Low-Dose versus Standard-Dose Intravenous Alteplase in Acute Ischemic Stroke

Sex differences in treatment and outcome after stroke: Pooled analysis including 19,000 participants

OBJECTIVE

To explore the sex differences in outcomes and management after stroke using a large sample with high-quality international trial data.

METHODS

Individual participant data were obtained from 5 acute stroke randomized controlled trials. Data were obtained on demographics, medication use, in-hospital treatment, and functional outcome. Study-specific crude and adjusted models were used to estimate sex differences in outcomes and management, and then pooled using random-effects meta-analysis.

RESULTS

There were 19,652 participants, of whom 7,721 (40%) were women. After multivariable adjustments, women with ischemic stroke had higher survival at 3-6 months (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.70-0.97), higher likelihood of disability (OR 1.20, 95% CI 1.06-1.36), and worse quality of life (weighted mean difference -0.07, 95% CI -0.09 to 0.04). For management, women were more likely to be admitted to an acute stroke unit (OR 1.17, 95% CI 1.01-1.34), but less likely to be intubated (OR 0.58, 95% CI 0.36-0.93), treated for fever (OR 0.82, 95% CI 0.70-0.95), or admitted to an intensive care unit (OR 0.83, 95% CI 0.74-0.93). For preadmission medications, women had higher odds of being prescribed antihypertensive agents (OR 1.22, 95% CI 1.13-1.31) and lower odds of being prescribed antiplatelets (OR 0.86, 95% CI 0.79-0.93), glucose-lowering agents (OR 0.86, 95% CI 0.78-0.94), or lipid-lowering agents (OR 0.85, 95% CI 0.77-0.94).

CONCLUSIONS

This analysis suggests that women who had ischemic stroke had better survival but were also more disabled and had poorer quality of life. Variations in hospital and out-of-hospital management may partly explain the disparities.

A stepwise thrombolysis regimen in the management of acute portal vein thrombosis in patients with evidence of intestinal ischaemia

BACKGROUND

Anticoagulation alone in acute, extensive portomesenteric vein thrombosis (PVT) does not always result in spontaneous clot lysis, and leaves the patient at risk of complications including intestinal infarction and portal hypertension.

AIM

To develop a new standard of care for patients with acute PVT and evidence of intestinal ischaemia.

METHODS

We present a case series of patients with acute PVT and evidence of intestinal ischaemia plus ongoing symptoms despite initial systemic anticoagulation, who were treated with a thrombolysis protocol between 2014 and 2019. This stepwise protocol initially uses low-dose systemic alteplase, and in patients with ongoing abdominal pain, and no evidence of radiological improvement, is followed by local clot dissolution therapy (CDT) through a TIPSS. Outcomes and safety were assessed.

RESULTS

Twenty-two patients were included. The mean age was 44.6 (standard deviation [SD] 16.0) years, and 64% had an identifiable prothrombotic risk factor. All patients had intestinal wall oedema and 77% had complete occlusion of all portomesenteric veins. Systemic thrombolysis was started 18.7 (SD 11.2) days after the onset of symptoms. 55% of patients underwent TIPSS insertion for CDT. At the end of treatment, symptoms resolved in 91% of patients and recanalisation in 86%. Only one patient required resection for intestinal ischaemia, and there were no deaths. Major complications occurred in two patients (9%).

CONCLUSIONS

Our stepwise protocol is effective, resulting in good recanalisation rates. It can be commenced early while organising transfer to a centre capable of performing local CDT.

Bacterial staphylokinase as a promising third-generation drug in the treatment for vascular occlusion

Vascular occlusion is one of the major causes of mortality and morbidity. Blood vessel blockage can lead to thrombotic complications such as myocardial infarction, stroke, deep venous thrombosis, peripheral occlusive disease, and pulmonary embolism. Thrombolytic therapy currently aims to rectify this through the administration of recombinant tissue plasminogen activator. Research is underway to design an ideal thrombolytic drug with the lowest risk. Despite the potent clot lysis achievable using approved thrombolytic drugs such as alteplase, reteplase, streptokinase, tenecteplase, and some other fibrinolytic agents, there are some drawbacks, such as high production cost, systemic bleeding, intracranial hemorrhage, vessel re-occlusion by platelet-rich and retracted secondary clots, and non-fibrin specificity. In comparison, bacterial staphylokinase, is a new, small-size plasminogen activator, unlike bacterial streptokinase, it hinders the systemic degradation of fibrinogen and reduces the risk of severe hemorrhage. A fibrin-bound plasmin-staphylokinase complex shows high resistance to a₂-antiplasmin-related inhibition. Staphylokinase has the potential to be considered as a promising thrombolytic agent with properties of cost-effective production and the least side effects.

