Projections of Endovascular Therapy-Eligible Patients With Stroke for the US Population

BACKGROUND

As stroke endovascular thrombectomy (EVT) treatment indications expand, understanding population-based EVT eligibility becomes critical for resource planning. We aimed to project current and future population-based EVT eligibility in the United States.

METHODS

We conducted a post hoc analysis of the physician-adjudicated GCNKSS (Greater Cincinnati Northern Kentucky Stroke Study; 2015 epoch), a population-based, cross sectional, observational study of stroke incidence, treatment, and outcomes across a 5-county region. All hospitalized patients ≥18 years of age with acute ischemic stroke were ascertained using the International Classification of Diseases, Ninth Revision codes 430-436 and Tenth Revision codes I60-I67 and G45-G46 and extrapolated to the US adult census 2020. We determined the rate of EVT eligibility within the GCNKSS population using time from last known well to presentation (0-5 versus 5-23 hours), presenting National Institutes of Health Stroke Scale, and prestroke modified Rankin Scale. Both conservative and liberal estimates of prevalence of large vessel occlusion and large core were then applied based on literature review (unavailable within the 2015 GCNKSS). This eligibility was then extrapolated to the 2020 US population.

RESULTS

Of the 1 057 183 adults within GCNKSS in 2015, 2741 had an ischemic stroke and 2176 had data available for analysis. We calculated that 8659 to 17 219 patients (conservative to liberal) meet the current guideline-recommended EVT criteria (nonlarge core, no prestroke disability, and National Institutes of Health Stroke Scale score ≥6) in the United States. Estimates (conservative to liberal) for expanded EVT eligibility subpopulations include (1) 5316 to 10 635 by large core; (2) 10 635 to 21 270 by mild presenting deficits with low National Institutes of Health Stroke Scale score; (3) 13 572 to 27 089 by higher prestroke disability; and (4) 7039 to 14 180 by >1 criteria. These expanded eligibility subpopulations amount to 36 562 to 73 174 patients.

CONCLUSIONS

An estimated 8659 to 17 219 adult patients in the United States met strict EVT eligibility criteria in 2020. A 4-fold increase in population-based EVT eligibility can be anticipated with incremental adoption of recent or future positive trials. US stroke systems need to be rapidly optimized to handle all EVT-eligible patients with stroke.

Effect of computed tomography vs. computed tomography perfusion on mechanical thrombectomy outcomes within 6 hours

OBJECTIVES

It is unclear which selection strategy, plain CT vs. CT perfusion (CTP), is more powerful in predicting outcome after mechanical thrombectomy (MT). We aimed to compare the effect of plain CT and CTP in predicting outcome after MT within 6 h.

METHODS

We conducted a prospective analysis of a retrospective cohort from our single-center study, which had occlusion of the internal carotid artery and middle cerebral artery up to the proximal M2 segment and received MT within 6 h. According to the Alberta Stroke Program Early CT Score (ASPECTS), patients were divided into a high-ASPECTS group (≥ 6) and a low ASPECTS group (< 6). Similarly, patients were divided into mismatch and no-mismatch groups according to the DEFUSE3 criteria for CTP. A good outcome was defined as a 90-day modified Rankin Scale (mRS) score of ≤ 3. Univariate and binary logistic regression analyses were used to investigate the association between different imaging modality and 90-day mRS score, and mortalities, respectively.

RESULTS

The high ASPECTS group included 307 patients (89.2%). The mismatch group included 189 (54.9%) patients meeting the DEFUSE3 criterion. Compared to the low ASPECTS group, the high ASPECTS group had a good outcome (odds ratio (OR), 2.285; [95% confidence interval (CI) (1.106, 4.723)], p = 0.026) and lower mortality (OR, 0.350; [95% CI (0.163, 0.752)], p = 0.007). However, there were no significant differences in good outcomes and mortality between the mismatch and no-mismatch groups.

CONCLUSIONS

Compared with plain CT, CTP does not provide additional benefits in the selection of patients suitable for MT within 6 h.

CLINICAL RELEVANCE STATEMENT

CT perfusion is not superior to plain CT for the prediction of clinical outcomes when selecting patients for mechanical thrombectomy in the first 6 h. In that clinical setting, plain CT may be safe in the absence of perfusion data.

KEY POINTS

• The advantage of CT perfusion (CTP) over CT in pre-mechanical thrombectomy (MT) screening has not been proven for patients with a large infarct core. • CTP is not better than plain CT in predicting good outcome following MT within 6 h. • Plain CT is sufficient for selecting patients suitable for MT within 6 h of large artery occlusion.

