Imaging as a Selection Tool for Thrombectomy in Acute Ischemic Stroke

Large vessel occlusion (LVO) stroke represents a stroke subset associated with the highest morbidity and mortality. Multiple prospective randomized trials have shown that thrombectomy, alone or in conjunction with IV thrombolysis, is highly effective in reestablishing cerebral perfusion and improving clinical outcomes. In unselected patients and especially in patients with poor collaterals, the benefit of reperfusion therapy is exquisitely time sensitive; the earlier thrombectomy is started, the lower the likelihood of disability or death. Understanding both the pathophysiologic underpinnings and the modifying factors of this strong time-to-treatment effect demonstrated in numerous randomized clinical trials is important for implementation of intrahospital workflow measures to maximize time efficiency of thrombectomy. Reducing delays in reperfusion therapy initiation has become a priority in acute stroke care, and therefore a thorough understanding of the main systems-based factors responsible for these delays is critical. Because the time spent evaluating the patient in the emergency department, which typically includes neuroimaging studies performed in scanners remote from the angiography suite, represents the main source of delays in thrombectomy initiation, the direct to angiography (DTA) model has emerged as a means to substantially reduce treatment times and is being instituted at an increasing number of thrombectomy centers across the world. The aim of this report is to introduce DTA as an emerging stroke care paradigm for patients with suspicion of LVO stroke, review results from studies evaluating its feasibility and impact on outcomes, describe current barriers to its more widespread adoption, and propose potential solutions to overcoming these barriers.

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Abstract 1122‐000223: Direct to Angiography Suite versus Conventional Imaging in Suspected Large Vessel Occlusion Strokes: A Meta‐Analysis

Stroke: Vascular and Interventional Neurology ◽

10.1161/svin.01.suppl_1.000223 ◽

2021 ◽

Vol 1 (S1) ◽

Author(s):

Mahmoud H Mohammaden ◽

Mohamed Elfil ◽

Mohamed Fahmy Doheim ◽

Agostinho Camara Pinheiro ◽

Alhamza R Al‐Bayati ◽

...

Keyword(s):

Randomized Clinical Trials ◽

Meta Analysis ◽

Functional Independence ◽

Large Vessel ◽

Cochrane Library ◽

Conventional Imaging ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Angiography Suite ◽

Significant Difference

Introduction : Direct transfer to angiography suite (DTAS) for patients with suspected large vessel occlusion strokes potentially requiring mechanical thrombectomy has been shown to shorten treatment times and improve outcomes compared to conventional imaging (CI) selection. This meta‐analysis compares both approaches to build more concrete evidence. Methods : The potentially relevant studies that were published in four electronic databases/search engines (PubMed, Web of Science, Cochrane Library, and Scopus) till August 2021 were reviewed. Eligible studies were included if they enrolled >10 patients in both groups, were published in English and reported baseline and procedural characteristics and 90‐day outcomes. Relevant data were then extracted and analyzed. Results : Among 4514 searched studies, six qualified for the analysis. Time from door to puncture (MD = ‐26.76minutes, 95 % CI [‐39.48, ‐14.03], P< 0.0001) as well as door to reperfusion (MD = ‐27.21 minutes,95% CI [‐47.42, ‐7.01], P = 0.008) were significantly shorter and the rates of functional independence(mRS0‐2: RR = 1.28, 95% CI [1.03, 1.60], P = 0.03) at 90‐days were significantly higher in the DTAS versus the CI approach. There was no statistically significant difference between DTAS and CI groups in terms of successful reperfusion (modified Thrombolysis In Cerebral Infraction [mTICI] score2B‐3: RR = 0.99, 95% CI [0.93, 1.06], P = 0.86), near complete/ full reperfusion (mTICI 2C‐3: RR = 0.84,95% CI [0.68, 1.04], P = 0.11), or fair outcomes at 90‐days (mRS 0–3: RR = 1.05, 95% CI [0.67, 1.64],P = 0.84). Moreover, there was no difference between groups regarding symptomatic intracranial hemorrhage (RR = 0.81, 95% CI [0.55, 1.17], P = 0.26) or 90 day‐mortality (RR = 0.85, 95% CI [0.59, 1.24],P = 0.41). Conclusions : Our meta‐analysis showed that DTAS significantly improves time metrics and functional outcome with comparable safety to the CI approach. Multicenter randomized clinical trials are ongoing to confirm these results.

