Endovascular versus medical therapy in posterior cerebral artery stroke: role of baseline NIHSS and occlusion site

Background: Acute ischemic stroke (AIS) with isolated posterior cerebral artery occlusion (iPCAO) lacks management evidence from randomized trials. We aimed to evaluate whether the association between endovascular treatment (EVT) and outcomes in iPCAO-AIS is modified by initial stroke severity (baseline NIHSS) and arterial occlusion site. Methods: Based on the multicenter, retrospective, case-control study of consecutive iPCAO-AIS patients (PLATO study), we assessed the heterogeneity of EVT outcomes compared to medical management (MM) for iPCAO, according to baseline NIHSS (≤6 vs. >6) and occlusion site (P1 vs. P2), using multivariable regression modelling with interaction terms. The primary outcome was the favorable shift of 3-month mRS. Secondary outcomes included excellent outcome (mRS 0-1), functional independence (mRS 0-2), symptomatic intracranial hemorrhage (sICH) and mortality. Results: From 1344 patients assessed for eligibility, 1,059 were included (median age 74 years, 43.7% women, 41.3% had intravenous thrombolysis), 364 receiving EVT and 695 MM. Baseline stroke severity did not modify the association of EVT with 3-month mRS distribution (pint=0.312), but did with functional independence (pint=0.010), with a similar trend on excellent outcome (pint=0.069). EVT was associated with more favorable outcomes than MM in patients with baseline NIHSS>6 (mRS 0-1: 30.6% vs. 17.7%, aOR=2.01, 95%CI=1.22-3.31; mRS 0-2: 46.1% vs. 31.9%, aOR=1.64, 95%CI=1.08-2.51), but not in those with NIHSS≤6 (mRS 0-1: 43.8% vs. 46.3%, aOR=0.90, 95%CI=0.49-1.64; mRS 0-2: 65.3% vs. 74.3%, aOR=0.55, 95%CI=0.30-1.0). EVT was associated with more sICH regardless of baseline NIHSS (pint=0.467), while the mortality increase was more pronounced in patients with NIHSS≤6 (pint=0.044, NIHSS≤6: aOR=7.95,95%CI=3.11-20.28, NIHSS>6: aOR=1.98,95%CI=1.08-3.65). Arterial occlusion site did not modify the association of EVT with outcomes compared to MM. Conclusion: Baseline clinical stroke severity, rather than the occlusion site, may be an important modifier of the association between EVT and outcomes in iPCAO. Only severely affected patients with iPCAO (NIHSS>6) had more favorable disability outcomes with EVT than MM, despite increased mortality and sICH.

Global, Regional, and National Economic Consequences of Stroke

BACKGROUND

An understanding of global, regional, and national macroeconomic losses caused by stroke is important for allocation of clinical and research resources. The authors investigated the macroeconomic consequences of stroke disease burden in the year 2019 in 173 countries.

METHODS

Disability-adjusted life year data for overall stroke and its subtypes (ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage) were collected from the GBD study (Global Burden of Disease) 2019 database. Gross domestic product (GDP, adjusted for purchasing power parity [PPP]) data were collected from the World Bank; GDP and disability-adjusted life year data were combined to estimate macroeconomic losses using a value of lost welfare (VLW) approach. All results are presented in 2017 international US dollars adjusted for PPP.

RESULTS

Globally, in 2019, VLW due to stroke was $2059.67 billion or 1.66% of the global GDP. Global VLW/GDP for stroke subtypes was 0.78% (VLW=$964.51 billion) for ischemic stroke, 0.71% (VLW=$882.81 billion) for intracerebral hemorrhage, and 0.17% (VLW=$212.36 billion) for subarachnoid hemorrhage. The Central European, Eastern European, and Central Asian GBD super-region reported the highest VLW/GDP for stroke overall (3.01%), ischemic stroke (1.86%), and for subarachnoid hemorrhage (0.26%). The Southeast Asian, East Asian, and Oceanian GBD super-region reported the highest VLW/GDP for intracerebral hemorrhage (1.48%).

CONCLUSIONS

The global macroeconomic consequences related to stroke are vast even when considering stroke subtypes. The present quantification may be leveraged to help justify increased spending of finite resources on stroke in an effort to improve outcomes for patients with stroke globally.

Delayed Functional Independence After Neurothrombectomy (DEFIANT) score: analysis of the Trevo Retriever Registry

BACKGROUND

Chronological heterogeneity in neurological improvement after endovascular thrombectomy (EVT) for large vessel occlusion (LVO) stroke is commonly observed in clinical practice. Understanding the temporal progression of functional independence after EVT, especially delayed functional independence in patients who do not improve early, is essential for prognostication and rehabilitation. We aim to determine the incidence of early functional independence (EFI) and delayed functional independence (DFI), identify associated predictors after EVT, and develop the Delayed Functional Independence After Neurothrombectomy (DEFIANT) score.

METHODS

Demographic, clinical, radiological, treatment, and procedural information were analyzed from the Trevo Registry (patients undergoing EVT due to anterior LVO using the Trevo stent retriever). Incidence and predictors of EFI (modified Rankin Scale (mRS) score 0-2 at discharge) and DFI (mRS score 0-2 at 90 days in non-EFI patients) were analyzed.

RESULTS

A total of 1623 patients met study criteria. EFI was observed in 45% (730) of patients. Among surviving non-EFI patients (884), DFI was observed in 35% (308). Younger age (p=0.003), lower discharge National Institutes of Health Stroke Scale (NIHSS) score (p<0.0001), and absence of any hemorrhage (p=0.021) were independent predictors of DFI. After age 60, the probability of DFI declines significantly with 5 year age increments (approximately 7% decline for every 5 years; p(DFI)= 1.3559-0.0699, p for slope=0.001). The DEFIANT score is available online (https://bit.ly/3KZRVq5).

CONCLUSION

Approximately 45% of patients experience EFI. About one-third of non-early improvers experience DFI. Younger age, lower discharge NIHSS score, and absence of any hemorrhage were independent predictors of DFI among non-early improvers.

Cerebrospinal Fluid Biomarkers for Diagnosis and the Prognostication of Acute Ischemic Stroke: A Systematic Review

Despite the high incidence and burden of stroke, biological biomarkers are not used routinely in clinical practice to diagnose, determine progression, or prognosticate outcomes of acute ischemic stroke (AIS). Because of its direct interface with neural tissue, cerebrospinal fluid (CSF) is a potentially valuable source for biomarker development. This systematic review was conducted using three databases. All trials investigating clinical and preclinical models for CSF biomarkers for AIS diagnosis, prognostication, and severity grading were included, yielding 22 human trials and five animal studies for analysis. In total, 21 biomarkers and other multiomic proteomic markers were identified. S100B, inflammatory markers (including tumor necrosis factor-alpha and interleukin 6), and free fatty acids were the most frequently studied biomarkers. The review showed that CSF is an effective medium for biomarker acquisition for AIS. Although CSF is not routinely clinically obtained, a potential benefit of CSF studies is identifying valuable biomarkers from the pathophysiologic microenvironment that ultimately inform optimization of targeted low-abundance assays from peripheral biofluid samples (e.g., plasma). Several important catabolic and anabolic markers can serve as effective measures of diagnosis, etiology identification, prognostication, and severity grading. Trials with large cohorts studying the efficacy of biomarkers in altering clinical management are still needed.

Endovascular Versus Medical Management of Posterior Cerebral Artery Occlusion Stroke: The PLATO Study

BACKGROUND

The optimal management of patients with isolated posterior cerebral artery occlusion is uncertain. We compared clinical outcomes for endovascular therapy (EVT) versus medical management (MM) in patients with isolated posterior cerebral artery occlusion.

METHODS

This multinational case-control study conducted at 27 sites in Europe and North America included consecutive patients with isolated posterior cerebral artery occlusion presenting within 24 hours of time last well from January 2015 to August 2022. Patients treated with EVT or MM were compared with multivariable logistic regression and inverse probability of treatment weighting. The coprimary outcomes were the 90-day modified Rankin Scale ordinal shift and ≥2-point decrease in the National Institutes of Health Stroke Scale.

RESULTS

Of 1023 patients, 589 (57.6%) were male with median (interquartile range) age of 74 (64-82) years. The median (interquartile range) National Institutes of Health Stroke Scale was 6 (3-10). The occlusion segments were P1 (41.2%), P2 (49.2%), and P3 (7.1%). Overall, intravenous thrombolysis was administered in 43% and EVT in 37%. There was no difference between the EVT and MM groups in the 90-day modified Rankin Scale shift (aOR, 1.13 [95% CI, 0.85-1.50]; P=0.41). There were higher odds of a decrease in the National Institutes of Health Stroke Scale by ≥2 points with EVT (aOR, 1.84 [95% CI, 1.35-2.52]; P=0.0001). Compared with MM, EVT was associated with a higher likelihood of excellent outcome (aOR, 1.50 [95% CI, 1.07-2.09]; P=0.018), complete vision recovery, and similar rates of functional independence (modified Rankin Scale score, 0-2), despite a higher rate of SICH and mortality (symptomatic intracranial hemorrhage, 6.2% versus 1.7%; P=0.0001; mortality, 10.1% versus 5.0%; P=0.002).

CONCLUSIONS

In patients with isolated posterior cerebral artery occlusion, EVT was associated with similar odds of disability by ordinal modified Rankin Scale, higher odds of early National Institutes of Health stroke scale improvement, and complete vision recovery compared with MM. There was a higher likelihood of excellent outcome in the EVT group despite a higher rate of symptomatic intracranial hemorrhage and mortality. Continued enrollment into ongoing distal vessel occlusion randomized trials is warranted.

Direct Transfer to the Neuroangiography Suite for Patients With Stroke

The therapeutic focus in acute ischemic stroke over the last 2.5 decades has been to balance the benefits of rapid reperfusion therapy with the risks of treatment-related complications. Both intravenous thrombolytics and endovascular thrombectomy are proven to substantially improve outcomes in a time-dependent manner. Each minute saved in achieving successful reperfusion grants an additional week of healthy life and may salvage up to 27 million neurons. The current approach to patient triage is inherited from the preendovascular thrombectomy era of stroke care. Current workflow concentrates on stabilization, diagnosis, and decision-making in the emergency department, followed by thrombolysis if eligible and subsequent transfer to the angiography suite as needed for further treatment. Multiple efforts have been directed toward minimizing the time from first medical contact to reperfusion therapy including prehospital triage and intrahospital workflow. Novel approaches for stroke patient triage such as the direct to angio approach, (also referred to as One Stop Management) are currently in development. The concept was initially introduced as several single-center experiences. In this narrative review article, we will consider various definitions of direct to angio and its variants, discuss its rationale, review its safety and efficacy, assess its feasibility, and delineate its limitations. Further, we will address methods to overcome these limitations and the potential impact of emerging data and new technologies on the direct-to-angio approach.

