bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P513: Effect of Premorbid Antiplatelet Medication on Infarct Volume at 24 Hours After Late Window Presentation With Anterior Circulation Large Vessel Occlusion
Authors: de Havenon Adam H , Christensen Soren , Lansberg Maarten G , Mlynash Michael , Albers Gregory W , Yaghi Shadi
Published: March 2021

Introduction:
We sought to evaluate the effect of premorbid antiplatelet medication on 24 hour infarct volume in late presenting patients with anterior circulation large vessel occlusion.

Methods:
This is a secondary analysis of the DEFUSE 3 trial. The primary outcome is infarct volume on a 24-hour MRI scan (volume of DWI positive tissue). The primary predictor is premorbid use of an antiplatelet medication. We fit linear regression models to 24-hour infarct volume and adjusted for admission infarct volume, age, sex, treatment arm, anticoagulant use, time from stroke onset to presentation, hypoperfusion intensity ratio, tPA administration, admission NIH Stroke Scale, glucose, and systolic blood pressure. In a sensitivity analysis, we included recanalization status in the model (no vs. partial vs. complete recanalization). All models had variance inflation factors <2, indicating acceptable multicollinearity.

Results:
We included 149 patients, of which 51 (34.2%) took premorbid antiplatelet medication. The mean±SD 24-hour infarct volume was 51.7±50.1 in antiplatelet versus 80.4±93.6 ml in control patients (p=0.04). In the adjusted regression model, taking an antiplatelet medication had a beta coefficient of -31.2 (95% CI, -55.0, -7.4; p=0.011). The other significant predictors of 24-hour infarct volume were admission glucose, baseline infarct volume, and HIR. In the sensitivity analysis with recanalization status in the model (n=132), premorbid antiplatelet use remained associated with 24-hour infarct volume (beta=-29.6, 95% CI -55.8, -3.4, p=0.027).

Conclusion:
For patients with late window anterior circulation large vessel occlusion stroke, premorbid use of an antiplatelet medication was associated with a ~30 mL smaller 24-hour infarct volume on MRI. Possible explanations for this finding include reduced clot burden, improved clot lysis, the anti-inflammatory effects of antiplatelet medications, or the results could be due to chance.
Abstract P515: Early Neurological Deterioration in Minor Stroke Symptom Large Vessel Occlusion Patients
Authors: Ouf Aya , Wu Katty , Elsayed Sherif M , Rai Hamid , Nael Kambiz , Shigematsu Tomoyoshi , Kellner Christopher P , Oxley Thomas , Fifi Johanna , DeLeacy Reade , Mocco J D , Siddiqui Adnan H , Shoirah Hazem
Published: March 2021

Background:
30% of minor stroke symptom (MSS) patients (NIHSS=<5) have underlying large vessel occlusions (LVO). MSS patients are less likely to receive endovascular therapy (EVT) and thrombolytic therapy. 20-25% of patients with LVO suffer early neurological deterioration (END), ≥ 4 points decrease on NIHSS, which is associated with worse outcomes. The predictability of END is currently unclear and there is need for elucidation on the factors which precipitate rapid decline.

Methods:
Retrospective review of MSS-LVO patients across two multi-hospital centers from June 2015 thru June 2018 was conducted. Patients who underwent immediate EVT without signs of deterioration were excluded. Baseline characteristics, management, and outcomes were compared with t-tests, Mann-Whitney U, Chi-square, Fisher’s exact test, and Fisher-Freeman-Halton test for continuous and categorical variables, as appropriate using SPSS Software.

Results:
Of the 45 MSS-LVO patients who were included, 12 suffered END. Demographics and baseline characteristics were not significantly different across groups. Weakness was more often a presenting symptom in the No-END cohort (84.8% vs 41.7% in END group, p=0.01). The END group showed a lower diastolic BP at the time of the highest NIHSS (86mmHg vs 72mmHg in END group, p= 0.03). The highest BP was comparable across groups (180/84 in the No END group vs 182/91 in END group, p>0.05); although in the END group, the high BP correlated with a higher NIHSS (3 vs 0 in No END group, p=0.01). Patients in the END group were more likely to receive tpA (58.3% vs 15.2% in No END group, p=0.01). The 24-hour NIHSS was greater in the END group (2.5 vs. 0, p=0.02). 84.4% of patients in the No END group had good functional outcome at 3-5 days (mRS 0-2), compared to 45.5% of the END patients (p=0.02). 25% of the END group had in-hospital mortality, while there were no deaths in the No END group. Fewer patients were discharged home (72.7% in No END vs 58.3% in END group, p=0.04).

Conclusion:
END in MSS patients is associated with worse outcomes at 3-5 days and higher in-hospital mortality. Presenting symptoms and BP fluctuations may be factors in predicting END. Further studies are needed to elucidate the risk factors associated with END in MSS-LVO patients.
Abstract P516: A Comparison of Transradial and Transfemoral Approaches for Performance of Carotid Angioplasty and Stent Placement
Authors: Kumar Nitish , Bhagavan Sachin , Balasetti Vamshi , Hamid Tariq , Ishfaq Muhammad F , Huang Wei , French Brandi R , Siddiq Farhan , Gomez Camilo r , Qureshi Adnan I
Published: March 2021

Context:
Over the past few decades, transradial access has been increasingly utilized for neurointerventional procedures including carotid angioplasty and stent placement (CAS).

Objective:
To compare the outcomes of CAS performed via transradial approach with those performed using transfemoral approach within the same institution.

Methods:
We analyzed all the elective CAS procedures performed at our institute in the last 48 months and divided the procedures based on initial approach (transradial or transfemoral). Both approaches were used by same interventionalists to minimize inter-operator variability. We compared the rates of technical failure; hemorrhagic complications classified as major (hemoglobin decrease >5 g/dL or intracranial hemorrhage with deficits), minor (hemoglobin decreases 3-5 g/dL or intracranial hemorrhage without residual deficits), or insignificant; and any stroke and/or death within 1-month post procedure.