Strategies to reduce delays in delivering mechanical thrombectomy for acute ischaemic stroke - an umbrella review

Background

Mechanical thrombectomy is a time-sensitive treatment, with rapid initiation and reduced delays being associated with better patient outcomes. Several systematic reviews reported on various interventions to address delays. Hence, we performed an umbrella review of systematic reviews to summarise the current evidence.

Methods

Medline, Embase, Cochrane Library and JBI were searched for published systematic reviews. Systematic Reviews that detailed outcomes related to time-to-thrombectomy or functional independence were included. Methodological quality was assessed using the JBI critical appraisal tool by two independent reviewers.

Results

A total of 17 systematic reviews were included in the review. These were all assessed as high-quality reviews. A total of 13 reviews reported on functional outcomes, and 12 reviews reported on time-to-thrombectomy outcomes. Various interventions were identified as beneficial. The most frequently reported beneficial interventions that improved functional and time-related outcomes included: direct-to-angio-suite and using a mothership model (compared to drip-and-ship). Only a few studies investigated other strategies including other pre-hospital and teamwork strategies.

Conclusion

Overall, there were various strategies that can be used to reduce delays in the delivery of mechanical thrombectomy with different effectiveness. The mothership model appears to be superior to the drip-and-ship model in reducing delays and improving functional outcomes. Additionally, the direct-to-angiosuite approach appears to be beneficial, but further research is required for broader implementation of this approach and to determine which groups of patients would benefit the most.

Frequency and predictors of decompressive craniectomy in ischemic stroke patients treated by mechanical thrombectomy in the ETIS registry

BACKGROUND AND AIMS

Mechanical thrombectomy (MT) for patients with acute ischemic stroke (AIS) is usually performed in a comprehensive stroke center with on-site neurosurgical expertise. The question of whether MT can be performed in a primary stroke center without a neurosurgical facility is debated. In this context, there is a need to determine the frequency, delay and predictors of neurosurgical procedures in patients treated by MT. This study aims to determine these factors.

METHODS

In total, 432 patients under 60years old, diagnosed with an acute ischemic stroke with a large vessel occlusion and treated by MT between January 2018 and December 2019 in six French stroke centers, were selected from the French clinical registry ETIS. Univariate and multivariate logistic regression models were used to identify predictive factors for decompressive craniectomy.

RESULTS

Among the 432 included patients, 43 (9.9%) patients with an anterior circulation infarct underwent decompressive craniectomy. Higher admission NIHSS (OR: 1.08 [95% CI: 1.02-1.16]), lower ASPECT (OR per 1 point of decrease 1.53 [1.31-1.79] P<0.001) and preadmission antiplatelet use (OR: 3.03 [1.31-7.01]) were independent risk factors for decompressive craniectomy. The risk of decompressive craniectomy increases to more than 30% with an ASPECT score<4, an NIHSS>16, and current antiplatelet use.

CONCLUSION

In this multicenter registry, 9% of acute ischemic stroke patients (<60years old) treated with MT, required decompressive craniectomy. Higher NIHSS score, lower ASPECT score, and preadmission antiplatelet use increase the risk of subsequent requirement for decompressive craniectomy.

Differential thrombectomy utilization across hospital classifications in the United States

OBJECTIVES

To determine hospital-level factors associated with thrombectomy uptake.

MATERIALS AND METHODS

The Nationwide Emergency Department Sample was retrospectively queried to determine the total number of thrombectomies performed based on different hospital characteristics. Joint point analysis was used to determine which years were associated with significant increases in the number of high-volume thrombectomy centers (ostensibly defined as >50 thrombectomies/year), thrombectomy-capable centers (>15 thrombectomies/year), and total number of thrombectomies performed. Multivariable logistic regression was used to determine hospital factors associated with having an increased odds of performing thrombectomies, and of being classified as a high-volume thrombectomy or a thrombectomy-capable center.

RESULTS

Between 2007-2020 there was a stepwise increase in the number of thrombectomy-capable and high-volume thrombectomy centers in the United States. In 2020, there were a total of 15,705 thrombectomies performed, with 89 high-volume thrombectomy centers, and 359 thrombectomy-capable centers. The number of thrombectomy-capable centers significantly increased after 2011. After 2013 and 2016 there was a significant change in the growth rate of high-volume thrombectomy centers. There was also a significant increase in the total number of thrombectomies performed after 2016. Hospital characteristics that were associated with an increased likelihood of being classified as thrombectomy-capable or high-volume included trauma level 1 and 2 hospitals.

CONCLUSIONS

Between 2007 and 2020, there was a marked growth in thrombectomy utilization for acute ischemic stroke. This growth outpaced new diagnoses of ischemic stroke, and was driven largely by certain hospital types, with the greatest rises following seminal publications of positive randomized thrombectomy trials.

