Endovascular therapy after intravenous t-PA versus t-PA alone for stroke

Neuroimaging in Randomized, Multi-Center Clinical Trials of Endovascular Treatment for Acute Ischemic Stroke: A Systematic Review

Appropriate use and analysis of neuroimaging techniques is an inevitable aspect of clinical trials for patients with acute ischemic stroke. Neuroimaging examinations were recently used to define the core eligibility criteria and outcomes in acute ischemic stroke research. Recent clinical trials for endovascular treatment in acute ischemic stroke have also demonstrated the efficacy or safety of endovascular treatment using various imaging modalities as well as clinical indices. Furthermore, independent imaging reviews and imaging core laboratory assessments are essential to manage and analyze imaging data in order to enhance the reliability of the outcomes. Therefore, we systematically reviewed the use of neuroimaging in recent randomized clinical trials for endovascular treatment of acute ischemic stroke in order to provide a thorough summary, which would serve as a resource guiding the use of appropriate imaging protocols and analyses in future clinical trials for acute ischemic stroke. This review will help researchers select appropriate imaging biomarkers among the various imaging protocols available and apply the selected type of imaging examination for each study in accordance with the academic purpose.

Automated MRI perfusion-diffusion mismatch estimation may be significantly different in individual patients when using different software packages

Objective

To compare two established software applications in terms of apparent diffusion coefficient (ADC) lesion volumes, volume of critically hypoperfused brain tissue, and calculated volumes of perfusion-diffusion mismatch in brain MRI of patients with acute ischemic stroke.

Methods

Brain MRI examinations of 81 patients with acute stroke due to large vessel occlusion of the anterior circulation were analyzed. The volume of hypoperfused brain tissue, ADC volume, and the volume of perfusion-diffusion mismatch were calculated automatically with two different software packages. The calculated parameters were compared quantitatively using formal statistics.

Results

Significant difference was found for the volume of hypoperfused tissue (median 91.0 ml vs. 102.2 ml; p < 0.05) and the ADC volume (median 30.0 ml vs. 23.9 ml; p < 0.05) between different software packages. The volume of the perfusion-diffusion mismatch differed significantly (median 47.0 ml vs. 67.2 ml; p < 0.05). Evaluation of the results on a single-subject basis revealed a mean absolute difference of 20.5 ml for hypoperfused tissue, 10.8 ml for ADC volumes, and 27.6 ml for mismatch volumes, respectively. Application of the DEFUSE 3 threshold of 70 ml infarction core would have resulted in dissenting treatment decisions in 6/81 (7.4%) patients.

Conclusion

Volume segmentation in different software products may lead to significantly different results in the individual patient and may thus seriously influence the decision for or against mechanical thrombectomy.

Key Points

• Automated calculation of MRI perfusion-diffusion mismatch helps clinicians to apply inclusion and exclusion criteria derived from randomized trials.

• Infarct volume segmentation plays a crucial role and lead to significantly different result for different computer programs.

• Perfusion-diffusion mismatch estimation from different computer programs may influence the decision for or against mechanical thrombectomy.

Effects of Exoskeletal Lower Limb Robot Training on the Activities of Daily Living in Stroke Patients: Retrospective Pre-Post Comparison Using Propensity Score Matched Analysis

PURPOSE

There is limited evidence of gait training using newly developed exoskeletal lower limb robot called Hybrid Assistive Limb (HAL) on the function and ability to perform ADL in stroke patients. In clinical settings, we frequently find it challenging to conduct a randomized controlled trial; thus, a large-scale observational study using propensity score analysis methods is a feasible alternative. The present study aimed to determine whether exoskeletal lower limb robot training improved the ability to perform ADL in stroke patients.

MATERIALS AND METHODS

Acute stroke patients who were admitted to our facility from April 2016 to March 2017 were evaluated in the conventional rehabilitation period (CRP) and those admitted from April 2017 to June 2019 were evaluated in the HAL rehabilitation period (HRP). We started a new gait rehabilitation program using HAL at the midpoint of these two periods. The functional outcomes or ADL ability outcomes of the patients in the CRP and the subsequent HRP were compared using propensity score matched analyses.

RESULTS

Propensity score matching analysis was performed for 108 stroke patients (63 from the CRP and 45 from the HRP), and 36 pairs were matched. The ADL ability, defined by the FIM scores and FIM score change, was significantly higher in patients admitted during the HRP. In addition, more stroke patients obtained practical walking ability during hospitalization in the HRP.

CONCLUSION

Gait training using HAL affects the ADL ability and obtaining of practical walking ability of stroke patients.

Clinical considerations and assessment of risk factors when choosing endovascular thrombectomy for acute stroke

INTRODUCTION

The advent of endovascular thrombectomy (EVT) has been a game changer for the management of acute ischemic stroke due to large vessel occlusion. However, the selection of suitable candidates for EVT remains a significant challenge.

AREAS COVERED

This review focuses on the clinical, radiological, and procedural considerations for EVT in acute stroke that assist in optimal patient selection.

EXPERT OPINION

All patients presenting with significant clinical deficits with treatable occlusions, who have salvageable brain tissue at presentation might benefit from treatment up to twenty-four hours from symptom onset. Neuroimaging tools form the backbone for this decision making.

Local tirofiban infusion for remnant stenosis in large vessel occlusion: tirofiban ASSIST study

BACKGROUND

Compared with embolic occlusions, intracranial atherosclerotic stenosis (ICAS)-related large vessel occlusions (LVOs) often require rescue treatment following mechanical thrombectomy (MT). Herein, we hypothesized that local tirofiban infusion can be effective and safe for remnant stenosis in LVO during endovascular treatment and can improve clinical outcomes.

METHODS

This observational multicenter registry study (January 2011 to February 2016) included patients with ICAS who underwent endovascular treatment for LVO within 24 h after stroke onset. An underlying fixed focal stenosis at the occlusion site observed on cerebral angiography during and after MT was retrospectively determined as a surrogate marker of ICAS. Procedural and clinical outcomes were compared between the tirofiban and non-tirofiban groups.

RESULTS

Of 118 patients, 59 received local tirofiban infusion. Compared to the non-tirofiban group, patients were older (non-tirofiban group versus tirofiban group; median, 63 years vs. 71 years, p = 0.015) and the onset-to-puncture time was longer (median, 275 min vs. 395 min, p = 0.036) in the tirofiban group. The median percent of residual stenosis prior to rescue treatment tended to be higher in the tirofiban group (80 [71-86] vs. 83 [79-90], p = 0.056). Final reperfusion success (modified Treatment In Cerebral Ischemic 2b-3) was more frequent (42.4%vs. 86.4%, p = 0.016) and post-procedure parenchymal hematoma type 2 and/or thick subarachnoid hemorrhages were less frequent (15.3%vs. 5.1%, p = 0.068) in the tirofiban group. The frequency of favorable outcomes 3 months after endovascular treatment (modified Rankin Scale 0-2) was significantly higher in the tirofiban group (32.2% vs. 52.5%, p = 0.025), and tirofiban administration was an independent predictor of favorable outcomes (odds ratio, 2.991; 95% confidence interval, 1.011-8.848; p = 0.048).

CONCLUSIONS

Local tirofiban infusion can be a feasible adjuvant treatment option for patients with ICAS-LVO.

Perfusion recovery on TTP maps after endovascular stroke treatment might predict favorable neurological outcomes

OBJECTIVES

Early recanalization and adequate collateral blood flow are surrogates for functional recovery in endovascular stroke treatment (EVT). We evaluated the prognostic value of pre- and immediate post-thrombectomy perfusion-weighted magnetic resonance imaging (PWI) parameters.

