Clinical Policy: Use of Intravenous Tissue Plasminogen Activator for the Management of Acute Ischemic Stroke in the Emergency Department

Minimally Invasive Surgery With Thrombolysis for Intracerebral Hemorrhage Evacuation: Bayesian Reanalysis of a Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Bayesian analysis of randomized controlled trials (RCTs) can extend the value of trial data beyond interpretations based on conventional p value-based binary cutoffs. We conducted an exploratory post hoc Bayesian reanalysis of the minimally invasive surgery with thrombolysis for intracerebral hemorrhage (ICH) evacuation (MISTIE-3) trial and derived probabilities of potential intervention effect on functional and survival outcomes.

METHODS

MISTIE-3 was a multicenter phase 3 RCT designed to evaluate the efficacy and safety of the MISTIE intervention. Five hundred and six adults (18 years or older) with spontaneous, nontraumatic, supratentorial ICH of ≥30 mL were randomized to receive either the MISTIE intervention (n = 255) or standard medical care (n = 251). We provide Bayesian-derived estimates of the effect of the MISTIE intervention on achieving a good 365-day modified Rankin Scale score (mRS score 0-3) as relative risk (RR) and absolute risk difference (ARD), and the probabilities that these treatment effects are greater than prespecified thresholds. We used 2 sets of prior distributions: (1) reference priors, including minimally informative, enthusiastic, and skeptical priors, and (2) data-derived prior distribution, using a hierarchical random effects model. We additionally evaluated the potential effects of the MISTIE intervention on 180-day and 30-day mRS and 365-, 180-, and 30-day mortality using data-derived priors.

RESULTS

The Bayesian-derived probability that MISTIE intervention has any beneficial effect (RR >1) on achieving a good 365-day mRS score was 70% using minimally informative prior, 87% with enthusiastic prior, 68% with skeptical prior, and 73% with data-derived prior. However, these probabilities were ≤55% for RR >1.10 and 0% for RR >1.52 across a range of priors. The probabilities of achieving RR >1 for 180- and 30-day mRS scores are 65% and 80%, respectively. Furthermore, the probabilities of achieving RR <1 for 365-, 180-, and 30-day mortality are 93%, 98%, and 99%, respectively.

DISCUSSION

Our exploratory analyses indicate that across a range of priors, the Bayesian-derived probability of MISTIE intervention having any beneficial effect on 365-day mRS for patients with ICH is between 68% and 87%. These analyses do not change the frequentist-based interpretation of the trial. However, unlike the frequentist p values, which indirectly evaluate treatment effects and only provide an arbitrary binary cutoff (such as 0.05), the Bayesian framework directly estimates the probabilities of potential treatment effects.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov/ct2/show/NCT01827046.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that minimally invasive surgery (MIS) + recombinant tissue plasminogen activator (rt-PA) does not significantly improve functional outcome in patients with ICH. However, this study lacks the precision to exclude a potential benefit of MIS + rt-PA.

A systematic review and synthesis of global stroke guidelines on behalf of the World Stroke Organization

BACKGROUND

There are multiple stroke guidelines globally. To synthesize these and summarize what existing stroke guidelines recommend about the management of people with stroke, the World Stroke Organization (WSO) Guideline committee, under the auspices of the WSO, reviewed available guidelines.

AIMS

To systematically review the literature to identify stroke guidelines (excluding primary stroke prevention and subarachnoid hemorrhage) since 1 January 2011, evaluate quality (The international Appraisal of Guidelines, Research and Evaluation (AGREE II)), tabulate strong recommendations, and judge applicability according to stroke care available (minimal, essential, advanced).

SUMMARY OF REVIEW

Searches identified 15,400 titles; 911 texts were retrieved, 200 publications scrutinized by the three subgroups (acute, secondary prevention, rehabilitation), and recommendations extracted from most recent version of relevant guidelines. For acute treatment, there were more guidelines about ischemic stroke than intracerebral hemorrhage; recommendations addressed pre-hospital, emergency, and acute hospital care. Strong recommendations were made for reperfusion therapies for acute ischemic stroke. For secondary prevention, strong recommendations included establishing etiological diagnosis; management of hypertension, weight, diabetes, lipids, and lifestyle modification; and for ischemic stroke, management of atrial fibrillation, valvular heart disease, left ventricular and atrial thrombi, patent foramen ovale, atherosclerotic extracranial large vessel disease, intracranial atherosclerotic disease, and antithrombotics in non-cardioembolic stroke. For rehabilitation, there were strong recommendations for organized stroke unit care, multidisciplinary rehabilitation, task-specific training, fitness training, and specific interventions for post-stroke impairments. Most recommendations were from high-income countries, and most did not consider comorbidity, resource implications, and implementation. Patient and public involvement was limited.

CONCLUSION

The review identified a number of areas of stroke care where there was strong consensus. However, there was extensive repetition and redundancy in guideline recommendations. Future guideline groups should consider closer collaboration to improve efficiency, include more people with lived experience in the development process, consider comorbidity, and advise on implementation.