Real-World Outcomes of Endovascular Thrombectomy for Basilar Artery Occlusion: Results of the BArONIS Study

OBJECTIVE

To evaluate clinical outcomes of endovascular thrombectomy (EVT) for acute basilar artery occlusion (BAO) using population-level data from the United States.

METHODS

Weighted discharge data from the National Inpatient Sample were queried to identify adult patients with acute BAO during the period of 2015 to 2019 treated with EVT or medical management only. Complex samples statistical methods and propensity-score adjustment using inverse probability of treatment weighting (IPTW) were performed to assess clinical endpoints.

RESULTS

Among 3,950 BAO patients identified, 1,425 (36.1%) were treated with EVT [mean age 66.7 years, median National Institute of Health Stroke Scale (NIHSS) score 22]. On unadjusted analysis, 155 (10.9%) EVT patients achieved favorable functional outcomes (discharge disposition to home without services), while 515 (36.1%) experienced in-hospital mortality, and 20 (1.4%) developed symptomatic intracranial hemorrhage (sICH). Following propensity-score adjustment by IPTW accounting for age, stroke severity, and comorbidity burden, EVT was independently associated with favorable functional outcome [adjusted odds ratio (aOR) 1.25, 95% confidence interval (CI) 1.07, 1.46; p = 0.004], but not with in-hospital mortality or sICH. In an IPTW-adjusted sub-group analysis of patients with NIHSS scores >20, EVT was associated with both favorable functional outcome (discharge disposition to home or to acute rehabilitation) (aOR 1.55, 95% CI 1.24, 1.94; p < 0.001) and decreased mortality (aOR 0.78, 95% CI 0.69, 0.89; p < 0.001), but not with sICH.

INTERPRETATION

This retrospective population-based analysis using a large national registry provides real-world evidence of a potential benefit of EVT in acute BAO patients. ANN NEUROL 2023.

Mechanical Thrombectomy Global Access For Stroke (MT-GLASS): A Mission Thrombectomy (MT-2020 Plus) Study

BACKGROUND

Despite the well-established potent benefit of mechanical thrombectomy (MT) for large vessel occlusion (LVO) stroke, access to MT has not been studied globally. We conducted a worldwide survey of countries on 6 continents to define MT access (MTA), the disparities in MTA, and its determinants on a global scale.

METHODS

Our survey was conducted in 75 countries through the Mission Thrombectomy 2020+ global network between November 22, 2020, and February 28, 2021. The primary end points were the current annual MTA, MT operator availability, and MT center availability. MTA was defined as the estimated proportion of patients with LVO receiving MT in a given region annually. The availability metrics were defined as ([current MT operators×50/current annual number of estimated thrombectomy-eligible LVOs]×100 = MT operator availability) and ([current MT centers×150/current annual number of estimated thrombectomy-eligible LVOs]×100= MT center availability). The metrics used optimal MT volume per operator as 50 and an optimal MT volume per center as 150. Multivariable-adjusted generalized linear models were used to evaluate factors associated with MTA.

RESULTS

We received 887 responses from 67 countries. The median global MTA was 2.79% (interquartile range, 0.70-11.74). MTA was <1.0% for 18 (27%) countries and 0 for 7 (10%) countries. There was a 460-fold disparity between the highest and lowest nonzero MTA regions and low-income countries had 88% lower MTA compared with high-income countries. The global MT operator availability was 16.5% of optimal and the MT center availability was 20.8% of optimal. On multivariable regression, country income level (low or lower-middle versus high: odds ratio, 0.08 [95% CI, 0.04-0.12]), MT operator availability (odds ratio, 3.35 [95% CI, 2.07-5.42]), MT center availability (odds ratio, 2.86 [95% CI, 1.84-4.48]), and presence of prehospital acute stroke bypass protocol (odds ratio, 4.00 [95% CI, 1.70-9.42]) were significantly associated with increased odds of MTA.

CONCLUSIONS

Access to MT on a global level is extremely low, with enormous disparities between countries by income level. The significant determinants of MT access are the country's per capita gross national income, prehospital LVO triage policy, and MT operator and center availability.

Factors associated with readmission after minimally invasive transforaminal lumbar interbody fusion

OBJECTIVE

The objective of this study was to identify factors that lead to a prolonged hospital stay or 30-day readmission after minimally invasive surgery (MIS) for transforaminal lumbar interbody fusion (TLIF) at a single institution.

METHODS

Consecutive patients who underwent MIS TLIF from January 1, 2016, to March 31, 2018, were retrospectively analyzed. Demographic data, including age, sex, ethnicity, smoking status, and body mass index, were collected along with operative details, indications, affected spinal levels, estimated blood loss, and operative duration. The effects of these data were evaluated relative to the hospital length of stay (LOS) and 30-day readmission.

RESULTS

The authors identified 174 consecutive patients who underwent MIS TLIF at 1 or 2 levels from a prospectively collected database. The mean (range) patient age was 64.1 (31-81) years, 97 were women (56%), and 77 were men (44%). Of 182 levels fused, 127 were done at L4-5 (70%), 32 at L3-4 (18%), 13 at L5-S1 (7%), and 10 at L2-3 (5%). Patients underwent 166 (95%) single-level procedures and 8 (5%) 2-level procedures. The mean (range) procedural duration, defined as the time from incision to closure, was 164.6 (90-529) minutes. The mean (range) LOS was 1.8 (0-8) days. Eleven patients (6%) were readmitted within 30 days; the most frequent causes were urinary retention, constipation, and persistent or contralateral symptoms. Seventeen patients had LOS greater than 3 days. Six of those patients (35%) were identified as widows, widowers, or divorced, and 5 of them lived alone. Six patients with prolonged LOS (35%) required placement in either skilled nursing or acute inpatient rehabilitation. Regression analyses showed living alone (p = 0.04) and diabetes (p = 0.04) as predictors of readmission. Regression analyses revealed female sex (p = 0.03), diabetes (p = 0.03), and multilevel surgery (p = 0.006) as predictors of LOS > 3 days.

CONCLUSIONS

Urinary retention, constipation, and persistent radicular symptoms were the leading causes of readmission within 30 days of surgery in this series, which is distinct from data from the American College of Surgeons National Surgical Quality Improvement Program. The inability to discharge a patient home for social reasons led to prolonged inpatient hospital stays. Identifying these risk factors and proactively addressing them could lower readmission rates and decrease LOS among patients undergoing MIS TLIF.

Utility of tPA Administration in Acute Treatment of Internal Carotid Artery Occlusions

Background

Intravenous tissue plasminogen activator (IV-tPA) remains part of the guidelines for acute ischemic stroke treatment, yet internal carotid artery occlusions (ICAO) are known to be poorly responsive to IV-tPA. It is unknown whether bridging thrombolysis (BT) is beneficial in such cases.

Purpose

We sought to evaluate whether the use of IV-tPA improved overall clinical outcomes in patients undergoing endovascular thrombectomy (EVT) for ICA occlusions.

Methods

Data from 1367 consecutive stroke cases treated with EVT from 2012-2019 were prospectively collected from a single center. Univariate and multivariate logistic regression were used to assess the relationship between IV-tPA administration and clinical outcome.

Results

153 patients were found to have carotid terminus and tandem ICAO who received EVT and presented within 4.5h of last seen well. 50% (n = 82) received IV tPA. There were no differences between the groups with respect to age, NIHSS, time to EVT and ASPECTS score. 53% had tandem ICA-MCA occlusions. Rate of recanalization (≥ TICI 2B) and sICH did not significantly differ between the two groups. Regression analysis demonstrated no effect of IV-tPA on modified Rankin Score (mRS) at 90 days and overall mortality. Factors significantly associated with reduced mortality included lower age, lower NIHSS, and better rate of recanalization.

Conclusions

There was no significant difference in clinical outcomes in those receiving BT vs. direct EVT for ICAO. For centers with optimal door-to-puncture times, bypassing IV-tPA may expedite recanalization times and potentially yield more favorable outcomes. Patients with higher NIHSS and tandem lesions may have better outcomes with BT.

Endovascular Therapy vs Medical Management for Patients With Acute Stroke With Medium Vessel Occlusion in the Anterior Circulation

IMPORTANCE

Randomized clinical trials have shown the efficacy of endovascular therapy (EVT) for acute large vessel occlusion strokes. The benefit of EVT in acute stroke with distal, medium vessel occlusion (DMVO) remains unclear.

OBJECTIVE

To examine the efficacy and safety outcomes associated with EVT in patients with primary DMVO stroke when compared with a control cohort treated with medical management (MM) alone.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, retrospective cohort study pooled data from patients who had an acute stroke and a primary anterior circulation emergency DMVO, defined as any segment of the anterior cerebral artery (ACA) or distal middle cerebral artery, between January 1, 2015, and December 31, 2019. Those with a concomitant proximal occlusion were excluded. Outcomes were compared between the 2 treatment groups using propensity score methods. Data analysis was performed from March to June 2021.

EXPOSURES

Patients were divided into EVT and MM groups.

MAIN OUTCOMES AND MEASURES

Main efficacy outcomes included 3-month functional independence (modified Rankin Scale [mRS] scores, 0-2) and 3-month excellent outcome (mRS scores, 0-1). Safety outcomes included 3-month mortality and symptomatic intracranial hemorrhage.

RESULTS

A total of 286 patients with DMVO were evaluated, including 156 treated with EVT (mean [SD] age, 66.7 [13.7] years; 90 men [57.6%]; median National Institute of Health Stroke Scale [NIHSS] score, 13.5 [IQR, 8.5-18.5]; intravenous tissue plasminogen activator [IV tPA] use, 75 [49.7%]; ACA involvement, 49 [31.4%]) and 130 treated with medical management (mean [SD] age, 69.8 [14.9] years; 62 men [47.7%]; median NIHSS score, 7.0 [IQR, 4.0-14.0], IV tPA use, 58 [44.6%]; ACA involvement, 31 [24.0%]). There was no difference in the unadjusted rate of 3-month functional independence in the EVT vs MM groups (151 [51.7%] vs 124 [50.0%]; P = .78), excellent outcome (151 [38.4%] vs 123 [31.7%]; P = .25), or mortality (139 [18.7%] vs 106 [11.3%]; P = .15). The rate of symptomatic intracranial hemorrhage was similar in the EVT vs MM groups (weighted: 4.0% vs 3.1%; P = .90). In inverse probability of treatment weighting propensity analyses, there was no significant difference between groups for functional independence (adjusted odds ratio [aOR], 1.36; 95% CI, 0.84-2.19; P = .20) or mortality (aOR, 1.24; 95% CI, 0.63-2.43; P = .53), whereas the EVT group had higher odds of an excellent outcome (mRS scores, 0-1) at 3 months (aOR, 1.71; 95% CI, 1.02-2.87; P = .04).