METHODS

Consecutive patients with acute ischemic stroke who underwent EVT were enrolled. Lesion volumes and their corresponding changes on diffusion-weighted (DWI) and PWI were assessed. Outcome was measured with modified Rankin Scale (mRS) at 90 days, and early neurological improvement (> 8 points improvement on National Institutes of Health Stroke Scale [NIHSS] or 0 to 1) at 7 days.

RESULTS

Fifty-two patients were enrolled. After control of initial NIHSS and recanalization status, post-thrombectomy time-to-peak (TTP) hypoperfused volume and TTP hypoperfused volume change remained independent predictors of favorable functional outcome (odds ratio [OR] = 0.13, 95% confidence interval [CI] = 0.03-0.54, p = 0.005; OR = 1.018, 95% CI = 1.00-1.03, p = 0.017), and early neurological improvement (OR = 0.20, 95% CI 0.07-0.58, p = 0.003; OR = 1.02, 95% CI = 1.00-1.03, p = 0.010). The areas under the curve of post-thrombectomy TTP hypoperfused volume and TTP hypoperfused volume change were 0.90 and 0.82 (cutoff 68 mL and 56 mL) for favorable outcome and 0.86 and 0.82 (cutoff 76 mL and 58 mL) for early neurological improvement, which had better prognostic values than other MR parameters and recanalization grades.

CONCLUSIONS

These results suggest a large amount of perfusion recovery on TTP is associated with favorable outcome as well as early neurological improvement after EVT, and may be a useful prognostic marker.

KEY POINTS

• A large amount of perfusion recovery on TTP map is associated with favorable outcome and early neurological improvement after EVT. • The best cutoff value for favorable functional outcome was 68 mL for post-EVT TTP hypoperfused volume and 56 mL decrease for TTP hypoperfused volume. • Amount of perfusion recovery on TTP map has better performance on the prediction of favorable functional recovery and early neurological improvement than other diffusion- and perfusion-weighted MRI parameters and recanalization grades.

Antithrombotic Therapy in Patients with Recent Stroke and Atrial Fibrillation

:

Atrial fibrillation (AF) is a common arrhythmia which carries a significant risk of stroke. Secondary prevention, particularly in the acute phase of stroke with anti-thrombotic therapy, has not been validated. The aim of this review is to evaluate the available evidence on the use of antithrombotic therapy in patients with recent stroke who have AF, and suggest a treatment algorithm for the various time points, taking into account both the bleeding and thrombosis risks posed at each stage.

Stroke

Stroke is a major cause of death and disability globally. Diagnosis depends on clinical features and brain imaging to differentiate between ischaemic stroke and intracerebral haemorrhage. Non-contrast CT can exclude haemorrhage, but the addition of CT perfusion imaging and angiography allows a positive diagnosis of ischaemic stroke versus mimics and can identify a large vessel occlusion target for endovascular thrombectomy. Management of ischaemic stroke has greatly advanced, with rapid reperfusion by use of intravenous thrombolysis and endovascular thrombectomy shown to reduce disability. These therapies can now be applied in selected patients who present late to medical care if there is imaging evidence of salvageable brain tissue. Both haemostatic agents and surgical interventions are investigational for intracerebral haemorrhage. Prevention of recurrent stroke requires an understanding of the mechanism of stroke to target interventions, such as carotid endarterectomy, anticoagulation for atrial fibrillation, and patent foramen ovale closure. However, interventions such as lowering blood pressure, smoking cessation, and lifestyle optimisation are common to all stroke subtypes.

Path From Clinical Research to Implementation: Endovascular Treatment of Ischemic Stroke in the Netherlands

Before 2015, endovascular treatment (EVT) for acute ischemic stroke was considered a promising treatment option. Based on limited evidence, it was performed in several dedicated stroke centers worldwide on selected patients. Since 2015, EVT for patients with intracranial large vessel occlusion has quickly been implemented as standard treatment in many countries worldwide, supported by the revised international guidelines based on solid evidence from multiple clinical trials. We describe the development in use of EVT in the Netherlands before, during, and after the pivotal EVT trials. We used data from all patients who were treated with EVT in the Netherlands from January 2002 until December 2018. We undertook a time-series analysis to examine trends in the use of EVT using Poisson regression analysis. Incidence rate ratios per year with 95% CIs were obtained to demonstrate the impact and implementation after the publication of the EVT trial results. We made regional observation plots, adjusted for stroke incidence, to assess the availability and use of the treatment in the country. In the buildup to the MR CLEAN (Multicenter Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands), a slow increase of EVT patients was observed, with 0.2% of all ischemic stroke patients receiving EVT. Before the trial results were formally announced, a statistically significant increase in EVT-treated patients per year was observed (incidence rate ratio, 1.72 [95% CI, 1.46-2.04]), and after the trial publication, an immediate steep increase was seen, followed by a more gradual increase (incidence rate ratio, 2.14 [95% CI, 1.77-2.59]). In 2018, the percentage of ischemic stroke patients receiving EVT increased to 5.8%. A well-developed infrastructure, a pragmatic approach toward the use of EVT in clinical practice, in combination with a strict adherence by the regulatory authorities to national evidence-based guidelines has led to successful implementation of EVT in the Netherlands. Ongoing efforts are directed at further increasing the proportion of stroke patients with EVT in all regions of the country.

Revascularization outcomes following acute ischemic stroke in patients taking direct oral anticoagulants: a single hospital cohort study

Successful revascularization therapy is of paramount importance in patients suffering acute ischemic stroke (AIS). However, there is currently only limited evidence on revascularization outcomes for patients suffering AIS while treated with direct oral anticoagulants (DOACs). The aim of our study was to determine the efficacy and safety of intravenous thrombolysis (IVT) and mechanical reperfusion (MeR) in AIS patients taking DOACs, and compare them to randomized clinical trials (RCTs), which included patients without DOAC treatment. In an observational cohort study, we analyzed clinical and radiological outcomes following AIS for all consecutive patients on DOAC therapy treated by IVT or MeR, between 2013 and 2019, at the University Medical Center Ljubljana. Patients in the IVT group were on dabigatran treatment and have received idarucizumab as a reversal agent prior to IVT. Patients in the MeR group had a large vessel occlusion. The primary outcome of the study was efficiency, defined as significant improvement after recanalization (National Institutes of Health Stroke Scale (NIHSS) score improvement of ≥8 points after 24 h and modified Rankin Scale (mRS) ≤2 after 3 months) and safety, defined as occurrence of symptomatic intracerebral hemorrhage (SICH) and mortality. Fifty-one DOAC-treated patients with AIS were included. Nineteen dabigatran-treated patients received IVT after reversal by idarucizumab. Thirty-two patients with a large vessel occlusion (12 on dabigatran, 12 on rivaroxaban, and 8 on apixaban) received MeR. Median NIHSS at admission was 9 in the IVT group and 17 in the MeR group. A significant clinical improvement, 24 h after revascularization (median improvement of NIHSS ≥8), occurred in 84% of patients treated with IVT and 25% of patients treated with MeR. A favorable functional outcome after 3 months (modified Rankin Scale (mRS) ≤2) occurred in 84 % of patients treated with IVT and 44% of patients treated with MeR. SICH occurred in one patient (5%) in the IVT group, and in two patients (6%) in the MeR group. In summary, in our observational study of DOAC-treated AIS patients, the level of IVT efficiency was substantially better than in the RCTs. At the same time, the results of MeR treatment were on the same level as in non-DOAC AIS patients included in the RCTs. The observed safety of IVT and MeR treatment was similar to the RCTs. We propose that thrombi in patients on dabigatran may have increased susceptibility to IVT, thereby allowing for better clinical results.