Thrombectomy with and without computed tomography perfusion imaging for large-vessel occlusion stroke in the extended time window: a meta-analysis of randomized clinical trials

Objective

In recent years, several studies have used computed tomography perfusion (CTP) to assess whether mechanical thrombectomy can be performed in patients with large-vessel occlusion (LVO) stroke in an extended time window. However, it has the disadvantage of being time-consuming and expensive. This study aimed to compare the impact of the CTP group with the non-CTP group [non-contrast CT (NCCT) ± CT angiography (CTA)] on the prognosis of this patient population.

Methods

A search of PubMed, EMBASE, and the Cochrane Library databases was conducted to collect randomized controlled trials (RCTs) comparing the two strategies. Outcome indicators and factors influencing prognosis were summarized by standardized mean differences, ratios, and relative risks with 95% confidence intervals using a random-effects model.

Results

A total of two RCTs were included in the combined analysis. There were no significant differences in the main outcome indicators (modified Rankin Scale score at 90 days, successful postoperative reperfusion rate) or the incidence of adverse events (90-day mortality and symptomatic intracranial hemorrhage) between the NCCT ± CTA and CTP groups. The time from the last puncture appeared to be significantly shorter in the NCCT ± CTA group than in the CTP group (SMD: -0.14; 95% CI: -0.24, -0.04). Among them, age (OR: 0.96; 95% CI: 0.94, 0.98), ASPECTS (OR: 1.18; 95% CI: 1.12, 1.24), NIHSS score (OR: 0.90; 95% CI: 0.89, 0.91), and diabetes (OR: 0.69; 95% CI: 0.54, 0.88) were associated with a 90-day independent functional outcome.

Conclusion

These findings suggest that the choice of NCCT ± CTA (without CTP) for the assessment of mechanical thrombectomy within 6-24 h after LVO in the anterior circulation is not significantly different from CTP; instead, the choice of NCCT ± CTA significantly reduces the time from onset to arterial puncture.

Moving from traditional to more advanced treatments in stroke care is cost-effective: A case study from Greece

OBJECTIVES

Stroke is the most common cause of disability in high-income countries. Several countries offer a limited range of advanced treatments with implications for outcomes, disability and costs. This study estimates the burden of disability that could have been avoided through the transition from traditional (no intravenous thrombolytic therapy (IVT), or endovascular thrombectomy (EVT)) to modern stroke treatments (treatment in stroke units, IVT and EVT). We perform a cost-effectiveness analysis comparing best practice with traditional stroke care, using Greece as a case study.

MATERIALS AND METHODS

A Markov model was used to calculate costs and Quality Adjusted Life Years (QALYs) for each treatment strategy, using a lifetime horizon. Data for model inputs were derived from meta-analyses of trials, and national and international cost databases. Sensitivity analyses were also performed to address potential uncertainty and test the robustness of the findings.

RESULTS

Incremental effectiveness comprised 0.22 QALYs per patient and year. Best practice was cost-effective for more than 90% of all iterations (ICER for the baseline scenario: €2,109.25/QALY). Sensitivity analysis demonstrated that the findings remain robust. Considering the stroke incidence in Greece, the annual additional cost to implement best practice was calculated to be between 0.07%-0.15% of the total health expenditure.

CONCLUSION

Best practice stroke treatment was cost-effective and affordable in a case study based on Greece. The results could be leveraged by including effects of preventive policies and rehabilitation. They also highlight the importance of adopting modern treatment strategies from a cost-effectiveness perspective, apart from the improved clinical outcomes.

Transient Middle Cerebral Artery Occlusion with an Intraluminal Suture Enables Reproducible Induction of Ischemic Stroke in Mice

Ischemic stroke is a leading cause of mortality and chronic disability worldwide, underscoring the need for reliable and accurate animal models to study this disease's pathology, molecular mechanisms of injury, and treatment approaches. As most clinical strokes occur in regions supplied by the middle cerebral artery (MCA), several experimental models have been developed to simulate an MCA occlusion (MCAO), including transcranial MCAO, micro- or macro-sphere embolism, thromboembolisation, photothrombosis, Endothelin-1 injection, and - the most common method for ischemic stroke induction in murine models - intraluminal MCAO. In the intraluminal MCAO model, the external carotid artery (ECA) is permanently ligated, after which a partially-coated monofilament is inserted and advanced proximally to the common carotid artery (CCA) bifurcation, before being introduced into the internal carotid artery (ICA). The coated tip of the monofilament is then advanced to the origin of the MCA and secured for the duration of occlusion. With respect to other MCAO models, this model offers enhanced reproducibility regarding infarct volume and cognitive/functional deficits, and does not require a craniotomy. Here, we provide a detailed protocol for the surgical induction of unilateral transient ischemic stroke in mice, using the intraluminal MCAO model. Graphic abstract: Overview of the intraluminal monofilament method for transient middle cerebral artery occlusion (MCAO) in mouse.