Effectiveness and safety of the Trevo® Retriever for mechanical thrombectomy in Chinese patients with acute ischemic stroke: Trevo Retriever China Registry

BACKGROUND

To quantify the effectiveness and safety of the Trevo® Retriever for endovascular treatment of acute ischemic stroke (AIS) patients in China.

METHODS

Trevo Retriever Registry (China) was a prospective, multicenter, non-comparative, open-label study of patients with AIS treated with the Trevo Retriever. The primary outcome was the proportion of patients achieving an expanded Thrombolysis in Cerebral Infarction (eTICI) score ≥2b at the end of endovascular treatment. Secondary outcomes included first-pass eTICI score ≥2b and 90-day modified Rankin Scale (mRS) score ≤2.

RESULTS

The Trevo Retriever Registry (China) enrolled and followed 201 patients (62.1 ± 12.5 years-old; 70.6% male) at 11 centers. The pre-procedure NIHSS score and ASPECTS were 16 (interquartile range (IQR), 13-21) and 7 (IQR, 6-9), respectively, and 188 (93.5%) patients had an mRS score of 0 prior to the stroke. The main stroke etiology was large artery atherosclerosis, accounting for 71.6% (144/201) of patients. Post-procedure eTICI ≥2b was 98.4% (187/190). First-pass eTICI ≥2b was 74.7% (136/182). The 90-day good outcome (mRS ≤2) rate was 73.6% (148/201). The 90-day all-cause mortality was 5.5% (11/201). Neurological deterioration at 24 h post-procedure was observed in 7.7% (15/195) patients. Embolism in a new territory was seen in one patient (0.5%). Two (1.0%) procedure-related adverse events (AEs) occurred, which were intra-procedure cerebral artery embolism. No Trevo related AEs occurred.

CONCLUSIONS

This real-world study of the Trevo Retriever in China demonstrated a high rate of revascularization and first-pass success that resulted in an overall high good function outcome rate and low mortality.

Hidden Telltale Signs in Hyperacute Ischemic Stroke Caused by Aortic Dissection: A Case Report and Post Hoc Analysis

INTRODUCTION

Rapid identification of hidden telltale signs in hyperacute ischemic stroke caused by aortic dissection (AD) is challenging, mainly owing to the narrow time window for bridging therapy.

CASE REPORT

A 63-year-old man was referred for sudden right-side weakness accompanied by a decreased level of consciousness for almost 1 hour and 37 minutes. He had a history of hypertension. His skin was clammy, and on physical examination, there was involuntary chest thumping in the left upper limb. Hyperacute cerebral infarction was considered after no bleeding was observed on emergency head computed tomography, and intravenous thrombolysis with alteplase was administered immediately after. The patient was then taken to the catheter room, ready for endovascular thrombectomy. Stanford type A AD was found by cerebral angiography before endovascular thrombectomy. The infusion of alteplase was stopped immediately during cerebral angiography, but the patient's blood pressure, heart rate, and blood oxygen were still declining progressively, and the degree of consciousness disturbance deepened. The patient died after the combined but failed rescue attempts of multiple departments.

CONCLUSION

Hyperacute ischemic stroke caused by AD often hides some telltale signs. Clinicians should master basic clinical skills to exclude AD by looking for these telltale signs hidden in hyperacute ischemic stroke to avoid the fatal consequences of intravenous thrombolysis and/or cerebral angiography within the narrow window of time.

Stroke or No Stroke: A Case Report of Bilingual Aphasia

Introduction

Bilingual aphasia is an atypical stroke presentation in the multilingual patient where an isolated aphasia occurs in one language while the other remains unaffected.

Case Report

A multilingual male presented to the emergency department with expressive aphasia to English but who was still able to speak fluently in French. Receptive English was preserved. While his National Institute of Health Stroke Scale score was technically zero, his pure aphasia component qualified him as an exception. He regained some repetitive English, so fibrinolyitic therapy was not initiated.

Conclusion

Bilingual aphasia is an indication for fibrinolysis given the impact that a pure aphasic stroke has on quality of life.

Potential accuracy of prehospital NIHSS-based triage for selection of candidates for acute endovascular stroke therapy

OBJECTIVE

Whether patients with acute stroke and large vessel occlusion (LVO) benefit from prehospital identification and diversion by emergency medical services (EMS) to an endovascular stroke therapy (EST)-capable center is controversial. We sought to estimate the accuracy of field-based identification of potential EST candidates in a hypothetical best-of-all-worlds situation.

METHODS

In Kaiser Permanente Northern California, all acute stroke patients arriving at its 21 stroke centers between 7:00 am and midnight from January 2016 to December 2019 were evaluated by teleneurologists on arrival. Initial National Institutes of Health Stroke Scale (NIHSS) score, presence of LVO, and referral for EST were obtained from standardized teleneurology notes. Factors associated with LVO were evaluated using generalized estimating equations accounting for clustering by facility.