Dynamic cerebral autoregulation is an independent outcome predictor of acute ischemic stroke after endovascular therapy

Background

Endovascular therapy (EVT) is increasingly used to improve cerebral reperfusion after moderate-to-severe acute ischemic stroke (AIS). However, the influence of hemodynamic factors on clinical outcome is still unclear after EVT. Dynamic cerebral autoregulation (dCA) is an important brain reserve mechanism and is impaired after AIS. This study aimed to explore the role of dCA in predicting the outcome of AIS patients after EVT.

Methods

AIS patients with severe stenosis/occlusion of unilateral middle cerebral artery (MCA) or internal carotid and treatment with EVT were enrolled to receive dCA examinations at the 24 h, 72 h and 7th day after stroke onset. Healthy volunteers were also recruited as controls. DCA was recorded from spontaneous fluctuations of blood pressure and MCA flow velocity. Transfer function analysis was used to derive dCA parameters, including phase difference (PD) and coherence in the low-frequency range (0.06–0.12 Hz). The clinical outcome was measured using the modified Rankin Scale (mRS) at 90 days after onset. Multivariate logistic regression was performed to reveal the correlation between dCA and clinical outcomes. The receiver operation characteristics (ROC) curve was performed to determine the cut-off point of PD.

Results

A total of 62 AIS patients and 77 healthy controls were included. Compared with controls, dCA were impaired bilaterally till to 7th day after onset in patients, presenting as much lower PD value on the ipsilateral side. During follow-up, we found that PD on the ipsilateral side at 24 h after onset was significantly lower in patients with unfavourable outcome (n = 41) than those with favourable outcome (n = 21), even after adjustment of confounding factors (p = 0.009). ROC curve analysis revealed that PD < 26.93° was an independent predictor of unfavourable-outcome.

Conclusion

In AIS patients after EVT, dCA was impaired on both sides over the first 7 days. PD on the ipsilateral side at 24 h after onset is an independent unfavourable-outcome predictor for AIS after EVT.

Evolution of Stroke Thrombectomy Techniques to Optimize First-Pass Complete Reperfusion

Since 2015, endovascular therapy (EVT) has become the standard of care for acute ischemic stroke (AIS) due to large vessel occlusion. It is a safe and highly effective treatment, and its number needed to treat of 2.6 is one of the highest throughout medicine. The ultimate goal when performing EVT is to maximize chances of good outcome through achievement of fast first-pass complete reperfusion, as incomplete and delayed reperfusion increases complication rates and negatively affects outcome. Since EVT has been established as standard of care, new devices have been developed and treatment techniques have been refined. This review provides a brief overview about the rationale for and history of EVT, followed by a detailed step-by-step description of how to perform EVT using the BADDASS (BAlloon guide with large bore Distal access catheter with Dual Aspiration with Stent-retriever as Standard approach), a combined technique, which is in our opinion the safest and most effective way to achieve fast first-pass complete reperfusion. We also discuss treatment strategies for patients with simultaneous high-grade carotid stenosis/pseudoocclusion/occlusion and gaining carotid access in challenging arch anatomy, as these are commonly encountered situations in AIS, and conclude with an outlook on new technologies and future directions of EVT.

Endovascular treatment or general treatment: how should acute ischemic stroke patients choose to benefit from them the most?: A systematic review and meta-analysis

BACKGROUND

Acute ischemic stroke due to large-vessel occlusion is a leading cause of death and disability, and therapeutic time window was limited to 4.5 hour when treated with intravenous thrombolysis. It has been acknowledged that endovascular treatment (EVT) is superior to general treatment (only medication, including intravenous recombinant tissue plasminogen activator (rt-PA)) in improving the outcome of AIS since 2015. However, the benefits were limited to improvement of functional outcomes and functional independence. Hence, this meta-analysis was conducted to summarize the benefits of EVT for acute ischemic stroke, explore underlying indications of EVT for AIS patients and suggest implications for clinical practice and future research.

METHODS

A search was performed to identify eligible studies in PubMed, Scopus and Web of Science updated to February 5, 2019. Functional outcomes, the modified Rankin Scale (mRS) 0-1, mRS 0-2, all-cause mortality, symptomatic intracerebral hemorrhage and asymptomatic intracerebral hemorrhage (aICH) at 90 days were selected as outcomes. Data was pooled to calculate the odds ratio (OR) and 95% confidence interval (CI). Heterogeneity, subgroup analysis, sensitivity analysis and publication bias were also performed in this meta-analysis.

RESULTS

Eighteen studies comprising 3831 patients were included and analyzed in this meta-analysis. In comparison with general treatment, improved functional outcomes (mRS 0-1: OR = 1.68, 95% CI = 1.43-1.97, inconsistency index [I = 57%, P < .00001; mRS 0-2: OR = 1.78, 95% CI = 1.55-2.03, I = 69%, P < .00001), reduced risk of all-cause mortality (OR = 0.82, 95% CI = 0.70-0.98, I = 27%, P = .03) but higher risk of aICH (OR = 1.43, 95% CI = 1.05-1.95, I = 0%, P = .02) at 90 days were found in AIS patients treated with EVT. Age < 70, National Institutes of Health Stroke Scale ≥20 and maximum delay for invention>5 hours could improve clinical outcomes following EVT. In sensitivity analysis, it showed that 2 studies had a great influence on the pooled ORs. No potential publication bias was found in this meta-analysis.

CONCLUSION

Taken together, EVT, which led to improved functional outcomes and decreased risk of death, is superior to general treatment for AIS patients with age < 70, National Institutes of Health Stroke Scale ≥20 and maximum delay for invention>5 hours. Moreover, it suggests that "with mechanical thrombectomy" is potential favorable factor for improving aICH in comparison with general treatment.

The Future of Stroke Interventions

Mechanical thrombectomy (MT) has revolutionized the treatment of large-vessel occlusion stroke and markedly improved patient outcomes. Unfortunately, there remains a large proportion of patients that do not benefit from this technology. This review takes a look at recent and upcoming technologies that may help to increase the number of MT-treated patients, thereby improving their outcomes. To that end, an overview of digital health solutions, innovative pharmacological treatment, and futuristic robotic endovascular interventions is provided.

Biomaterials to Neuroprotect the Stroke Brain: A Large Opportunity for Narrow Time Windows

Ischemic stroke represents one of the most prevalent pathologies in humans and is a leading cause of death and disability. Anti-thrombolytic therapy with tissue plasminogen activator (t-PA) and surgical thrombectomy are the primary treatments to recanalize occluded vessels and normalize the blood flow in ischemic and peri-ischemic regions. A large majority of stroke patients are refractory to treatment or are not eligible due to the narrow time window of therapeutic efficacy. In recent decades, we have significantly increased our knowledge of the molecular and cellular mechanisms that inexorably lead to progressive damage in infarcted and peri-lesional brain areas. As a result, promising neuroprotective targets have been identified and exploited in several stroke models. However, these considerable advances have been unsuccessful in clinical contexts. This lack of clinical translatability and the emerging use of biomaterials in different biomedical disciplines have contributed to developing a new class of biomaterial-based systems for the better control of drug delivery in cerebral disorders. These systems are based on specific polymer formulations structured in nanoparticles and hydrogels that can be administered through different routes and, in general, bring the concentrations of drugs to therapeutic levels for prolonged times. In this review, we first provide the general context of the molecular and cellular mechanisms impaired by cerebral ischemia, highlighting the role of excitotoxicity, inflammation, oxidative stress, and depolarization waves as the main pathways and targets to promote neuroprotection avoiding neuronal dysfunction. In the second part, we discuss the versatile role played by distinct biomaterials and formats to support the sustained administration of particular compounds to neuroprotect the cerebral tissue at risk of damage.