Stroke Center Designations, Neurointerventionalist Demand, and the Finances of Stroke Thrombectomy in the United States

PURPOSE OF THE REVIEW

This article aims to provide an update on the designation of stroke centers, neurointerventionalist demand, and cost-effectiveness of stroke thrombectomy in the United States.

RECENT FINDINGS

There are now more than 1,660 stroke centers certified by national accrediting bodies in the United States, 306 of which are designated as thrombectomy-capable or comprehensive stroke centers. Considering the amount of nationally certified centers and the number of patients with acute stroke eligible for thrombectomy, each center would be responsible for 64 to 104 thrombectomies per year. As a result, there is a growing demand placed on neurointerventionalists, who have the ability to alter the trajectory of large vessel occlusive strokes. Numbers needed to achieve functional independence after stroke thrombectomy at 90 days range from 3.2 to 7.4 patients in the early time window and 2.8 to 3.6 patients in the extended time window in appropriately selected candidates. With the low number needed to treat, in a variety of valued-based calculations and cost-effectiveness analyses, stroke thrombectomy has proved to be both clinically effective and cost-effective.

SUMMARY

Advancements in the early recognition and treatment of stroke have been paralleled by a remodeling of health care systems to ensure best practices in a timely manner. Stroke center-accrediting bodies provide oversight to safeguard these standards. As successful trial data from high volume centers transform into real-world experience, we must continue to re-evaluate cost-effectiveness, strike a balance between sufficient case volumes to maintain clinical excellence vs the burden and burnout associated with call responsibilities, and improve access to care for all.

Disparities among neurointerventionalists suggest further investigation of conscious sedation versus general anesthesia during thrombectomy for acute stroke

INTRODUCTION:

Prior retrospective and case-control studies have shown that the use of general anesthesia (GA) during endovascular therapy (EVT) for acute ischemic stroke with large vessel occlusion (AIS-LVO) was independently associated with poor clinical outcomes compared with cases performed under conscious sedation (CS). Conversely, recent small randomized clinical trials (RCT) demonstrated a trend toward better outcome in cases performed under GA.

METHODS:

We submitted an online survey to 193 Society of Vascular Interventional Neurology and 78 American Association of Neurological Surgeons and Congress of Neurological Surgeons – Cerebrovascular Section neuroendovascular practitioners. Questions were aimed at understanding the current state of anesthesia practice during EVT, and to determine if there is clinical equipoise for a large multicenter RCT comparing GA versus CS during EVT.

RESULTS:

Between March and May of 2017, we received 116 (43%) responses. Anesthesiologists were responsible for managing 96% of the GA cases as compared to only 51% of the CS cases (P < 0.0001). Notable 56% of providers reported performing less than a quarter of their cases under GA. Only 7% performed all cases under GA compared with 17% who used solely CS (P = 0.048). More than half of respondents thought a new RCT was necessary, of whom 61% were interested in participating. Among interested responders, 59% were located in centers with 3 or more neurointerventionalists.

CONCLUSION:

The significant variation among neuroendovascular providers, added with the lack of consensus among recent trials and meta-analyses, demonstrate clinical equipoise for further studies to explore the effects of anesthesia during EVT in AIS-LVO.

Non-contrast head CT alone for thrombectomy in acute ischemic stroke: analysis of the ANGEL-ACT registry

BACKGROUD

The goal of this study was to determine if the choice of imaging paradigm performed in the emergency department influences the procedural or clinical outcomes after mechanical thrombectomy (MT).

METHODS

This is a retrospective comparative outcome study which was conducted from the ANGEL-ACT registry. Comparisons were made between baseline characteristics and clinical outcomes of patients with acute ischemic stroke undergoing MT with non-contrast head computed tomography (NCHCT) alone versus patients undergoing NCHCT plus non-invasive vessel imaging (NVI) (including CT angiography (with or without CT perfusion) and magnetic resonance angiography). The primary outcome was the modified Rankin Scale (mRS) score at 90 days. Secondary outcomes included change in mRS score from baseline to 90 days, the proportions of mRS 0-1, 0-2, and 0-3, and dramatic clinical improvement at 24 hours. The safety outcomes were any intracranial hemorrhage (ICH), symptomatic ICH, and mortality within 90 days.

RESULTS

A total of 894 patients met the inclusion criteria; 476 (53%) underwent NCHCT alone and 418 (47%) underwent NCHCT + NVI. In the NCHCT alone group, the door-to-reperfusion time was shorter by 47 min compared with the NCHCT + NVI group (219 vs 266 min, P<0.001). Patients in the NCHCT alone group showed a smaller increase in baseline mRS score at 90 days (median 3 vs 2 points; P=0.004) after adjustment. There were no significant differences between groups in the remaining clinical outcomes.