CONCLUSIONS AND RELEVANCE

The findings of this multicenter cohort study suggest that EVT may be considered for selected patients with ACA or distal middle cerebral artery strokes. Further larger randomized investigation regarding the risk-benefit ratio for DMVO treatment is indicated.

Decreased DNA Methylation of RGMA is Associated with Intracranial Hypertension After Severe Traumatic Brain Injury: An Exploratory Epigenome-Wide Association Study

BACKGROUND

Cerebral edema and intracranial hypertension are major contributors to unfavorable prognosis in traumatic brain injury (TBI). Local epigenetic changes, particularly in DNA methylation, may influence gene expression and thus host response/secondary injury after TBI. It remains unknown whether DNA methylation in the central nervous system is associated with cerebral edema severity or intracranial hypertension post TBI. We sought to identify epigenome-wide DNA methylation patterns associated with these forms of secondary injury after TBI.

METHODS

We obtained genome-wide DNA methylation profiles of DNA extracted from ventricular cerebrospinal fluid samples at three different postinjury time points from a prospective cohort of patients with severe TBI (n = 89 patients, 254 samples). Cerebral edema and intracranial pressure (ICP) measures were clustered to generate composite end points of cerebral edema and ICP severity. We performed an unbiased epigenome-wide association study (EWAS) to test associations between DNA methylation at 419,895 cytosine-phosphate-guanine (CpG) sites and cerebral edema/ICP severity categories. Given inflated p values, we conducted permutation tests for top CpG sites to filter out potential false discoveries.

RESULTS

Our data-driven hierarchical clustering across six cerebral edema and ICP measures identified two groups differing significantly in ICP based on the EWAS-identified CpG site cg22111818 in RGMA (Repulsive guidance molecule A, permutation p = 4.20 × 10-8). At 3-4 days post TBI, patients with severe intracranial hypertension had significantly lower levels of methylation at cg22111818.

CONCLUSIONS

We report a novel potential relationship between intracranial hypertension after TBI and an acute, nonsustained reduction in DNA methylation at cg22111818 in the RGMA gene. To our knowledge, this is the largest EWAS in severe TBI. Our findings are further strengthened by previous findings that RGMA modulates axonal repair in other central nervous system disorders, but a role in intracranial hypertension or TBI has not been previously identified. Additional work is warranted to validate and extend these findings, including assessment of its possible role in risk stratification, identification of novel druggable targets, and ultimately our ability to personalize therapy in TBI.

Predictors of first pass effect and effect on outcomes in mechanical thrombectomy for basilar artery occlusion

INTRODUCTION

For patients undergoing endovascular thrombectomy (EVT), those who are recanalized with a successful single pass (first pass effect, FPE) have better functional outcomes than those who do not. There is a scarcity of data regarding predictors of FPE in basilar artery occlusion (BAO). We aim to determine what characteristics may predict FPE for posterior circulation thrombectomies in a cohort of patients undergoing EVT for BAO.

METHODS

We reviewed prospectively-collected data for patients presenting to a comprehensive stroke center with BAO between December 2015 and April 2019. Patients were included in this study if they underwent manual aspiration thrombectomy for BAO. Patients were excluded if they had occlusions of the posterior cerebral or vertebral arteries or if they had tandem lesions. Patients were stratified by whether FPE or modified FPE (mFPE) was achieved, and multivariate logistic regression analyses were performed to identify predictors of FPE and the effect of FPE on clinical outcome.

RESULTS

100 patients with BAO underwent thrombectomy. Mean age was 64.7 ± 16.7, 42% were female, and median NIHSS was 20 (IQR 11-27). 33% met criteria for FPE and 60% for mFPE. Univariate analysis identified female gender, lack of IV-tPA use, pcASPECTS, atrial fibrillation, and hyperlipidemia as possible predictors of FPE. On multivariate analysis, age, pcASPECTs, atrial fibrillation, hyperlipidemia and IV-tPA use were not independent predictors of FPE or mFPE. Female gender was an independent predictor of mFPE (p = 0.02), but not FPE (p = 0.18). FPE was a predictor of mRS 0-2 at 90 days (p = 0.04). Predictors of mortality were age (p < 0.01), baseline NIHSS (p < 0.01) and mFPE (p = 0.01).

CONCLUSION

In this cohort analysis of 100 patients with basilar artery occlusion undergoing manual aspiration thrombectomy, female gender was associated with mFPE but not FPE. Previously-reported anterior circulation FPE predictors including age, ASPECTS and atrial fibrillation were not predictors of FPE in this cohort of patients with BAO.

Thrombectomy With and Without Computed Tomography Perfusion Imaging in the Early Time Window: A Pooled Analysis of Patient-Level Data

BACKGROUND

The optimal imaging paradigm for endovascular thrombectomy (EVT) patient selection in early time window (0-6 hours) treated acute ischemic stroke patients remains uncertain. We aimed to compare post-EVT outcomes between patients who underwent prerandomization basic (noncontrast computed tomography [CT], CT angiography only) versus additional advanced imaging (computed tomography perfusion [CTP] imaging) and to determine the association of performance of prerandomization CTP imaging with clinical outcomes.

METHODS

The HERMES collaboration (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) pooled patient-level data from randomized controlled trials comparing EVT with usual care for acute ischemic stroke due to anterior circulation large vessel occlusion. Good functional outcome, defined as modified Rankin Scale score 0 to 2 at 90 days, was compared between randomized patients with and without CTP baseline imaging. Univariable and multivariable binary logistic regression analysis was performed to determine the association of baseline CTP imaging and good functional outcome.

RESULTS

We analyzed 1348 patients 610 (45.3%) of whom underwent CTP prerandomization. The benefit of EVT compared with best medical management was maintained irrespective of the baseline imaging paradigm (90-day modified Rankin Scale score 0-2 in EVT versus control patients: with CTP: 46.0% (137/298) versus 28.9% (88/305), without CTP: 44.1% (162/367) versus 27.3% (100/366). Performance of CTP baseline imaging compared with baseline noncontrast CT and CT angiography only yielded similar rates of good outcome (odds ratio, 1.05 [95% CI, 0.82-1.33], adjusted odds ratio, 1.04, [95% CI, 0.80-1.35]).

CONCLUSIONS

Rates of good functional outcome were similar among patients in whom CTP was or was not performed, and EVT treatment effect in the 0- to 6-hour time window was similar in patients with and without baseline CTP imaging.

Endovascular Thrombectomy Eligibility in the 0-24-Hour Time Window at a Large Academic Center in India

BACKGROUND

The data regarding patients eligible for endovascular thrombectomy (EVT), especially in the developing world is lacking.

OBJECTIVE

To determine the proportion of patients with acute ischemic stroke (AIS) who are eligible for EVT in the 0-24-h time window.

MATERIALS AND METHODS

We performed a retrospective cohort study using prospectively collected AIS data between July 2017 and September 2019. Demographic, clinical, and management information were analyzed. EVT eligibility was explored using the following criteria: National Institutes of Health Stroke Scale (NIHSS) score ≥6, presence of anterior circulation large-vessel occlusion (ACLVO), Alberta stroke program early Computerized Tomography score (ASPECTS) ≥6, baseline modified Rankin Scale (mRS) score 0-2, and within 24 h of time last seen well (TLSW). EVT-eligible patients were further evaluated for in-hospital course and outcomes.

RESULTS

In the study period of 27 months, there were 221 patients with AIS who presented within 24 h. The mean age of the patients was 54.4 (16.0) years and 66.1% (146) were males. A majority (61.5% [136/221]) arrived within 6 h of TLSW. Of these, 81.6% (111/136) presented in the time window for thrombolysis (0-4.5 h). The patients with NIHSS ≥6 and ACLVO constituted 41.2% (91/221) of the patients. AIS eligible for EVT constituted 19.5% (43/221) of the patients.

CONCLUSION

In our study, the proportion of AIS eligible for endovascular thrombectomy was comparable to the developed world. These data predict a large potential for the late-window EVT in India.

Abstract WMP91: Angiographic Predictors Of Balloon Test Occlusion Outcomes

Introduction: Balloon test occlusion (BTO) with adjunctive single-photon emission computed tomography (SPECT) has been utilized to predict clinical tolerance after permanent internal carotid artery (ICA) occlusion. Cerebrovascular anatomical characteristics might predict BTO outcomes and identify patients susceptible to test failure.

Methods: We performed a single center retrospective study of patients who underwent catheter based cerebral angiogram and ICA BTO from July 2013 to June 2020. SPECT imaging was completed in all the patients who passed the clinical BTO; technetium 99m-ethyl cysteinate dimer was injected intravenously after 15-30 min of occlusion and induced hypotension. The diameter of each of the vessels of the Circle of Willis was measured angiographically. The severity of hypoperfusion on SPECT imaging was classified as none, mild, low intermediate, high intermediate, and severe.

Results: A total of 57 patients underwent BTO; neoplasia was the most common indication (n=43, 75%). Twelve patients (21.1%) developed neurologic symptoms and clinically failed the BTO; 45 patients (78.9%) passed and proceeded to SPECT. Contralateral dominant vertebral artery (p=0.02), smaller ACom (p=0.002) and ipsilateral PCom (p=0.03) diameters were correlated with clinical BTO failure. Smaller ACom was most predictive with an AUC of 0.907. The Youden index identified an ACom diameter threshold of 1.1 mm, which demonstrated a sensitivity of 91.7% and specificity of 77.8% (OR 0.026, 95% CI 0.003 - 0.226, ROC=0.847) for the prediction of BTO failure. Patients with severe SPECT asymmetry had significantly smaller caliber ACom arteries (ACom median diameter 0.95 mm vs. rest of cohort median 1.4; p=0.0073).

Conclusions: BTO outcomes may be predicted using angiographic findings. A small (<1.1 mm) anterior communicating artery, and, less significantly, a small ipsilateral posterior communicating artery can be used to identify patients who are likely to fail BTO.

