bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP166: Prediction of Recurrent Stroke in Lacunar Stroke Patients: Performance of the Small Vessel Disease (SVD) Score in the SPS3 Trial
Authors: Field Thalia S , Pearce Lesly , Doubal Fergus , McClure Leslie , Bazan Carlos , Shoamanesh Ashkan , Ohba Hideki , Catanese Luciana , White Carole , Hart Robert , Benavente Oscar , Wardlaw Joanna
Published: March 2022

Introduction:
The previously published cerebral SVD Score is a four-point rating scale based on the four cardinal MRI markers of SVD: moderate-severe white matter hyperintensities, , lacune(s), moderate-severe enlarged perivascular spaces (PVS), and microbleed(s). We evaluated the score’s ability to predict recurrent stroke in the Secondary Prevention of Small Subcortical Strokes (SPS3) Trial.

Methods:
One point each was awarded for these 4 MRI findings: max periventricular Fazekas score = 3 and/or max subcortical Fazekas score > 2; >1 cerebral microbleed 2 (i.e. > 11 PVS unilaterally); > 1 old lacune (3-15 mm) on FLAIR/T1. Annualized rates of recurrent stroke were computed assuming a Poisson model, and c-statistics were calculated for the SVD score model and for two other previously published SPS3 derived models.

Results:
Of 3020 participants, 1137 had complete data available for SVD scoring. Prevalence of SVD scores 0, 1, 2, 3, and 4 were 19% (n=219), 29% (n=325), 24% (n=277), 18% (n=200), and 10% (n=116). PVS (55%) were most common, followed by moderate-severe white matter hyperintensities (45), lacunes (41), and microbleeds (30). Recurrent stroke rates did not strictly increase with increasing SVD score, i.e. rates were 2.4%/pt-yr (95% CI 1.5, 3.9), 1.4 (0.8, 2.3), 2.0 (1.3, 3.2), 3.8 (2.5, 5.7), and 3.2 (1.8, 5.6) respectively. When SVD scores of 0-2 vs. 3-4 were grouped and compared with two other models for predicting recurrent stroke in this cohort, the SVD score model did not outperform. (Table)

Conclusions:
SVD score features were very common in the SPS3 cohort. Higher (3-4) vs. lower (0-2) SVD scores predicted recurrent stroke with similar predictive ability to models including clinical risk factors only +/- fewer MRI features. Further testing of the SVD score is warranted.
Abstract WP17: Effect of Solitaire Retriever-predominant Thrombectomy in Acute Ischemic Stroke: a Pooled, Individual Patient Data, Systematic Analysis
Authors: Hill Michael D , Saver Jeffrey L , Bonafe Alain , Campbell Bruce , Davalos Antoni , Davis Stephen , Demchuk Andrew M , Diener Hans-Christophe , Donnan Geoff , Jahan Reza , Jovin Tudor G , Levy Elad I , Menon Bijoy K , Millan Monica , de Miquel Maria A , Mitchell Peter , Pereira Vitor M , Poppe Alexandre Y , Rempel Jeremy L , Ribo Marc , San Roman Luis , Stouch Bruce , Thornton John , Goyal Mayank ,   SEER Trialists
Published: March 2022

Introduction:
Endovascular thrombectomy predominantly with the Solitaire stent retriever results in better outcomes among ischemic stroke patients with proximal, anterior circulation occlusions. The overall effect size and benefit in important subgroups are best estimated using pooled, individual participant-level data meta-analysis.

Methods:
The SEER consortium pooled individual patient-level data from the 4 major randomized trials in which Solitaire retrievable stents were the predominant endovascular device, ESCAPE, SWIFT-PRIME, REVASCAT, and EXTEND-IA. A formal statistical analysis plan was pre-specified. The primary outcome is the modified Rankin Score at 90 days. Secondary outcomes include functional independence (mRS 0-2) and mortality at 90 days. Clinical sub-groups assessed are age, sex, NIHSS score, and target occlusion location. Full results will be presented at the meeting.

Results:
Among 777 patients randomized (400 intervention, 377 control), mean age was 68 (sd 13), 51% were female, pretreatment NIHSS was median 17 (iqr 7), median ASPECTS score was 8 (iqr 2). More favorable outcomes over the entire mRS were observed with thrombectomy, CMH test p <0.001. Treatment benefit was homogenous across all subgroups of age, sex, baseline NIHSS, and target occlusion location. The rate of functional independence (mRS 0-2) at 90d was 55.0% endovascular vs. 31.5% control (RR = 1.7 CI95 1.4-2.1). The risk of death trended lower in the endovascular group (RR = 0.75 CI95 0.5-1.1). Among 128 patients ≥ 80 years of age, 37.8% (endovascular) vs. 18.5% (control) achieved an independent outcome (RR 2.0 CI95 1.1-3.8). Among 206 subjects with ICA occlusion, 45.9% (endovascular) vs. 18.9% (control) achieved an independent outcome (RR 2.4 CI95 1.5-3.8). Among 561 with MCA occlusions, 58.6% (endovascular) and 38.9% (control) achieved an independent outcome (RR 1.6 CI95 1.3-2.0).

Conclusions:
Endovascular treatment for anterior circulation, large vessel occlusion ischemic stroke is a robust therapy in old and young, men and women, more and less severe deficits, and both ICA and MCA occlusions. The magnitude of benefit is large and consistent across trials; overall, 1 of every 4 treated patients achieves functional independence as a result of therapy.
Abstract WP170: Infections Present on Admission and Stroke in the Young
Authors: Hazan Rebecca , Boehme Amelia K , Miller Eliza , Yaghi Shadi , Rostanski Sara , Willey Joshua , Marshall Randolph , Elkind Mitchell
Published: March 2022

Background and Purpose:
Antecedent infections have been identified as possible risk factors and triggers for stroke, while infections after stroke lead to worse outcomes. The impact of infections present at the time of admission (IPOA) has not been well characterized. We hypothesized that IPOA would be associated with stroke severity and outcomes in young stroke patients.