CONCLUSIONS

In patients selected for MT using NCHCT alone versus NCHCT + NVI, there were improved procedural outcomes and smaller increases in baseline mRS scores at 90 days.

Cost-Effectiveness Study of Initial Imaging Selection in Acute Ischemic Stroke Care

PURPOSE

National guidelines recommend prompt identification of candidates for acute ischemic stroke (AIS) treatment, requiring timely neuroimaging with CT and/or MRI. CT is often preferred because of its widespread availability and rapid acquisition. Despite higher diagnostic accuracy of MRI, it commonly involves complex workflows that could potentially cause treatment time delays. The purpose of this study was to analyze the impact on outcomes of imaging utilization before treatment decisions at comprehensive stroke centers for patients presenting with suspected AIS in the anterior circulation with last-known-well-to-arrival time 0 to 24 hours.

METHODS

A decision simulation model based on the American Heart Association's recommendations for AIS care pathways was developed from a health care perspective to compare initial imaging strategies: (1) stepwise-CT: noncontrast CT (NCCT) at the time of presentation, with CT angiography (CTA) ± CT perfusion (CTP) only in select patients (initial imaging to exclude hemorrhage and extensive ischemia) for mechanical thrombectomy (MT) evaluation; (2) stepwise-hybrid: NCCT at the time of presentation, with MR angiography (MRA) ± MR perfusion (MRP) only for MT evaluation; (3) stepwise-advanced: NCCT + CTA at presentation, with MR diffusion-weighted imaging (MR DWI) + MRP only for MT evaluation; (4) comprehensive-CT: NCCT + CTA + CTP at the time of presentation; and (5) comprehensive-MR: MR DWI + MRA + MRP at the time of presentation. Model parameters were defined using evidence-based data. Cost-effectiveness and sensitivity analyses were performed.

RESULTS

The cost-effectiveness analyses revealed that comprehensive-CT and comprehensive-MR yield the highest lifetime quality-adjusted life-years (QALYs) (4.81 and 4.82, respectively). However, the incremental cost-effectiveness ratio of comprehensive-MR is $233,000/QALY compared with comprehensive-CT. Stepwise-CT, stepwise-hybrid, and stepwise-advanced strategies are dominated, yielding lower QALYs and higher costs compared with comprehensive-CT.

CONCLUSIONS

Performing comprehensive-CT at presentation is the most cost-effective initial imaging strategy at comprehensive stroke centers.

Expanding indications for endovascular thrombectomy-how to leave no patient behind

Endovascular thrombectomy (EVT) has become standard of care for large vessel occlusion strokes but current guidelines exclude a large proportion of patients from this highly effective treatment. This review therefore focuses on expanding indications for EVT in several borderline indications such as patients in the extended time window, patients with extensive signs of infarction on admission imaging, elderly patients and patients with pre-existing deficits. It also discusses the current knowledge on intravenous thrombolysis as an adjunct to EVT and EVT as primary therapy for distal vessel occlusions, for tandem occlusions, for basilar artery occlusions and in pediatric patients. We provide clear recommendations based on current guidelines and further literature.

Stroke Imaging Selection Modality and Endovascular Therapy Outcomes in the Early and Extended Time Windows

BACKGROUND AND PURPOSE

Advanced imaging has been increasingly used for patient selection in endovascular stroke therapy. The impact of imaging selection modality on endovascular stroke therapy clinical outcomes in extended time window remains to be defined. We aimed to study this relationship and compare it to that noted in early-treated patients.

METHODS

Patients from a prospective multicentric registry (n=2008) with occlusions involving the intracranial internal carotid or the M1- or M2-segments of the middle cerebral arteries, premorbid modified Rankin Scale score 0 to 2 and time to treatment 0 to 24 hours were categorized according to treatment times within the early (0-6 hour) or extended (6-24 hour) window as well as imaging modality with noncontrast computed tomography (NCCT)±CT angiography (CTA) or NCCT±CTA and CT perfusion (CTP). The association between imaging modality and 90-day modified Rankin Scale, analyzed in ordinal (modified Rankin Scale shift) and dichotomized (functional independence, modified Rankin Scale score 0-2) manner, was evaluated and compared within and across the extended and early windows.