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.

Intravenous Thrombolysis Administration 3-4.5 h After Acute Ischemic Stroke: A Retrospective, Multicenter Study

Background and Objectives: Intravenous recombinant tissue plasminogen activator (rt-PA) has been approved for acute ischemic stroke (AIS) within 3 h after onset and the treatment was then extended to 4.5 h. However, the Food and Drug Administration did not approve the indication in the expanded time window. This retrospective, matched cohort study aims to investigate the effectiveness and safety of rt-PA in AIS at 3-4.5 h after onset. Materials and Methods: The treatment group included AIS patients receiving rt-PA at 3-4.5 h after onset, otherwise complying with the regulation, in the stroke registries in 16 hospitals between 2008 and 2017. The control group included age- and sex-matched patients not receiving intravenous thrombolysis from the same registries, excluding those with contraindications. The primary outcome was modified Rankin Scale (mRS) 0-1 at day 90. The safety outcomes were any intracerebral hemorrhage (ICH), early neurological deterioration and 3-month mortality. Results: Each group had 374 patients. There were 34.0% of patients with 3-month mRS 0-1 in the treatment group vs. 22.7% in the control group with an odds ratio of 1.75 (95% confidence intervals, 1.27 to 2.42, P = 0.001). There was no difference in symptomatic ICH, early neurological deterioration and 3-month mortality rates between two groups. The 3-month mRS and symptomatic ICH did not differ significantly in patients receiving standard dose or low dose of rt-PA. Conclusions: Our results support the prescription of rt-PA in AIS patients 3-4.5 h after onset as an effective and tolerable treatment in their functional recovery.

Ischaemic stroke

Stroke is the second highest cause of death globally and a leading cause of disability, with an increasing incidence in developing countries. Ischaemic stroke caused by arterial occlusion is responsible for the majority of strokes. Management focuses on rapid reperfusion with intravenous thrombolysis and endovascular thrombectomy, which both reduce disability but are time-critical. Accordingly, improving the system of care to reduce treatment delays is key to maximizing the benefits of reperfusion therapies. Intravenous thrombolysis reduces disability when administered within 4.5 h of the onset of stroke. Thrombolysis also benefits selected patients with evidence from perfusion imaging of salvageable brain tissue for up to 9 h and in patients who awake with stroke symptoms. Endovascular thrombectomy reduces disability in a broad group of patients with large vessel occlusion when performed within 6 h of stroke onset and in patients selected by perfusion imaging up to 24 h following stroke onset. Secondary prevention of ischaemic stroke shares many common elements with cardiovascular risk management in other fields, including blood pressure control, cholesterol management and antithrombotic medications. Other preventative interventions are tailored to the mechanism of stroke, such as anticoagulation for atrial fibrillation and carotid endarterectomy for severe symptomatic carotid artery stenosis.

Thrombolysis Following Heparin Reversal With Protamine Sulfate in Acute Ischemic Stroke: Case Series and Literature Review

INTRODUCTION

Administering intravenous IV tissue plasminogen activator (tPA) is the recommended standard of care in acute ischemic stroke (AIS), although it is not recommended to administer intravenous thrombolysis with tPA following heparin reversal with protamine sulfate in patients with AIS.

METHODS

We describe a case series of three patients and the most comprehensive literature review published to date in this specific subset of AIS patients undergoing thrombolysis following heparin reversal with protamine sulfate. The literature review was based on a scoping review methodology performed on four databases; PubMed, CINAHL, Web of Science, and Cochrane Library. All sources were searched from the inauguration of the database until February 2019. A total of six articles involving eight patients were identified.

RESULTS

The primary safety outcome of no symptomatic intracranial hemorrhage (sICH) was met in all eleven patients, although only seven cases had a good functional outcome at 3 months.

CONCLUSIONS

In appropriately selected AIS patients, coagulopathy correction appears to be safe from an sICH standpoint and may be beneficial. However, given the potential for bias with observational databases, case reports and case series, extreme caution is warranted in applying these results to routine clinical practice.

Dramatic thrombolysis after rapid injection of tissue plasminogen activator: A case report

RATIONALE

The regimen of the recombinant tissue plasminogen activator (rt-PA) is identical in every case where it is indicated in the treatment of cerebral infarction. We report a case of efficient recanalization of large arterial occlusion after rapid injection of rt-PA.