Methods:
A retrospective review of consecutive ischemic stroke patients aged 18-40 years admitted between January 2008 and June 2014 was performed. IPOA were defined as present if the infection was diagnosed within the first 24 hours of admission. The primary outcomes were stroke severity using the National Institutes of Health Stroke Scale (NIHSS) and poor functional outcome at discharge (modified Rankin Scale (mRS) 3-6)).

Results:
Of 235 patients, 41 (17.4%) had IPOA. Patients with IPOA were more likely to be women (87.8% vs. 51.0%; p<0.0001), younger (30 vs. 34 years; p=0.0317) and to have a higher NIHSS (median 4 vs. 2; p=0.029). In the overall sample, IPOA, age, and female sex were associated with poor outcome. The effect of age on the relationship between IPOA and outcomes appeared to be an interaction, however, the sample size is small; therefore analyses stratified on age were conducted to assess the relationship between IPOA and outcomes. Among patients 18-30, those with IPOA had NIHSS scores 6 points higher than those without IPOA after adjusting for age and sex (p=0.0039), whereas there was no relationship between IPOA and NIHSS in patients > 30 years. In patients 18-30, after adjusting for age, sex, and NIHSS, IPOA was associated with a greater odds of poor outcome (OR 3.69, 95%CI 1.20-11.3); NIHSS was not associated with mRS 3-6 (OR 1.00, 95%CI 0.99-1.01). IPOA was not significantly associated with poor outcome after adjusting for age, sex and NIHSS in patients >30 years (OR 1.29, 95%CI 0.48-3.51).

Discussion:
Infections present at time of admission in young stroke patients are closely associated with NIHSS and subsequent poor outcomes at discharge. Further studies are needed to understand the role of infection and whether infections moderate the effect of stroke severity on stroke outcomes in young patients.
Abstract WP171: Long Sleep is a Stronger Predictor of Stroke Than Short Sleep: Comparative Analysis of Multiple Linear Regression Model and Bayesian Belief Network Model
Authors: Seixas Azizi , Henclewood Dwayne , Williams Stephen , Williams Olajide , Rogers April , Ogedegbe Gbenga , Jean-Louis Girardin
Published: March 2022

Background:
Short (<6hrs) and long (>8 hrs) sleep durations are linked to stroke and cardiovascular disease. However, results have relied primarily on regression analysis, which may not be optimal to model associations between sleep and medical outcomes. Big-data and machine learning analyses provide unique opportunities to quantify dynamic interactions between sleep and medical outcomes, adjusting for multiple risk factors.

Method:
The current study utilized two types of analyses: logistic regression and Bayesian Belief Network, a form of machine learning analysis, to assess sleep-related stroke risk. We used data from the 2004-2013 National Health Interview Survey, yielding 288,888 cases, to investigate how short (<7hrs.) and long (>8hrs.) sleep durations impact stroke risk. In both analyses, we assessed the contribution of 34 demographic, medical, behavioral, and psychosocial factors. We used SPSS 20 to conduct regression analyses and BayesiaLab’s Tree Augmented Naïve Bayes learning algorithm for complex system analysis. We compared results of both analytic models to determine their ecological and clinical utility.

Results:
Forty-eight percent of volunteers were ≤45 yrs.; 77.40% were White; 15.96%, Black/African American; and 45.1% made < $35K annually; 29.55% reported short sleep and 8.9%, long sleep; 61.55% were average sleepers (7-8hrs.). Adjusted regression models indicated that relationships between short sleep and stroke were not significant (OR=.97, 95% CI=0.92-1.02,
p
=.21); however, long sleep was associated with stroke (OR=1.43, 95% CI= 1.32-1.52,
p
<.001). Results from Bayesian analysis indicated both short and long sleep were associated with stroke, but that long sleep doubled stroke risk (7.48%) relative to short sleep (3.74%). Regression model had a R
2
of 0.24 for short sleep and long sleep, while the R
2
for Bayesia was 0.73.

Conclusion:
Bayesian Belief Network analysis is superior to regression modeling because it provides ecologically and clinically valid findings. Although both short and long sleep durations are associated with stroke risk, long sleep seems to be a stronger predictor.
Abstract WP172: Ethnic Disparities in the Use of Tissue Plasminogen Activator Among Young Adult Stroke Patients in Hawaii
Authors: Ito Cherisse S , King Sage L , Nakagawa Kazuma
Published: March 2022

Introduction:
Minorities with ischemic strokes are younger and less likely to receive intravenous tissue plasminogen activator (IV tPA) compared to whites; However, disparities in the use of IV tPA in the multi-ethnic population of Hawaii have not been adequately studied.

Hypothesis:
Native Hawaiians and other Pacific Islanders (NHOPI) and Asians who are hospitalized with ischemic stroke receive less IV tPA compared to whites.

Methods:
We conducted a retrospective study on consecutive young adult patients (age ≤55) hospitalized for ischemic stroke at a single tertiary center on Oahu between 2006 and 2012. Clinical characteristics and the use of IV tPA among NHOPI and Asians were compared to whites. Patients without race/ethnicity data (n=28) and postoperative strokes (n=22) were excluded.

Results:
A total of 462 consecutive young adult (mean age 47±9 years) ischemic stroke patients (whites 16%, Asians 36%, NHOPI 43%, Other 5%) were studied. NHOPI had higher prevalence of hypertension (NHOPI 75% vs. whites 49%, p<0.0001), diabetes (NHOPI 46% vs. whites 22%, p=0.0003), higher body mass index (NHOPI 33±9 cm/m2 vs. whites 28±7 cm/m2, p<0.0001), and hemoglobin A1c (NHOPI 8.9 ± 2.9% vs. whites 7.2 ± 2.5%, p=0.002) compared to whites. Clinical characteristics were similar between Asians and whites. The use of IV tPA was lower among NHOPI (4.6%, p=0.01) and Asians (3.0%, p=0.002) compared to whites (13.2%).