RESULTS

In the early window, 332 patients were selected with NCCT±CTA alone while 373 also underwent CTP. After adjusting for identifiable confounders, there were no significant differences in terms of 90-day functional disability (ordinal shift: adjusted odd ratio [aOR], 0.936 [95% CI, 0.709-1.238], P=0.644) or independence (aOR, 1.178 [95% CI, 0.833-1.666], P=0.355) across the CTP and NCCT±CTA groups. In the extended window, 67 patients were selected with NCCT±CTA alone while 180 also underwent CTP. No significant differences in 90-day functional disability (aOR, 0.983 [95% CI, 0.81-1.662], P=0.949) or independence (aOR, 0.640 [95% CI, 0.318-1.289], P=0.212) were seen across the CTP and NCCT±CTA groups. There was no interaction between the treatment time window (0-6 versus 6-24 hours) and CT selection modality (CTP versus NCCT±CTA) in terms of functional disability at 90 days (P=0.45).

CONCLUSIONS

CTP acquisition was not associated with better outcomes in patients treated in the early or extended time windows. While confirmatory data is needed, our data suggests that extended window endovascular stroke therapy may remain beneficial even in the absence of advanced imaging.

Acute ischemic stroke endovascular therapy

Endovascular therapy (EVT) has become the standard treatment for large-vessel occlusion (LVO) acute ischemic stroke (AIS). EVT is now indicated in patients up to 24h from their last known well, provided that the patient meets specific clinical and imaging criteria. Improvements in thrombectomy devices, techniques, and operator experience have allowed successful EVT of ICA terminus, M1-MCA occlusions as well as proximal M2-MCA, basilar artery occlusions, and revascularization of tandem lesions. Mechanical thrombectomy failures still occur due to several factors, however, highlighting the need for further device and technical improvements. An ongoing debate exists regarding the need for pre-EVT thrombolytic agents, thrombectomy techniques, distal occlusions, anesthesia methods, the role of advanced neuroimaging, the treatment of patients with larger infarct core, and those presenting with milder stroke symptoms. Many of these questions are the subject of current or upcoming clinical trials. This review aims to provide an outline and discussion about the established recommendations and emerging topics regarding EVT for LVO AIS.

Public health and cost consequences of time delays to thrombectomy for acute ischemic stroke

OBJECTIVE

To determine public health and cost consequences of time delays to endovascular thrombectomy (EVT) for patients, health care systems, and society, we estimated quality-adjusted life-years (QALYs) of EVT-treated patients and associated costs based on times to treatment.

METHODS

The Markov model analysis was performed from US health care and societal perspectives over a lifetime horizon. Contemporary data from 7 trials within the Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials (HERMES) collaboration served as data source. Aside from cumulative lifetime costs, we calculated the net monetary benefit (NMB) to determine the economic value of care. We used a contemporary willingness-to-pay threshold of $100,000 per QALY for NMB calculations.

RESULTS

Every 10 minutes of earlier treatment resulted in an average gain of 39 days (95% prediction interval 23-53 days) of disability-free life. Overall, the cumulative lifetime costs for patients with earlier or later treatment were similar. Patients with later treatment had higher morbidity-related costs but over a shorter time span due to their shorter life expectancy, resulting in similar lifetime costs as in patients with early treatment. Regarding the economic value of care, every 10 minutes of earlier treatment increased the NMB by $10,593 (95% prediction interval $5,549-$14,847) and by $10,915 (95% prediction interval $5,928-$15,356) taking health care and societal perspectives, respectively.

CONCLUSIONS

Any time delay to EVT reduces QALYs and decreases the economic value of care provided by this intervention. Health care policies to implement efficient prehospital triage and to accelerate in-hospital workflow are urgently needed.

Do you want to perform endovascular therapy? Perspectives from neurology trainees across Europe

BACKGROUND AND PURPOSE

Endovascular therapy (EVT) has become standard care for acute ischaemic stroke caused by large-vessel occlusion in the anterior circulation. However, access to this treatment in Europe remains poor. The lack of operators is a contributing factor and there is on-going discussion as to whether other specialists, including neurologists, could contribute to the EVT workforce. The question remains whether the next generation of neurologists want to become 'interventional neurologists'. The aim of this study was to address this question.

METHODS

We conducted a short survey within the National Representatives Network (a division of the Resident and Research Fellow Section, European Academy of Neurology) in order to determine the interest of future neurologists in performing EVT.

RESULTS

A total of 1218 responses from 27 European countries were received, with some variation in the number of respondents and results among individual countries. In total, 568 neurology trainees (47%) stated that they would want to be an 'interventional neurologist'.

CONCLUSION

Our findings suggest that neurologists could make a significant contribution to the workforce performing EVT and have important implications for the development and uptake of training programmes in Europe.

Large Vessel Occlusion in Acute Ischemic Stroke Patients: A Dual-Center Estimate Based on a Broad Definition of Occlusion Site

BACKGROUND

Accurate assessment of the frequency of large vessel occlusion (LVO) is important to determine needs for neurointerventionists and thrombectomy-capable stroke facilities. Current estimates vary from 13% to 52%, depending on acute ischemic stroke (AIS) definition and methods for AIS and LVO determination. We sought to estimate LVO prevalence among confirmed and suspected AIS patients at 2 comprehensive US stroke centers using a broad occlusion site definition: internal carotid artery (ICA), first and second segments of the middle cerebral artery (MCA M1,M2), the anterior cerebral artery, vertebral artery, basilar artery, or the proximal posterior cerebral artery.