RESULTS

Among 13,377 patients brought in by EMS with potential stroke, 7168 (53.6%) were not candidates for acute stroke interventions. Of the remaining 6089 cases, 2,573 (42.3%) had an NIHSS score >10, the cutoff with a higher association for LVO. Only 703 patients (27.3% with NIHSS score >10) were ultimately diagnosed with LVO and referred for EST. Across all NIHSS scores, only 884 (6.6%) suspected acute stroke patients had LVO and EST referral.

CONCLUSIONS

Even if field-based tools were as accurate as NIHSS scoring and predictions by stroke neurologists, only about 1 in 4 acute stroke patients diverted to EST-capable centers would benefit by receiving EST. Depending on geography and stroke center performance on door-to-needle time, many systems may be better served by focusing on expediting evaluation, treatment with intravenous thrombolysis, and transfer to EST-capable centers.

Novel Treatments for Transient Ischemic Attack and Acute Ischemic Stroke

The treatment of acute ischemic stroke is one of the most rapidly evolving areas in medicine. Like all ischemic vascular emergencies, the priority is reperfusion before irreversible infarction. The central nervous system is sensitive to brief periods of hypoperfusion, making stroke a golden hour diagnosis. Although the phrase "time is brain" is relevant today, emerging treatment strategies use more specific markers for consideration of reperfusion than time alone. Innovations in early stroke detection and individualized patient selection for reperfusion therapies have equipped the emergency medicine clinician with more opportunities to help stroke patients and minimize the impact of this disease.

Thrombolysis with alteplase 3-4.5 hours after acute ischaemic stroke: trial reanalysis adjusted for baseline imbalances

OBJECTIVES

Alteplase is commonly recommended for acute ischaemic stroke within 4.5 hours after stroke onset. The Third European Cooperative Acute Stroke Study (ECASS III) is the only trial reporting statistically significant efficacy for clinical outcomes for alteplase use 3-4.5 hours after stroke onset. However, baseline imbalances in history of prior stroke and stroke severity score may confound this apparent finding of efficacy. We reanalysed the ECASS III trial data adjusting for baseline imbalances to determine the robustness or sensitivity of the efficacy estimates.

DESIGN

Reanalysis of randomised placebo-controlled trial. We obtained access to the ECASS III trial data and replicated the previously reported analyses to confirm our understanding of the data. We adjusted for baseline imbalances using multivariable analyses and stratified analyses and performed sensitivity analysis for missing data.

SETTING

Emergency care.

PARTICIPANTS

821 adults with acute ischaemic stroke who could be treated 3-4.5 hours after symptom onset.

INTERVENTIONS

Intravenous alteplase (0.9 mg/kg of body weight) or placebo.

MAIN OUTCOME MEASURES

The original primary efficacy outcome was modified Rankin Scale (mRS) score 0 or 1 (ie, being alive without any disability) and the original secondary efficacy outcome was a global outcome based on a composite of functional end points, both at 90 days. Adjusted analyses were only reported for the primary efficacy outcome and the original study protocol did not specify methods for adjusted analyses. Our adjusted reanalysis included these outcomes, symptom-free status (mRS 0), dependence-free status (mRS 0-2), mortality (mRS 6) and change across the mRS 0-6 spectrum at 90 days; and mortality and symptomatic intracranial haemorrhage at 7 days.

RESULTS

We replicated previously reported unadjusted analyses but discovered they were based on a modified interpretation of the National Institutes of Health Stroke Scale (NIHSS) score. The secondary efficacy outcome was no longer significant using the original NIHSS score. Previously reported adjusted analyses could only be replicated with significant effects for the primary efficacy outcome by using statistical approaches not reported in the trial protocol or statistical analysis plan. In analyses adjusting for baseline imbalances, all efficacy outcomes were not significant, but increases in symptomatic intracranial haemorrhage remained significant.

CONCLUSIONS

Reanalysis of the ECASS III trial data with multiple approaches adjusting for baseline imbalances does not support any significant benefits and continues to support harms for the use of alteplase 3-4.5 hours after stroke onset. Clinicians, patients and policymakers should reconsider interpretations and decisions regarding management of acute ischaemic stroke that were based on ECASS III results.

TRIAL REGISTRATION NUMBER

NCT00153036.