Conclusions:
NHOPI represented the major ethnic group among the young adult stroke population in Hawaii and had higher instances of hypertension and diabetes compared to whites. NHOPI and Asians both had significantly lower rates of IV tPA use compared to whites. Further study is needed to assess the barriers associated with the use of IV tPA among these minority groups.
Abstract WP174: Prestroke Selective Serotonin Reuptake Inhibitor Use and Functional Outcomes in Ischemic Stroke
Authors: Etherton Mark , Siddiqui Khawja A , Ayres Alison , Schwamm Lee H
Published: March 2022

Introduction:
Selective serotonin reuptake inhibitors (SSRIs) have been implicated in contributing to recovery after acute ischemic stroke. In particular, post stroke initiation of an SSRI has been demonstrated to improve motor recovery. The role of prestroke SSRI use on functional outcomes and stroke recovery is less clear. We aimed to examine the effect of prestroke SSRI use on metrics of hospitalization and functional recovery.

Hypothesis:
Pre-event SSRI therapy improves functional outcome in acute ischemic stroke.

Methods:
We included 4968 consecutive patients from January 2006 to June 2015 in our local Get with the Guidelines-Stroke registry in whom the preadmission admission drug list could be extracted from an administrative research data registry. Univariate and multivariable analyses were performed to identify predictors of functional outcomes.

Results:
Among 4698 ischemic strokes (740 SSRI users and 3948 nonusers) univariate analysis of SSRI use before acute ischemic stroke did not impact admission NIHSS, length of stay or rate of symptomatic hemorrhage (Table 1). Patients using SSRIs prior to their stroke were more likely to present with weakness (57% vs 47.3%, p<0.001) and have hospitalizations complicated by pneumonia (7.6% vs 5.7%, p<0.001). Moreover, pre-stroke SSRI use was associated with a negative impact on ambulatory status at discharge and discharge to home. On multivariable regression analysis, SSRI use was associated with lower likelihood of discharge to home (aOR 0.79, 95%CI 0.62, 0.997; p<0.05).

Conclusions:
SSRI use preceding an acute ischemic stroke is associated with lower rates of discharge to home despite no significant increase in length of stay or NIHSS. Further studies evaluating potential confounding factors, the influence of prior SSRI use on infarct size, and longer term outcomes are warranted.
Abstract WP176: Electrocardiographic Left Atrial Abnormality and Silent Vascular Brain Injury: The Northern Manhattan Study
Authors: Hunter Madeleine D , Moon Yeseon P , Varela Dalila , DeCarli Charles , Gutierrez Jose , Wright Clinton B , Di Tullio Marco R , Sacco Ralph L , Kamel Hooman , Elkind Mitchell S
Published: March 2022

Background:
Increased P-wave terminal force in lead V1 (PTFV1) of a standard 12-lead electrocardiogram (EKG), a marker of left atrial dilatation and possibly fibrosis, has been associated with stroke risk in the absence of atrial fibrillation (AF), and with subclinical infarcts in some cohorts. We hypothesized that PTFV1 would be associated with an increased prevalence of subclinical infarcts, especially cortical ones, and leukoaraiosis in a population-based, multi-ethnic cohort.

Methods:
PTFV1 was collected manually from baseline EKGs of participants in the population-based, prospective Northern Manhattan Study (NOMAS) who had remained clinically stroke-free and undergone brain MRI (n=1,290). MRIs were read for superficial and deep infarcts and white matter hyperintensity volume adjusted for head size (WMHV). Logistic regression models were used for the association of PTFV1 with all subclinical infarcts and with cortical infarcts, and linear regression models with logWMHV. Models were adjusted for demographics and risk factors.

Results:
Among the 1174 participants with PTFV1, mean age was 70 + 9 SD years at the time of MRI, 40.3% were male, and 14.4% were white, 17.6% black, and 65.8% Hispanic. Hypertension was present in 68.0%. Mean PTFV1 was 3587.35 ± 2315.62 μV-ms. MRIs were performed a mean of 6.0 + 3.4 years after EKG. Subclinical infarcts were present in 170 (15.1%) participants, and were cortical in 40 (3.6%). PTFV1 >5000 μV-ms was associated with greater WMHV even after adjusting for demographics and risk factors, including baseline AF (mean difference in logWMHV 0.14, 95% CL 0.01-0.28). There was a trend toward an association of PTFV1 with cortical (unadjusted OR per SD change logPTFV1 1.30, 95% CI 0.94-1.81) but not with all subclinical infarcts (unadjusted OR 1.00, 95% CI 0.85-1.18).

Conclusion:
EKG evidence of left atrial abnormality was associated with leukoaraiosis, and possibly with subclinical cortical infarcts, though the limited number of outcomes did not permit us to confirm this finding. Left atrial cardiopathy may be a source of emboli, but may also cause cerebral hypoperfusion-related injury. Further studies in large cohorts are needed to determine the relationship of PTFV1 to risk of subclinical cerebrovascular disease.
Abstract WP18: Futility and Predicted Therapeutic Gain of Endovascular Treatment According to the Baseline Stroke Severity in Acute Ischemic Stroke
Authors: Lee Sanghwa , Kim Beom Joon , Han Moon-Ku , Park Seong-Ho , Park Tai Hwan , Lee Kyung Bok , Lee Byung-Chul , Yu Kyung-Ho , Oh Mi Sun , Jang Min Uk , Cha Jae Kwan , Cha Jae Kwan , Kim Dae-Hyun , Nah Hyun-Wook , Lee Jun , Lee Soo Joo , Ko Youngchai , Park Jong-Moo , Kang Kyusik , Cho Yong-Jin , Hong Keun-Sik , Choi Jay Chol , Kim Joon-Tae , Choi Kangho , Kim Dong-Eog , Kim Wook-Joo , Lee Juneyoung , Lee Ji sung , Bae Hee-Joon ,   on behalf of CRCS-5 investigators
Published: March 2022

Introduction:
To describe the distribution of futile recanalization, defined by 3-month modified Rankin scale (mRS) 3 to 6 despite of successful recanalization (Thrombolysis in Cerebral Infarction grade 2b-3), and therapeutic gain of endovascular treatment (EVT) across the whole range of initial National Institutes of Health Stroke Scale (NIHSS) in patients with acute ischemic stroke attributable to major cerebral artery occlusion.