Results:
A total of 120 elective CAS procedures were performed at our institution; 84 patients (70%) were initiated as transfemoral and 36 patients (30%) were initiated as transradial approach. There were 6 (16%) CAS procedures initiated as trans-radial but later switched to transfemoral due to anatomical and/or technical difficulties. Similarly, 1(1.2%) procedure was switched to transradial from transfemoral. So finally, 89 (74%) patients had transfemoral approach and 31 (26%) patients had transradial approach to CAS. The median age was similar between the two groups (66.5 years versus 67.3 years).The rates of major hemorrhagic complications were 2 (2.2 %) and 0 (0%) in CAS performed using tranfemoral and tranradial approaches, respectively. The rate of any stroke and/or death within 30 days post procedure was 5 (5.6 %) and 1 (3.2 %) in CAS performed using transfemoral and transradial approaches, respectively.The median fluoroscopy time was 36.1 minutes and 34.4 minutes using transfemoral and transfemoral approaches, respectively (p =0.72).

Conclusions:
Transradial approach is comparable to transfemoral approach for performance of CAS in regard to clinical endpoints although the rates of technical failure remain relatively high in patients in whom CAS was initiated from transradial approach.
Abstract P517: The Effect of Unfavorable Vascular Anatomy on Mechanical Thrombectomy for Middle Cerebral Artery Occlusion Strokes Preliminary Evaluation of the AIM2 Score System
Authors: Kuybu Okkes , Mohammaden Mahmoud , Haussen Diogo C , Al-bayati Alhamza R , Belagaje Samir R , Frankel Michael R , Nogueira Raul G
Published: March 2021

Background:
Time to reperfusion remains one of the strongest predictors of outcome in large vessel occlusion strokes (LVOS). Herein, we aim to assess the impact of unfavorable vascular anatomy on mechanical thrombectomy (MT) number of passes and procedural times.

Methods:
Retrospectively review of a prospective MT database spanning January-July 2018 including acute LVOS involving the middle cerebral artery-M1 segment and available baseline CT angiography. The AIM2 score (Table 1) was applied with patients categorized as favorable (AIM2: 0-2) versus unfavorable (AIM2: >=3) anatomy. The primary outcome was the rate of <3 device passes. Secondary outcomes included procedural times and the rates of successful reperfusion (mTICI2b-3) and 90-day mRS 0-2. Safety measures included rates of sICH and 90-day mortality.

Results:
Patients with unfavorable anatomy (n=15) were significantly younger (52±19, p=0.02) and had lower rates of hypertension (46% vs 80%, p=0.01) and smoking (0% vs 39%, p<0.001) versus those with favorable anatomy (n=50). Successful reperfusion with <3 passes was more often achieved with AIM2 scores 0-2 vs. ≥3 (84% vs 60%, p=0.04). There were no significant difference in other outcome measures (Table 2).

Conclusions:
The AIM2 score system represents a simple method for the systematically evaluation of vascular anatomy in MT and correlates significantly with increased number of MT passes.
Abstract P528: Intra-Arterial Adjunctive Medications for Acute Ischemic Stroke During Mechanical Thrombectomy a Meta-Analysis
Authors: Lee Grace K , Chen Vanessa , Tan Choon Han , Leow Aloysius , Gopinathan Anil , Yang Cunli , Chan Bernard P , Sharma Vijay , Tan Benjamin Y , Yeo Leonard L
Published: March 2021

Introduction and hypothesis:
In patients with acute ischemic stroke with large vessel occlusion (AIS-LVO), the role of intra-arterial adjunctive medications (IAM) like urokinase, tPA or glycoprotein IIb/IIIa inhibitors, during mechanical thrombectomy (MT) has not been clearly established. We hypothesize that AIS-LVO patients treated with both MT + IAM (rescue or concurrent) achieve better safety and efficacy outcomes than patients treated with MT alone and aim to determine the efficacy and safety of concomitant or rescue IAM for AIS-LVO patients undergoing MT.

Methods:
We searched Medline, Embase and Cochrane Stroke Group Trials Register databases from inception until 13th March 2020. We analysed all studies with patients diagnosed with AIS-LVO in the anterior or posterior circulation, that provided data for the two treatment arms: 1)MT+IAM and 2)MT-only, and also reported on at least one of the following outcomes: reperfusion, 90-days modified Rankin Scale (mRS), symptomatic intracranial hemorrhage (sICH) and 90-days mortality. Data were collated in accordance with the PRISMA guidelines.

Results:
Sixteen non-randomized observational studies with a total of 4581 patients were analysed. MT-only was performed in 3233 (70.6%) patients, while 1348 (29.4%) patients were treated with both MT+IAM. As compared to patients treated with MT alone, patients treated with combination therapy (MT +IAM) had a higher likelihood of achieving good functional outcome (risk ratio=1.13, 95% CI 1.03-1.24) and a lower risk of 90-day mortality (risk ratio=0.82, 95% CI 0.72-0.94). There was no significant difference in successful reperfusion (risk ratio=1.02, 95% CI 0.99-1.06) and sICH between the two groups (risk ratio = 1.13, 95% CI 0.87-1.46) (Figure 1).