Emerging Technologies in Optimizing Pre-Intervention Workflow for Acute Stroke

Over the last several years, thrombectomy for large vessel occlusions (LVOs) has emerged as a standard of care for acute stroke patients. Furthermore, the time to reperfusion has been identified as a predictor of overall patient outcomes, and much effort has been made to identify potential areas to target in enhancing preintervention workflow. As medical technology and stroke devices improve, nearly all time points can be affected, from field stroke triage to automated imaging interpretation to mass mobile stroke code communications. In this article, we review the preintervention stroke workflow with specific regard to emerging technologies in improving time to reperfusion and overall patient outcomes.

The Continued Role and Value of Imaging for Acute Ischemic Stroke

Advances in neuroimaging in the last 2 decades have revolutionized the management of acute ischemic stroke (AIS). Here we review the development of computed tomography (CT) and magnetic resonance imaging (MRI) modalities used to guide treatment of patients with AIS characterized by large vessel occlusion. In particular, we highlight recent randomized trials and their patient selection methodologies to detail the progression of these selection paradigms. With advanced imaging, distinction between at-risk penumbra and ischemic core in AIS may be performed using either CT or MRI. While limitations exist for methodologies to quantify core and penumbra, commercially available fully automated software packages provide useful information to guide treatment decisions. Randomized controlled trials implementing perfusion imaging to patient selection algorithms have demonstrated marked success in improving functional outcomes in patients with large vessel occlusions. As such, imaging has become a vital aspect of AIS treatment in selecting patients who may benefit from mechanical thrombectomy.

Health Utility Weighting of the Modified Rankin Scale: A Systematic Review and Meta-analysis

IMPORTANCE

The utility-weighted modified Rankin Scale (UW-mRS) has been proposed as a patient-centered alternative primary outcome for stroke clinical trials. However, to date, there is no clear consensus on an approach to weighting the mRS.

OBJECTIVE

To characterize the between-study variability in utility weighting of the mRS in a population of patients who experienced stroke and its implications when applied to the results of a clinical trial.

DATA SOURCES

In this systematic review and meta-analysis, MEDLINE, Embase, and PsycINFO were searched from January 1987 through May 2019 using major search terms for stroke, health utility, and mRS.

STUDY SELECTION

Original research articles published in English were reviewed. Included were studies with participants 18 years or older with ischemic or hemorrhagic stroke, transient ischemic attack, or subarachnoid hemorrhage, with mRS scores and utility weights evaluated concurrently. A total of 5725 unique articles were identified. Of these, 283 met criteria for full-text review, and 24 were included in the meta-analysis.

DATA EXTRACTION AND SYNTHESIS

PRISMA guidelines for systematic review were followed. Data extraction was performed independently by multiple researchers. Data were pooled using mixed models.

MAIN OUTCOMES AND MEASURES

The mean utility weights and 95% CIs were calculated for each mRS score and health utility scale. Geographic differences in weighting for the EuroQoL 5-dimension (EQ-5D) and Stroke Impact Scale-based UW-mRS were explored using inverse variance-weighted linear models. The results of 18 major acute stroke trials cited in current guidelines were then reanalyzed using the UW-mRS weighting scales identified in the systematic review.

RESULTS

The meta-analysis included 22 389 individuals; the mean (SD) age of participants was 65.9 (4.0) years, and the mean (SD) proportion of male participants was 58.2% (7.5%). For all health utility scales evaluated, statistically significant differences were observed between the mean utility weights by mRS score. For studies using an EQ-5D-weighted mRS, between-study variance was higher for worse (mRS 2-5) compared with better (mRS 0-1) scores. Of the 18 major acute stroke trials with reanalyzed results, 3 had an unstable outcome when using different UW-mRSs.

CONCLUSIONS AND RELEVANCE

Multiple factors, including cohort-specific characteristics and health utility scale selection, can influence mRS utility weighting. If the UW-mRS is selected as a primary outcome, the approach to weighting may alter the results of a clinical trial. Researchers using the UW-mRS should prospectively and concurrently obtain mRS scores and utility weights to characterize study-specific outcomes.

Antiplatelet therapy within 24 hours of tPA: lessons learned from patients requiring combined thrombectomy and stenting for acute ischemic stroke

Objective

Although stroke guidelines recommend antiplatelets be started 24 hours after tissue plasminogen activator (tPA), select mechanical thrombectomy (MT) patients with luminal irregularities or underlying intracranial atherosclerotic disease may benefit from earlier antiplatelet administration.

Methods

We explore the safety of early (<24 hours) post-tPA antiplatelet use by retrospectively reviewing patients who underwent MT and stent placement for acute ischemic stroke from June 2015 to April 2018 at our institution.

Results

Six patients met inclusion criteria. Median presenting and pre-operative National Institutes of Health Stroke Scale scores were 14 (Interquartile Range [IQR] 5.5–17.3) and 16 (IQR 13.7–18.7), respectively. Five patients received standard intravenous (IV) tPA and one patient received intra-arterial tPA. Median time from symptom onset to IV tPA was 120 min (IQR 78–204 min). Median time between tPA and antiplatelet administration was 4.9 hours (IQR 3.0–6.7 hours). Clots were successfully removed from the internal carotid artery (ICA) or middle cerebral artery (MCA) in 5 patients, the anterior cerebral artery (ACA) in one patient, and the vertebrobasilar junction in one patient. All patients underwent MT before stenting and achieved thrombolysis in cerebral infarction 2B recanalization. Stents were placed in the ICA (n=4), common carotid artery (n=1), and basilar artery (n=1). The median time from stroke onset to endovascular access was 185 min (IQR 136–417 min). No patients experienced symptomatic post-procedure intracranial hemorrhage (ICH). Median modified Rankin Scale score on discharge was 3.5.

Conclusions

Antiplatelets within 24 hours of tPA did not result in symptomatic ICH in this series. The safety and efficacy of early antiplatelet administration after tPA in select patients following mechanical thrombectomy warrants further study.

Critical appraisal of Bayesian dynamic borrowing from an imperfectly commensurate historical control

Bayesian dynamic borrowing designs facilitate borrowing information from historical studies. Historical data, when perfectly commensurate with current data, have been shown to reduce the trial duration and the sample size, while inflation in the type I error and reduction in the power have been reported, when imperfectly commensurate. These results, however, were obtained without considering that Bayesian designs are calibrated to meet regulatory requirements in practice and even no-borrowing designs may use information from historical data in the calibration. The implicit borrowing of historical data suggests that imperfectly commensurate historical data may similarly impact no-borrowing designs negatively. We will provide a fair appraiser of Bayesian dynamic borrowing and no-borrowing designs. We used a published selective adaptive randomization design and real clinical trial setting and conducted simulation studies under varying degrees of imperfectly commensurate historical control scenarios. The type I error was inflated under the null scenario of no intervention effect, while larger inflation was noted with borrowing. The larger inflation in type I error under the null setting can be offset by the greater probability to stop early correctly under the alternative. Response rates were estimated more precisely and the average sample size was smaller with borrowing. The expected increase in bias with borrowing was noted, but was negligible. Using Bayesian dynamic borrowing designs may improve trial efficiency by stopping trials early correctly and reducing trial length at the small cost of inflated type I error.