METHODS

We analyzed prospectively maintained stroke databases of patients presenting to the centers between January and December 2017. ICD-10 coding was used to determine the number of patients discharged with an AIS diagnosis. Computed tomography angiography (CTA) or magnetic resonance angiography (MRA) was reviewed to determine LVO presence and site. Percentages of patients with LVO among the confirmed AIS population were reported.

RESULTS

Among 2245 patients with an AIS discharge diagnosis, 418 (18.6%:95% confidence interval [CI] 17.3%-20.0%) had LVO documented on CTA or MRA. Most common occlusion site was M1 (n=139 [33.3%]), followed by M2 (n=114 [27.3%]), ICA (n=69[16.5%]), and tandem ICA-MCA lesions (n=44 [10.5%]). Presentation National Institutes of Health Stroke Scale scores were significantly different for different occlusion sites (P=.02).

CONCLUSIONS

The LVO prevalence in our large series of consecutive AIS patients was 18.6% (95% CI 17.3%-20.0%). Despite the use of a broad definition, this estimate is less than that reported in most previous studies.

Outcomes associated with endovascular treatment among patients with acute ischemic stroke in the USA

BACKGROUND

Few studies have examined the trends in clinical and economic outcomes of patients with acute ischemic stroke (AIS) who receive endovascular therapy (ET) in the real-world setting.

OBJECTIVE

To evaluate characteristics and trends in clinical and economic outcomes among commercially insured patients with AIS undergoing ET between 2011 and 2017.

METHODS

Patients with AIS undergoing ET from January 1, 2011 to June 30, 2017 were identified from administrative claims contained in the IBM MarketScan Commercial and Medicare Supplemental databases. The Mann-Kendall trend test was performed to examine clinical and economic trends.Between 2011 and 2017, 3411 patients (mean age 62.85±15 years) with a primary diagnosis of AIS underwent ET (coverage: Commercial 59%, n=2008; Medicare Supplemental 41%, n=1403). In the Commercial cohort, discharge to home increased significantly (from 29.54% to 39.18%, p<0.05). Length of stay declined significantly among the overall cohort (from 10.96 to 9.05 days, p<0.01) and the Medicare Supplemental cohort (from 10.03 to 8.43 days, p<0.05). All-cause 365-day readmission decreased significantly among the overall cohort (from 47.5% to 36.7%, p<0.05) and the Commercial cohort (from 51.54% to 36.43%, p<0.05) but remained unchanged in the Medicare Supplemental cohort. While index procedure cost did not change significantly ($93 955 to $87 906, p=0.8806), total cost significantly declined in the overall cohort (from $166 922 to $130 678, p<0.05).

CONCLUSIONS

Although with some variation across the samples studied, outcomes including discharge to home, length of stay, readmission, and total cost associated with endovascular stroke therapy seemed to have improved between 2011 and 2017. Index admission cost remained unchanged.

Effect of definition and methods on estimates of prevalence of large vessel occlusion in acute ischemic stroke: a systematic review and meta-analysis

Introduction

Accurate estimation of the incidence of large vessel occlusion (LVO) is critical for planning stroke systems of care and approximating workforce requirements. This systematic review aimed to estimate the prevalence of LVO among patients with acute ischemic stroke (AIS), with emphasis on definitions and methods used by different studies.

Methods

A systematic literature review was performed to search for articles on the prevalence of LVO and AIS. All articles describing the frequency of LVO frequency among AIS patients were included. Studies without consecutive recruitment or confirmation of LVO with CT angiography or MR angiography were excluded. Heterogeneity of the studies was assessed; meta-regression was performed to estimate the effect of LVO definition and study methods on LVO prevalence.

Results

18 articles met the inclusion criteria: 5 studies presented population based estimates; 13 provided single hospital experiences (5 prospective, 8 retrospective). The AIS denominator (number of all AIS) from which LVO rates were generated was variable. Nine different definitions were used, based on occlusion site. Significant heterogeneity existed among the studies (I2=99%, P<0.001). The prevalence of LVO among patients with suspected AIS ranged from 13% to 52%. Overall prevalence was 30.0% (95% CI 25.0% to 35.0%). Pooled prevalence of LVO among suspected AIS patients was 21% (95% CI 19% to 30%). Based on meta-regression, the method of AIS denominator determination significantly influenced heterogeneity (P=0.018).