Conclusions:
In AIS-LVO, use of IAM together with MT may achieve better functional outcomes and lower mortality rates. Randomized controlled trials are warranted to confirm the safety and efficacy of IAM as adjunctive treatment of MT.
Abstract P532: Does Atrial Fibrillation Impact Rate of Symptomatic Intracranial Hemorrhage in Acute Ischemic Stroke Patients Treated With rt-PA and/or Endovascular Treatment?
Authors: Bavarsad Shahripour Reza , Shifflett Benjamin , Labin Edward , Figurelle Morgan , Barminova Anna , Meyer Brett C , Meyer Dawn M
Published: March 2021

Background:
Patients with acute ischemic stroke (AIS) due to atrial fibrillation (afib) may have increased complications from intravenous thrombolysis or endovascular treatment (ET) compared to other stroke subtypes. The purpose of this study was to compare the rates of symptomatic intracranial hemorrhage (sICH) in patients with and without a history of a fib treated with IV rt-PA and/or ET.

Methods:
Consecutive stroke code activations were retrospectively analyzed from January 2004-June 2020 at an academic comprehensive stroke center. Patients were included if they were treated with IV rt-PA and/or ET within 24 hours of stroke onset. Patients were stratified into the six groups:1-No hx of a fib with ET only, 2-Hx of a fib with ET only, 3-No hx of a fib with IV rt-PA plus ET, 4-Hx of a fib with IV rt-PA plus ET, 5-No hx of a fib with IV rt-PA only, 6-Hx of a fib with IV rt-PA only. Primary outcome was defined as any sICH within 72 hours of treatment using the NINDS definition. Baseline demographics were compared. Chi squared was used to assess differences in sICH rates and logistic regression to compare individual groups. Analyses were both unadjusted and adjusted for baseline NIHSS, age, sex, baseline blood pressure, pre-stroke mRS, smoking status, and baseline glucose.

Results:
We identified 720 AIS patients who received acute treatment (IV rt-PA: n=578; ET: n=100; IV rt-PA+ET:n=18). There was a significant difference in sex (p=0.005); Hispanic ethnicity (p=0.002); current smoking (p=<0.001); current alcohol use (p=0.03), CHF (p=0.01); and age (p<0.0001) between groups. Baseline NIHSS was significantly higher in Group 4 (23, SD 8, p=<0.001).In adjusted analysis, there was no significant difference in sICH in patients with a fib after receiving IVtPA (OR 1.53, CI 0.47-4.99, p=0.48), ET (OR 0.93 , CI 0-∞, p=1.00), or both (OR 0.25,CI 0.00-9.07, p=0.45) compared to those without afib. There was no significant difference in sICH in adjusted analyses in patients with and without a fib overall (OR 0.93, CI 0-∞, p=1.00).

Conclusion:
In this study, atrial fibrillation did not have a significant impact on rates of sICH in AIS patients treated with IV rt-PA, ET, or both. This study supports the safety of IV rt-PA, ET, and combination therapy in the atrial fibrillation population.
Abstract P533: Incidence and Outcomes of Thrombectomy Rescue Therapies in Acute Basilar Artery Occlusions
Authors: Lun Ronda , Walker Greg B , Weisenburger-Lile David , Lapergue Bertrand , Guenego Adrien , heran navraj s , Siu William , Dargazanli Cyril , Benali Amel , Gory Benjamin , Richard Sebastien , Ducroux Celina , Piotin Michel , BLANC RAPHAEL , Labreuche Julien , Lucas Ludovic , Haddad John , Aubertin Mathilde , vannier stephane , Guillen Maud , Eugene Francois , Maier Benjamin , Marnat Gaultier , Detraz Lili , Bourcier Romain , FAHED Robert
Published: March 2021

Background:
Hematoma expansion (HE) is an important therapeutic target in intracerebral hemorrhage. Recently proposed HE definitions have not been validated, and no previous definition has accounted for withdrawal of care (WOC).

Objective:
To compare conventional and revised definitions of hematoma expansion (HE), while accounting for WOC.

Methods:
We analyzed data from the ATACH-2 trial, comparing revised definitions of HE incorporating intraventricular hemorrhage (IVH) expansion to the conventional definition of “≥6 mL or ≥33%”. The primary outcome was modified Rankin Scale of 4-6 at 90-days. We calculated the incidence, sensitivity, specificity, positive and negative predictive values, and
c-
statistic for all definitions of HE. Definitions were compared using non-parametric methods. Secondary analyses were performed after removing patients who experienced WOC.

Results:
Primary analysis included 948 patients. Using the conventional definition, the sensitivity was 37.1% and specificity was 83.2% for the primary outcome. Sensitivity improved with all three revised definitions (53.3%, 48.7%, and 45.3%, respectively), with minimal change to specificity (78.4%, 80.5%, and 81.0%, respectively). The greatest improvement was seen with the definition “≥6 mL or ≥33% or any IVH”, with increased
c
-statistic from 60.2% to 65.9% (p < 0.001). Secondary analysis excluded 46 participants who experienced WOC. The revised definitions outperformed the conventional definition in this population as well, with the greatest improvement in
c
-statistic using “≥6 mL or ≥33% or any IVH” (58.1% vs 64.1%, p < 0.001).

Conclusions:
HE definitions incorporating intraventricular expansion outperformed conventional definitions for predicting poor outcome, even after accounting for care limitations.
Abstract P540: Safety of Carotid Artery Stenting Without Embolic Protection: A Single Centre Experience
Authors: Hawkes Christine , Deshmukh Aviraj , van Adel Brian
Published: March 2021

Introduction:
One of the most feared complications of carotid revascularization, including carotid artery stenting (CAS), is peri-procedural ischemic stroke. Several studies suggest that the use of a distal embolic protection device (EPD), as well as over-sized pre- and post-stenting balloon angioplasty, may increase the risk of dislodgement of atheromatous plaque in patients undergoing CAS. The CREST trial, that mandated the use of an EPD, had a peri-procedural ischemic stroke rate of 4.1%. We hypothesize that our technique of stenting without the use of an EPD and sub-maximal angioplasty will have a low risk of peri-procedural complications.