Efficacy of the sphingosine-1-phosphate receptor agonist fingolimod in animal models of stroke: an updated meta-analysis

Objective: Neuroinflammation is a central part of cerebral ischemia/reperfusion injury. The novel immune suppressant, fingolimod, is a promising candidate to ameliorate stroke-induced damage. Fingolimod is efficacious in experimental ischemic models, but a rigorous meta-analysis is lacking that considers how different experiment variables affect outcomes.Methods: We conducted a systematic literature review of fingolimod in stroke models, with the aim of rigorously evaluating fingolimod's effects on reducing infarct volume improving neurological outcomes. Seventeen variables were evaluated as covariates for the source of heterogeneity, and effect sizes were combined by using normalized mean difference meta-analysis to evaluate efficacy. Study quality was evaluated by the CAMARADES ten-item checklist, and publication bias was evaluated by funnel plots and Egger's tests.Results: About 123 unduplicated articles were identified in the literature research. Of these papers, 118 articles were excluded after reading titles and abstracts. Another 17 articles were selected in this study. Study quality was moderate (median = 6; interquartile range = 4), and publication bias was statistically insignificant. fingolimod reduced infarct volume by 30.4% (95% CI 22.4%-38.3%; n = 24; I² = 90.0%; p < 0.0001) and consistently enhanced neurobehavioral outcome by 34.2% (95% CI 23.1%-45.2%; n = 14; I² = 76.5%; p < 0.0001). No single factors accounted for heterogeneity.Conclusions: Our rigorous statistical evaluation confirmed the neuroprotective properties of fingolimod. New data can be used in designing future clinical trials.

Hematoma enlargement characteristics in deep versus lobar intracerebral hemorrhage

OBJECTIVE

Hematoma enlargement (HE) is associated with clinical outcomes after supratentorial intracerebral hemorrhage (ICH). This study evaluates whether HE characteristics and association with functional outcome differ in deep versus lobar ICH.

METHODS

Pooled analysis of individual patient data between January 2006 and December 2015 from a German-wide cohort study (RETRACE, I + II) investigating ICH related to oral anticoagulants (OAC) at 22 participating centers, and from one single-center registry (UKER-ICH) investigating non-OAC-ICH patients. Altogether, 1954 supratentorial ICH patients were eligible for outcome analyses, which were separately conducted or controlled for OAC, that is, vitamin-K-antagonists (VKA, n = 1186) and non-vitamin-K-antagonist-oral-anticoagulants (NOAC, n = 107). Confounding was addressed using propensity score matching, cox regression modeling and multivariate modeling. Main outcomes were occurrence, extent, and timing of HE (>33%/>6 mL) and its association with 3-month functional outcome.

RESULTS

Occurrence of HE was not different after deep versus lobar ICH in patients with non-OAC-ICH (39/356 [11.0%] vs. 36/305 [11.8%], P = 0.73), VKA-ICH (249/681 [36.6%] vs. 183/505 [36.2%], P = 0.91), and NOAC-ICH (21/69 [30.4%] vs. 12/38 [31.6%], P = 0.90). HE extent did not differ after non-OAC-ICH (deep:+59% [40-122] vs. lobar:+74% [37-124], P = 0.65), but both patients with VKA-ICH and NOAC-ICH showed greater HE extent after deep ICH [VKA-ICH, deep: +94% [54-199] vs. lobar: +56% [35-116], P < 0.001; NOAC-ICH, deep: +74% [56-123] vs. lobar: +40% [21-49], P = 0.001). Deep compared to lobar ICH patients had higher HE hazard during first 13.5 h after onset (Hazard ratio [HR]: 1.85 [1.03-3.31], P = 0.04), followed by lower hazard (13.5-26.5 h, HR: 0.46 [0.23-0.89], P = 0.02), and equal hazard thereafter (HR: 0.96 [0.56-1.65], P = 0.89). Odds ratio for unfavorable outcome was higher after HE in deep (4.31 [2.71-6.86], P < 0.001) versus lobar ICH (2.82 [1.71-4.66], P < 0.001), and only significant after small-medium (1st volume-quarter, deep: 3.09 [1.52-6.29], P < 0.01; lobar: 3.86 [1.35-11.04], P = 0.01) as opposed to large-sized ICH (4th volume-quarter, deep: 1.09 [0.13-9.20], P = 0.94; lobar: 2.24 [0.72-7.04], P = 0.17).

INTERPRETATION

HE occurrence does not differ among deep and lobar ICH. However, compared to lobar ICH, HE after deep ICH is of greater extent in OAC-ICH, occurs earlier and may be of greater clinical relevance. Overall, clinical significance is more apparent after small-medium compared to large-sized bleedings.

Prior Anticoagulation and Short- or Long-Term Clinical Outcomes in Ischemic Stroke or Transient Ischemic Attack Patients With Nonvalvular Atrial Fibrillation

Background

We aimed to clarify associations between prior anticoagulation and short‐ or long‐term clinical outcomes in ischemic stroke or transient ischemic attack patients with nonvalvular atrial fibrillation.

Methods and Results

A total of 1189 ischemic stroke or transient ischemic attack patients with nonvalvular atrial fibrillation who were hospitalized within 7 days after onset were analyzed. Of these, 813 patients (68.4%) received no prior anticoagulation, 310 (26.1%) received prior warfarin treatment with an international normalized ratio (INR) <2 on admission, 28 (2.4%) received prior warfarin treatment with an INR ≥2 on admission, and the remaining 38 (3.2%) received prior direct oral anticoagulant treatment. Prior warfarin treatment was associated with a lower risk of death or disability at 3 months compared with no prior anticoagulation (INR <2: adjusted odds ratio: 0.58; 95% CI, 0.42–0.81; P=0.001; INR ≥2: adjusted odds ratio: 0.40; 95% CI, 0.16–0.97; P=0.043) but was not associated with a lower risk of death or disability at 2 years. Prior warfarin treatment with an INR ≥2 on admission was associated with a higher risk of ischemic events within 2 years compared with no prior anticoagulation (adjusted hazard ratio: 2.94; 95% CI, 1.20–6.15; P=0.021).

Conclusions

Prior warfarin treatment was associated with a lower risk of death or disability at 3 months but was not associated with a lower risk of death or disability at 2 years in ischemic stroke or transient ischemic attack patients with nonvalvular atrial fibrillation. Prior warfarin treatment with an INR ≥2 on admission was associated with a higher risk of ischemic events within 2 years.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01581502.

Endovascular Treatment of Ischemic Stroke in a Developing Country

BACKGROUND

There is inequality in access to recent advancements in endovascular treatment of acute ischemic stroke (AIS), and Mexico is unusually sensitive to such inequality.

AIMS

To report the initial experience of the Mexican Endovascular Reperfusion Registry (MERR).

METHODS

The MERR is an academic, independent, prospective, multicenter, observational registry of patients treated with endovascular reperfusion techniques in Mexican hospitals. The registry includes information on demographic and clinical characteristics, diagnostic procedures, treatments, selected time metrics, and outcomes.

RESULTS

In all, 49 (57.1% female) patients from 8 centers were included and had the following characteristics: median National Institute of Health Stroke Scale score, 16; median Alberta Stroke Program Early CT Score score, 9; received intravenous tissue-type plasminogen activator, 49%; and treated with mechanical devices, 39 (79.6%), including 20 treated with stent retriever alone, 2 with retriever and intra-arterial thrombolysis (IAt), 10 with catheter aspiration (4 in combination with IAt), 6 with a combination of catheter aspiration and stent retriever, and 1 with IAt followed by balloon angioplasty. Recanalization (TICI 2b or better) was achieved in 69.4% of the patients. The median clot to recanalization time was 30 minutes. A modified Rankin scale ≤2 was achieved in 44.9% of the patients, and 68.2% of these were treated with stent retriever (P = .011). Procedure-related morbidity was 12.2%, 7 patients presented intracerebral hemorrhage (71.4% asymptomatic), and all-cause mortality was 6.1%.

CONCLUSIONS

Endovascular treatment of AIS in Mexico is feasible and has an efficacy comparable to that of other countries. Still, many challenges remain, especially pertaining to high costs and difficulties in equality in access to treatment.

