patients presenting with SSS infarcts. However, medical management was changed in only 4.5 % of patients. Other medium risk findings did not change management, but warrant further research. Overall, our data suggest that there is a small but potentially important yield of TTE in patients presenting with SSS infarcts.
Abstract WP249: Comparison of Telestroke Metrics Between an Internal Telestroke Model to an External Telestroke Vendor Within the Same System of Care
Authors: Noroozi Jared , Warren Noelani , Diep Elizabeth , Lipiz Jorge , Ajani Zahra A , Arbuckle Robert A , Sangha Navdeep S
Published: June 2021

Background:
Telestroke (TS) has been used to provide acute stroke care through a variety of different models. Two of these include an external vendor model (EVM), where care is provided by specialists that are not intrinsically related to the hospitals to which the care is being delivered, and another is an internally designed model (IDM) run by neurologists employed by the same hospital system. Our hospital system at Kaiser Permanente employed coverage via an outside vendor at certain sites as well as concurrently used an internally designed telestroke program at other sites.

Objective:
We aimed to determine if an IDM would provide quicker telestroke services and improve the door to needle time (DTN) to that provided by EVM in the management of acute ischemic stroke.

Methods:
Charts in which tPA was administered using TS, from 1/1/2015 to 12/31/2015, were retrospectively reviewed from two different medical centers of similar size and patient volume. One center utilized an EVM while the other employed an IDM. Several metrics were compared including DTN, door to telestroke consultation time and call back time from telestroke neurologist. A 2 tailed T-test was used to compare the differences between both groups.

Results:
Thirty three patients received tPA via IDM, and 37 patients via EVM. The median door to telestroke consultation placement time was 11 minutes (mins) in both hospitals (p=0.10). The median telestroke physician call back was 16 (IQR 13-18) mins in EVM vs. 7 (IQR 10-24) mins in IDM (p=0.024). The overall door to telestroke consultation was 44 (IQR 29-40) mins in the EVM vs. 21 (IQR 14-40) mins in IDM (P=0.006). The median DTN was 86 (IQR 69-107) mins in EVM vs. 51 (IQR 42-70) mins in IDM (p= 0.005).

Conclusion:
The IDM cohort had quicker call back and consultation times compared to the EVM group. However, there was no difference between door to consult placement time helping to remove local emergency department variability. This suggests that a model that is internally developed with physicians intrinsically related to the hospital system compared to an external vendor may provide quicker telestroke services and improve DTN.
Abstract WP25: Gender Disparity in Mechanical Thrombectomy Outcomes: The Role of Arterial Caliber
Authors: Davison Mark A , Keppetipola Kavantissa M , Ouyang Bichun , Chen Michael
Published: June 2021

Introduction:
Despite level 1a evidence demonstrating the clinical benefit of mechanical thrombectomy in selected large vessel ischemic stroke patients, a gender disparity exists. Women not only have less favorable clinical outcomes after all stroke types, but the causes of this disparity remain elusive. Gender differences in cerebral vascular anatomy have been previously published. We hypothesize that differences in circle of Willis diameters may contribute to the gender disparity seen in clinical outcomes after mechanical thrombectomy for acute ischemic stroke.

Methods:
Clinical and radiographic data from a consecutive series undergoing mechanical thrombectomy for anterior circulation large vessel ischemic strokes were reviewed. Measurements of the proximal middle cerebral artery (M1) segment and supraclinoid internal carotid artery (ICA) diameters were obtained in a standardized fashion from the thrombectomy procedure angiogram. All M1 measurements were recorded at 3 mm of the vessel origin while ICA measurements were taken 3 mm proximal to the ICA terminus. Covariates included age, occlusion location, vascular risk factors, admission NIHSS score and final TICI grade. Modified Rankin score (mRS) at 90 days was the dependent variable. Variable significance between male and female cohorts was determined using student T-Tests. Multivariate regression analysis was also performed.