Methods:
Using a prospective multicenter stroke registry database, acute ischemic stroke patients, who were confirmed anterior circulation large artery occlusion and were treated with EVT within 12h of onset between November 2009 and July 2014, were identified. Futile recanalization rates were described across the whole range of NIHSS score, categorized as ≤ 5, 6∼10, 11∼20 and >20. To estimate therapeutic gain, defined as a difference in the proportions of mRS 3-6 between those recanalized completely with EVT and those not treated, a proportion of mRS 3-6 in those not treated was obtained through age-specific direct standardization using a population who were hospitalized within 12 h due to acute ischemic stroke, had major anterior circulation large artery occlusion and were not treated with recanalization therapy.

Results:
Among 21,591 patients with acute ischemic stroke, 4.5% (n=972) received EVT within 12 h of onset. Of those 972 patients, 54.8% (n=533) were successfully recanalized. Of those 533, 440 with anterior circulation larger artery occlusion were enrolled for study (male 58%, age 67.3±12.3 years, onset to EVT starting time 4.19±1.96 hours). Seventy percent of patients were treated with intravenous alteplase prior to EVT. Futile recanalization was observed in 51.4% (n=226). Futile recanalization increased with the increase of stroke severity; 20.9% in NIHSS≤ 5; 34.6% in 6∼10; 58.9% in 11∼20; 63.8% in >20 (p for trends <0.001). Therapeutic gain of EVT significantly differed by initial stroke severity (p for interaction<0.001); -1.9% in NIHSS≤ 5; 14.3% in 6∼10; 27.7% in 11∼20; 34.3% in >20.

Conclusions:
This study emphasized the impact of initial stroke severity on futile recanalization and therapeutic gain in patients receiving EVT for acute ischemic stroke caused by anterior circulation large artery occlusion.
Abstract WP182: Long Term Risk of Ischemic Stroke After Acute Coronary Syndrome
Authors: Yaghi Shadi , Pilot Markeith , Blum Christina A , Silver Brian , Furie Karen L , Elkind Mitchell S , Sherzai Dean , Sherzai Ayesha Z
Published: March 2022

Background:
Prior studies have shown an increased risk of ischemic stroke (IS) after myocardial infarction (MI), particularly in the first few days after the event. There is limited evidence, however, on the long-term risk and whether it is directly related to cardiac injury. We hypothesized that the risk of IS after acute coronary syndrome (ACS) is significantly higher when there is evidence of cardiac injury such as ST elevation MI (STEMI) or non-STEMI (NSTEMI) than when there is no evidence of cardiac injury such as Unstable Angina (UA).

Methods:
Administrative claims data were obtained from all emergency department encounters and hospitalizations at California’s nonfederal acute care hospitals between 2008 and 2011. Patients with STEMI, NSTEMI, and UA were identified using appropriate ICD-9 codes. Age and ICD-9 codes for sex, race-ethnicity, hypertension, diabetes, hyperlipidemia, congestive heart failure, and atrial fibrillation were analyzed. The outcome was IS during 2 years follow-up. Unadjusted and adjusted Cox proportional hazards models were used to determine the association between ACS subtype and ischemic stroke risk.

Results:
We identified 74,962 ACS patients: 35.9% STEMI, 54.8% NSTEMI, and 9.3% UA. The mean age in years was 66.7 ± 14.4 and 61.5% females; 3.2% of patients had IS during the two year follow-up. When compared to UA, the long term risk of IS was higher in patients with STEMI (adjusted HR 2.07 95% CI 1.67-2.56) and NSTEMI (adjusted HR 1.87, 95% CI 1.51-2.30), even after adjusting for stroke risk factors at baseline and incident atrial fibrillation (Figure). Other stroke risk factors after ACS are shown in the Figure.

Conclusion:
Analysis from a large administrative dataset revealed that both NSTEMI and STEMI confer an increased risk of ischemic stroke, independent of risk factors, which may be related to cardiac injury. Studies exploring ischemic stroke mechanisms in cardiac patients are needed to improve and tailor stroke prevention strategies.
Abstract WP183: Renal function is Associated With Severity of White Matter Hyperintensity in Patients With Acute Ischemic Stroke/TIA
Authors: Zong Lixia , Ni Jun , Yao Ming , Zhou Lixin , Yuan Jing , Peng Bin , Zhu Yi-Cheng , Cui Liying
Published: March 2022

Introduction:
Renal function impairment is characterized by glomerular endothelial dysfunction and lipohyalinosis, both of which are typical features of cerebral small vessel diseases(CSVD). We thus presume that renal function might be associated with silent CSVD-related MRI changes including white matter hyperintensity (WMH), lacune and microbleeds, which was supported by previous findings observed from the individuals without stroke. However, the relationship between renal function and WMH in patients with acute ischemic stroke or transcient ischemic stroke (AIS/TIA) remains unclear. Thus we aim to explore the potential risk factors of WMH in patients with AIS/TIA, especially the association between renal function and WMH located in both periventricular and deep area.