Methods:
A retrospective review was conducted of consecutive cases of ICA stenting without use of an embolic protection device between January 2012 and June 2020 at a Canadian stroke centre. Data was extracted from the patient electronic medical record and Picture Archives and Communications Systems (PACS). Both symptomatic and asymptomatic CAS cases were included.

Results:
A total of 220 patients were included in the study, with a median age of 70 years (range 39-93 years), and 83 patients (38%) were female. The vast majority of patients were symptomatic (216 patients [98%]). A large portion of patients had a contralateral ICA occlusion or near occlusion (56 patients [25%]). In the majority of cases, a Precise Cordis RX carotid stent (Cordis) was placed. There were four patients with peri-procedural ischemic strokes (1.8%), with two occurring 8-30 days after stenting. There was one case of acute stent occlusion associated with an ischemic stroke. Two patients (less than 1%) had hyperperfusion syndrome after CAS. Median length of stay following the procedure was one day.

Conclusions:
In this single centre series, the peri-procedural risks of CAS without using an EPD are low. The ischemic stroke rate is less than 2%, lower than what has been reported in large randomized controlled trials using embolic protection.
Abstract P541: Avoiding the Radial Paradox: Radial Adoption is Not Associated With Worse Femoral Outcomes in Neuroendovascular Cases
Authors: Wilkinson D. Andrew , Majmundar Neil , Catapano Joshua , Cole Tyler , Baranoski Jacob , Hendricks Benjamin , Ducruet Andrew F , Albuquerque Felipe C
Published: March 2021

Background and Purpose:
Transradial access (TRA) for neuroendovascular procedures is increasing in prevalence, although numerous procedures are still performed using transfemoral access (TFA). Some cardiology studies have suggested the safety benefits of TRA at a patient level may be offset at a population level by a paradoxical increase in TFA vascular access site complications (VASCs) associated with radial adoption, the so-called “radial paradox.” We studied the effect of TRA adoption on TFA performance and VASC rates in neuroendovascular procedures.

Methods:
Data were collected for all neuroendovascular procedures performed over a 10-month period by trainees after implementation of a radial-first paradigm at a single center.

Results:
Over the study period, 1,084 procedures were performed, including 689 (63.6%) via TRA and 395 (36.4%) via TFA. In comparison to TRA, TFA cases were performed in older patients (TFA 63 ±15 vs. TRA 56 ±16), were predominantly male (TFA 52.9% vs. TRA 38.6%), used larger sheath sizes (≥7 French, TFA 56.6% vs. TRA 2.3%), were more often emergent (TFA 37.7% vs. TRA 1.1%), and used tPA administration (TFA 15.3% vs. TRA 0%) (p<.001 for all comparisons). Overall, 29 VASCs occurred (2.7%), including 27 minor (TFA 4.6% [18/395] vs. TRA 1.3% [9/689], p=.002) and 2 major (TFA 0.3% [1/395] vs. TRA 0.1% [1/689], p>.99) complications. After multivariate analysis, independent predictors of any VASC included TFA (OR 2.8, 95% CI 1.1-7.4) and use of dual antiplatelets (OR 4.2, 95% CI 1.6—11.1).

Conclusions:
TFA remains an essential route for neuroendovascular procedures, accounting for 36.4% of cases under a radial-first paradigm. TFA is disproportionately performed in patients undergoing procedures with an increased-risk for VASCs, though the minor and major VASC rates are comparable to historical controls. TFA proficiency may still be achieved in radial-first training without an increase in femoral complications.
Abstract P543: Duration of Ischemia is Associated With Outcome After Endovascular Reperfusion Independent of Infarct Size
Authors: Sheth Sunil A , Zaidat Osama O , Hassan Ameer E , Fifi Johanna , Nanda Ashish , Atchie Benjamin , Woodward Keith , Doerfler Arnd , Tomasello Alejandro , Yoo Albert J
Published: March 2021

Introduction:
Despite advanced imaging and rapid recanalization, the majority of patients with large vessel occlusion (LVO) acute ischemic stroke (AIS) do not achieve functional independence at 90 days. Here, we explore the hypothesis that prolonged ischemia worsens clinical outcome beyond changes reflected in final infarct size, particularly in elderly patients.

Methods:
From the prospective, multicenter COMPLETE (Penumbra, Inc) registry, patients were included if they underwent endovascular therapy (EVT) for anterior circulation LVO, achieved TICI 2b/3 reperfusion, and EVT began within 90 minutes of imaging. Final infarct volumes (FIV) were measured on 24-48h post-EVT scans using ASPECTS. Multivariable logistic regression was used to determine the effect of stroke onset to hospital arrival time (OTA) on likelihood of functional independence (mRS 0-2) at 90 days, adjusting for age, NIHSS, occlusion location, pre-morbid mRS and final infarct. The effect of OTA on outcome was evaluated in older vs. younger patients using propensity score matching. Data are presented as median [IQR] or OR [95% CI].

Results:
Among 302 patients, median age was 71 [61-79], NIHSS was 15 [10-20], 56% were female, median OTA was 154 [75-320]. Median FIV ASPECTS was 7 [6-8]. In multivariable analysis adjusting for FIV, longer OTA was associated with decreased likelihood of functional independence (OR 0.74 [0.57-0.96]). FIV-independent worsening with prolonged OTA was more pronounced with advanced age (Figure). Using propensity score matching, elderly patients (age > 70) matched by age, NIHSS, occlusion location and FIV were less likely to have functional independence with prolonged OTA (Coef -0.2, p<0.01), but not younger patients (age ≤ 70, Coef -0.1, p=0.3).