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Abstract TMP8: Predictors of Large Vessel Occlusion in Kaiser Stroke EXPRESS Program

Stroke ◽

10.1161/str.48.suppl_1.tmp8 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Jeffrey G Klingman ◽

Anne C Kim ◽

Meghan Hatfield ◽

Benjamin Wilson ◽

Lauren Klingman ◽

...

Keyword(s):

Acute Stroke ◽

Patient Characteristics ◽

Stroke Care ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Acute Stroke Care ◽

Kaiser Permanente ◽

Vessel Occlusion ◽

Stroke Treatment ◽

Improved Outcomes

Background: In 2015, trials showed that rapid endovascular stroke treatment (EST) of qualified patients with large vessel occlusion (LVO) resulted in improved outcomes over treatment with IV tPA alone. In 2015, Kaiser Permanente Northern California (KPNC) redesigned its acute stroke care work flow for its 21 stroke centers, which included expedited IV t-pa treatment, rapid CTA investigation, expedited transfer of appropriate patients for EST. We assessed for predictors of LVO post-implementation. Methods: The KPNC Stroke EXPRESS program was live in all centers by January 2016. Using clinical data for 1/1/16 - 7/10/16, we evaluated the frequency and locations of LVO, and patient characteristics of those with LVO. Multivariate logistic regression was used to examine whether age, gender, race, or an NIHSS ≥ 8 are predictors of LVO. Results: There were 2,204 tele-stroke alert cases from the ED. Among 993 (39.3%) that proceeded as likely acute stroke, 812 (81.8%) were evaluated with CTA. Out of those who had a CTA, 152 (18.7%) were found to have LVO as followed: 27 (17.8%) ICA, 87 (57.2%) M1, 24 (15.8%) M2, 6 (4.0%) basilar, 5 (3.3%) PCA, and 3 (2.0%) vertebral. Of those with LVO, 97 (63.8%) were treated with EST. Patients with LVO had a higher median NIHSS (15 vs. 5 in those without LVO). Neglect (27% vs. 7%) and gaze deviation (16% vs. 1%) were more likely to be seen among those with LVO and treated with EST compared to those without LVO. In multivariate analysis, age (OR=1.02, 95% CI 1.00 - 1.03, p=0.01) and NIHSS ≥8 (OR = 4.99, 95% CI 3.32- 7.49, p < 0.001) were associated with LVO. PPV for NIHSS ≥8 was 75.7%. Conclusions: In our large multi-ethnic population of acute stroke patients, a relatively small percentage (19%) was found to have LVO and only a subset qualified for EST. Predictors of LVO included NIHSS ≥8, increasing age, and presence of neglect and gaze preference. Given the low numbers of patients brought in for acute stroke treatment who ended up with a LVO requiring EST, further research is needed to assess a given system’s ability to rapidly evaluate and transfer as appropriate for EST rather than paramedic based diversion.

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Global Epidemiology of Stroke and Access to Acute Ischemic Stroke Interventions

Neurology ◽

10.1212/wnl.0000000000012781 ◽

2021 ◽

Vol 97 (20 Supplement 2) ◽

pp. S6-S16

Author(s):

Vasu Saini ◽

Luis Guada ◽

Dileep R. Yavagal

Keyword(s):

Ischemic Stroke ◽

Acute Stroke ◽

Acute Ischemic Stroke ◽

Randomized Clinical Trials ◽

Time Window ◽

Systems Of Care ◽

Stroke Care ◽

Acute Stroke Care ◽

Vessel Occlusion ◽

Global Epidemiology

Purpose of the ReviewTo provide an up-to-date review of the incidence of stroke and large vessel occlusion (LVO) around the globe, as well as the eligibility and access to IV thrombolysis (IVT) and mechanical thrombectomy (MT) worldwide.Recent FindingsRandomized clinical trials have established MT with or without IVT as the usual care for patients with LVO stroke for up to 24 hours from symptom onset. Eligibility for IVT has extended beyond 4.5 hours based on permissible imaging criteria. With these advances in the last 5 years, there has been a notable increase in the population of patients eligible for acute stroke interventions. However, access to acute stroke care and utilization of MT or IVT is lagging in these patients.SummaryStroke is the second leading cause of both disability and death worldwide, with the highest burden of the disease shared by low- and middle-income countries. In 2016, there were 13.7 million new incident strokes globally; ≈87% of these were ischemic strokes and by conservative estimation about 10%–20% of these account for LVO. Fewer than 5% of patients with acute ischemic stroke received IVT globally in the eligible therapeutic time window and fewer than 100,000 MTs were performed worldwide in 2016. This highlights the large gap among eligible patients and the low utilization rates of these advances across the globe. Multiple global initiatives are underway to investigate interventions to improve systems of care and bridge this gap.