Results:
Ninety-four patients (41 female) between 6/2013 and 6/2016 fit the inclusion criteria. ICA terminus measurements for men and women were 3.07 mm (SD=0.46) and 2.88 mm (SD=0.47), respectively. M1 origin measurements for men and women were 2.46 mm (SD=0.31) and 2.21 mm (SD=0.37), respectively. Male ICA terminus and M1 origin measurements were larger than female (p = 0.05 and p < 0.001, respectively). 61% of men vs. 25% of women had 90-day mRS ≤ 2. Multivariate analysis indicated that only age was significantly associated with 90-day mRS ≤ 2.

Conclusions:
Our single center series suggests that differences in intracranial vessel diameter may contribute to the gender disparity in outcomes after mechanical thrombectomy. Smaller circle of Willis arterial diameters may compromise collateral blood flow and increase the difficulty in achieving sufficient reperfusion.
Abstract WP255: Rapid Coagulation Tests for Acute Ischemic Stroke
Authors: Nah Hyun-Wook , Kim Dae-Hyun , Cha Jae-Kwan
Published: June 2021

Background and objectives:
The results of coagulation tests are important for the decision of thrombolysis in acute ischemic stroke patients who are taking oral anticoagulants. In coagulation tests, the preparation of blood specimens is a major bottleneck in the workflow. Clinical and Laboratory Standard Institute (CLSI) guidelines require that routine coagulation tests are performed with platelet-poor plasma (<10,000 platelets per microliter). We investigated whether high acceleration centrifugation can reduce the time of coagulation tests without breaking the guidelines.

Methods:
We compared the high acceleration centrifugation condition (3 minutes, 8000 rpm) with the standard centrifugation condition (15 minutes, 3000 rpm) in 32 patients. The pre- and post-centrifugation platelet counts were measured and compared between the groups.

Results:
Sixteen samples were centrifuged in high acceleration condition and another 16 samples in standard condition. The pre-centrifugation platelet counts were not different (median, 165,000 (interquartile range, 146,750-185,500) per microliter vs. 166,500 (128,000-193,250), p=0.675) between the groups. Although the post-centrifugation platelet counts were higher in the high acceleration group than the standard group (4,500 (2,250-6,000) vs. 1,000 (0-2,000), p<0.001), all the samples in the high acceleration group met the requirements of platelet-poor plasma. Using the high acceleration centrifugation method, the reporting time of coagulation tests decreased from 24 (23-25) to 12 (12-13.5) minutes.

Conclusion:
High acceleration centrifugation can reduce the time of coagulation tests for 12 minutes without breaking the guidelines. This method may help to shorten the door-to-needle time in acute ischemic stroke patients who are taking oral anticoagulants.
Abstract WP260: Imaging Appropriateness Criteria May Guide Effective Use of CT Angiography in Acute Stroke Workup
Authors: Goiney Christopher , Carlson Blake , Relyea-Chew Annemarie , Creutzfeldt Claire , Yuan Chun , Mossa-Basha Mahmud
Published: June 2021

Introduction:
CT angiography (CTA) is a front-line imaging tool for the evaluation of acute stroke patients in the emergency department. In our experience, however, many CTAs performed for suspected stroke may not be appropriate and patients are found to have alternative diagnoses upon further work-up. We hypothesize that use of an evidence-based imaging guideline such as the American College of Radiology Appropriateness Criteria (ACR-AC) could facilitate more judicious use of CTA by identifying patients who are likely to have alternative diagnoses.

Methods:
We retrospectively reviewed patients who underwent CTA for stroke workup in the emergency department between January 2014 and January 2015. Patients evaluated for trauma, intracranial hemorrhage and known infarcts were excluded. Through PACS and EMR review, we identified 144 patients. Using a double-reader consensus method, we categorized each patient’s presenting symptoms based on the ACR-AC Neurologic Variants. Categories included: “usually appropriate,” “may be appropriate,” and “usually not appropriate”. We performed contingency table analyses using Fisher’s exact test and calculated odds ratios to correlate ACR-AC categories with CTA findings which explained stroke presentation such as arterial thrombosis, dissection, or high grade stenosis in a relevant vascular distribution.