Conclusion

The heterogeneity of LVO estimates was remarkably high. The method of AIS denominator determination was the most significant predictor of LVO estimates. Studies with a standardized LVO definition and methods of AIS estimation are necessary to estimate the true prevalence of LVO among patients with AIS.

Prevalence and Temporal Distribution of Fast and Slow Progressors of Infarct Growth in Large Vessel Occlusion Stroke

Background and Purpose—

Fast and slow progressors of infarct growth due to anterior circulation large vessel occlusion are commonly observed in clinical practice. We aimed to estimate the prevalence and temporal distribution of fast and slow progressors among anterior circulation large vessel occlusion patients diagnosed within 24 hours of stroke onset.

Methods—

Single-center retrospective study of all patients with anterior circulation large vessel occlusion who underwent baseline computed tomographic perfusion or magnetic resonance imaging within 24 hours of stroke onset. Prevalence was determined for fast progressors (ischemic core >70 mL, <6 hours of stroke onset) and slow progressors (ischemic core ≤30 mL, >6–24 hours of stroke onset).

Results—

One hundred eighty-five patients were included. The median time interval from stroke onset to baseline core imaging was 7.6 hours (interquartile range, 3.9–13.2), and median core volume was 17 mL (range, 0–405). Patients had core volume ≤70 mL in 72% of cases in the overall cohort. The prevalence of fast progressors was 25% (95% CI, 17%–37%) and reached 40% (95% CI, 24%–59%) between 3 and 4.5 hours after stroke onset. The prevalence of slow progressors was 55% (95% CI, 46%–64%) and was similar across time intervals beyond 6 hours after stroke onset.

Conclusions—

Most anterior circulation large vessel occlusion patients had small-to-moderate ischemic core volume, irrespective of early or delayed presentation within 24 hours of stroke onset. Fast progressors were highly prevalent between 3 and 4.5 hours after stroke onset.

Real-world stent retriever thrombectomy for acute ischemic stroke beyond 6 hours of onset: analysis of the NASA and TRACK registries

Background

The DEFUSE 3 and DAWN trials have shown the benefit of thrombectomy beyond 6 hours of stroke symptom onset in carefully selected patients.

Objective

To evaluate the real-world outcomes of stent retriever thrombectomy beyond 6 hours of stroke onset using combined individual patient data from the North American Solitaire Stent Retriever Acute Stroke (NASA) and Trevo Stent-Retriever Acute Stroke (TRACK) registries.

Methods

Pooled analysis of individual patient data of all cases of anterior circulation acute ischemic stroke (AIS) from NASA and TRACK was performed to compare outcomes of patients presenting within the first hours 6 or beyond 6 hours of stroke symptom onset.

Results

Of 830 patients with anterior circulation AIS from the NASA and TRACK registries, 32.7% (271 patients) underwent thrombectomy beyond the first 6 hours of symptom onset. The rates of good clinical outcome (modified Rankin scale score of 0–2 at 90 days), mortality, and symptomatic intracranial hemorrhage were similar: 48.1%, 20.6%, and 8.0% within 0–6 hours, 46.2%, 21.6%, and 10.9% within 6–16 hours, and 38.9%, 33.3%, and 5% within 16–24 hours (p=0.8, 0.6, and 0.5, respectively). The rates of successful recanalization (Thrombolysis in Cerebral Infarction 2b/3) were 79.4% in patients with stroke within 0–6 hours, 72.6% within 6–16 hours, and 85.0% within 16–24 hours (p=0.04).

Conclusions

Real-world experience with patients with anterior circulation AIS treated with the Solitaire and Trevo thrombectomy devices beyond the first 6 hours of symptom onset proved to be equally safe and effective as for patients with symptom onset within the first 6 hours.

[Imaging in acute ischemic stroke using automated postprocessing algorithms]

There are several automated analytical methods to detect thromboembolic vascular occlusions, the infarct core and the potential infarct-endangered tissue (tissue at risk) by means of multimodal computed tomography (CT) and magnetic resonance imaging (MRI). The infarct core is more reliably visualized by diffusion-weighted imaging (DWI) MRI or CT perfusion than by native CT. The extent of tissue at risk and endangerment can only be estimated; however, it seems essential whether "tissue at risk" actually exists. To ensure consistent patient care, uniform imaging protocols should be acquired in the referring hospital and thrombectomy center and the collected data should be standardized and automatically evaluated and presented. Whether patients with a large infarct core and with or without tissue at risk or patients with large vessel occlusion (LVO) but low NIHSS benefit from thrombectomy has to be evaluated in controlled clinical trials using standardized imaging protocols. A promising, potentially time-saving approach is also native CT and CT angiography using a flat-panel detector angiography system for assessment of vessel occlusion and leptomeningeal collaterals.