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Abstract WP273: Evolution of a U.S. County System for Acute Comprehensive Stroke Care

Stroke ◽

10.1161/str.48.suppl_1.wp273 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Radoslav I Raychev ◽

Dana Stradling ◽

David M Brown ◽

Joey R Gee ◽

David L Lombardi ◽

...

Keyword(s):

Acute Stroke ◽

Systems Of Care ◽

Early Recognition ◽

Stroke Care ◽

Reperfusion Therapy ◽

Acute Stroke Care ◽

Vessel Occlusion ◽

Transfer Rates ◽

Over Time ◽

Iv Tpa

Introduction: In an effort to maximize provision of acute stroke therapies, the Emergency Medical Services (EMS) in Orange County, CA (6 th most populous U.S. county) established a system of care whereby patients with suspected acute stroke are taken to hub sites with endovascular treatment (EVT) capability or to spoke hospitals. Patients at spokes with acute ischemic stroke (AIS) and suspected large vessel occlusion (LVO) are transferred by EMS to hubs. Here we examined the relationship between stroke features, hospital transfers, and mortality; and their change over time. Methods: All patients during 2013-2015 were included for whom 911 was called within 7 hours of onset, and EMS personnel declared “acute stroke" at end of initial evaluation. Results: A total of 6,188 patients (mean age 72) had suspected stroke, of which 54.9% were AIS and 19.4% hemorrhagic stroke. Across all patients, transfer rates into hub sites increased over time (OR 1.12 per 3-months, p<0.0001) and differed by diagnosis (p<0.0001), with transfer in 12.0% of hemorrhages (n=122) but only 3.5% of AIS (n=101). Among patients with AIS only, transfer rates into a hub site increased over time (OR 1.08, p<0.0001), spiking mid-2015. Acute reperfusion therapy was given to 28.3% (20.9% IV tPA only, 3.6% IA therapy only, 3.8% IV tPA+IA), but its usage was unrelated to transfer status, and only 11% of all transferred AIS patients received EVT. Across all patients, mortality during acute hospitalization was 8.2% and did not differ by transfer status, but did differ by diagnosis (p<0.0001): 23.6% of hemorrhages vs. 5.4% of AIS. Over time, mortality decreased only among patients with AIS (OR 0.95, p=0.03). Conclusions: There were several favorable features of this acute stroke care system, including that 28.3% of AIS patients received reperfusion therapy and that mortality decreased over time. However, while transfer to EVT-ready sites increased, rates of IA therapy were low. Continued efforts to optimize acute stroke systems of care should be tailored toward increasing EVT by early recognition of LVO and timely triage to hub facilities.

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Stroke Intervention: Geographic Disparities in Acute Stroke Care and the Role of Interventional Cardiology

EMJ Interventional Cardiology ◽

10.33590/emjintcardiol/20-00009 ◽

2020 ◽

Keyword(s):

Acute Stroke ◽

Case Series ◽

Intravenous Thrombolysis ◽

Interventional Cardiology ◽

Stroke Care ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Acute Stroke Care ◽

Vessel Occlusion ◽

Geographic Disparities

Stroke is the second-leading cause of death and a major cause of disability worldwide. The majority of strokes are ischaemic, and effective therapy to achieve reperfusion includes intravenous thrombolysis and, for proximal large vessel occlusion strokes, endovascular mechanical thrombectomy (MT). There has been a paradigm shift in acute stroke care, driven by a series of randomised controlled trials demonstrating that timely reperfusion with MT results in superior outcomes compared to intravenous thrombolysis in patients with large vessel occlusion strokes. There are significant geographic disparities in delivering acute stroke care because of the maldistribution of neurointerventional specialists. There are now several case series demonstrating the feasibility and safety of first medical contact MT by carotid stent-capable interventional cardiologists and noninvasive neurologists working on stroke teams, which is a solution to the uneven distribution of neurointerventionalists and allows stroke interventions to be delivered in local communities.