Endovascular thrombectomy time metrics in the era of COVID-19: observations from the Society of Vascular and Interventional Neurology Multicenter Collaboration

BACKGROUND

Unprecedented workflow shifts during the coronavirus disease 2019 (COVID-19) pandemic have contributed to delays in acute care delivery, but whether it adversely affected endovascular thrombectomy metrics in acute large vessel occlusion (LVO) is unknown.

METHODS

We performed a retrospective review of observational data from 14 comprehensive stroke centers in nine US states with acute LVO. EVT metrics were compared between March to July 2019 against March to July 2020 (primary analysis), and between state-specific pre-peak and peak COVID-19 months (secondary analysis), with multivariable adjustment.

RESULTS

Of the 1364 patients included in the primary analysis (51% female, median NIHSS 14 [IQR 7-21], and 74% of whom underwent EVT), there was no difference in the primary outcome of door-to-puncture (DTP) time between the 2019 control period and the COVID-19 period (median 71 vs 67 min, P=0.10). After adjustment for variables associated with faster DTP, and clustering by site, there remained a trend toward shorter DTP during the pandemic (βadj=-73.2, 95% CI -153.8-7.4, Pp=0.07). There was no difference in DTP times according to local COVID-19 peaks vs pre-peak months in unadjusted or adjusted multivariable regression (βadj=-3.85, 95% CI -36.9-29.2, P=0.80). In this final multivariable model (secondary analysis), faster DTP times were significantly associated with transfer from an outside institution (βadj=-46.44, 95% CI -62.8 to - -30.0, P<0.01) and higher NIHSS (βadj=-2.15, 95% CI -4.2to - -0.1, P=0.05).

CONCLUSIONS

In this multi-center study, there was no delay in EVT among patients treated for intracranial occlusion during the COVID-19 era compared with the pre-COVID era.

First Pass Effect With Neurothrombectomy for Acute Ischemic Stroke: Analysis of the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke Registry

BACKGROUND AND PURPOSE

Achieving complete revascularization after a single pass of a mechanical thrombectomy device (first pass effect [FPE]) is associated with good clinical outcomes in patients with acute ischemic stroke due to large vessel occlusion. We assessed patient characteristics, outcomes, and predictors of FPE among a large real-world cohort of patients (Systematic Evaluation of Patients Treated with Stroke Devices for Acute Ischemic Stroke registry).

METHODS

Demographics, clinical outcomes, and procedural characteristics were analyzed among patients in whom FPE (modified Thrombolysis in Cerebral Infarction 2c/3 after first pass) was achieved versus those requiring multiple passes (MP). Modified FPE and modified MP included patients achieving modified Thrombolysis in Cerebral Infarction 2B-3. Primary outcomes included 90-day modified Rankin Scale (mRS) score and mortality.

RESULTS

Among 984 Systematic Evaluation of Patients Treated with Stroke Devices for Acute Ischemic Stroke patients, 930 had complete 90-day follow-up. FPE was achieved in 40.5% (377/930) of patients and MP in 20.0% (186/930). Baseline characteristics were similar across all groups. The FPE group had fewer internal carotid artery occlusions compared with MP (P=0.029). The FPE group had faster puncture to recanalization time (P≤0.001), higher rates of 90-day mRS score of 0 to 1 (52.6% versus 38.6%, P=0.003), mRS score of 0 to 2 (65.4% versus 52.0%, P=0.003), and lower 90-day mortality compared with the MP group (12.0% versus 18.7%, P=0.038). Similarly, compared with modified MP patients, the modified FPE group had fewer internal carotid artery occlusions (P=0.004), faster puncture to recanalization time (P≤0.001), and higher rates of 90-day mRS score of 0 to 1 (P=0.002) and mRS score of 0 to 2 (P=0.003).

CONCLUSIONS

Our findings demonstrate that FPE and modified FPE are associated with superior clinical outcomes.

Collateral Circulation Augmentation and Neuroprotection as Adjuvant to Mechanical Thrombectomy in Acute Ischemic Stroke

PURPOSE OF THE REVIEW

Mechanical thrombectomy (MT)-mediated endovascular recanalization has dramatically transformed treatment and outcomes after acute ischemic stroke caused by a large vessel occlusion (LVO). Current guidelines recommend MT up to 24 hours from stroke onset in carefully selected patients based on favorable clinical and imaging parameters. Despite optimal patient selection and low complication rates with current recanalization technology, approximately 1 in 2 patients with LVO stroke do not achieve functional independence at 3 months. This ceiling effect of MT efficacy may be explained by ischemic core expansion into the ischemic penumbra before recanalization and neuronal loss occurring after recanalization. Factors affecting the efficacy of MT, or the degree of irreversible injury, include time from symptom onset to recanalization, collateral circulation status, and differences in neuronal vulnerability. The purpose of this brief review is to discuss potential targets for neuroprotection, present and future potential pharmacologic and nonpharmacologic agents, and the data available in the literature.

RECENT FINDINGS

In experimental ischemia models, several authors reported that pharmacologic and nonpharmacologic agents are able to slow the progression of ischemic core expansion. However, in the era of unsuccessful recanalization of the occluded artery, several neuroprotective agents that were promising in the preclinical stage failed phase II/III clinical trials.

SUMMARY

Providing neuroprotection before and after recanalization of an LVO may play an important role in improving outcomes in the era of MT. Neuroprotection is classically defined as a process that results in the salvage, recovery, or regeneration of neuronal (and other supporting CNS cell) structure or function. The advent of successful recanalization of acute LVO by MT in the majority of patients may spur the growth of effective neuroprotection.

Indications for Mechanical Thrombectomy for Acute Ischemic Stroke: Current Guidelines and Beyond

PURPOSE OF THE REVIEW

This article reviews recent breakthroughs in the treatment of acute ischemic stroke, mainly focusing on the evolution of endovascular thrombectomy, its impact on guidelines, and the need for and implications of next-generation randomized controlled trials.

RECENT FINDINGS

Endovascular thrombectomy is a powerful tool to treat large vessel occlusion strokes and multiple trials over the past 5 years have established its safety and efficacy in the treatment of anterior circulation large vessel occlusion strokes up to 24 hours from stroke onset.

SUMMARY

In 2015, multiple landmark trials (MR CLEAN, ESCAPE, SWIFT PRIME, REVASCAT, and EXTEND IA) established the superiority of endovascular thrombectomy over medical management for the treatment of anterior circulation large vessel occlusion strokes. Endovascular thrombectomy has a strong treatment effect with a number needed to treat ranging from 3 to 10. These trials selected patients based on occlusion location (proximal anterior occlusion: internal carotid or middle cerebral artery), time from stroke onset (early window: up to 6-12 hours), and acceptable infarct burden (Alberta Stroke Program Early CT Score [ASPECTS] ≥6 or infarct volume <50 mL). In 2017, the DAWN and DEFUSE-3 trials successfully extended the time window up to 24 hours in appropriately selected patients. Societal and national thrombectomy guidelines have incorporated these findings and offer Class 1A recommendation to a subset of well-selected patients. Thrombectomy ineligible stroke subpopulations are being studied in ongoing randomized controlled trials. These trials, built on encouraging data from pooled analysis of early trials (HERMES collaboration) and emerging retrospective data, are studying large vessel occlusion strokes with mild deficits (National Institutes of Health Stroke Scale <6) and large infarct burden (core volume >70 mL).

Sulfonylurea Receptor 1 in Central Nervous System Injury: An Updated Review

Sulfonylurea receptor 1 (SUR1) is a member of the adenosine triphosphate (ATP)-binding cassette (ABC) protein superfamily, encoded by Abcc8, and is recognized as a key mediator of central nervous system (CNS) cellular swelling via the transient receptor potential melastatin 4 (TRPM4) channel. Discovered approximately 20 years ago, this channel is normally absent in the CNS but is transcriptionally upregulated after CNS injury. A comprehensive review on the pathophysiology and role of SUR1 in the CNS was published in 2012. Since then, the breadth and depth of understanding of the involvement of this channel in secondary injury has undergone exponential growth: SUR1-TRPM4 inhibition has been shown to decrease cerebral edema and hemorrhage progression in multiple preclinical models as well as in early clinical studies across a range of CNS diseases including ischemic stroke, traumatic brain injury, cardiac arrest, subarachnoid hemorrhage, spinal cord injury, intracerebral hemorrhage, multiple sclerosis, encephalitis, neuromalignancies, pain, liver failure, status epilepticus, retinopathies and HIV-associated neurocognitive disorder. Given these substantial developments, combined with the timeliness of ongoing clinical trials of SUR1 inhibition, now, another decade later, we review advances pertaining to SUR1-TRPM4 pathobiology in this spectrum of CNS disease—providing an overview of the journey from patch-clamp experiments to phase III trials.

Rescue of Neglect and Language Impairment After Stroke Thrombectomy

BACKGROUND AND PURPOSE

Although National Institutes of Health Stroke Scale scores provide an objective measure of clinical deficits, data regarding the impact of neglect or language impairment on outcomes after mechanical thrombectomy (MT) is lacking. We assessed the frequency of neglect and language impairment, rate of their rescue by MT, and impact of rescue on clinical outcomes.

METHODS

This is a retrospective analysis of a prospectively collected database from a comprehensive stroke center. We assessed right (RHS) and left hemispheric strokes (LHS) patients with anterior circulation large vessel occlusion undergoing MT to assess the impact of neglect and language impairment on clinical outcomes, respectively. Safety and efficacy outcomes were compared between patients with and without rescue of neglect or language impairment.

RESULTS

Among 324 RHS and 210 LHS patients, 71% of patients presented with neglect whereas 93% of patients had language impairment, respectively. Mean age was 71±15, 56% were females, and median National Institutes of Health Stroke Scale score was 16 (12-20). At 24 hours, MT resulted in rescue of neglect in 31% of RHS and rescue of language impairment in 23% of LHS patients, respectively. RHS patients with rescue of neglect (56% versus 34%, P<0.001) and LHS patients with rescue of language impairment (64 % versus 25%, P<0.01) were observed to have a higher rate of functional independence compared to patients without rescue. After adjusting for confounders including 24-hour National Institutes of Health Stroke Scale, rescue of neglect among RHS patients was associated with functional independence (P=0.01) and lower mortality (P=0.01). Similarly, rescue of language impairment among LHS patients was associated with functional independence (P=0.02) and lower mortality (P=0.001).

CONCLUSIONS

Majority of LHS-anterior circulation large vessel occlusion and of RHS-anterior circulation large vessel occlusion patients present with the impairment of language and neglect, respectively. In comparison to 24-hour National Institutes of Health Stroke Scale, rescue of these deficits by MT is an independent and a better predictor of functional independence and lower mortality.