Results:
Of the 144 patients who underwent CTA for stroke evaluation, 87 patients fell into the “usually appropriate” ACR-AC category, with 49 “may be appropriate” and 8 “usually not appropriate”. Within the first group, 19/87 CTAs were positive (21.8%) with an odds ratio of 4.98 (p=<0.01). In the second group, 3/49 CTAs were positive (6.1%) with an odds ratio of 0.26 (p=<0.03). In the third group, 0/8 CTAs were positive, with an odds ratio of 0.49 (p=0.61).

Conclusion:
Our data suggest that ACR-AC correlate with CTA findings relevant to stroke. Specifically, patients in the “usually appropriate” category were more likely to have a positive finding on CTA, while no positive CTAs were seen in the “usually not appropriate” category. These preliminary data suggest that the use of ACR-AC or similar criteria may aid clinical decision making and facilitate evidence-based use of CTA for suspected stroke workup.
Abstract WP273: Evolution of a U.S. County System for Acute Comprehensive Stroke Care
Authors: Raychev Radoslav I , Stradling Dana , Brown David M , Gee Joey R , Lombardi David L , Moon Johnson L , Patel Nirav , Pathak Mayank , Yu Wengui , Stratton Samuel J , Cramer Steven C
Published: June 2021

Introduction:
In an effort to maximize provision of acute stroke therapies, the Emergency Medical Services (EMS) in Orange County, CA (6
th
most populous U.S. county) established a system of care whereby patients with suspected acute stroke are taken to hub sites with endovascular treatment (EVT) capability or to spoke hospitals. Patients at spokes with acute ischemic stroke (AIS) and suspected large vessel occlusion (LVO) are transferred by EMS to hubs. Here we examined the relationship between stroke features, hospital transfers, and mortality; and their change over time.

Methods:
All patients during 2013-2015 were included for whom 911 was called within 7 hours of onset, and EMS personnel declared “acute stroke" at end of initial evaluation.

Results:
A total of 6,188 patients (mean age 72) had suspected stroke, of which 54.9% were AIS and 19.4% hemorrhagic stroke. Across all patients, transfer rates into hub sites increased over time (OR 1.12 per 3-months, p<0.0001) and differed by diagnosis (p<0.0001), with transfer in 12.0% of hemorrhages (n=122) but only 3.5% of AIS (n=101). Among patients with AIS only, transfer rates into a hub site increased over time (OR 1.08, p<0.0001), spiking mid-2015. Acute reperfusion therapy was given to 28.3% (20.9% IV tPA only, 3.6% IA therapy only, 3.8% IV tPA+IA), but its usage was unrelated to transfer status, and only 11% of all transferred AIS patients received EVT. Across all patients, mortality during acute hospitalization was 8.2% and did not differ by transfer status, but did differ by diagnosis (p<0.0001): 23.6% of hemorrhages vs. 5.4% of AIS. Over time, mortality decreased only among patients with AIS (OR 0.95, p=0.03).

Conclusions:
There were several favorable features of this acute stroke care system, including that 28.3% of AIS patients received reperfusion therapy and that mortality decreased over time. However, while transfer to EVT-ready sites increased, rates of IA therapy were low. Continued efforts to optimize acute stroke systems of care should be tailored toward increasing EVT by early recognition of LVO and timely triage to hub facilities.
Abstract WP283: Sex Differences in Hipoxic-ischemic Encephalopathy Are Modulated by Cx3cl1/Cx3cr1 Signaling
Authors: Bravo-Alegria Javiera B , McCullough Louise D , Liu Fudong
Published: June 2021

Background:
Neonatal hypoxic-ischemic encephalopathy (HIE) is a major cause of cognitive impairment in children. Clinically, male infants are more sensitive to the ischemic insult and have worse long-term deficits than girls. The mechanism underlying the sex difference remains elusive. Our previous study using an HIE animal model on post-natal day 10 (P10) mice has revealed that male animals exhibited worse outcomes than females, corresponding to an increased microglial activation that initiates post-ischemia immune responses. CX3CL1/CX3CR1 axis is an endogenous inhibitory signaling pathway that keeps microglia quiescent in normal brains. Whether the CX3CL1/CX3CR1 axis is sex-differently expressed in neonatal brains to cause the sexually dimorphic phenotypes of HIE is not known.