Methods:
A total of 1632 patients having an MRI examination were enrolled from SMART cohort for this analysis.The severity of WMH in both periventricular(PVH) and deep subcortical area(SDWMH) was evaluated using Fazekas scale. Estimated glomerular filtration rate(eGFR) was calculated by the equation of the Modification Diet for Renal Disease modified by the Chinese coefficient: eGFR(ml/min/1.73m
2
)=186хserum creatinine(exp[-1.154])хage(exp[-0.203])х1.233х0.742(if female).Multinomial logistic regression, adjusting for age, gender and vascular risk factors was performed to evaluate the association between the severity of WMH and eGFR.

Results:
Advanced age and hypertension were independently associated with the severity of PVH and SDWMH (all p<0.001). Adjusting for age, gender and hypertension, the severity of PVH was found to be inversely related to eGFR. Each 30 ml/min/1.73m
2
increase in eGFR was related to a lower risk of having degree 3 of WMH in periventricular areas, (p=0.04, OR=0.75, 95%CI 0.61-0.92). However this inverse association was not found between eGFR and SDWMH(P=0.50).

Conclusion:
Our study demonstrates that renal dysfunction is independently associated with the severity of PVH but not SDWMH in patients with acute ischemic stroke. This result highlights different risk factors and mechanisms involved in the pathogenesis of PVH and SDWMH.
Abstract WP19: Rate and Speed of Reperfusion Explains Variations in Treatment Effect Sizes Across Recent Trials of Endovascular Therapy for Acute Ischemic Stroke
Authors: Liang Conrad W , Jahan Reza , Saver Jeffrey L
Published: March 2022

Background:
Five recent trials demonstrated benefit of endovascular treatment (ET) for large-vessel ischemic stroke. But, while all were positive, the trials differed in their estimates of benefit magnitude. We tested whether trial differences in rate and speed of successful accounted for their variations in effect size estimates.

Methods:
We analyzed all 5 recent positive endovascular stroke trials, MR CLEAN, ESCAPE, EXTEND-IA, REVASCAT, and SWIFT-PRIME. An expanded analysis also included the 2 prior neutral trials, IMS-3 and MR RESCUE. Linear regression and correlation coefficients probed variable relations.

Results:
Among the 5 positive trials, rates of substantial reperfusion ranged from 59%-88% and OTR from 241-355 minutes. Independent functional outcome rates ranged in the endovascular arms from 32.6% to 71.4%, and in the control arms from 19.1% to 40.0%. Absolute differences in functional independence between treatment arms ranged from 13.5% - 31.4%. In the 2 neutral trials, reperfusion rates were lower, OTR longer, and outcome differences much less. Linear regression demonstrated very strong relation of both trial reperfusion rate and trial reperfusion speed to trial magnitude of treatment benefit (Figure). Across all 7 trials, the correlation between reperfusion rate and treatment effect size was r= 0.98, and between reperfusion speed and treatment effect size was r=0.85. Among just the 5 positive trials, reperfusion rate correlation with treatment effect size was r=0.87, and between reperfusion speed and treatment effect size was r=0.89.

Conclusion:
Achievement of successful reperfusion and speed of reperfusion are potent determinants of the degree of benefit with endovascular reperfusion therapy, and account for more than three-quarters of the variation in degree of treatment benefit in the 5 recent positive thrombectomy trials. To maximize patient benefit from endovascular intervention, open arteries fully and fast.
Abstract WP194: Stroke Risk and Mortality in Patients with Ventricular Assist Devices
Authors: Cool Josephine A , Parikh Neal S , Kamel Hooman , Karas Maria G , Boehme Amelia K
Published: March 2022

Background:
Ventricular assist devices (VADs) have revolutionized the management of end-stage heart failure. However, these devices are associated with many complications, including stroke.

Hypothesis:
We sought to determine the risk and risk factors for stroke after VAD placement and to assess the hypothesis that stroke is associated with increased mortality after VAD placement.

Methods:
From administrative claims data on all discharges from nonfederal acute care hospitals in California, Florida, and New York from 2005-2012, we used

International Classification of Diseases, 9
th
Revision, Clinical Modification

(
ICD-9-CM
) code 37.66 to identify patients who underwent VAD placement. Patients were included regardless of whether they underwent VAD placement as destination therapy or as bridge to transplant. Ischemic and hemorrhagic strokes were identified by validated coding algorithms. Kaplan-Meier statistics were used to calculate cumulative rates. Cox proportional hazard analyses were used to identify risk factors for stroke in patients with VADs and to evaluate the association between stroke (modeled as a time-varying covariate) and mortality.

Results:
We had 3.0 (±1.7) years of follow-up data on 1,398 patients after implantation of a VAD. The mean age of the patients was 55.4 years (±13.2), and patients were predominantly male. A total of 227 strokes were identified: 147 ischemic and 79 hemorrhagic. The cumulative stroke rate was 24.3% (95% confidence interval [CI], 21.3-27.7%). After adjustment for age, race, insurance status, and comorbidities, women had a higher hazard of stroke than men (hazard ratio [HR], 1.7; 95% CI, 1.2-2.3), particularly hemorrhagic stroke (HR, 2.6; 95% CI, 1.5-4.3). Stroke was strongly associated with subsequent mortality (HR, 4.1; 95% CI, 3.3-5.1).

Conclusion:
Stroke is common in patients after VAD placement and is strongly associated with mortality in this vulnerable population. Women appear to be at higher stroke risk than men, particularly for hemorrhagic stroke.
Abstract WP197: Spinal Manipulation Therapy and Risk of Cerebrovascular Events: Evidence Map and Meta-analysis
Authors: Paulus Jessica K , Redden Lisa M , Murashka Katie , Dahabreh Issa J , Thaler David E
Published: March 2022

Introduction:
Cervical spinal manipulation therapy (SMT) has been associated with cerebrovascular events, including arterial dissection and stroke. We constructed an evidence map of the published literature and systematically reviewed epidemiological studies on the association between SMT and cerebrovascular events.