Large Vessel Occlusion Stroke Secondary to Acute Aortic Dissection

Aortic dissection carries a high mortality of up to 40% at the time of initial dissection and an additional 1% per hour the dissection is untreated. Patients with acute aortic dissection most commonly present with chest or back pain. Less frequently, it manifests without pain with predominant neurologic symptoms secondary to an acute stroke. We present the case of a 53-year-old male presenting with acute onset aphasia and right-sided weakness. Incidentally, CT angiography of his neck revealed a carotid artery dissection, which was found an extension of a Stanford type A acute aortic dissection resulting in a large vessel occlusion stroke. The patient's concomitant pathologies resulted in uncertainty as to the priority of management between the interventional neurology and cardiothoracic surgery services, ultimately resulting in the transfer of the patient to an aorta specialist at an outside facility. This case highlights several areas of difficulty in the management of patients with presenting with both large vessel occlusion stroke and acute aortic dissection and the need for consideration of acute aortic dissection in patients presenting with symptoms consistent with large vessel occlusion stroke. Optimal blood pressure control is unknown, as is the ideal timing of aortic repair and the potential for endovascular therapy for large vessel occlusion stroke in the setting of acute aortic dissection. Emergency physicians must rapidly engage with neurology, interventional neurology, and cardiothoracic surgery to determine appropriate interventions and timing of operative repair. The emergency physician must consider acute aortic dissection in patients presenting with signs and symptoms concerning for large vessel occlusion stroke, even if they have no complaint of chest pain, as administration of thrombolytics in these patients may be deadly.

The predictive value of red cell distribution width for stroke severity and outcome

Objectives

In the present study, we sought to investigate the association between red cell distribution width (RDW) and stroke severity and outcome in patients who underwent anti-thrombolytic therapy with tissue plasminogen activator (tPA).

Results

In this prospective study, 282 stroke patients who underwent tPA injection were included. The categorization of RDW to < 12.9% and > 13% values revealed insignificant difference in stroke severity score, accounting for the mean 36-h NIHSS of 8.19 ± 8.2 in normal RDW values and 9.94 ± 8.28in higher RDW group (p = 0.64). In seventh day, NIHSS was 6.46 ± 7.28 in normal RDW group and was 8.52 ± 8.35 in increased RDW group (p = 0.058). Neither the 36-h, nor the seventh day and 3-month mRS demonstrated significant difference between those with normal and higher RDW values.

Heat shock protein 27 as a neuroprotective biomarker and a suitable target for stem cell therapy and pharmacotherapy in ischemic stroke

Ischemic stroke is a major common cause of death and long-term disability worldwide. Several pathophysiological events including excitotoxicity, oxidative/nitrative stress, inflammation, and apoptosis are involved in ischemic injuries. Recently, the molecular mechanisms involved in cerebral ischemia through a focus on a member of small heat shock proteins family, Hsp27, has been developed. Notably, following exposure to ischemia, Hsp27 expression in the brain could be increased rather than the normal condition and it may play an important role in neuroprotection after ischemic stroke. The neuroprotection effects of Hsp27 may arise from its anti-oxidant, anti-inflammatory, anti-apoptotic, and chaperonic properties. Moreover, some therapeutic strategies such as stem cell therapy and pharmacotherapy have been developed with Hsp27 targeting. In this review, we describe the function and structure of Hsp27 and its possible role in neuroprotection after ischemic stroke. Finally, we present current studies in stroke therapy, which focused on Hsp27 targeting.

Cutting Edge Acute Ischemic Stroke Management

Acute ischemic stroke (AIS) is a medical emergency that requires prompt recognition and streamlined work-up to ensure that time-dependent therapies are initiated to achieve the best outcomes. This article discusses frequently missed AIS in the emergency department, the role of various imagining modalities in the work-up of AIS, updates on the use of intravenous thrombolytics and endovascular therapy for AIS, pearls on supportive care management of AIS, and prehospital and hospital process improvements to shorten door-to-needle time.

Evaluation of Spin in the Abstracts of Emergency Medicine Randomized Controlled Trials

STUDY OBJECTIVE

We aim to investigate spin in emergency medicine abstracts, using a sample of randomized controlled trials from high-impact-factor journals with statistically nonsignificant primary endpoints.

METHODS

This study investigated spin in abstracts of emergency medicine randomized controlled trials from emergency medicine literature, with studies from 2013 to 2017 from the top 5 emergency medicine journals and general medical journals. Investigators screened records for inclusion and extracted data for spin. We considered evidence of spin if trial authors focused on statistically significant results, interpreted statistically nonsignificant results as equivalent or noninferior, used favorable rhetoric in the interpretation of nonsignificant results, or claimed benefit of an intervention despite statistically nonsignificant results.

RESULTS

Of 772 abstracts screened, 114 randomized controlled trials reported statistically nonsignificant primary endpoints. Spin was found in 50 of 114 abstracts (44.3%). Industry-funded trials were more likely to have evidence of spin in the abstract (unadjusted odds ratio 3.4; 95% confidence interval 1.1 to 11.9). In the abstracts' results, evidence of spin was most often due to authors' emphasizing a statistically significant subgroup analysis (n=9). In the abstracts' conclusions, spin was most often due to authors' claiming they accomplished an objective that was not a prespecified endpoint (n=14).

CONCLUSION

Spin was prevalent in the selected randomized controlled trial, emergency medicine abstracts. Authors most commonly incorporated spin into their reports by focusing on statistically significant results for secondary outcomes or subgroup analyses when the primary outcome was statistically nonsignificant. Spin was more common in studies that had some component of industry funding.