Management of acute ischemic stroke

Stroke is the leading cause of long term disability in developed countries and one of the top causes of mortality worldwide. The past decade has seen substantial advances in the diagnostic and treatment options available to minimize the impact of acute ischemic stroke. The key first step in stroke care is early identification of patients with stroke and triage to centers capable of delivering the appropriate treatment, as fast as possible. Here, we review the data supporting pre-hospital and emergency stroke care, including use of emergency medical services protocols for identification of patients with stroke, intravenous thrombolysis in acute ischemic stroke including updates to recommended patient eligibility criteria and treatment time windows, and advanced imaging techniques with automated interpretation to identify patients with large areas of brain at risk but without large completed infarcts who are likely to benefit from endovascular thrombectomy in extended time windows from symptom onset. We also review protocols for management of patient physiologic parameters to minimize infarct volumes and recent updates in secondary prevention recommendations including short term use of dual antiplatelet therapy to prevent recurrent stroke in the high risk period immediately after stroke. Finally, we discuss emerging therapies and questions for future research.

Mechanical Thrombectomy for Acute Ischemic Stroke in Octogenarians: A Systematic Review and Meta-Analysis

Background and purpose: Multiple randomized trials have confirmed that mechanical thrombectomy (MT) is an effective treatment method for patients with acute ischemic stroke (AIS). However, evidence on the safety and efficacy of MT in elderly patients compared with younger patients is controversial. This meta-analysis is aimed to systematically compare the outcomes of elderly patients and younger patients after MT for AIS.

Methods: A systematic literature search was conducted through the PubMed, EMBASE, and Cochrane Library database. The primary outcomes were favorable functional outcome at 90 days and mortality. The secondary outcomes were symptomatic intracerebral hemorrhage (sICH) and successful recanalization rate. Odds ratios (ORs) were estimated using a random effects model.

Results: Sixteen studies published between 2014 and 2019 were included in this meta-analysis totally involving 3,954 patients. The pooled results showed that patients aged ≥80 years had worse functional outcome (OR = 0.40; 95% CI, 0.32–0.50; P < 0.001) and higher rates of mortality (OR = 2.26; 95% CI, 1.73–2.95; P < 0.001). There was a trend of higher rates of sICH in patients aged ≥80 years compared with patients aged <80 years, whereas this did not reach statistical significance (OR = 1.28; 95% CI, 0.89–1.84; P = 0.18). Furthermore, the frequency of successful recanalization was also lower in patients aged ≥80 years compared with patients aged <80 years (OR = 0.72; 95% CI, 0.55–0.95; P = 0.02). The subgroup analysis indicated that in comparison with those studies published between 2014 and 2016, elderly patients undergoing MT had better outcomes in studies published between 2017 and 2019.

Conclusion: Elderly patients undergoing MT had higher risk of mortality and worse functional outcome. Meanwhile, there was a trend toward higher rates of sICH and lower probability of achieving successful recanalization in elderly patients. These findings emphasize the need for improving the rates of successful recanalization in elderly patients with AIS. In addition, advanced technology of endovascular intervention and peri-interventional management might be associated with the prognosis in elderly patients. However, more prospective or randomized studies should be conducted to further explore this issue.

Advances in stroke medicine

In recent years, reperfusion therapies such as intravenous thrombolysis and endovascular thrombectomy for ischaemic stroke have dramatically reduced disability and revolutionised stroke management. Thrombolysis with alteplase is effective when administered to patients with potentially disabling stroke, who are not at high risk of bleeding, within 4.5 hours of the time the patient was last known to be well. Emerging evidence suggests that other thrombolytics such as tenecteplase may be even more effective. Treatment may be possible beyond 4.5 hours in patients selected using brain imaging. Endovascular thrombectomy (via angiography) effectively reduces risk of death or dependency in patients with large vessel occlusion (internal carotid, proximal middle cerebral and basilar arteries) if applied within 6 hours of the time they were last known to be well. Endovascular thrombectomy is also beneficial 6-24 hours from the last known well time in selected patients with favourable brain imaging. Thus, some patients with wake-up stroke are now treatable, and protocols for stroke need to include computed tomography (CT) perfusion scan and CT angiography as routine, in addition to the non-contrast CT brain scan. Optimised pre-hospital and emergency department systems (eg, code stroke response teams, pre-notification by ambulance, direct transport from triage to CT scanner) are essential to maximise the benefit of these strongly time-dependent therapies. Telemedicine is increasingly providing specialist guidance for these more complex treatment decisions in rural areas. Important developments in secondary stroke prevention include the use of direct oral anticoagulants or left atrial appendage occlusion for atrial fibrillation, and endovascular closure of patent foramen ovale.

The protective effect of polyethylene glycol-conjugated urokinase nanogels in rat models of ischemic stroke when administrated outside the usual time window

pH-sensitive polyethylene glycol-conjugated urokinase nanogels (PEG-UK) is a new form of urokinase (UK) nanogels that could release UK at certain pH values. In our former study, we demonstrated that the pH value in the infarcted brain significantly declined to the level that could trigger the delivery of UK from PEG-UK. Thrombolysis is recommended as the first choice for ischemic stroke within the time window. However, it is common for the patients to miss the thrombolysis time window, which is one of the major causes of bad prognosis from ischemic stroke. It remains promising for seeking therapeutic approaches for ischemic stroke by investigating potential protective reagents delivered out of the usually thrombolysis time window. In this study, the protective effect of administration of PEG-UK outside the usual time window and the underlying mechanisms were investigated. PEG-UK was administrated 2 h and a half after ischemic stroke Delayed administration of PEG-UK significantly ameliorated the severity of neurological deficits of permanent middle cerebral occlusion (pMCAO) rats and reduced the infiltration of inflammatory cells and the concentration of interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the brain tissues. The content of water and the leakage of Evans Blue (EB) in the PEG-UK group were also decreased. Maintenance of the expression of platelet-derived growth factor-C (PDGF-C) and inhibition of the upregulation of metalloproteinase proteins, low-density lipoprotein receptor-related protein (LRP), nuclear factor κB (NF-κB) p65 and cyclooxygenase-2 (Cox-2) were observed through western blotting and realtime PCR in the PEG-UK group. Besides, delayed administration of PEG-UK attenuated the up regulation of Caspase8 and Caspase9 and the cleavage of Caspase3 and poly (ADP-ribose) polymerase 1 (PARP1) in ischemic lesion sites. Moreover, PEG-UK treatment also inhibited the upregulation and phosphorylation of N-methyl-D-aspartic acid receptors (NMDARs), which has been revealed to play a vital role in mediating excito-neurotoxicity in ischemic stroke. In conclusion, through the inhibition of LRP/NF-κB/Cox-2 pathway, the Caspase cascade and activation of NMDARs, administration of PEG-UK outside the usual time window could still exert protective effects in pMCAO rats through the maintenance of the integrity of BBB and the inhibition of apoptosis and excito-neurotoxicity.

Paradigm Shift in Intra-Arterial Mechanical Thrombectomy for Acute Ischemic Stroke : A Review of Randomized Controlled Trials after 2015

Three randomized control trials (RCTs), published in 2013, investigated efficacy of mechanical thrombectomy in large vessel occlusions and did not show better results compared to intravenous (IV) recombinant tissue-type plasminogen activator (tPA) alone. However, most clinicians treating stroke consider mechanical thrombectomy as the standard treatment rather than using IV tPA alone. This paradigm shift was based on five RCTs investigating efficacy of mechanical thrombectomy in acute ischemic stroke conducted from 2010 to 2015. They demonstrated that mechanical thrombectomy was effective and safe in acute ischemic stroke with anterior circulation occlusion when performed within 6 hours of stroke onset. There are four reasons underlying the different results observed between the trials conducted in 2013 and 2015. First, the three RCTs of 2013 used low-efficiency thrombectomy devices. Second, the three RCTs used insufficient image selection criteria. Third, following the initial presentation at the hospital, reperfusion treatment required a long time. Fourth, the three RCTs showed a low rate of successful recanalization. Time is the most important factor in the treatment of acute ischemic stroke. However, current trends utilize advanced imaging techniques, such as diffusion-weighted imaging and multi-channel computer tomographic perfusion, to facilitate the detection of core infarction, penumbra, and collateral flows. These efforts demonstrate that patient selection may overcome the barriers of time in specific cases.