Hypothesis:
We hypothesize that neonatal female brains are protected against HIE due to a more robust CX3CL1/CX3CR1 signaling compared to males and that manipulation of CX3CL1/CX3CR1 axis has sex-specific effects on HIE.

Methods:
C57BL6 P10 mice (WT) of both sexes were subjected to a 45-min Rice-Vanucci model (RVM) to induce HIE. CX3CR1 expression, microglial activation, and the infiltration of peripheral leukocytes were examined by flow cytometry. CX3CR1 knockout mice were also used to evaluate the effect of genetic deletion of CX3CL1/CX3CR1 signaling.

Results:
WT females had a better outcome after neonatal HIE. In addition, WT females have significantly higher expression of CX3CR1 on microglia at baseline than males, measured by CX3CR1 MFI with flow cytometry. Importantly, the majority of the CX3CR1
+
microglia co-expressed CD206, a marker of anti-inflammatory phenotype for phagocytes. CX3CR1 KO females lost the resistance to ischemic damage as the knockout of CX3CR1 gene led to exacerbate HIE outcomes only in females.

Conclusions:
The high expression of CX3CR1 primes female brains to resist inflammatory responses to HIE and has beneficial effects, though the protective mechanism is not sufficient in male brains. Sex differences seen in neonatal HIE are at least in part ascribed to the sexually dimorphic CX3CL1/CX3CR1 signaling.

Funding:
R01: NS093042 and R21: NS091794 to Fudong Liu.
Abstract WP284: Pro-inflammatory Response Elicited by Porphyromonas Gingivalis Lipopolysaccharide Exacerbates the Rupture of Experimental Cerebral Aneurysms
Authors: Miyamoto Takeshi , Kitazato Keiko T , Tada Yoshiteru , Shimada Kenji , Yagi Kenji , Korai Masaaki , Maekawa Hidetsugu , Yamaguchi Tadashi , Yoshioka Shotaro , Kinouchi Tomoya , Kanematsu Yasuhisa , Satomi Junichiro , Nagahiro Shinji
Published: June 2021

Introduction:
Subarachnoid hemorrhage (SAH) is a catastrophic event with high morbidity and a poor prognosis. To prevent SAH, its pathogenesis must be understood. Dental infection may play a part in the pathophysiology of intracranial aneurysms. In our newly established rat model of aneurysms, the vascular inflammatory response was associated with their rupture. Therefore we hypothesized that the inflammatory response exacerbated by periodontal pathogens affects experimental cerebral aneurysm rupture.

Methods:
Aneurysms were induced in 10-week-old female Sprague-Dawley rats by eliciting estrogen deficiency, renal hypertension, and hemodynamic stress. Two weeks later they were divided into 2 groups; group 1 (n=13) was treated with Porphyromonas gingivalis lipopolysaccharide (LPS), group 2 (n=17) was the saline control. Both groups were intraperitoneally injected once a week.

Results:
During the 90-day observation period, 7 group 1 (54%) and 6 group 2 rats (35%) suffered aneurysmal rupture. The incidence of rupture within 60 days was significantly higher in group 1 than group 2 (38% vs 6%, p<0.05), indicating that LPS promoted experimental aneurysmal rupture. The administration of LPS increased the plasma level of IL-1β and MMP-9 and the mRNA level of TLR2, IL-1β, and MMP-9 in the vascular wall prone to rupture on day 60. In our
in vitro
studies, IL-1β mRNA was increased in vascular smooth muscle cells exposed to LPS. These results suggest that LPS enhances the rupture of intracranial aneurysms via the promotion of local and systemic pro-inflammatory responses.

Conclusion:
Our study first documents that in rats, Porphyromonas gingivalis LPS exacerbates vascular inflammation and enhances the rupture of intracranial aneurysms.