Understanding determinants of acute stroke thrombolysis using the tailored implementation for chronic diseases framework: a qualitative study

BACKGROUND

The Tailored Implementation in Chronic Disease (TICD) framework is a comprehensive framework describing the determinants of implementation success that has been used extensively in primary care settings. We explored the utility of the TICD to identify determinants of practice in an acute setting, namely guideline concordant acute stroke thrombolysis in a low-resourced, predominately minority serving, large, Emergency Department (ED).

METHODS

Through workshops and expert review, we developed an interview guide informed by the TICD framework. We then conducted semi-structured interviews with data collected through written transcripts, audio transcripts or interviewer notes based on participant availability. Three independent coders then performed a content analysis using template analysis, but open to new determinants that arose from the data, into the TICD framework.

RESULTS

We performed a total of 15 semi-structured interviews with ED acute stroke providers including medical technicians, nurses, and physicians. We found that guideline factors, individual health professional factors, and patient factors domains were barriers to guideline concordant acute stroke thrombolysis. The domain professional interactions was a facilitator to treatment. We identified three determinants, healthcare professional burnout, health care professional turnover and surrogate decision making, that are not part of the TICD framework.

CONCLUSIONS

Most determinants of acute stroke thrombolysis are included within the TICD framework. Inclusion of healthcare professional burnout, healthcare professional turnover and surrogate decision making may assist in expanding the TICD to time-sensitive ED conditions. Further work is needed to confirm this finding and to establish whether the TICD is applicable for use in non-time sensitive ED conditions. Interventions that address guideline, individual health professional and patient factors may improve guideline concordant acute stroke thrombolysis.

An appraisal of emergency medicine clinical practice guidelines: Do we agree?

BACKGROUND

Clinical practice guidelines (CPGs) have been published by the American College of Emergency Physicians (ACEP) since 1990 to advance evidence-based emergency care. ACEP clinical policies have drawn anecdotal criticism for bias, yet the overall quality of these guidelines has not previously been quantified. We sought to examine ACEP clinical policies using a recognised, validated appraisal instrument: Appraisal of Guidelines for Research & Evaluation (AGREE II).

METHODS

Systematic assessment of current ACEP clinical policies was conducted using the AGREE II instrument, which contains 23 appraisal items (scored on a 1-7 scale) in six domains and two overall assessments. Each policy was independently appraised by five trained appraisers. Primary outcomes were AGREE II ratings for each item, domain and "Overall Assessment," and scores were reported as standardised percentages from all five appraisers. Secondary analyses examined associations between AGREE II ratings and policy publication date, strength of underlying evidence and strength of recommendations. Additional analysis examined relationships between domain and "Overall Assessment" ratings.

RESULTS

Twenty guidelines published from April 2007 to November 2017 were included. Of the six domains, "Scope and Purpose" scored highest (mean 90%) and "Applicability" scored lowest (mean 35%). The four remaining domains ("Stakeholder Involvement," "Rigor of Development," "Clarity of Presentation" and "Editorial Independence") had mean scores of 53%-78%. The mean "Overall Assessment" rating was 69% and was not associated with policy publication date, strength of underlying evidence or strength of recommendations. We found positive associations between "Overall Assessment" ratings and two domains: "Rigor of Development" (r = 0.70) and "Clarity of Presentation" (r = 0.70).

CONCLUSIONS

Based on validated AGREE II criteria, ACEP clinical policies can be most improved by addressing their application in practice. ACEP clinical policies' overall quality did not improve over the assessed time period and is not explained by the quality of underlying evidence.

Financial relationships with industry among guideline authors for the management of acute ischemic stroke

OBJECTIVE

To characterize the prevalence of industry relationships among authors of acute ischemic stroke (AIS) guidelines and its association with graded evidence.

METHODS

A cross-sectional study of five policy papers on AIS published by the American Heart Association (AHA)/American Stroke Association (ASA), American Academy of Emergency Physicians (AAEM), and American College of Emergency Physicians (ACEP). Financial conflicts of interest (FCOI) data were obtained using the Open Payments Database for the years 2013 through 2017. A search of publicly available information was done to determine post-guideline employment. We characterized the prevalence of FCOI, as well as employment with industry engaged in thrombolysis or neurointerventional treatment of AIS after guideline publication.

RESULTS

76 unique authors were identified in 5 policy statements. The prevalence of FCOI among authors of AAEM, ACEP, and AHA/ASA guidelines was 0%, 0%, and 35%, respectively. Post-publication increase in FCOI was 0% for authors of the AAEM and ACEP guidelines, and a 300% increase for authors of the 2013 AHA/ASA guidelines with data unavailable to assess post-publication FCOI for authors of the 2018 AHA/ASA guidelines. 2 authors were found to engage in new industry employment following recommendation publication. Finally, 9% (n = 3) authors of the 2013/2018 AHA/ASA guidelines were employees of the Genentech Speakers Bureau.

CONCLUSIONS

Our results suggest an association between current Graded Evidence and FCOI of major academic societies for the management of AIS. Due to the bias inherent to such conflicts, future recommendation groups should take steps to insulate against FCOI both during and following guideline publication.