Causes, Predictors, and Timing of Early Neurological Deterioration and Symptomatic Intracranial Hemorrhage After Administration of IV tPA

Background

Acute ischemic stroke (AIS) is a major contributor toward healthcare-associated costs and services. Symptomatic intracranial hemorrhage (sICH) and early neurologic decline (END), defined as a National Health Institute Stroke Scale score decline of ≥ 4 within 24 h (with or without sICH), remain major concerns when administering intravenous tissue plasminogen activator (IV tPA) despite improved functional neurologic outcomes with its use. Given these risks, current guidelines recommend comprehensive stroke care (most often in an intensive care unit setting) for 24 h posttreatment. However, a number of patients may remain stable after IV tPA and thus not require such intensive resources. We sought to determine causes of END, along with timing and predictors of both sICH and END, to identify patients at lower risk of neurological deterioration and those suitable for earlier transition to a lower level of care.

Methods

This present study analyzed patients with AIS that presented within 4.5 h of being last seen well and received IV tPA. Baseline demographic, clinical, and radiographic findings were collected. Outcomes included END from any cause, parenchymal hemorrhage (PH1 or PH2), sICH, and mortality at 90 days.

Results

A total of 1238 patients with AIS without acute treatment of large vessel occlusion received IV tPA. 9.4% (116) had presence of any degree of ICH on noncontrast computed tomography head and 7.4% (91) experienced associated END. 2.7% (33) of patients experienced sICH, while 6.7% (83) experienced asymptomatic ICH. Of the patients with END, 63.7% did not have ICH. Predictive factors at presentation for END included an older age (72.6 ± 16.1 vs. 69.1 ± 14.8, p = 0.03), history of tobacco use (odds ratio [OR] 2.1 [1.1–4.3], p = 0.04), and hyperlipidemia (OR 1.7 [1.1–2.8], p = 0.02), along with the presence of an untreated large vessel occlusion (OR 2.1 [1.4–3.1], p = 0.02). Most END occurred within a mean time of 242 ± 251 min (4 ± 4 h). Because of the small proportion of patients suffering from sICH (33), predictors could not be determined; however, for patients with any ICH, predictive factors included an older age (74.6 ± 12.4 vs. 68.8 ± 15.1, p = 0.001), higher baseline National Health Institute Stroke Scale score (14.6 ± 7.3 vs. 10.8 ± 7.9, p = 0.002), and higher baseline glucose levels (155.1 ± 87.5 vs. 140.4 ± 70.5, p = 0.04).

Conclusions

In this study, only a small proportion suffered from either sICH and/or END, typically within 12 h of tPA administration. These findings may support earlier deescalation of higher acuity monitoring in clinically stable post-IV tPA patients without large vessel occlusion.

Genetic Variants Associated With Intraparenchymal Hemorrhage Progression After Traumatic Brain Injury

IMPORTANCE

Intracerebral hemorrhage progression is associated with unfavorable outcome after traumatic brain injury (TBI). No effective treatments are currently available. This secondary injury process reflects an extreme form of vasogenic edema and blood-brain barrier breakdown. The sulfonylurea receptor 1-transient receptor potential melastatin 4 (SUR1-TRPM4) cation channel is a key underlying mechanism. A phase 2 trial of SUR1-TRPM4 inhibition in contusional TBI is ongoing, and a phase 3 trial is being designed. Targeted identification of patients at increased risk for hemorrhage progression may inform prognostication, trial design (including patient selection), and ultimately treatment response.

OBJECTIVE

To determine whether ABCC8 (SUR1) and TRPM4 genetic variability are associated with intraparenchymal hemorrhage (IPH) progression after severe TBI, based on the putative involvement of the SUR1-TRPM4 channel in this pathophysiology.

DESIGN, SETTING, AND PARTICIPANTS

In this genetic association study, DNA was extracted from 416 patients with severe TBI prospectively enrolled from a level I trauma academic medical center from May 9, 2002, to August 8, 2014. Forty ABCC8 and TRPM4 single-nucleotide variants (SNVs) were genotyped (multiplex, unbiased). Data were analyzed from January 7, 2020, to May 3, 2021.

MAIN OUTCOMES AND MEASURES

Primary analyses addressed IPH progression at 6, 24, and 120 hours in patients without acute craniectomy (n = 321). Multivariable regressions and receiver operating characteristic curves assessed SNV and haplotype associations with progression. Spatial modeling and functional predictions were determined using standard software.

RESULTS

Of the 321 patients included in the analysis (mean [SD] age, 37.0 [16.3] years; 247 [76.9%] male), IPH progression occurred in 102. Four ABCC8 SNVs were associated with markedly increased odds of progression (rs2237982 [odds ratio (OR), 2.60-3.80; 95% CI, 1.14-5.90 to 1.80-8.02; P = .02 to P < .001], rs2283261 [OR, 3.37-4.77; 95% CI, 1.07-10.77 to 1.89-12.07; P = .04 to P = .001], rs3819521 [OR, 2.96-3.92; 95% CI, 1.13-7.75 to 1.42-10.87; P = .03 to P = .009], and rs8192695 [OR, 3.06-4.95; 95% CI, 1.02-9.12 to 1.67-14.68]; P = .03-.004). These are brain-specific expression quantitative trait loci (eQTL) associated with increased ABCC8 messenger RNA levels. Regulatory annotations revealed promoter and enhancer marks and strong and/or active brain-tissue transcription, directionally consistent with increased progression. Three SNVs (rs2283261, rs2237982, and rs3819521) in this cohort have been associated with intracranial hypertension. Four TRPM4 SNVs were associated with decreased IPH progression (rs3760666 [OR, 0.40-0.49; 95% CI, 0.19-0.86 to 0.27-0.89; P = .02 to P = .009], rs1477363 [OR, 0.40-0.43; 95% CI, 0.18-0.88 to 0.23-0.81; P = .02 to P = .006], rs10410857 [OR, 0.36-0.41; 95% CI, 0.20-0.67 to 0.20-0.85; P = .02 to P = .001], and rs909010 [OR, 0.27-0.40; 95% CI, 0.12-0.62 to 0.16-0.58; P = .002 to P < .001]). Significant SNVs in both genes cluster downstream, flanking exons encoding the receptor site and SUR1-TRPM4 binding interface. Adding genetic variation to clinical models improved receiver operating characteristic curve performance from 0.6959 to 0.8030 (P = .003).

CONCLUSIONS AND RELEVANCE

In this genetic association study, 8 ABCC8 and TRPM4 SNVs were associated with IPH progression. Spatial clustering, brain-specific eQTL, and regulatory annotations suggest biological plausibility. These findings may have important implications for neurocritical care risk stratification, patient selection, and precision medicine, including an upcoming phase 3 trial design for SUR1-TRPM4 inhibition in severe TBI.

Does stroke etiology influence outcome in the posterior circulation? An analysis of 107 consecutive acute basilar occlusion thrombectomies

OBJECTIVE

Acute basilar artery occlusion (BAO) harbors a more guarded prognosis after thrombectomy compared with anterior circulation large-vessel occlusion. Whether this is a function of a greater proportion of atherosclerotic/intrinsic lesions is not well studied. The authors aimed to elucidate the prevalence and predictors of intracranial intrinsic atherosclerotic disease in patients with acute BAO and to compare angiographic and clinical outcomes between patients with BAO secondary to embolic versus intrinsic disease.

METHODS

A prospectively maintained stroke database was reviewed for all patients presenting between January 2013 and December 2019 to a tertiary care academic comprehensive stroke center with acute, nontandem BAO. Patient data were extracted, subdivided by stroke mechanism and treatment modality (embolic [thrombectomy only] and intrinsic [thrombectomy + stenting]), and angiographic and clinical results were compared.

RESULTS

Of 107 patients, 83 (78%) had embolic occlusions (thrombectomy only) and 24 (22%) had intrinsic disease (thrombectomy + stenting). There was no significant difference in patient age, presenting National Institutes of Health Stroke Scale score, time to presentation, selected medical comorbidities (hypertension, hyperlipidemia, diabetes, and atrial fibrillation), prior stroke, and posterior circulation Alberta Stroke Program Early CT Score. Patients with intrinsic disease were more likely to be active smokers (50% vs 26%, p = 0.04) and more likely to be male (88% vs 48%, p = 0.001). Successful recanalization, defined as a modified Thrombolysis in Cerebral Infarction (mTICI) grade of 2b or 3, was achieved in 90% of patients and did not differ significantly between the embolic versus intrinsic groups (89% vs 92%, p > 0.99). A 90-day good outcome (modified Rankin Scale [mRS] score 0-2) was found in 37% of patients overall and did not differ significantly between the two groups (36% vs 41%, p = 0.41). Mortality was 40% overall and did not significantly differ between groups (41% vs 36%, p = 0.45).

CONCLUSIONS

In the current study, demographic and clinical results for acute BAO showed that compared with intrinsic disease, thromboembolic disease is a more common mechanism of acute BAO, with 78% of patients undergoing thrombectomy alone. However, there was no significant difference in revascularization and outcome results between patients with embolic disease and those with intrinsic disease.

Symptomatic nonstenotic carotid disease: Evaluation of a proposed classification scheme in a prospective cohort

INTRODUCTION

Unraveling symptomatic nonstenotic carotid disease (SyNC) as a stroke etiology from other cryptogenic stroke may have important implications for defining natural history and for tailoring secondary prevention strategies. We aim to describe the characteristics of the plaques in a prospectively-collected cohort of patients with non-invasive imaging suggesting symptomatic carotid stenosis but whose DSA demonstrated nonstenotic atheromatous disease, and to evaluate the recurrence rate depending on the type of SyNC.

METHODS

We reviewed prospectively-collected data for patients presenting with new neurologic events and non-invasive imaging suggestive of moderate or severe (≥50%) carotid stenosis between July 2016 and October 2018. Patients were included in the present study if the degree of stenosis on DSA was < 50%. We assigned these patients into groups based on a previously-proposed working definition of SyNC, and analyzed the rate of recurrent stroke in the following 6 months.

RESULTS

28 patients had DSA-confirmed < 50% stenosis and constituted the study cohort. The median age was 73 years and 64% were male; median presenting NIHSS was 1 (IQR 0-3). The great majority (86%) of carotid plaques had high-risk features including ulcerated plaque (n = 21, 75%) and plaque > 3 mm thick (n = 18, 64%). 17 of 28 patients (61%) met classification criteria for "definite" or "probable" SyNC. Three of five patients in the "definite SyNC" group experienced recurrent neurologic events.