Methods:
We searched MEDLINE, EMBASE, Cochrane, the ISI database, and reference lists through 7/14 to identify studies with data, evidence, or opinions on stroke or dissection occurring after SMT. Descriptive statistics were used to summarize the study design and publication date of studies. Summary ORs with 95% confidence intervals (CI) were estimated using random effects inverse variance analyses.

Results:
Among 311 studies meeting eligibility criteria, most were case reports (105, 34%), editorials/letters (n=81, 26%) and case series (n=51, 16%). Six eligible analytic epidemiologic studies (in 5 publications) were found: 5 case control studies included a median of 53 cases (range 47-818; total 1546) and 100 controls (range 43-3164; total 5671) and one case-crossover study used 818 cases from one of the case control studies. SMT exposure within 30 days of the index date was not statistically significantly associated with stroke/dissection risk (OR = 1.79, 95% CI 0.88-3.64, p=0.11; I2 = 63%, p for heterogeneity = 0.03). Three studies used more reliable case definitions (imaging-confirmed dissection), and found that SMT was associated with a significantly increased risk (OR=4.31, 95% CI 1.32-14.07, p=0.015).

Conclusion:
Most studies published on the relation between SMT and cerebrovascular events cannot provide robust information on causal inference, but the few available epidemiologic studies indicate possible harm associated with SMT. More well-powered studies with better case ascertainment are needed to guide inference about SMT safety.
Abstract WP2: Symptom Onset to Groin Puncture Determines Stroke Outcome: a Meta-analysis of Recent Acute Cerebrovascular Thrombectomy-after-Infarction Trials (MR ACTION)
Authors: Kirmani Jawad , Korya Daniel , Mehta Siddhart , Brar Jaskiran , Shaikh Azka , Kalola Rushil , Samaan Mena , Arango Audrey , Panezai Spozhmy , Moussavi Mohammad
Published: March 2022

Background:
Several major trials assessing ischemic stroke therapy with endovascular revascularization have shown better clinical and functional outcomes. A systematic review and pooled analyses of six recent multi-centered prospective randomized control trials (MPRCT) was performed to compare intravenous tissue plasminogen activator (IV tPA) and endovascular therapy (intervention) with IV tPA alone (control). We sought to evaluate the role of time of onset to groin puncture in determining outcome after endovascular therapy.

Methods:
We reviewed the results of the six most recent MPRCTs: MR CLEAN, ESCAPE, IA EXTEND, SWIFT PRIME, REVASCAT and THERAPY. To be included, trials pre-specified primary clinical outcomes of AIS patients in intervention and control arms. We categorized outcome at 90 days as "good" with modified Rankin Scale (mRS) of 0-2, "moderate" with mRS of 3-4, and "bad" with mRS of 5-6. We looked at recorded symptom onset to groin puncture (STG) times, compared them with the percentage of patients in the good, moderate and bad category and found correlations between the times from onset to groin puncture and the category of outcome. SPSS Version 22 was used for all statistical analysis.

Results:
A total of 1,386 patients were included. Good outcomes at 90-days were seen in 46% patients in intervention (p<.00001) and 27% of patients in control (p<.00002). mTICI 2b/3 was achieved in 70.2 % patients in intervention arm. Patients with good outcome (mRS 0-2), had a mean STG of 176 minutes (p= .0001), those with moderate outcome (mRS 3-4) had a mean STG of 195 minutes (p=.0001), and those with bad outcome (mRS 5-6), had a mean STG of 208 minutes (p= .0001). A longer STG time correlated with bad outcome (r= .815; p<.05).

Conclusion:
Endovascular therapy combined with IV tPA was superior to IV tPA alone. However, time is still of the essence and the longer delays to groin puncture were associated with more death and disability. More efforts should aim toward reducing the time of stroke onset to groin puncture time. Data on the reasons for delays should be reviewed to better understand where reductions in time are most applicable.
Abstract WP201: Ischemic Stroke Risk After Traumatic Head or Neck Injury
Authors: Fox Christine K , Hills Nancy K , Sidney Stephen , Vinson David R , Fullerton Heather J
Published: March 2022

Introduction:
Traumatic arterial dissection is an important cause of ischemic stroke in the young, but data are needed to guide selection of trauma patients to screen with cerebrovascular imaging.

Hypothesis:
Ischemic stroke risk after head or neck trauma can be stratified by demographic and clinical factors.

Methods:
In a Northern California integrated health care system, we identified people (age < 50) with head or neck trauma from 1997-2011 by ICD-9 searches (800-806, 850-854; 873, 874, 900, 920, 925, 950-953; excluding fifth digit codes for injury below the neck). Ischemic strokes within 4 weeks were identified by ICD-9 (433-438) and confirmed by chart review. We randomly selected 3 controls per case from the remaining cohort. Characteristics potentially associated with stroke were abstracted and examined using logistic regression. Stroke incidence rates were calculated using survival analysis, right censoring at death or 4 weeks post-trauma.

Results:
From 120,494 trauma encounters in the emergency department or for hospital admission, we confirmed 45 ischemic strokes related to head or neck trauma. The 4-week stroke incidence was 0.04% (95% CI 0.03-0.05%) (Figure: Kaplan-Meier stroke failure function and 95% CI). The majority of ischemic strokes occurred early after trauma, with 40% on the day of the trauma. Stroke risk was not associated with gender or race/ethnicity, but was age-related: for each decade older, stroke risk increased 70% (OR 1.7, 95% CI 1.4-2.2%, P<0.001). Any neck trauma (OR 14, 95% CI 4.9-42, P<0.0001 compared to those with isolated head trauma) and altered mental status on exam (OR 18, 95% CI 6.7-46, P < 0.0001) were also associated with increased risk of ischemic stroke. Neck trauma and altered mental status remained independently associated with ischemic stroke even after age-adjustment.