Conclusions:
In patients with LVO AIS who achieve successful reperfusion, delays in EVT reduce the likelihood of good clinical outcomes independent of FIV. This effect is more pronounced with advanced age.
Abstract P548: Multiple Attempts Complete Reperfusion versus Single Pass Successful Reperfusion: A Sub-Analysis From the Select Study
Authors: Hassan Ameer E , Blackburn Spiros , Abraham Michael G , G Tekle Wondwossen , Vora Nirav , Dannenbaum Mark , Day Arthur , Dibas Mahmoud , Pujara Deep , Shaker Faris , Hellinger Kevin , Edgell Randi , Budzik Ronald , Gupta Rishi , Sarraj Amrou
Published: March 2021

Introduction:
Successful and fast reperfusion with endovascular thrombectomy (EVT) improves outcomes in acute ischemic strokes due to large vessel occlusion (LVO). While complete reperfusion (mTICI 3) is the ideal target, multiple passes could prolong EVT and increase complications likelihood without improving clinical outcomes. We hypothesized that pts with a single pass mTICI2b would have similar good outcomes to those with multiple passes mTICI3 with a better safety profile.

Methods:
From the prospective multicenter cohort study of imaging selection (SELECT), EVT pts who achieved mTICI2b and mTICI3 were stratified into those with single pass vs multiple passes. Functional independence rates at 90 day mRS and safety (sICH, neuro-worsening and mortality) were compared between pts with single pass mTICI 2b and multiple passes mTICI 3.

Results:
Of 361 pts enrolled, 285 received EVT, of those 70 (25%) achieved mTICI 2b and 159 (56%) mTICI 3. 89 (31%) achieved mTICI 3 with single pass, 70 (25%) with multiple passes, 33 (12%) had mTICI 2b with a single pass and 37 (13%) with multiple passes. Baseline characteristics were similar between the two groups except for larger perfusion deficit (Tmax >6s) volume in pts with multiple passes mTICI3 55 (25, 99) cc vs first pass mTICI 2b 43 (4, 79), p=0.047). Functional independence rates were higher with single pass mTICI 2b as compared to multiple passes mTICI 3 (70% vs 56%, aOR=1.51, 95% CI=0.48-4.76, p=0.78), fig 1 but did not reach statistical significance. Multiple passes mTICI 3 was associated with numerically higher mortality (13% vs 3%, p=0.16) and Neuro-worsening (13% vs 3%, p=0.16) with similar sICH: 4% vs 3%, p=1.00 rates.

Conclusion:
Complete reperfusion with multiple passes did not confer better outcome rates than single pass mTICI 2b and was associated with worse safety profiles. These results suggest that in the absence of complete reperfusion on first attempt, a single pass mTICI 2b may be sufficient for a successful thrombectomy.
Abstract P549: Total Small Vessel Disease Burden Not Associated With Functional Independence After Endovascular Treatment in Acute Ischemic Stroke Patients
Authors: Zheng Lina , Leng Xinyi , Nie Ximing , Yan Hongyi , Leung Thomas W , Liu Liping
Published: March 2021

Background:
Individual small vessel disease (SVD) markers had been associated with outcomes of endovascular treatment (EVT) in acute stroke patients. We aimed to investigate the associations between total SVD burden and outcomes in such patients.

Methods:
In a nation-wide multicenter registration study, we enrolled stroke patients with anterior circulation large vessel occlusion (LVO) receiving EVT, who had undergone 3T MRI. Presence of lacunes, white matter hyperintensities, cerebral microbleeds and perivascular spaces in both hemispheres were assessed in MRI and each marker was assigned a score of 0 or 1 by presence. A total SVD burden score (0-4) was calculated by summing up the individual scores, which was dichotomized as none-to-mild (score 0-2) and moderate-to-severe (score 3-4). The primary outcome was 90-day functional independence, defined as modified Rankin Scale (mRS) of 0-2. Secondary outcomes included change in NIHSS from baseline to 7 days, early neurological deterioration (END), symptomatic intracranial hemorrhage and 90-day mortality. We investigated the associations of dichotomized total SVD burden score with the outcomes using binary logistic regression analyses.

Results:
Of the 202 patients (65.38% male; mean age 65.54
±
11.93 years) enrolled, 176 patients had none-to-mild and 26 had moderate-to-severe total SVD burden. Those with moderate-to-severe SVD were older (mean age 69.8 versus 64.7; P=0.043) and more of them had a prior stroke (42.31% versus 23.3%; P=0.039), compared with otherwise. Dichotomized total SVD burden was not significantly associated with the primary outcome, 90-day functional independence (moderate-to-severe versus none-to-mild SVD burden: 53.85% versus 47.13%; OR 0.76, 95% CI 0.33-1.75; P=0.523). Although moderate-to-severe total SVD burden was associated with a higher rate of END (15.38% versus 3.43%; OR 5.12; 95% CI 1.34-19.58; P=0.017), no significant association was detected between the total SVD burden and other secondary outcomes.

Conclusions:
The total SVD burden as assessed in MRI was not significantly associated with the chance of obtaining functional independence at 90 days in LVO-stroke patients receiving EVT. A higher total SVD burden may not be an exclusion criteria for clinical decision for EVT.
Abstract P551: Impact of Chronic Kidney Disease on Stroke Outcomes After Endovascular Thrombectomy - A Matched Cohort Study
Authors: Ravelo Aaron , Hackett Chris , Cerejo Russell , Wright David G , Williamson Richard , Tayal Ashis H , Malhotra Konark
Published: March 2021

Objective:
To determine the impact of chronic kidney disease (CKD) on stroke outcomes stratified by severity of renal impairment among acute ischemic strokes (AIS) patients treated with endovascular therapy (EVT).