CONCLUSION

The majority of patients with non-invasive imaging suggesting carotid stenosis harbor symptomatic carotid disease per current classifications despite DSA stenosis < 50%. Current classification schema may allow for risk stratification of SyNC patients and these findings warrant further study.

Clinically Approximated Hypoperfused Tissue in Large Vessel Occlusion Stroke

[Figure: see text].

Bigger is Still Better: A Step Forward in Reperfusion With React 71

BACKGROUND

While multiple new larger-bore aspiration catheters have been introduced for stroke thrombectomy, sizeable cohort outcome studies are lacking along with meaningful comparative studies to evaluate whether they represent a clinically relevant improvement compared to predecessors.

OBJECTIVE

To evaluate comparative angiographic and clinical outcomes between an 071 and 068 aspiration catheter.

METHODS

The authors reviewed an institutional thrombectomy database extracting the first 150 consecutive cases utilizing React 71 (Medtronic, Dublin, Ireland) with a comparison of background/demographic, procedural, angiographic, and clinical outcome variables to a cohort of patients treated with our previously most frequently utilized 0.068-inch aspiration catheter.

RESULTS

In our React 71 cohort, successful reperfusion (thrombolysis in cerebral infarction [TICI] 2b-3) was achieved in 95% of cases. In comparison to a prior cohort of 96 patients treated with a 0.068-inch catheter, there was no statistically significant difference in rates of successful reperfusion (TICI 2b-3), initial disposition, and 90-d outcome. However, the frequency of single pass cases was significantly higher in the React 71 cohort (47% vs 35%, P = .019 on multivariate analysis) along with the rate of TICI 2c-3 reperfusion after the first pass (26% vs 14%, P = .019 on multivariate analysis), and final TICI 2c-3 reperfusion (39% vs 28%, P = .04 on multivariate analysis).

CONCLUSION

While rates of TICI 2b-3 reperfusion and clinical outcome results were similar, our study suggests that a newer, larger bore aspiration catheter may be associated with a greater frequency of single pass cases and higher quality reperfusion, judged as TICI 2c-3 frequency after the first and final pass.

Fast and slow progressors of infarct growth in basilar artery occlusion strokes

BACKGROUND

Heterogeneity in the infarct growth rate among anterior circulation large vessel occlusion (LVO) strokes has triage and treatment implications. Such data are lacking for basilar artery occlusion (BAO) strokes. We aim to describe the variability in brainstem infarct volume at presentation and compute the distribution of the infarct growth rate (IGR) and rate of loss of neurons during BAO strokes.

METHODS

A retrospective review of consecutive patients with BAO stroke with pretreatment MRI was performed. Ischemic core volume was manually calculated (product of slice thickness and sum of area of region of interests) for the brainstem lesion. The distribution of various brainstem infarct volume groups was analyzed and the IGR (including rate of loss of neurons) was computed.

RESULTS

Fifty-nine patients were included. Mean age was 64±13 and 34% were men. Mean National Institutes of Health Stroke Scale score was 20±11 and time to MRI was 9±5 hours. Mean brainstem ischemic core volume was 4.5±4.6 mL. According to predefined thresholds, 13% and 6% of patients with BAO stroke in the 0-6 hour time window were fast (5-10 mL) and ultra-fast progressors (>10 mL), respectively, and 14% of patients in the 6-24 hour time window were slow progressors (<1 mL). Median and mean rate of loss of neurons was 146 300 neurons/min and 261 300 (±400 000) neurons/min, respectively, and ranged from <19 400 to >2.12 million.

CONCLUSION

Approximately 14% of BAO strokes are slow progressors and 19% are fast/ultra-fast progressors, with the rate of loss of neurons ranging from <19 000 to >2.1 million/min. Large heterogeneity exists in brainstem infarct volume at presentation and IGR among patients with BAO stroke.

First pass effect in patients with large vessel occlusion strokes undergoing neurothrombectomy: insights from the Trevo Retriever Registry

BACKGROUND

First pass effect (FPE), defined as near-total/total reperfusion of the territory (modified Thrombolysis in Cerebral Infarction (mTICI) 2c/3) of the occluded artery after a single thrombectomy attempt (single pass), has been associated with superior safety and efficacy outcomes than in patients not experiencing FPE.

OBJECTIVE

To characterize the clinical features, incidence, and predictors of FPE in the anterior and posterior circulation among patients enrolled in the Trevo Registry.

METHODS

Data were analyzed from the Trevo Retriever Registry. Univariate and multivariable analyses were used to assess the relationship of patient (demographics, clinical, occlusion location, collateral grade, Alberta Stroke Program Early CT Score (ASPECTS)) and device/technique characteristics with FPE (mTICI 2c/3 after single pass).

RESULTS

FPE was achieved in 27.8% (378/1358) of patients undergoing anterior large vessel occlusion (LVO) thrombectomy. Multivariable regression analysis identified American Society of Interventional and Therapeutic Neuroradiology (ASITN) levels 2-4, higher ASPECTS, and presence of atrial fibrillation as independent predictors of FPE in anterior LVO thrombectomy. Rates of modified Rankin Scale (mRS) score 0-2 at 90 days were higher (63.9% vs 53.5%, p<0.0006), and 90-day mortality (11.4% vs 12.8%, p=0.49) was comparable in the FPE group and non-FPE group. Rate of FPE was 23.8% (19/80) among basilar artery occlusion strokes, and outcomes were similar between FPE and non-FPE groups (mRS score 0-2, 47.4% vs 52.5%, p=0.70; mortality 26.3% vs 18.0%, p=0.43). Notably, there were no difference in outcomes in FPE versus non-FPE mTICI 2c/3 patients.

CONCLUSION

Twenty-eight percent of patients undergoing anterior LVO thrombectomy and 24% of patients undergoing basilar artery occlusion thrombectomy experience FPE. Independent predictors of FPE in anterior circulation LVO thrombectomy include higher ASITN levels, higher ASPECTS, and the presence of atrial fibrillation.

Influence of the COVID-19 Pandemic on Treatment Times for Acute Ischemic Stroke: The Society of Vascular and Interventional Neurology Multicenter Collaboration

BACKGROUND AND PURPOSE

The pandemic caused by the novel coronavirus disease 2019 (COVID-19) has led to an unprecedented paradigm shift in medical care. We sought to evaluate whether the COVID-19 pandemic may have contributed to delays in acute stroke management at comprehensive stroke centers.

METHODS

Pooled clinical data of consecutive adult stroke patients from 14 US comprehensive stroke centers (January 1, 2019, to July 31, 2020) were queried. The rate of thrombolysis for nontransferred patients within the Target: Stroke goal of 60 minutes was compared between patients admitted from March 1, 2019, and July 31, 2019 (pre-COVID-19), and March 1, 2020, to July 31, 2020 (COVID-19). The time from arrival to imaging and treatment with thrombolysis or thrombectomy, as continuous variables, were also assessed.

RESULTS

Of the 2955 patients who met inclusion criteria, 1491 were admitted during the pre-COVID-19 period and 1464 were admitted during COVID-19, 15% of whom underwent intravenous thrombolysis. Patients treated during COVID-19 were at lower odds of receiving thrombolysis within 60 minutes of arrival (odds ratio, 0.61 [95% CI, 0.38-0.98]; P=0.04), with a median delay in door-to-needle time of 4 minutes (P=0.03). The lower odds of achieving treatment in the Target: Stroke goal persisted after adjustment for all variables associated with earlier treatment (adjusted odds ratio, 0.55 [95% CI, 0.35-0.85]; P<0.01). The delay in thrombolysis appeared driven by the longer delay from imaging to bolus (median, 29 [interquartile range, 18-41] versus 22 [interquartile range, 13-37] minutes; P=0.02). There was no significant delay in door-to-groin puncture for patients who underwent thrombectomy (median, 83 [interquartile range, 63-133] versus 90 [interquartile range, 73-129] minutes; P=0.30). Delays in thrombolysis were observed in the months of June and July.

CONCLUSIONS

Evaluation for acute ischemic stroke during the COVID-19 period was associated with a small but significant delay in intravenous thrombolysis but no significant delay in thrombectomy time metrics. Taking steps to reduce delays from imaging to bolus time has the potential to attenuate this collateral effect of the pandemic.

Neurothrombectomy for Acute Ischemic Stroke Across Clinical Trial Design and Technique: A Single Center Pooled Analysis

Introduction: The practice of endovascular therapy has evolved dramatically over the last 10 years with randomized clinical trials investigating the benefit of thrombectomy in select patient populations based on time of presentation, imaging criteria, and procedural technique. We sought to understand the benefit of thrombectomy in patients treated within the context of a clinical trial at a single academic center.

Methods: Patient-level data recorded in case forms and core-lab adjudicated data were analyzed from patients enrolled in RCTs investigating the benefit of endovascular thrombectomy over medical management (IMSIII, MR RESCUE, ESCAPE, SWIFT PRIME, and DAWN) between 2007 and 2017 at a single academic referral center.

Results: A total of 134 patients (intervention group, n = 81; medical group, n = 53) were identified across five clinical trials (IMSIII, n = 46; MR RESCUE, n = 4; ESCAPE, n = 24; SWIFT PRIME, n = 14; DAWN, n = 46). There were no significant differences between the treatment arm and control arm in terms of age, gender, baseline NIHSS, ASPECTS, and site of occlusion. Rates of good outcome were superior in the intervention group with early neurological recovery (NIHSS of 0–1 or increase NIHSS of 8 points at 24 h) at a higher rate of 49% vs. 17% (p = <0.001) and higher rates of functional independence (90 day mRS 0–2 of 53% vs. 26%, p = 0.002). In multivariate logistic regression analysis, lower NIHSS and younger age were predictors of good outcome. There were comparable rates of good outcome irrespective of clinical trial, imaging selection criteria (CTP vs. MRI), early vs. late time window (0–6 h vs. 6–24 h) and procedural technique (Merci vs. Solitaire/Trevo device). There were no differences in rates of sICH, PH-2 or mortality in the intervention group vs. medical group.

Conclusions: At a large academic center, the benefit of endovascular therapy over medical therapy is observed irrespective of clinical trial design, patient selection or procedural technique.

Last Electrically Well: Intraoperative Neurophysiological Monitoring for Identification and Triage of Large Vessel Occlusions

INTRODUCTION

Intra-operative stroke (IOS) is associated with poor clinical outcome as detection is often delayed and time of symptom onset or patient's last known well (LKW) is uncertain. Intra-operative neurophysiological monitoring (IONM) is uniquely capable of detecting onset of neurological dysfunction in anesthetized patients, thereby precisely defining time last electrically well (LEW). This novel parameter may aid in the detection of large vessel occlusion (LVO) and prompt treatment with endovascular thrombectomy (EVT).