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Support of New Triage Protocol among Acute Stroke Care Providers

Interventional Neurology ◽

10.1159/000486459 ◽

2018 ◽

Vol 7 (5) ◽

pp. 241-245

Author(s):

Haitham M. Hussein ◽

David C. Anderson

Keyword(s):

Acute Stroke ◽

Online Survey ◽

Medical Service ◽

Stroke Care ◽

Care Providers ◽

Large Vessel Occlusion ◽

Acute Stroke Care ◽

Vessel Occlusion ◽

Triage Protocol ◽

Almost All

Objective: We conducted an online survey to gauge the acceptance of sending acute stroke patients with suspected large vessel occlusion (LVO) directly to an endovascular-capable hospital (ECH) even if that means bypassing a closer alteplase-capable hospital (ACH) without endovascular capability. Methods: The survey was composed of two cases of acute stroke, one with cortical symptoms suggestive of LVO and the other without. In each case, responders were asked to choose between triaging to a closer ACH or an ECH that is further away and to provide an opinion regarding the maximum extra travel time they would tolerate if they chose the ECH. The survey was sent electronically to national groups of neurologists, emergency department (ED) physicians, emergency medical service (EMS) directors, and stroke coordinators. Results: There were 320 responders from 44 states, most of them with 10 years or more of experience. Most of the responders, 72.5%, chose ECH for the LVO case, while 56% chose ACH for the non-LVO case. There were marked differences in responses by specialty: neurology strongly supported ECH for LVO and strongly supported ACH for non-LVO, most ED and EMS chose ECH for both cases, and stroke coordinators were the least supportive of bypassing ACH. Almost all groups agreed on 30 min as the acceptable extra transfer time to ECH. Conclusion: Among the survey responders, there is a broad acceptance of the idea of bypassing ACH and going straight to ECH when LVO is suspected; however, there is less agreement on triaging patients with non-LVO stroke.

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Therapeutic Advancements in the Endovascular Management of Acute Ischemic Stroke

Stroke: Vascular and Interventional Neurology ◽

10.1161/svin.121.000168 ◽

2021 ◽

Author(s):

Mahmoud H. Mohammaden ◽

Diogo C. Haussen ◽

Raul G. Nogueira

Keyword(s):

Ischemic Stroke ◽

Endovascular Treatment ◽

Acute Ischemic Stroke ◽

Randomized Trials ◽

Randomized Clinical Trials ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

The Past ◽

Technological Advances ◽

Device Technology

Abstract Stroke is the major cause of disability and the second leading cause of death worldwide. Acute ischemic stroke is responsible for ∼85% of all strokes, with 24% to 46% attributable to large‐vessel occlusion, which are typically associated with worse outcomes. Although the initial efforts to develop endovascular treatment for acute ischemic stroke took place over 6 decades ago, critical gaps in device technology and treatment selection existed, resulting in 3 failed randomized clinical trials published in 2013. Fortunately, devices and techniques have dramatically evolved over the past decade, leading to significant improvements in the safety, speed, and completeness of reperfusion. Since 2015, a total of 9 randomized trials have consistently demonstrated an overwhelming benefit to endovascular reperfusion. In this article, we will review the evolution of endovascular treatment for acute ischemic stroke, including the technical and technological advances as well as the perspectives in terms of patient selection and procedural and clinical outcomes of the landmark past and recent trials.

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Which Imaging Approach Should Be Used for Stroke of Unknown Time of Onset?

Stroke ◽

10.1161/strokeaha.120.032020 ◽

2021 ◽

Vol 52 (1) ◽

pp. 373-380

Author(s):

Claus Z. Simonsen ◽

Thabele M. Leslie-Mazwi ◽

Götz Thomalla

Keyword(s):

Clinical Practice ◽

Mechanical Thrombectomy ◽

Intravenous Thrombolysis ◽

Stroke Care ◽

Reperfusion Therapy ◽

Imaging Biomarkers ◽

Acute Stroke Care ◽

Vessel Occlusion ◽

Imaging Approach ◽

Different Populations

Reperfusion therapy with intravenous thrombolysis or mechanical thrombectomy is effective in improving outcome for ischemic stroke but remains underused. Patients presenting with stroke of unknown onset are a common clinical scenario and a common reason for not offering reperfusion therapy. Recent studies have demonstrated the efficacy of reperfusion therapy in stroke of unknown time of onset, when guided by advanced brain imaging. However, translation into clinical practice is challenged by variability in the available data. Comparison between studies is difficult because of use of different imaging modalities (magnetic resonance imaging or computed tomography), different imaging paradigms (imaging biomarkers of lesion age versus imaging biomarkers of tissue viability), and different populations studied (ie, both patients with large vessel occlusion or those with less severe strokes). Physicians involved in acute stroke care are faced with the key question of which imaging approach they should use to guide reperfusion treatment for stroke with unknown time of onset. In this review, we provide an overview of the available evidence for selecting and treating patients with strokes of unknown onset, based on the underlying imaging concepts. The perspective provided is from the viewpoint of the clinician seeing these patients acutely, to provide pragmatic recommendations for clinical practice.