Institution of Code Neurointervention and Its Impact on Reaction and Treatment Times

BACKGROUND/OBJECTIVE

Various strategies have been implemented to reduce acute stroke treatment times. Recent studies have shown a significant benefit of acute endovascular therapy. The JFK Comprehensive Stroke Center instituted Code Neurointervention (NI) on May 1, 2014 for the purpose of rapidly assembling the NI team and rapidly providing acute endovascular therapy.

DESIGN/METHODS

We performed a retrospective analysis of all patients who had Code NI (Code NI group) called from May 1, 2014 to July 30, 2018 and compared them to patients who underwent acute endovascular treatment prior to initiation of the code (pre-Code NI group) between January 2012 and April 30, 2014. The following parameters were compared: door to puncture (DTP) and door to recanalization (DTR) times, as well as preprocedure NIHSS, 24-hour postprocedure NIHSS, and 90-day modified Rankin scores.

RESULTS

There were 67 pre-Code NI patients compared to 193 Code NI patients. Mean and median DTP times for pre-code NI vs Code NI patients were 161 minutes(mins) vs 115mins (p<0.0001, 31.76-58.86) and 153mins vs 112mins (p <0.0001), respectively. Mean and median DTR times were 220 mins vs 167mins (p <0.0001, 37.76-69.97) and 225mins vs 171mins (p <0.0001). Mean pre-procedure NIHSS was 16 for both groups while 24 hours post procedure NIHSS was 10.6 vs 10.8 (p =.078, 1.8-2.38). Mean 90 day mRS was 2.15 vs 1.65 (p=0.036, 0.32-0.96).

CONCLUSION

Institution of Code NI significantly improved DTP and DTR times as well as mRS at 3-months postprocedure. Rapid assembly of the NI team, rapid availability of imaging and angiography suite, and streamlining of processes, likely contribute to these differences. These lessons and more widespread institution of such codes will further aid in improving acute stroke care for patients.

Organizing Healthcare for Optimal Acute Ischemic Stroke Treatment

Stroke is a major health-care problem that represents a leading cause of death and also the top cause of disability in adulthood. In recent years there has been a significant paradigm shift in treatments for acute ischemic stroke to favor earlier reperfusion therapy, mainly using the systemic infusion of recombinant tissue plasminogen activator. Subsequent trials found that combining this treatment with endovascular therapy was effective in selected patients. The increased complexity of acute stroke treatments has resulted in a substantial reorganization of stroke care. This review reports on the evolution of acute ischemic stroke treatment and describes the main organizational models based on the hub-and-spoke system. The lack of evidence for comparisons of the effectiveness of different paradigms means that some decision-analysis models predicting the best organizational pathways are also reported, with a particular emphasis on the workflow timing in the prehospital and in-hospital settings. Major benchmarks and performance measures are also reported, focusing on the timing of interventions and rates of process indicators. Finally, future directions are illustrated, including using telemedicine for stroke, mobile stroke units, and artificial intelligence and automated machines to produce software for detecting large-vessel occlusion.

Endovascular Treatment of Acute Ischemic Stroke

급성 허혈성 뇌졸중은 심각한 후유증이나 사망에 이르는 가장 큰 원인 질환들 중 하나이다. 제2세대 혈전제거기구가 도입된 이후로 급성 허혈성 뇌졸중에서 혈관 내 재개통 치료는 급속히 발전해 왔고, 최근에는 표준 치료 중의 하나가 되었다. 이 종설에서는 급성 허혈성 뇌졸중에서 혈관 내 치료와 고식적인 치료를 무작위 배정으로 비교한 임상 연구들의 결과를 간략히 기술하고, 새로이 개정된 급성 허혈성 뇌졸중에서의 혈관 내 치료의 적응증과, 현재 혈관내 치료에 쓰이는 기구들과 방법에 대해 알아보고자 한다.

TRIAGE-STROKE: Treatment strategy In Acute larGE vessel occlusion: Prioritize IV or endovascular treatment-A randomized trial

RATIONALE

For patients with acute ischemic stroke and large vessel occlusions, intravenous thrombolysis and endovascular therapy are standard of care, but the effect of endovascular therapy is superior to intravenous thrombolysis. If a severe stroke with symptoms indicating large vessel occlusions occurs in the catchment area of a primary stroke center, there is equipoise regarding optimal transport strategy.

AIM

For patients presenting with suspected large vessel occlusions (PASS ≥ 2) and a final diagnosis of acute ischemic stroke, we hypothesize that bypassing the primary stroke center will result in an improved 90-day functional outcome.

SAMPLE SIZE

We aim to randomize 600 patients, 1:1.

DESIGN

A national investigator-driven, multi-center, randomized assessor-blinded clinical trial. The Prehospital Acute Stroke Severity Scale has been developed. It identifies most patients with large vessel occlusions in the pre-hospital setting. Patients without a contraindication for intravenous thrombolysis are randomized to either transport directly to a comprehensive stroke centers for intravenous thrombolysis and of endovascular therapy or to a primary stroke center for intravenous thrombolysis and subsequent transport to a comprehensive stroke centers for of endovascular therapy, if needed.

OUTCOMES

The primary outcome will be the 90-day modified Rankin Scale score (mRS) for all patients with acute ischemic stroke. Secondary outcomes include 90-day mRS for all randomized patients, all patients with ischemic stroke but without large vessel occlusions, and patients with hemorrhagic stroke. The safety outcomes include severe dependency or death and time to intravenous thrombolysis for ischemic stroke patients.

DISCUSSION

Study results will influence decision making regarding transport strategy for patients with suspected large vessel occlusions.

Anesthetic Management of Emergency Endovascular Thrombectomy for Acute Ischemic Stroke, Part 1: Patient Characteristics, Determinants of Effectiveness, and Effect of Blood Pressure on Outcome

In the United States, stroke ranks fifth among all causes of death and is the leading cause of serious long-term disability. The 2018 American Heart Association stroke care guidelines consider endovascular thrombectomy to be the standard of care for patients who have acute ischemic stroke in the anterior circulation when arterial puncture can be made within 6 hours of symptom onset or within 6-24 hours of symptom onset when specific eligibility criteria are satisfied. The aim of this 2-part review is to provide practical perspective on the clinical literature regarding anesthesia care of patients treated with endovascular thrombectomy. Part 1 (this article) reviews the development of endovascular thrombectomy and the determinants of endovascular thrombectomy effectiveness irrespective of method of anesthesia. The first aim of part 1 is to explain why rapid workflow and maintenance of blood pressure are necessary to help support the ischemic brain until, as a result of endovascular thrombectomy, reperfusion is accomplished. The second aim of part 1, understanding the nonanesthesia factors determining endovascular thrombectomy effectiveness, is necessary to identify numerous biases present in observational reports regarding anesthesia for endovascular thrombectomy. With this background, in part 2 (the companion to this article), the observational literature is briefly summarized, largely to identify its weaknesses, but also to develop hypotheses derived from it that have been recently tested in 3 randomized clinical trials of sedation versus general anesthesia for endovascular thrombectomy. In part 2, these 3 trials are reviewed both from a functional outcomes perspective (meta-analysis) and a methodological perspective, providing specifics regarding anesthesia and hemodynamic management. Part 2 concludes with a pragmatic approach to anesthesia decision making (sedation versus general anesthesia) and acute phase anesthesia management of patients treated with endovascular thrombectomy.