METHODS

We performed a retrospective analysis of a prospectively maintained AIS and LVO database from May 2018-August 2019. Inclusion criteria required any surgical procedure under general anesthesia (GA) utilizing EEG (electroencephalography) and/or SSEP (somatosensory evoked potentials) monitoring with development of intraoperative focal persistent changes using predefined alarm criteria and who were considered for EVT.

RESULT

Five cases were identified. LKW to closure time ranged from 66 to 321 minutes, while LEW to closure time ranged from 43 to 174 min. All LVOs were in the anterior circulation. Angiography was not pursued in two cases due to large established infarct (both patients expired in the hospital). EVT was pursued in two cases with successful recanalization and spontaneous recanalization was noted in one patient (mRS 0-3 at 90 days was achieved in all 3 cases).

CONCLUSIONS

This study demonstrates that significant IONM changes can accurately identify patients with an acute LVO in the operative setting. Given the challenges of recognizing peri-operative stroke, LEW may be an appropriate surrogate to quickly identify and treat IOS.

Emergent Premedication for Contrast Allergy Prior to Endovascular Treatment of Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Management of contrast media allergies may lead to treatment delays in patients with acute ischemic stroke undergoing endovascular therapy. The optimal premedication strategy remains unclear. The aim of this report was to analyze our experience with emergent administration of premedication regimens before endovascular therapy.

MATERIALS AND METHODS

We retrospectively reviewed prospective data for all patients undergoing endovascular therapy from 2012 to 2019 at an academic comprehensive stroke center. Records of patients with documented contrast allergy were reviewed and analyzed. Data collected included stroke risk factors and characteristics, historical contrast reaction details, premedication regimens administered, and signs or symptoms of allergic reaction developing post-endovascular therapy. Hospital arrival time to endovascular therapy was compared with that in those who did not have a history of contrast allergy.

RESULTS

We analyzed 1521 patients undergoing endovascular therapy; 60 (4%) had documented contrast allergies and constituted the study cohort. The median age was 73 years (interquartile range, 66-81 years), and 65% were women. The median time from premedication to contrast was 24 minutes (interquartile range, 0-36 minutes). Forty-three patients (72%) proceeded directly to endovascular therapy; in 17 patients, the first contrast exposure was CTA. Time from hospital arrival to endovascular therapy was not slower for patients with documented allergies (96 versus 134 minutes, P = .32). No patients experienced a contrast media reaction.

CONCLUSIONS

In a single-institution cohort study of 60 consecutive patients with documented contrast allergies undergoing endovascular therapy with emergent premedication en route to (or in) the neuroangiography suite, no patients experienced allergic symptoms. This pragmatic approach may be safe for patients who have documented contrast media allergies.

Predicting outcomes after acute reperfusion therapy for basilar artery occlusion

BACKGROUND AND PURPOSE

Basilar artery occlusion (BAO) leads to high rates of morbidity and mortality, despite successful recanalization. The discordance between flow restoration and long-term functional status clouds clinical decision-making regarding further aggressive care. We sought to develop and validate a practical, prognostic tool for the prediction of 3-month favorable outcome after acute reperfusion therapy for BAO.

METHODS

This retrospective, multicenter, observational study was conducted at four high-volume stroke centers in the USA and Europe. Multivariate regression analysis was performed to identify predictors of favorable outcome (90-day modified Rankin scale scores 0-2) and derive a clinically applicable prognostic model (the Pittsburgh Outcomes after Stroke Thrombectomy-Vertebrobasilar (POST-VB) score). The POST-VB score was evaluated and internally validated with regard to calibration and discriminatory ability. External validity was assessed in patient cohorts at three separate centers.

RESULTS

In the derivation cohort of 59 patients, independent predictors of favorable outcome included smaller brainstem infarct volume on post-procedure magnetic resonance imaging (P < 0.01) and younger age (P = 0.01). POST-VB score was calculated as: age + (10 × brainstem infarct volume). POST-VB score demonstrated excellent discriminatory ability [area under the receiver-operating characteristic curve (AUC) = 0.91] and adequate calibration (P = 0.88) in the derivation cohort (Center A). It performed equally well across the three external validation cohorts (Center B, AUC = 0.89; Center C, AUC = 0.78; Center D, AUC = 0.80). Overall, a POST-VB score < 49 was associated with an 88% likelihood of favorable outcome, as compared to 4% with a score ≥ 125.

CONCLUSIONS

The POST-VB score effectively predicts 3-month functional outcome following acute reperfusion therapy for BAO and may aid in guiding post-procedural care.

Capitated pricing model for stroke thrombectomies: a single center experience across three companies

BACKGROUND

With a continued rise in healthcare expenditures, there is a demonstrable focus on curbing expenses. Mechanical thrombectomy (MT) is the standard of treatment for large vessel occlusions (LVOs); however, considerable costs are associated with devices utilized in each procedure. We report our institution's experience with capitation pricing models negotiated with three different companies.

METHODS

We retrospectively reviewed a prospectively maintained database from February 2018 to August 2019 identifying cases performed under capitation models. We calculated the cost of equipment for each thrombectomy using the cost for individual devices utilized (virtual) and compared this sum to the total derived from cost-negotiated bundled equipment packages. This was compared with real-world cases that did not meet capitation criteria during this study period.

RESULTS

107 cases met the criteria for capitation; 39 cases used company A's models (28 with stentrievers), 44 cases used company B's models (3 with stentrievers), and 24 cases used company C's models (14 with stentrievers). Overall, there was a net savings of $202 370.50 utilizing the capitated model ($689 435 vs $891 805.50), amounting to $1891.31 savings per case. Mean capitation was lower ($6972±2774) compared with virtual ($8794±4614) and real-world non-capitation costs ($7176±3672).

CONCLUSION

The negotiated capitated pricing model yielded total cost savings associated with equipment from each company. Overall mean capitation costs were lower than virtual and real-world cases. This may serve as a model for other centers in controlling costs for patients undergoing MT for LVO.

Ballast and NeuronMax in stroke thrombectomy

BACKGROUND

Comparative evaluation of long sheath performance in stroke thrombectomy has not been performed.

OBJECTIVE

To review an initial experience with the new Ballast 6F long sheath compared with the NeuronMax, to evaluate comparative benchmarks in trackability, navigability, and procedural outcomes.

METHODS

A prospectively maintained thrombectomy database was evaluated over a 6-month period to compare procedural and angiographic results between a cohort of patients treated with the historical institutional standard long sheath (NeuronMax) and another with the new Ballast long sheath via a transfemoral approach.

RESULTS

Of 156 stroke thrombectomy cases, 69 were performed using NeuronMax and 40 using Ballast via a transfemoral approach; the remainder of cases employed alternative long sheaths or were performed via initial radial access. There was no significant difference in patient age, medical history, baseline National Institutes of Health Stroke Scale score, Alberta Stroke Program Early CT Score, arch type, tissue plasminogen activator use, and clot location between the two groups. Single-pass case frequency (41% for NeuronMax vs 44% for Ballast, p=0.84), and final successful revascularization (TICI 2b or greater) were similar between the two cohorts (91% vs 98%, p=0.42). Good 90-day outcome (modified Rankin Scale score 0-2) was also similar (33% for NeuronMax, 43% for Ballast, p=0.41). Excluding tandem occlusions, mean procedural time was 31 min for NeuronMax and 25 min for Ballast (p=0.09). Puncture to long sheath access and angiography in the base target vessel was faster for Ballast than NeuronMax (6.5 min vs 9.2 min, p=0.04).

CONCLUSION

Among a cohort of practitioners with historical, preferential experience with NeuronMax for stroke thrombectomy, faster procedural times were achieved with Ballast with similar final angiographic results.

Collateral damage - Impact of a pandemic on stroke emergency services

Background

The COVID-19 pandemic's impact on stroke care is two-fold — direct impact of the infection and indirect impact on non-COVID-19 diseases. Anecdotal evidence and clinical observation suggest that there is a decrease in the number of patients presenting with stroke during the pandemic. We aim to understand the impact of the COVID-19 pandemic on the utilization of stroke emergency services on a single comprehensive stroke center (CSC).

Methods

We performed a retrospective analysis of a prospectively maintained database and compared all emergency department (ED) encounters, acute stroke admissions (including TIA), and thrombectomy cases admitted in March 2017-2019 to patients admitted in March 2020 at a comprehensive stroke center.

Results

Number of total ED encounters (22%, p=0.005), acute ischemic strokes (40%, p=0.001), and TIAs (60%, p=0.163) decreased between March of 2017–2019 compared to March of 2020. The number of patients undergoing EVT in March 2020 was comparable to March 2017–2019 (p=0.430).

Conclusion

A pandemic-related stay-at-home policy reduces the utilization of stroke emergency services at a CSC. This effect appears to be more prominent for ED encounters, all stroke admissions and TIAs, and less impactful for severe strokes. Given the relatively low prevalence of COVID-19 cases in our region, this decrement is likely related to healthcare seeking behavior rather than capacity saturation.

Delayed functional independence after thrombectomy: temporal characteristics and predictors

Background

Variability in early neurological improvement after endovascular thrombectomy (EVT) for large vessel occlusion (LVO) stroke is well documented. Understanding the temporal progression of functional independence after EVT, especially delayed functional independence in patients who do not experience early improvement, is essential for prognostication and rehabilitation.

Objective

To determine the incidence of early and delayed functional independence and identify associated predictors after EVT.

Methods

A retrospective analysis of prospectively collected data on patients undergoing EVT in the setting of anterior circulation LVO was performed. Demographic, clinical, radiological, treatment, and procedural information were analyzed. Incidence and predictors of early functional independence (EFI, modified Rankin Scale (mRS) score 0–2 at discharge) and delayed functional independence (DFI, mRS score 0–2 at 90 days in non-EFI patients) were analyzed.

Results

Three hundred and fifty-five patients met the study criteria. 55% were women and mean age was 71±15. Mean National Institutes of Health Stroke Scale (NIHSS) score was 17±6 and median Alberta Stroke Program Early CT Score was 9 (8-10). EFI was observed in 21% (73) of patients. Among non-EFI patients (282), DFI was observed in 30% (85) of patients. Shorter time to treatment (p=0.03), lower 24 hours NIHSS score (p<0.001), and smaller follow-up infarct volume (p=0.003) were independent predictors of EFI. Younger age (p=0.011), lower 24 hours NIHSS score (p=0.001), and absence of parenchymal hemorrhage (PH2; p=0.039) were independent predictors of DFI.