A New Paradigm Shift in Acute Ischemic Stroke, Large Vessel Occlusions, and Endovascular Therapy

BACKGROUND

In the past three years, there have been several major studies published on the use of endovascular therapy (EVT) in large vessel occlusion (LVO) acute ischemic stroke. With multiple publications in such a short amount of time, it is difficult to keep up with the evolving landscape of ischemic stroke therapy.

OBJECTIVE

This narrative review discusses recent randomized controlled trials evaluating EVT and its effects on acute ischemic stroke management.

DISCUSSION

Ischemic stroke is the most common type of stroke overall, and recanalization is the predominant focus in stroke therapy to improve outcomes. Treatment first focused on systemic thrombolysis for ischemic stroke, followed by studies evaluating the use of thrombolysis with EVT. Early research did not find a benefit to EVT; however, recent studies using current devices and with narrow selection criteria demonstrate significant benefit to EVT in LVOs. In patients with LVOs and perfusion mismatches, reperfusion rates are higher with EVT compared with systemic thrombolysis alone. Recognition of patients with small infarct cores and large areas of ischemic but salvageable brain tissue up to 24 h after symptom onset stresses the need for advanced imaging to recognize the target group.

CONCLUSIONS

EVT technology for acute ischemic stroke has now become more efficient, minimizing complications and improving the efficacy of EVT. Several viable interventions for a small subgroup of patients with ischemic stroke up to 24 h after symptoms onset can significantly improve patient outcomes.

The Results of Randomized Controlled Trials in Emergency Medicine Are Frequently Fragile

STUDY OBJECTIVE

Randomized controlled trials govern evidence-based clinical practice, and it is therefore critical that their results be robust. We aim to investigate the fragility of randomized controlled trials in emergency medicine by determining how often significance would be nullified with small changes in outcomes using the fragility index.

METHODS

We conducted a methodological systematic review of randomized controlled trials in emergency medicine published in the top 10 general medicine journals and the top 10 emergency medicine journals. Inclusion criteria required that trials be emergency medicine studies structured with a 2-arm or 2-by-2 factorial design and report at least 1 statistically significant dichotomous outcome.

RESULTS

A total of 180 trials met inclusion criteria. The median fragility index across all trials in emergency medicine was 4 (interquartile range [IQR] 2 to 10) and the median sample size was 140 (IQR 69.5 to 286). For trials from general medicine journals (n=32), the median fragility index was 9 (IQR 4 to 16.5) and the median sample size was 415.5 (IQR 219.5 to 901); for trials from emergency medicine journals (n=148), the median fragility index was 4 (IQR 1 to 9) and the median sample size was 119 (IQR 60 to 227.25). One third of all trials (62/180) had a loss to follow-up that was greater than or equal to the fragility index. There was a modest correlation between fragility index and total number of events (r=0.36; 95% confidence interval [CI] 0.23 to 0.48) and a weak correlation between fragility index and total sample size (r=0.26; 95% CI 0.12 to 0.39). There was no correlation between fragility index and either P value (r=-0.14; 95% CI -0.28 to -0.006) or Science Citation Index (r=0.07; 95% CI -0.08 to 0.22).

CONCLUSION

The statistical significance of the results of randomized controlled trials in emergency medicine was often contingent on a small number of events. Until frequentist interpretation of clinical trials is replaced with Bayesian analysis, the fragility index may have utility as a tool to aid clinicians in assessing the robustness of randomized controlled trials in emergency medicine when considered in conjunction with the fragility quotient and other reported metrics.

Tenecteplase utility in acute ischemic stroke patients: A clinical review of current evidence

INTRODUCTION

Acute ischemic stroke is a leading cause of disability in the United States. Treatment is aimed at reducing impact of cerebral clot burden and life-long disability. Traditional fibrinolytic treatment with recombinant tissue plasminogen activator (tPA) has shown to be effective but at high risk of major bleeding. Multiple studies have evaluated tenecteplase as an alternative to tPA.

OBJECTIVE

This review evaluates literature and utility of tenecteplase for treatment of acute ischemic stroke.

DISCUSSION

Tenecteplase is modified, third generation fibrinolytic with greater specificity for fibrin bound clots. Current data in acute myocardial infarction suggest decreased bleeding events compared to alteplase. Multiple trials have investigated superiority of tenecteplase compared to tPA for treatment of acute ischemic stroke. Current guidelines designate tenecteplase as an alternative treatment for mild acute ischemic stroke patients based on recent literature.

CONCLUSION

Recent emerging literature and limited recommendation guidance from governing medical societies leave many emergency medicine providers to weigh benefit versus risk of fibrinolytic therapy and tenecteplase's place in therapy. This review evaluates the available literature regarding tenecteplase and its utility in the treatment of acute ischemic stroke patients.