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Bottlenecks in the Acute Stroke Care System during the COVID-19 Pandemic in Catalonia

Cerebrovascular Diseases ◽

10.1159/000516309 ◽

2021 ◽

pp. 1-9

Author(s):

Anna Ramos-Pachón ◽

Álvaro García-Tornel ◽

Mònica Millán ◽

Marc Ribó ◽

Sergi Amaro ◽

...

Keyword(s):

Acute Stroke ◽

Functional Outcome ◽

Stroke Care ◽

Care Quality ◽

Point Of View ◽

Stroke Severity ◽

Acute Stroke Care ◽

Vessel Occlusion ◽

Prehospital Delays ◽

The Impact

Introduction: The COVID-19 pandemic resulted in significant healthcare reorganizations, potentially striking standard medical care. We investigated the impact of the COVID-19 pandemic on acute stroke care quality and clinical outcomes to detect healthcare system’s bottlenecks from a territorial point of view. Methods: Crossed-data analysis between a prospective nation-based mandatory registry of acute stroke, Emergency Medical System (EMS) records, and daily incidence of COVID-19 in Catalonia (Spain). We included all stroke code activations during the pandemic (March 15–May 2, 2020) and an immediate prepandemic period (January 26–March 14, 2020). Primary outcomes were stroke code activations and reperfusion therapies in both periods. Secondary outcomes included clinical characteristics, workflow metrics, differences across types of stroke centers, correlation analysis between weekly EMS alerts, COVID-19 cases, and workflow metrics, and impact on mortality and clinical outcome at 90 days. Results: Stroke code activations decreased by 22% and reperfusion therapies dropped by 29% during the pandemic period, with no differences in age, stroke severity, or large vessel occlusion. Calls to EMS were handled 42 min later, and time from onset to hospital arrival increased by 53 min, with significant correlations between weekly COVID-19 cases and more EMS calls (rho = 0.81), less stroke code activations (rho = −0.37), and longer prehospital delays (rho = 0.25). Telestroke centers were afflicted with higher reductions in stroke code activations, reperfusion treatments, referrals to endovascular centers, and increased delays to thrombolytics. The independent odds of death increased (OR 1.6 [1.05–2.4], p 0.03) and good functional outcome decreased (mRS ≤2 at 90 days: OR 0.6 [0.4–0.9], p 0.015) during the pandemic period. Conclusion: During the COVID-19 pandemic, Catalonia’s stroke system’s weakest points were the delay to EMS alert and a decline of stroke code activations, reperfusion treatments, and interhospital transfers, mostly at local centers. Patients suffering an acute stroke during the pandemic period had higher odds of poor functional outcome and death. The complete stroke care system’s analysis is crucial to allocate resources appropriately.

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Detection of Large Vessel Occlusion Stroke in the Prehospital Setting

Stroke ◽

10.1161/strokeaha.120.033053 ◽

2021 ◽

Author(s):

Laura C.C. van Meenen ◽

Maritta N. van Stigt ◽

Arjen Siegers ◽

Martin D. Smeekes ◽

Joffry A.F. van Grondelle ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Stroke Care ◽

Prehospital Setting ◽

Large Vessel ◽

Large Vessel Occlusion ◽

User Friendliness ◽

Vessel Occlusion ◽

Comprehensive Stroke Center ◽

Stroke Center ◽

Good Diagnostic Accuracy

A reliable and fast instrument for prehospital detection of large vessel occlusion (LVO) stroke would be a game-changer in stroke care, because it would enable direct transportation of LVO stroke patients to the nearest comprehensive stroke center for endovascular treatment. This strategy would substantially improve treatment times and thus clinical outcomes of patients. Here, we outline our view on the requirements of an effective prehospital LVO detection method, namely: high diagnostic accuracy; fast application and interpretation; user-friendliness; compactness; and low costs. We argue that existing methods for prehospital LVO detection, including clinical scales, mobile stroke units and transcranial Doppler, do not fulfill all criteria, hindering broad implementation of these methods. Instead, electroencephalography may be suitable for prehospital LVO detection since in-hospital studies have shown that quantification of hypoxia-induced changes in the electroencephalography signal have good diagnostic accuracy for LVO stroke. Although performing electroencephalography measurements in the prehospital setting comes with challenges, solutions for fast and simple application of this method are available. Currently, the feasibility and diagnostic accuracy of electroencephalography in the prehospital setting are being investigated in clinical trials.

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