Methods:
Single center retrospective analysis was conducted from January 2012 to December 2019 involving AIS patients with CKD undergoing EVT. We evaluated following primary safety and efficacy outcomes: inpatient mortality and reperfusion status according to TICI score, respectively. Our secondary safety outcomes were symptomatic intracranial hemorrhage (sICH) per SITS-MOST definition, whereas secondary efficacy outcomes were length of hospitalization and favorable discharge disposition (discharge to home or inpatient rehabilitation). CKD was defined with estimated glomerular filtration rate (eGFR) ranging from mild (eGFR 60-89 mL/ min) to moderate (eGFR 30-59 mL/min) to severe (eGFR 15-29 mL/min). We performed propensity score matching to eliminate confounding variables between CKD and non-CKD patients (1:2). In our subgroup analysis, we compared patients with mild-moderate CKD patients and severe CKD and evaluated their association with various clinical outcomes.

Results:
From a total of 466 AIS patients undergoing EVT, 84 CKD and 165 patients with normal renal function were selected based on 1:2 propensity score matching. CKD was associated with increased risk of in-hospital mortality (Odds ratio [OR] 2.58, 95% confidence interval [CI] 1.49-4.64,
p
<0.001), whereas favorable discharge disposition, length of hospitalization, sICH, TICI 2B/3 were comparable between the two groups. Subgroup analysis showed that patients with mild and moderate CKD were observed to have favorable discharge disposition (p=0.002), whereas patients with severe CKD were noted to have a higher risk of sICH (
p
= 0.03) and prolonged hospitalization 11.54 ± 11.87 days (OR; 1.10, 95% CI 1.03-1.18,
p
= 0.006).

Conclusion:
History of CKD among AIS patients undergoing EVT were associated with a higher rate of inpatient mortality. In comparison to patients with mild and moderate CKD, patients with severe CKD were noted to have an increased risk of sICH, prolonged hospitalization, and poor discharge disposition.
Abstract P555: Safety and Efficacy of Daily Intra-Arterial Endovascular Therapy for Medically Refractory Cerebral Vasospasm Following Subarachnoid Hemorrhage
Authors: Chandra Rahul , Hackett Chris , Ku Andrew , Williamson Richard , MALHOTRA Konark , Cerejo Russell
Published: March 2021

Introduction:
Delayed cerebral ischemia (DCI) and cerebral infarction due to medically refractory vasospasm in aneurysmal SAH (aSAH) is a major cause of death and disability. The guidelines for endovascular therapy (EVT) for medically refractory vasospasm are not well established, especially regarding duration and frequency of therapy.

Methods:
Single center retrospective chart review was performed. We included patients with aSAH who had medically refractory vasospasm and underwent EVT. Demographics, clinical characteristics, imaging data, procedural details and outcomes were collected.

Results:
From 2016 to 2019, 303 subarachnoid hemorrhage (SAH) patients were identified. 133 (43.9%) were aSAH, of which 120 (90.2%) had DCI. Forty-one (34.1%) patients met our inclusion criteria. Median age was 56 years [Interquartile range (IQR) 46, 63] and 33 (80.5%) patients were female. We divided the EVT arm into two groups, group 1 underwent < 3 consecutive days of EVT comprising of 11 patients (26.8%) and group 2 underwent ≥3 consecutive days of EVT comprising of 30 patients (73.2%). Median Hunt and Hess score and Fisher grade were 1.5 (IQR 1,3) and 3.5 (IQR 2,4)in group 1 and 3 (IQR 2,4) and 4 (3,4) in group 2, (p =0.08) and (p =0.5) respectively . Median number of days of EVT was 4(IQR 2,6.5) for the entire cohort. Median days of EVT in group 1 was 2 (IQR 1,2) and for group 2 was 5 (IQR 3,7, p=0.24). Cerebral infarction was seen in 5/11 (45.4%) patients in group 1 and 16/30 (53.3%) patients in group 2 (p = 0.73). Median modified Rankin scale (mRS) at discharge in both groups was 4 (p=0.55, r=0.1). Good clinical outcome at discharge (mRS 0-2) was seen in 4/11 (36.3%) patients in group 1 and 5/30 (16.7%) patients in group 2 (p=0.22). Procedure related complications were seen in 3/11 (27.2%) patients in group 1 and 3/30 (10%) patients in group 2 (p=0.32) whereas mortality rate was 1/11(9.1%) and 8/30 (26.6%) (p=0.4)respectively. No mortality was associated with the procedure.

Conclusion:
Daily endovascular therapy in medically refractory vasospasm is safe but not efficacious in reducing the rates of cerebral infarctions.
Abstract P556: Emergent Use of Ticagrelor and Glycoprotein IIbIIIa in Neuroendovascular Interventions
Authors: Kim Song J , Nogueira Raul G , English Stephen W , Morgan Olivia , Chester Katleen , Al-bayati Alhamza R , Frankel Michael R , Haussen Diogo C
Published: March 2021

Introduction:
Evidence regarding the optimal acute antiplatelet strategies in emergent endovascular therapies is scarce, and practices varies institutionally. Ticagrelor, a P2Y3B inhibitor with a lower incidence of resistance, may be effective in achieving rapid platelet inhibition. We explore the safety and efficacy of emergent Ticagrelor use in patient undergoing neurointerventions.

Methods:
We reviewed our database for all consecutive patients from 2016 to 2019 who received emergent administration of Ticagrelor (within 30 minutes before or after) for neuro-interventional procedures. The primary outcome measure was the incidence of major systemic hemorrhages including symptomatic intracranial hemorrhage as well as intraprocedural and post-procedural thrombotic events.