Endovascular Treatment of Acute Ischemic Stroke

PURPOSE OF REVIEW

Endovascular thrombectomy (ET), the standard of treatment for emergent large vessel occlusion (ELVO) strokes, has been subject to rigorous efforts to further improve its usage and delivery for optimised patient outcomes. This review aims to provide an outline and discussion about the recently established and emerging recommendations regarding endovascular treatment of stroke.

RECENT FINDINGS

The indications for ET have expanded continually, with perfusion imaging now enabling selection of patients presenting 6-24 h after last-known-well, and improved device and operator proficiency allowing treatment of M2-MCA occlusions and tandem occlusions. Further inclusion of paediatric patients and patients with larger infarct core or milder stroke symptoms for ET has been proposed; however, this remains unproven. This growing applicability is supported by more efficient systems of care, employing modern techniques such as telemedicine, mobile stroke units and helicopter medical services. Ongoing debate exists regarding thrombolytic agent, thrombectomy technique, anaesthesia method and the role of advanced neuroimaging, with upcoming RCTs expected to provide clarification. The journey to further improving the efficacy of ET has advanced and diversified rapidly over recent years, involving improved patient selection, increased utility of advanced neuroimaging and ongoing device redevelopment, within the setting of more efficient, streamlined systems of care. This dynamic and ongoing influx of evidence-based refinements is key to further optimising outcomes for ELVO patients.

Endovascular treatment versus standard medical treatment for vertebrobasilar artery occlusion (BEST): an open-label, randomised controlled trial

BACKGROUND

Previous randomised trials have shown an overwhelming benefit of mechanical thrombectomy for treating patients with stroke caused by large vessel occlusion of the anterior circulation. Whether endovascular treatment is beneficial for vertebrobasilar artery occlusion remains unknown. In this study, we aimed to investigate the safety and efficacy of endovascular treatment of acute strokes due to vertebrobasilar artery occlusion.

METHODS

We did a multicentre, randomised, open-label trial, with blinded outcome assessment of thrombectomy in patients presenting within 8 h of vertebrobasilar occlusion at 28 centres in China. Patients were randomly assigned (1:1) to endovascular therapy plus standard medical therapy (intervention group) or standard medical therapy alone (control group). The randomisation sequence was computer-generated and stratified by participating centres. Allocation concealment was implemented by use of sealed envelopes. The primary outcome was a modified Rankin scale (mRS) score of 3 or lower (indicating ability to walk unassisted) at 90 days, assessed on an intention-to-treat basis. The primary safety outcome was mortality at 90 days. Secondary safety endpoints included the rates of symptomatic intracranial haemorrhage, device-related complications, and other severe adverse events. The BEST trial is registered with ClinicalTrials.gov, NCT02441556.

FINDINGS

Between April 27, 2015, and Sept 27, 2017, we assessed 288 patients for eligibility. The trial was terminated early after 131 patients had been randomly assigned (66 patients to the intervention group and 65 to the control group) because of high crossover rate and poor recruitment. In the intention-to-treat analysis, there was no evidence of a difference in the proportion of participants with mRS 0-3 at 90 days according to treatment (28 [42%] of 66 patients in the intervention group vs 21 [32%] of 65 in the control group; adjusted odds ratio [OR] 1·74, 95% CI 0·81-3·74). Secondary prespecified analyses of the primary outcome, done to assess the effect of crossovers, showed higher rates of mRS 0-3 at 90 days in patients who actually received the intervention compared with those who received standard medical therapy alone in both per-protocol (28 [44%] of 63 patients with intervention vs 13 [25%] of 51 with standard therapy; adjusted OR 2·90, 95% CI 1·20-7·03) and as-treated (36 [47%] of 77 patients with intervention vs 13 [24%] of 54 with standard therapy; 3·02, 1·31-7·00) populations. The 90-day mortality was similar between groups (22 [33%] of 66 patients in the intervention vs 25 [38%] of 65 in the control group; p=0·54) despite a numerically higher prevalence of symptomatic intracranial haemorrhage in the intervention group.

INTERPRETATION

There was no evidence of a difference in favourable outcomes of patients receiving endovascular therapy compared with those receiving standard medical therapy alone. Results might have been confounded by loss of equipoise over the course of the trial, resulting in poor adherence to the assigned study treatment and a reduced sample size due to the early termination of the study.

FUNDING

Jiangsu Provincial Special Program of Medical Science.

National Institutes of Health Stroke Scale: An Alternative Primary Outcome Measure for Trials of Acute Treatment for Ischemic Stroke

Supplemental Digital Content is available in the text.

The modified Rankin Scale (mRS) at 3 months is the most commonly used primary outcome measure in stroke treatment trials, but it lacks specificity and requires long-term follow-up interviews, which consume time and resources. An alternative may be the National Institutes of Health Stroke Scale (NIHSS), early after stroke. Our aim was to evaluate whether the NIHSS assessed within 1 week after treatment could serve as a primary outcome measure for trials of acute treatment for ischemic stroke.

Acute ischaemic stroke interventions: large vessel occlusion and beyond

Care for acute ischaemic stroke is one of the most rapidly evolving fields due to the robust outcomes achieved by mechanical thrombectomy. Large vessel occlusion (LVO) accounts for up to 38% of acute ischaemic stroke and comes with devastating outcomes for patients, families and society in the pre-intervention era. A paradigm shift and a breakthrough brought mechanical thrombectomy back into the spotlight for acute ischaemic stroke; this was because five randomised controlled trials from several countries concluded that mechanical thrombectomy for acute stroke offered overwhelming benefits. This review article will present a comprehensive overview of LVO management, techniques and devices used, and the future of stroke therapy. In addition, we review our institution experience of mechanical thrombectomy for posterior and distal circulation occlusion.

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Mortality reduction after thrombectomy for acute intracranial large vessel occlusion: meta-analysis of randomized trials

Background

Thrombectomy for patients with emergent large vessel occlusion (ELVO) is currently recognized as the standard of care for appropriately selected patients. As proven in several randomized clinical trials and meta-analyses, treatment with thrombectomy lowers rates of poor functional outcomes after ELVO, compared with standard medical management. However, combined mortality rates of the most recent, high-quality clinical trials have not been collectively assessed.

Objective

The goal of this study was to assess the combined mortality rates of patients with ELVO following thrombectomy using data from the most recent, high-quality clinical trials.

Methods

Meta-analysis was performed in clinical trials comparing thrombectomy and medical management for patients with anterior circulation ELVO. Cumulative rates of mortality (mRS 6) as well as mortality or severe disability (mRS 5-6) were calculated.

Results

Ten clinical trials fit the inclusion criteria, including PISTE, REVASCAT, DAWN, THRACE, SWIFT PRIME, ESCAPE, DEFUSE 3, THERAPY, EXTEND-IA, and MR CLEAN, with 2233 patients assessed for mortality alone and 2229 for mortality or severe disability. There was a significantly reduced risk of death with thrombectomy compared with standard medical care (14.9% vs 18.3%, P=0.03; RR 0.81, 95% CI 0.67 to 0.98), as well as a reduced risk of mortality or severe disability (mRS 5–6) in ELVO patients treated with thrombectomy (21.1% vs 30.5%, P<0.0001; RR 0.69, 95% CI 0.60 to 0.80).

Conclusions

Overall, these results suggest a lower risk of death, as well as death or severe disability, in patients with ELVO treated with thrombectomy compared with medical management alone.