Conclusion

Approximately one-fifth of patients experience EFI and one-third of non-early improvers experience DFI. Younger age, lower 24 hours NIHSS score, and absence of parenchymal hemorrhage were independent predictors of DFI among non-early improvers. Further studies are required to improve our understanding of DFI.

Large Infarct Volume Post Thrombectomy: Characteristics, Outcomes, and Predictors

BACKGROUND

Despite increasing interest in endovascular therapy (EVT) for large-core strokes, little is known about the predictors of good outcome in these patients. The aim of this study was to analyze patients with large-core strokes post-EVT and to define the predictors of favorable outcome in this population.

METHODS

A retrospective analysis of prospectively collected data on anterior circulation strokes undergoing EVT between January 2015 and February 2018 was performed. Patients with good baseline functional status who underwent EVT for occlusion of an anterior circulation artery and achieved successful recanalization (modified Treatment in Cerebral Ischemia score ≥2b) but had large follow-up infarct volume (FIV ≥70 cm³) were included in the study. Demographic characteristics, clinical and radiologic data, treatment and postprocedural outcomes were extracted and analyzed. The primary outcome was 90-day modified Rankin Scale (mRS) score, stratified by favorable (mRS 0-3) versus unfavorable (mRS 4-6).

RESULTS

Of 355 patients meeting inclusion criteria, 85 (24%) had large FIV on follow-up imaging after EVT and constituted the study cohort. No patients achieved mRS score 0-2 at hospital discharge; 32% had 90-day mRS score 0-3. On multivariate logistic regression analysis, lower FIV (OR, -0.96 [0.95-0.99]; P = 0.007), male sex (OR, -1.29 [1.07-12.3]; P = 0.026), and intravenous tissue plasminogen activator use (OR, 3.6 [2.01-8.9]; P = 0.003) were independent predictors of favorable outcome. Independent predictors of mortality on multivariate analysis were higher FIV (OR, -1.01 [1.007-1.02]; P = 0.001) and female sex (OR, 4.08 [1.25-13.3]; P = 0.02).

CONCLUSIONS

For patients with large-core strokes (≥70 cm³) after EVT, approximately one third have favorable outcome at 90 days. Independent predictors of favorable 90-day outcomes include male sex, intravenous tissue plasminogen activator use, and lower FIV.

Interaction between time, ASPECTS, and clinical mismatch

Background

Imaging-based patient selection for neurothrombectomy is reliant on the identification of irreversibly damaged brain tissue (core) and salvageable tissue (penumbra). The DAWN trial used the clinical-core mismatch (CCM) paradigm (clinical deficit out of proportion to infarct volume). We aim to determine the prevalence of CCM in large vessel occlusion (LVO) strokes and study the impact of time and the Alberta Stroke Program Early CT Score (ASPECTS) on the likelihood of mismatch.

Methods

We performed a retrospective observational analysis of internal carotid artery/middle cerebral artery M1 occlusions with available advanced imaging (relative cerebral blood flow/MRI). We used automated software for infarct volume analysis and ASPECTS determination. The prevalence of CCM and the impact of time and ASPECTS were analyzed.

Result

One hundred and eighty-five LVO strokes were included. Mean age was 71±15 years and median National Institutes of Health Stroke Scale score was 17 (range 12–21). Mean ischemic core volume was 50±69 mL. Within 0–24 hours, CCM was present in 53% and ranged from 63% in 0–3 hours to 25% at 21–24 hours (p=0.03). Prevalence of mismatch reduced 1.6% for every 1 hour increase in time to imaging. CCM prevalence by ASPECTS groups was: ASPECTS 9–10: 77%, ASPECTS 6–8: 65%, ASPECTS 0–5: 13% (p<0.01), with a 6.4% decrement for every 1 point decrease in ASPECTS. The prevalence of mismatch did not diminish over time among ASPECTS groups and higher ASPECTS was an independent predictor of CCM (OR 1.4 (95% CI 1.1 to 1.7), p<0.001).

Conclusions

CCM is present in 57% and 50% of LVO strokes in the 0–6 and 6–24 hour window, respectively. The prevalence of mismatch declines with increasing time (1.6%/hour) and decreasing ASPECTS (6.4%/point). Among ASPECTS groups the prevalence of mismatch does not decline over time. These data support the use of an ASPECTS-based paradigm for late window patient selection.

Abstract TP2: Impact of Neglect on Outcomes After Right Hemisphere Stroke Thrombectomy

Introduction: Right Hemisphere Strokes (RHS) are characterized by severe motor and sensory deficits and signs of neglect including extinction and inattention. National Institutes of Health Stroke Scale (NIHSS) score provides an objective measurement of presence or absence of neglect. Data regarding the impact of neglect on outcomes after RHS thrombectomy are lacking. We hypothesize that the presence of neglect in RHS is associated with worse outcomes after thrombectomy in RHS.

Methods: Retrospective analysis of prospectively collected database of right sided anterior circulation large vessel occlusion [internal carotid and/or middle cerebral artery M1] strokes at a comprehensive stroke center. Patients with successful recanalization (TICI≥ 2B) and complete follow-up data were included in the study. Two group of RHS were identified- with and without neglect by itemized NIHSS. Baseline characteristics and outcomes were compared.

Results: A total of 172 patients were included in the study. Median NIHSS score was 15 (11-18) and median ASPECTS was 9 (8-10). Signs of neglect were observed in 63% (108) of patients. In multivariate analyses, younger age [0.9 (0.8-0.95) p=<0.01] and higher ASPECTS [1.8 (1.1-3.1) p=0.015] were independent predictors of mRS 0-2 at 90 days. Absence of neglect [0.39 (0.13-1.1) p=0.07] may predict good outcome. Independent predictors of mortality on multivariate analyses included older age [1.1 (1.03-1.15) p =0.001], presence of atrial fibrillation [0.3 (0.1-1) p=0.05] and diabetes mellitus [0.16 (0.05-0.53) p=0.003]. Presence of neglect [2.5 (0.9-6.6) p=0.06] and lower ASPECTS [0.7 (0.4-1) p=0.06] may predict mortality.

Conclusion: Signs of neglect were observed in approximately 63% of right hemisphere LVO strokes. Presence of neglect may predict poor functional outcome and mortality at 90 days after thrombectomy for right hemisphere strokes. Further studies are required to evaluate the impact of thrombectomy on recovery of neglect.

Abstract WP34: The Relationship Between Reperfusion and Intracranial Hemorrhage After Thrombectomy

Introduction: Symptomatic intracerebral hemorrhage (sICH) is a devastating complication after endovascular thrombectomy (EVT). Prior reports have demonstrated that TICI ≥2b reperfusion is protective against sICH. We aimed to further examine the relationship between reperfusion grade and sICH, to elucidate whether a difference between TICI 2b and 3 exists, and to determine whether this relationship holds true for patients undergoing delayed thrombectomy (6-24 hours).

Methods: We performed a single-center retrospective review of prospectively-recorded data for patients undergoing EVT for large vessel occlusion (LVO) between January 2015 and February 2018. Multivariable logistic regression analyses were performed to identify predictors of PH and sICH (NINDS, SITS-MOST, ECASS III criteria) and to identify the role of reperfusion grade. This analysis was repeated for delayed thrombectomy patients.

Results: Five-hundred-and-twenty-eight patients were included. Mean age was 71.5 and 43% were male. Median NIHSS and TLSW to treatment were 17 and 4.8 hours, respectively. Successful recanalization was achieved in 94%. On multivariable analyses, ASPECTS was a predictor of PH [p=0.002, OR-0.7 (0.57-0.87)] for patients achieving any reperfusion grade. For patients achieving successful reperfusion, lower ASPECTS was a predictor of PH [p=0.005, OR-0.72 (0.58-0.89)]) and of sICH (ECASS III) [p=0.04, OR-0.67 (0.45-0.98)]; in addition, TICI 2b as compared to TICI 3 was a predictor of PH [p=0.04, OR-2.1 (1-4.4)] and of sICH (NINDS) [p=0.05, OR-7.5 (1-57)]. TLSW to treatment was not an independent predictor of PH or sICH.

Conclusion: Higher baseline ASPECTS and higher degree of reperfusion following EVT is associated with reduced likelihood of PH and sICH.

Transradial versus transfemoral approaches for diagnostic cerebral angiography: a prospective, single-center, non-inferiority comparative effectiveness study

Background

Interventional cardiology produced level 1 evidence recommending radial artery-first for coronary angiography given lower vascular complications. Neuroendovascular surgeons have not widely adopted the transradial approach. This prospective, single center, non-inferiority comparative effectiveness study aims to compare the transradial and transfemoral approaches for diagnostic cerebral angiography with respect to efficacy, safety and patient satisfaction.

Methods

Consecutive patients presenting for diagnostic cerebral angiography were selected to undergo right radial or femoral access based on date of presentation. Primary outcome was ability to answer the predefined diagnostic goal of the cerebral angiogram using the initial access site and was assessed with a non-inferiority design. Secondary outcomes included technical success per vessel, complications, procedure times and patient satisfaction.

Results

A total of 312 patients were enrolled, 158 and 154 for right radial and femoral access, respectively. The diagnostic goal of the angiogram was achieved in 152 of 154 (99%) patients who underwent attempted femoral access compared with 153 of 158 (97%) patients who underwent radial access, confirming non-inferiority of the transradial approach. Secondary outcomes showed equivalent technical success by vessel, no major complications, and similar frequency of minor complications between the two approaches. In-room time was similar between approaches, though post-procedure recovery room time was significantly shorter for transradial patients. Patient satisfaction results significantly favored the radial approach.

Conclusions

In patients undergoing diagnostic cerebral angiography, transfemoral and transradial access achieve procedural goals with similar effectiveness and safety, though patients strongly prefer the radial approach. Findings support consideration of adopting a radial-first strategy for diagnostic cerebral angiography.

Neuroimaging of Acute Stroke

Acute stroke is the clinical manifestation of disrupted blood flow or bleeding in the central nervous system. Imaging supports the clinical diagnosis and can aide in acute treatment decision making and guide information on prognosis. Features that are delineated include the parenchyma and the blood vessels. Parenchymal characteristics include early ischemic changes, established infarct and tissue at risk (penumbra), and hemorrhage. Vessel pathology includes arterial and venous steno-occlusive disease and vascular malformations. In the presence of a vessel occlusion, vessel imaging can assess collateral flow. This article outlines the role of neuroimaging as applied to patients presenting with acute stroke.