Results:
81 patients were analyzed (Mean age 62±11, 70% male, 73 undergoing interventions for ischemic strokes, 8 aneurysm patients undergoing embolization). Twenty (24.7%) patients received Ticagrelor pre-puncture, 28 (35%) during and 33 (41%) after closure. Median PRU achieved in 43 patients after excluding for concomitant use of GPIIbIIIa use was 54 [36-111]. Major bleeding occurred in 7/81 patients (9.2%) - 4 gastrointestinal bleeding and 3 symptomatic ICH. Eleven (14%) patients experienced intraprocedural occlusions. Five (6.2%) cases were complicated by post-procedural occlusions while on Ticagrelor, two of which were asymptomatic. Pre-procedural Ticagrelor was associated with less frequent administration of subsequent GPIIbIIIa (OR = 0.15, 95% CI (0.03-0.64), p=0.01), as well as shorter procedure duration (Spearman’s rho 0.409,
p
=0.001). The use of GPIIbIIIa plus Ticagrelor was associated with increased bleeding complications (0% vs. 14%;
p
=0.04) than in patients receiving Ticagrelor only. Bleeding was an independently predictive risk factor for death by 3 months (OR 7.18, 95% CI (1.33-38.8, p=0.02 or 43% vs. 9.5%; p=0.04)

Conclusion:
Early and emergent use of Ticagrelor, prior to endovascular procedure as early as within 30 minutes, may obviate the need for administration of GPIIbIIIa. Combined use of GPIIbIIa antithrombotics with Ticagrelor was associated with hemorrhagic complications, which could contribute to increased mortality.
Abstract P558: Identification of Embolic Stroke in Patients With Large Vessel Occlusion
Authors: Hong Lan , Lin Longting , Li Gang , Yang Jianhong , Yu Geng , Lou Min , Parsons Mark , Cheng Xin , Dong qiang
Published: March 2021

Objective:
To develop a simple and objective score using clinical variables and quantified perfusion measures to identify embolic stroke with large vessel occlusions.

Methods:
Eligible patients from the Chinese centers participating in the International Stroke Perfusion Imaging Registry were included in this study. Patients were split into a derivation cohort (n=213) and a validation cohort (n=116). A score was developed according to the coefficients of independent predictors of embolic stroke from stepwise logistic regression model in the derivation cohort. The performance of the score was validated by assessing its discrimination and calibration. Additionally, a comparison between the area under curve (AUC) of history of atrial fibrillation (AF) alone and history of AF plus the score was also conducted.

Results:
The independent predictors of embolic stroke made up the Chinese Embolic Stroke Score (CHESS). There were: age (≥64 years, 1 point), non-smoking history (1 point), non-hypertension history (1 point) , baseline NIH Stroke Scale (≥14, 1 point) and delay time>6s volume/delay time>3s volume on perfusion imaging (≥0.23, 2 points). The AUC of CHESS in the derivation cohort and validation cohort were 0.80 and 0.72 respectively. Calibration tests indicated high agreement between predicted and observed probabilities. The AUC of AF-plus-CHESS compared to history of AF alone was significant (derivation cohort P<0.001; validation cohort P=0.01).

Conclusions:
In a Chinese population, CHESS reliably and independently identified embolic stroke as the cause of large vessel occlusion.
Abstract P563: Prognosis Driven Definition of Carotid Near-Occlusion With Full Collapse
Authors: Cooray Charith , Gu Thomas , Fox Allan J , Johansson Elias
Published: March 2021

Introduction:
Carotid near-occlusion is a severe carotid stenosis causing distal artery collapse of varying degree. Near-occlusion is often divided into a “full collapse” group with a threadlike distal lumen, and the often overlooked “without full collapse” group with a normal-appearing, albeit small, distal lumen. By this division by appearance, symptomatic near-occlusion with full collapse has been reported to have worse short-term prognosis than those without full collapse, no other division has been assessed for prognosis. The aim of this study was to assess if a measurement based definition of full collapse might improve prognostic discrimination.

Methods:
99 consecutive patients with symptomatic near-occlusion diagnosed on CT-angiography were included. The risk of preoperative recurrent ipsilateral ischemic stroke within 28 days of presenting event was assessed with Kaplan-Meier analysis, censoring at revascularization. We assessed residual stenosis diameter, distal ICA diameter, ICA-ratio (side-to-side), and ICA-ECA ratio as risk markers.

Results:
By appearance, the 28-day risk of stroke tended to be higher for full collapse (27%, 11/42) than without full collapse (11%, 6/57), p=0.054 (figure). The best new definition of full collapse was distal ICA diameter ≤2.0 mm and/or ICA ratio ≤0.47. 10 patients were reclassified by this new definition compared to appearance definition, 5 in each direction. By the new definition, 28-day risk of stroke was higher in full collapse (34%, 14/42) than without full collapse (5%, 3/57), p<0.001 (fig 1B).

Conclusions:
Compared to the appearance based definition, our new definition of separating near-occlusions into with and without full collapse yields similar groups sizes but better prognostic discrimination. This new definition could be used as inclusion criteria in future treatment trials.
Abstract P564: Hypertriglyceridemia as a Treatment Target in Asymptomatic Carotid Stenosis
Authors: Chaturvedi Seemant , Turan Tanya N , Voeks Jenifer H , Goldstein Jeffrey , Teal Philip A , Chimowitz Marc I , Barrett Kevin M , Demaerschalk Bart M , Howard Virginia J , Lazar Ronald M , Moy Claudia S , Moore Wesley S , Roubin Gary S , Brown Robert D , Meschia James F , Lal Brajesh , Howard George , Brott Thomas
Published: March 2021

Background:
Data from the CDC show that approximately one-quarter of adults have elevated triglyceride (TG) levels. Recent trials have demonstrated that pharmacologic treatment of high TG levels, in patients already on statin therapy, reduces the rate of major vascular events such as myocardial infarction and stroke (REDUCE-IT trial). We sought to assess how often patients with asymptomatic carotid stenosis (CS) have elevated TG levels and factors associated with high TG values.