Model-based assessment of the benefits and risks of recombinant tissue plasminogen activator treatment in acute ischaemic stroke

AIMS

Recombinant tissue plasminogen activator (rt-PA) is the only first-line agent approved by the US Food and Drug Administration to treat acute ischaemic stroke. However, it often causes the serious adverse event (AE) of haemorrhagic transformation. The present study developed a pharmacometric model for the rt-PA treatment effect and AE and, using the developed model, proposed a benefit-to-risk ratio assessment scheme as a supportive tool to optimize treatment outcome.

METHODS

The data from 336 acute ischaemic stroke patients were used. The treatment effect was assessed based on an improvement in National Institutes of Health Stroke Scale (NIHSS) scores, which were described using an item response theory (IRT)-based disease progression model. Treatment failure and AE probabilities, and their occurrence times, were described by incidence and time-to-event models. Using the developed model, benefit-to-risk ratios were simulated under various scenarios using the global benefit-to-risk trade-off ratio (GBR).

RESULTS

High initial NIHSS score and middle cerebral artery (MCA) stroke were risk factors for treatment failure, where the failure rate with MCA stroke was 2.87-fold higher than with non-MCA stroke. The haemorrhagic transformation time was associated with longitudinal changes in NIHSS scores. The benefit-to-risk ratio simulated was highest in minor stroke severity, with GBR >1 in all scenarios, and the ratio with non-MCA stroke was 2-3 fold higher than with MCA stroke.

CONCLUSIONS

The study demonstrated the feasibility of applying an IRT model to describing the time course of the rt-PA treatment effect and AE. Benefit-to-risk ratio analyses showed that the treatment was optimal in non-MCA stroke with minor stroke severity.

Updated clinical guidelines experience major reporting limitations

BACKGROUND

The Checklist for the Reporting of Updated Guidelines (CheckUp) was recently developed. However, so far, no systematic assessment of the reporting of updated clinical guidelines (CGs) exists. We aimed to examine (1) the completeness of reporting the updating process in CGs and (2) the inter-observer reliability of CheckUp.

METHODS

We conducted a systematic assessment of the reporting of the updating process in a sample of updated CGs using CheckUp. We performed a systematic search to identify updated CGs published in 2015, developed by a professional society, reporting a systematic review of the evidence, and containing at least one recommendation. Three reviewers independently assessed the CGs with CheckUp (16 items). We calculated the median score per item, per domain, and overall, converting scores to a 10-point scale. Multiple linear regression analyses were used to identify differences according to country, type of organisation, scope, and health topic of updated CGs. We calculated the intraclass coefficient (ICC) and 95% confidence interval (95% CI) for domains and overall score.

RESULTS

We included in total 60 updated CGs. The median domain score on a 10-point scale for presentation was 5.8 (range 1.7 to 10), for editorial independence 8.3 (range 3.3 to 10), and for methodology 5.7 (range 0 to 10). The median overall score on a 10-point scale was 6.3 (range 3.1 to 10). Presentation and justification items at recommendation level (respectively reported by 27 and 38% of the CGs) and the methods used for the external review and implementing changes in practice were particularly poorly reported (both reported by 38% of the CGs). CGs developed by a European or international institution obtained a statistically significant higher overall score compared to North American or Asian institutions (p = 0.014). Finally, the agreement among the reviewers on the overall score was excellent (ICC 0.88, 95% CI 0.75 to 0.95).

CONCLUSIONS

The reporting of updated CGs varies considerably with significant room for improvement. We recommend using CheckUp to assess the updating process in updated CGs and as a blueprint to inform methods and reporting strategies in updating.

Effects of increasing IV tPA-treated stroke mimic rates at CT-based centers on clinical outcomes

OBJECTIVE

To determine to what degree stroke mimics skew clinical outcomes and the potential effects of incorrect stroke diagnosis.

METHODS

This retrospective analysis of data from 2005 to 2014 included IV tissue plasminogen activator (tPA)-treated adults with clinical suspicion for acute ischemic stroke who were transferred or admitted directly to our 2 hub hospitals. Primary outcome measures compared CT-based spoke hospitals' and MRI-based hub hospitals' mimic rates, hemorrhagic transformation, follow-up modified Rankin Scale (mRS), and discharge disposition. Secondary outcomes were compared over time.

RESULTS

Of the 725 thrombolysis-treated patients, 29% were at spoke hospitals and 71% at hubs. Spoke hospital patients differed from hubs by age (mean 62 ± 15 vs 72 ± 15 years, p < 0.0001), risk factors (atrial fibrillation, 17% vs 32%, p < 0.0001; alcohol consumption, 9% vs 4%, p = 0.007; smoking, 23% vs 13%, p = 0.001), and mimics (16% vs 0.6%, p < 0.0001). Inclusion of mimics resulted in better outcomes for spokes vs hubs by mRS ≤1 (40% vs 27%, p = 0.002), parenchymal hematoma type 2 (3% vs 7%, p = 0.037), and discharge home (47% vs 37%, p = 0.01). Excluding mimics, there were no significant differences. Comparing epochs, spoke stroke mimic rate doubled (9%-20%, p = 0.03); hub rate was unchanged (0%-1%, p = 0.175).