Conclusions:
Trauma patients with neck injuries or altered mental status have elevated stroke risk and should be considered for cerebrovascular imaging.
Abstract WP203: Subarachnoid Hemorrhage and Long-Term Stroke Risk After Traumatic Brain Injury
Authors: Morris Nicholas A , Cool Josephine , Merkler Alexander E , Kamel Hooman
Published: March 2022

Background:
Recent studies suggest that traumatic brain injury (TBI) is a risk factor for subsequent ischemic stroke, even years after the initial insult. The mechanisms of the association remain unclear.

Hypothesis:
The presence of traumatic subarachnoid hemorrhage (tSAH) may mediate the effect of TBI on long-term stroke risk, as it has previously been linked to short-term vasospasm and delayed cerebral ischemia.

Methods:
Using administrative claims data, we conducted a retrospective cohort study of acute care hospitalizations. Patients discharged with a first-recorded diagnosis of tSAH were followed for a primary diagnosis of stroke. They were matched to patients with TBI but no tSAH, based on age, sex, race, insurance status, income, admission year, coronary heart disease, hypertension, diabetes, congestive heart failure, peripheral vascular disease, chronic kidney disease, chronic obstructive pulmonary disease, atrial fibrillation, alcohol abuse, and tobacco use. Cox proportional hazards modeling was used to assess the association between tSAH and stroke while adjusting for covariates.

Results:
We identified 34,302 patients with TBI (17,151 patients with tSAH matched to 17,151 patients with non-tSAH TBI) who were followed for a mean of 3.2 ± 1.8 years. Overall, 481 of 34,302 patients with TBI (1.40%; 95% confidence interval [CI], 1.28-1.53%) experienced an ischemic stroke after discharge. There was no significant difference in stroke risk between those with tSAH (1.92%; 95% CI, 1.61-2.27%) as compared to no tSAH (2.08%; 95% CI, 1.78-2.44%). The same pattern was found in adjusted analyzes (hazard ratio [HR[, 0.86; 95% CI 0.70-1.06). This held true even when the group was stratified by age group or by proxies of TBI severity such as mechanical ventilation or discharge disposition during the index hospitalization for TBI.

Conclusion:
Recent data shows a protracted risk of ischemic stroke following TBI. Our findings do not support a role of vasospasm from tSAH in mediating this association. Further study is required to elucidate the mechanisms of long-term increased stroke risk after TBI
Abstract WP208: Incidence of Ischemic Stroke in Young Adults, a 4 Year Retrospective Review From an Urban Tertiary Care Center in North Philadelphia
Authors: Pirastehfar Mohsen , Katz Paul , Gentile Nina T , Jacobi Jaclyn E , Linares Guillermo
Published: March 2022

Background:
Stroke is the 5th leading cause of death in the United States .Every year, more than 795,000 people in the United States have a stroke. Ischemic Stroke in young adults age ≤50 years old has a prevalence of 3-5%. Many young patients with Ischemic Stroke don’t have common stroke risk factors such as high blood pressure, diabetes or hyperlipidemia and in general 33% of infarcts in this age group are cryptogenous.

Methods:
Retrospective review of prospectively collected data from the Temple University Hospital stroke database. Patients were selected based on age ≤50, clinical presentation and primary diagnosis of Ischemic Stroke. Characteristics including hypercoagulability work up, vessel imaging, heart studies and risk factors were reviewed. IRB approval was obtained.

Results:
From January 2011 through December 2014, we enrolled 1924 registered patients with Ischemic Stroke. 198 patients were ≤50 years old (10.2%). Baseline characteristics are Male (54%), NIHSS 0-16 (Median 6), Hypertension (48%), Diabetes (30%), Smoking (60%), Hyperlipidemia (20%), Positive drug screen (22%), Abnormal cardiac studies (42%). Despite 42% abnormal cardiac echocardiograms, there were no cardiac arrhythmias diagnosed. Abnormal brain or vessel imaging including brain MRI/MRA, CTH or CTA (36%). Hypercoagulability tests were checked in 68% of patients. Abnormalities showed factor-V Leiden (100% Normal), Prothrombin Mutation (100% Normal), Protein-C (80% Normal), Protein-S (84% Normal), Antithrombin-III (89% Normal), Antiphospholipid antibody (80% Normal), Lupus Anticoagulant (79% Normal), ANA (80% Normal)

Conclusions:
The incidence of Ischemic Stroke in this cohort is much higher than that reported in other observational studies. Despite an extensive work up, a cause was not found in the majority of patients. These data support the need for a more in depth investigation of the causes of stroke in the young in urban, underserved communities. Standard of care diagnostic tests fail to explain the unusually high incidence of Ischemic Stroke in the young in this cohort.
Abstract WP210: Urgent Detection of Acute Type A Aortic Dissection in Ischemic Stroke or TIA
Authors: Tokuda Naoki , Koga Masatoshi , Ohara Tomoyuki , Minatoya Kenji , Tahara Yoshio , Higashi Masahiro , Miyazaki Yuichi , Kajimoto Katsufumi , Matsubara Soichiro , Nagatsuka Kazuyuki , Toyoda Kazunori
Published: March 2022

Background and purpose:
Urgent diagnosis of acute Stanford type A aortic dissection (AAD) in patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA) is sometimes challenging. Several markers such as systolic blood pressure (SBP) laterality, initial D-dimer level, mediastinal-width to chest-width (M/C) ratio on X-ray, common carotid artery (CCA) dissection on carotid ultrasonography and pericardial effusion on echocardiography are reported to be useful to identify AAD in AIS or TIA. We validated these findings using our prospective stroke registry (ClinicalTrials.gov: NCT02251665).