Methods:
Patients enrolled in the Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST 2) were analyzed. Baseline lipid profiles were evaluated to determine high TG treatment eligibility as per the REDUCE-IT trial. We also evaluated baseline use of pharmacologic treatment for high TG levels. Demographic factors and baseline medical conditions were studied in relation to high (>150 mg/dl) TG values. Chi square and t tests were used to assess baseline factors and abnormal TG values.

Results:
As of August 10, 2020, 1655 of 1689 randomized patients (mean age 69.7 years, 61% men) had baseline lipid profiles suitable for analysis. Treatment eligibility according to REDUCE-IT (LDL 41-100 mg/dl, TG>150 mg/dl) was present in 21% (345) of subjects. In these patients, the median TG value was 205 (IQR 93) mg/dl. Fibrate medications were used at baseline in 4.5% of patients. Analysis of demographic and medical history factors and TG values greater than 150 mg/dl is found in the Table. There was significant positive correlation between baseline hemoglobin A1C and triglyceride values (p<0.0001)

Conclusions:
One in five patients in CREST 2 has TG values that potentially justify pharmacologic treatment. Elevated TG levels are most correlated with diabetes, hypertension, obesity, decreased physical activity, and heart disease. Clinicians should investigate treatment of elevated TG levels as a component of intensive medical therapy for stroke prevention.
Abstract P57: Risk Factors for Incidentally Discovered Silent Brain Infarcts and White Matter Disease in a Real World Cohort Identified by Artificial Intelligence
Authors: Leung Lester Y , Zhou Yichen , Fu Sunyang , Zheng Chengyi , Liu Hongfang , Chen Wansu , Kent David M
Published: March 2021

Introduction:
Silent brain infarcts (SBIs) and white matter disease (WMD) are highly prevalent and associated with increased risk of ischemic stroke in patients with traditional stroke risk factors (RFs) in prospective cohort studies. Their frequency and associations with stroke RFs have not been well described in real world populations.

Methods:
This was a cross-sectional study of patients age ≥ 50 in the Kaiser Permanente-Southern California (KPSC) health system between 2009-2019 with a head CT or MRI for non-stroke indications and no history of ischemic stroke, transient ischemic attack, or dementia. A natural language processing (NLP) algorithm developed at Mayo Clinic and Tufts Medical Center was applied to the KPSC EHR to identify individuals with reported SBIs or WMD. Multivariable Poisson regression with robust error variance was used to estimate risk ratios of demographics, stroke RFs (from the Framingham Stroke Risk Score), and scan modality on the presence of SBIs or WMD.

Results:
Among 262,875 individuals, the NLP identified 13,154 (5.0%) with SBIs and 78,330 (29.8%) with WMD. Stroke RFs were highly prevalent in this cohort. The majority underwent CTs (74.8%) instead of MRIs as their initial neuroimaging. After adjustment for demographics and RFs, advanced age demonstrated a strong association with increased risk of SBIs and WMD (table). MRI was associated with a reduced risk of reported SBIs (ARR: 0.87, 95% CI 0.83-0.91) and an increased risk of reported WMD (ARR 2.86, 95% CI 2.83-2.90). Despite being prevalent, traditional stroke RFs had weak associations with increased risk of SBIs or increased risk of WMD.

Conclusions:
Advanced age is strongly associated with incidentally discovered SBIs and WMD on neuroimaging studies obtained in routine care. The development of SBIs and WMD may not be fully attributable to traditional stroke RFs.
Abstract P574: Anatomic Distribution of High-Resolution Vessel Wall Imaging Findings in a Cohort of Patients With Moyamoya Disease Evaluated at a Midwest American Institution
Authors: Larson Anthony , Klaas James P , Lanzino Giuseppe , Lehman Vance
Published: March 2021

Introduction:
High-resolution vessel wall imaging (HR-VWI) of the intracranial vasculature may aid in the diagnosis and management of Moyamoya Disease (MMD). The patterns of HR-VWI findings of the cerebral vasculature of MMD patients remains uncertain, however. We sought to describe HR-VWI findings in a single-center cohort of MMD patients.

Methods:
Consecutive patients who were evaluated at a Midwest American medical center with a HR-VWI exam were included. Fourteen anterior circulation arterial segments in each patient were analyzed: proximal and distal supraclinoid Internal Carotid Artery, proximal M1 segment of the Middle Cerebral Artery, mid-portion of the M1, distal M1, proximal A1 segment of the Anterior Cerebral Artery and distal A1. Imaging variables that were collected from each segment included the presence of wall thickening (concentric vs eccentric), degree and pattern (concentric or eccentric) of contrast enhancement, and presence of positive or negative vessel remodeling. The total number and percentage of vessel segments demonstrating these characteristics were calculated. The number and percentage of patients with at least one segment demonstrating these characteristics were calculated.

Results:
Thirty-six patients (32 females, 88.9%) with a diagnosis of MMD were included. Overall, 221 of 504 segments (43.8%) demonstrated negative remodeling in 29 (75%) patients. Ninety-eight segments (19.4%) demonstrated wall enhancement (71 concentric, 27 eccentric; 22 high grade, 76 low grade) in 32 (88.9%) patients. Eighty-seven segments (17.3%) demonstrated wall thickening (52 concentric, 35 eccentric) in 32 patients (88.9%).

Conclusions:
Negative remodeling was the most-commonly observed vessel wall abnormality in all segments analyzed. However, a high percentage of patients had at least one segment demonstrating wall enhancement, wall thickening and negative remodeling. Continued study is necessary to further elucidate the HR-VWI patterns of the cerebral arterial system in MMD patients.