CONCLUSIONS

Thrombolysis of stroke mimics is increasing at our CT-based spoke hospitals and not at our MRI-based hub hospitals. Caution should be used in interpreting clinical outcomes based on large stroke databases when stroke diagnosis at discharge is unclear. Inadvertent reporting of treated stroke mimics as strokes will artificially elevate overall favorable clinical outcomes with additional downstream costs to patients and the health care system.

18F-positron-emitting/fluorescent labeled erythrocytes allow imaging of internal hemorrhage in a murine intracranial hemorrhage model

An agent for visualizing cells by positron emission tomography is described and used to label red blood cells. The labeled red blood cells are injected systemically so that intracranial hemorrhage can be visualized by positron emission tomography (PET). Red blood cells are labeled with 0.3 µg of a positron-emitting, fluorescent multimodal imaging probe, and used to non-invasively image cryolesion induced intracranial hemorrhage in a murine model (BALB/c, 2.36 × 10⁸ cells, 100 µCi, <4 mm hemorrhage). Intracranial hemorrhage is confirmed by histology, fluorescence, bright-field, and PET ex vivo imaging. The low required activity, minimal mass, and high resolution of this technique make this strategy an attractive alternative for imaging intracranial hemorrhage. PET is one solution to a spectrum of issues that complicate single photon emission computed tomography (SPECT). For this reason, this application serves as a PET alternative to [^99mTc]-agents, and SPECT technology that is used in 2 million annual medical procedures. PET contrast is also superior to gadolinium and iodide contrast angiography for its lack of clinical contraindications.

Citation bias favoring positive clinical trials of thrombolytics for acute ischemic stroke: a cross-sectional analysis

Background

Citation bias occurs when positive trials involving a medical intervention receive more citations than neutral or negative trials of similar quality. Several large clinical trials have studied the use of thrombolytic agents for the treatment of acute ischemic stroke with differing results, thereby presenting an opportunity to assess these trials for evidence of citation bias. We compared citation rates among positive, neutral, and negative trials of alteplase (tPA) and other thrombolytic agents for stroke.

Methods

We used a 2014 Cochrane Review of thrombolytic therapy for the treatment of acute stroke to identify non-pilot, English-language stroke trials published in MEDLINE-indexed journals comparing thrombolytic therapy with control. We classified trials as positive if there was a statistically significant primary outcome difference favoring the intervention, neutral if there was no difference in primary outcome, or negative for a significant primary outcome difference favoring the control group. Trials were also considered negative if safety concerns supported stopping the trial early. Using Scopus, we collected citation counts through 2015 and compared citation rates according to trial outcomes.

Results

Eight tPA trials met inclusion criteria: two were positive, four were neutral, and two were negative. The two positive trials received 9080 total citations, the four neutral trials received 4847 citations, and the two negative trials received 1096 citations. The mean annual per-trial citation rates were 333 citations per year for positive trials, 96 citations per year for neutral trials, and 35 citations per year for negative trials. Trials involving other thrombolytic agents were not cited as often, though as with tPA, positive trials were cited more frequently than neutral or negative trials.

Conclusions

Positive trials of tPA for ischemic stroke are cited approximately three times as often as neutral trials, and nearly 10 times as often as negative trials, indicating the presence of substantial citation bias.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1595-7) contains supplementary material, which is available to authorized users.

Perceived Appropriateness of Shared Decision-making in the Emergency Department: A Survey Study

OBJECTIVES

The objective was to describe perceptions of practicing emergency physicians (EPs) regarding the appropriateness and medicolegal implications of using shared decision-making (SDM) in the emergency department (ED).

METHODS

We conducted a cross-sectional survey of EPs at a large, national professional meeting to assess perceived appropriateness of SDM for different categories of ED management (e.g., diagnostic testing, treatment, disposition) and in common clinical scenarios (e.g., low-risk chest pain, syncope, minor head injury). A 21-item survey instrument was iteratively developed through review by content experts, cognitive testing, and pilot testing. Descriptive and multivariate analyses were conducted.

RESULTS

We approached 737 EPs; 709 (96%) completed the survey. Two-thirds (67.8%) of respondents were male; 51% practiced in an academic setting and 44% in the community. Of the seven management decision categories presented, SDM was reported to be most frequently appropriate for deciding on invasive procedures (71.5%), computed tomography (CT) scanning (56.7%), and post-ED disposition (56.3%). Among the specific clinical scenarios, use of thrombolytics for acute ischemic stroke was felt to be most frequently appropriate for SDM (83.4%), followed by lumbar puncture to rule out subarachnoid hemorrhage (73.8%) and CT head for pediatric minor head injury (69.9%). Most EPs (66.8%) felt that using and documenting SDM would decrease their medicolegal risk while a minority (14.2%) felt that it would increase their risk.

CONCLUSIONS

Acceptance of SDM among EPs appears to be strong across management categories (diagnostic testing, treatment, and disposition) and in a variety of clinical scenarios. SDM is perceived by most EPs to be medicolegally protective.