Methods:
Consecutive AIS or TIA patients with AAD who were admitted to our institute within 4.5 h of onset from Jan 2007 to Dec 2014 were reviewed. They were compared with AIS or TIA patients without AAD who admitted within 4.5 h of onset from Jan 2014 to Dec 2014.

Results:
We found 24 AIS/TIA patients with AAD (15 women, 75±12 y.o.), and 245 patients without AAD (86 women, 74±12 y.o.). As compared to patients without AAD, AAD patients had higher SBP laterality (30±20 mmHg vs. 10±9 mmHg, p<0.001), higher initial D-dimer level (median 1.0μg/ml, IQR 0.5-2.4μg/ml vs. median 38.1μg/ml, IQR 8.1-155.1μg/ml; p<0.001), and higher M/C ratio in the recumbent position (0.35±0.05 vs. 0.29±0.05, p<0.001), and more frequently had occlusion or the intimal flap of the proximal CCA (85% vs. 1%, p<0.001) and pericardial effusion (43% vs. 1%, p<0.001). Using receiver operating characteristic curve analysis, the cutoff of SBP laterality, D-dimer level and M/C ratio was 17 mmHg, 4.1μg and 0.32, respectively, with c-statistic of 0.84, 0.96 and 0.82, respectively. Sensitivity, specificity, positive predictive value and negative predictive value to identify AAD were as follows.

Conclusions:
High D-dimer level can be the most reliable screening test of AAD in AIS or TIA patients. Proximal CCA occlusion or flap appears to be the most disease specific finding with acceptable sensitivity.
Abstract WP215: Role of Conventional Mri Brain for Basilar Artery Plaque Detection in Solitary Pontine Infarct
Authors: Muengtaweepongsa Sombat , Kantrakul Waristha , Watcharakorn Arvemas , Chaumrattanakul Utairat
Published: March 2022

Background:
Solitary pontine infarct is divided into paramedian pontine infarct (PPI) and small deep pontine infarct (SDPI). The novel high-resolution MRI is the current useful imaging method to characterize vessel walls and detect atherosclerotic plaques of the intracranial arteries. However, high-resolution MRI is not included in routine imaging protocol for patient with acute stroke. We intend to determine the role of conventional MRI and MRA of the brain in solitary pontine infarct.

Material and Method:
Fifty patients with pontine infarct undergo imaging study of MRI of the brain on T1-weighted image, T2-weighted image and post-gadolinium T1-weighted image (if available) to assess the presence of atherosclerotic plaque, and MRA of the brain using 3-dimensional time-of-flight MRA (3D TOF MRA) to assess the basilar artery luminography. Basilar artery assesses by axial T2-weighted image was scored as “presence of plaque” or “absence of plaque” and 3D TOF MRA of basilar artery is scored as “normal”, “irregular” or “stenosis” ≥ 30%. Pontine infarction is divided into paramedian pontine infarction (PPI) and small deep pontine infarction (SDPI) groups.

Results:
Fifty patients with pontine infarction are included, thirty-five with PPI and fifteen with SDPI. Conventional axial T2WI MRI of the brain detected basilar artery atherosclerotic plaques in about 50% of patients with pontine infarction: 51.4% (18 of 35 cases) in PPI and 46.7% (7 of 15 cases) in SDPI. No plaque is found in all cases of normal-appearing basilar luminography on 3D TOF MRA and plaque was identified in all patients with basilar artery stenosis on 3D TOF MRA.

Conclusion:
Basilar artery atherosclerotic branch disease is frequently detected in both groups of solitary pontine infarct (PPI and SDPI). Conventional MRI and MRA of the brain are the useful imaging methods that may characterize intracranial vessel wall abnormalities and may be helpful in further study of intracranial arterial diseases and in comprehension of stroke mechanisms.
Abstract WP217: Sex Differences in Coagulation After Stroke: Factor XI Levels Drop After Acute Ischemic Stroke
Authors: Selvadurai Chindhuri , Wang Yu-Bo , Roy-O'Reilly Meaghan , Grady James J , McCullough Louise D
Published: March 2022

Introduction:
Sex differences in coagulation have been well documented, but it is unknown if post-stroke coagulation factor levels differ by sex. High levels of Factor XI (FXI) and Factor XII (FXII) have been associated with increased incidence of acute ischemic stroke (AIS), especially in women.

Hypothesis:
This study investigates the hypothesis that levels of FXI, FXII and Plasminogen Activating Inhibitor (PAI1) are different after AIS in men and women.

Methods:
This was a retrospective study using a biomarker database of patients who presented to the emergency department with stroke. Sample collection occurred 24 hours after AIS onset. Plasma levels of FXI, FXII and PAI1 were assessed with ELISA in a population of 73 patients with no prior history of coagulation disorders, including 29 controls and 44 AIS patients confirmed by MRI, mean age = 68.7+/- 15.1, and 47% female. Log transformation was done before fitting the model. ANOVA was used to investigate the relationship between factor levels in sex and stroke. Tukey-Kramer multiple comparison tests were used for paired group comparisons.

Results:
FXI levels were significantly higher in control subjects compared to AIS (p-value=0.007). FXI levels were also higher in females than in males, nearing statistical significance (p-value=0.053). PAI1 and FXII levels were not statistically different in men vs. women, or in control vs. AIS patients. Female controls had higher FXI levels than male AIS patients (0.487, 95% CI 0.085-0.889).

Conclusion:
Stroke patients were found to have significantly lower levels of FXI compared to controls. This demonstrates that the pathological process of AIS may result in depletion of circulating plasma FXI at 24 hours after stroke onset. Overall, in stroke and control patients, there was a trend for females to have higher levels of FXI than men. No significant sex or stroke differences were found in FXII or PAI1 levels, likely due to sample size. Additional samples are being evaluated to determine if this stroke-induced decrease in FXI levels is associated with functional outcomes.