PATIENT CONCERNS

A 78-year-old man was admitted with right-sided hemiplegia and global aphasia that occurred an hour ago.

DIAGNOSES

His brain computed tomography (CT) revealed no hemorrhage, suggesting cerebral infarction.

INTERVENTIONS

Ten percent of a total rt-PA dose was injected over 1 minute promptly. The remainder of rt-PA was designed to be infused for 60 minutes. Unexpectedly, during the study of CT angiography, administration of rt-PA was completed within 5 minutes. CT angiography showed occlusion from carotid bifurcation to the middle cerebral artery.

OUTCOMES

After 2 hours of rt-PA administration, the patient began to regain strength in his right arm and leg. By the next day, he had only mild dysarthria and aphasia. Follow-up CT angiography revealed recanalized internal cervical artery and severe residual stenosis with a plaque. He was discharged without any neurologic symptoms.

LESSONS

The infusion protocol of rt-PA administration is established in 1995 and has not changed. Successful recanalization of long segmental large vessel occlusion with only intravenous rt-PA is relatively low. In our case, a high concentration of rt-PA may have influenced the successful dissemination of large thrombus in the whole internal cervical artery. Our case is of significance as it raises the question of unanswered efficacy of diverse injection protocol according to thrombus size and bleeding risk.

Current Drug Treatment of Acute Ischemic Stroke: Challenges and Opportunities

Patient-level health outcomes for acute ischemic stroke have significantly improved in the last decade primarily because of superior overall case management, availability of tailored drug interventions, and advances in endovascular procedures. Nevertheless, disease registries show a "quality gap" across social determinants of health and between in-hospital and community-onset strokes. Several factors, including financing and infrastructure constraints, limited expertise, and clinical uncertainty, still prevent adherence to evidence-based clinical guidelines and optimal care pathways. This paper critically appraises existing evidence on the use of drug therapies in acute ischemic stroke, in an attempt to resolve physician-related subjective barriers for effective acute management of the disease. We conclude that intravenous administration of rt-PA (recombinant tissue-type plasminogen activator, alteplase) is an essential component of acute-phase pharmacologic treatment and a driver for the improvement of overall ischemic stroke health outcomes. The safety profile of alteplase and similar treatments are well within the patient benefit zone of eligible patients when compared to non-treatment alternatives. Monomodal neuroprotective drugs with single or pleiotropic mechanisms of action have failed to support long-term sustainable results. Drugs with complex mechanisms of action that promote neurorecovery, such as cerebrolysin, are valid options for adjunctive treatment of acute ischemic stroke. Recent years have shown clear improvements in the methodology and design of clinical trials, with an increase in overall internal and external validity. A better understanding of study limitations has not hindered, but enhanced their potential to contribute, together with sometimes superior data sources, to health decision making.

Towards precision critical care management of blood pressure in hemorrhagic stroke patients using dynamic linear models

Finding optimal blood pressure (BP) target and BP treatment after acute ischemic or hemorrhagic strokes is an area of controversy and a significant unmet need in the critical care of stroke victims. Numerous large prospective clinical trials have been done to address this question but have generated neutral or conflicting results. One major limitation that may have contributed to so many neutral or conflicting clinical trial results is the "one-size fit all" approach to BP targets, while the optimal BP target likely varies between individuals. We address this problem with the Acute Intervention Model of Blood Pressure (AIM-BP) framework: an individualized, human interpretable model of BP and its control in the acute care setting. The framework consists of two components: one, a model of BP homeostasis and the various effects that perturb it; and two, a parameter estimator that can learn clinically important model parameters on a patient by patient basis. By estimating the parameters of the AIM-BP model for a given patient, the effectiveness of antihypertensive medication can be quantified separately from the patient's spontaneous BP trends. We hypothesize that the AIM-BP is a sufficient framework for estimating parameters of a homeostasis perturbation model of a stroke patient's BP time course and the AIM-BP parameter estimator can do so as accurately and consistently as a state-of-the-art maximum likelihood estimation method. We demonstrate that this is the case in a proof of concept of the AIM-BP framework, using simulated clinical scenarios modeled on stroke patients from real world intensive care datasets.

Validation of a clinical-genetics score to predict hemorrhagic transformations after rtPA

OBJECTIVE

To validate the Genot-PA score, a clinical-genetic logistic regression score that stratifies the thrombolytic therapy safety, in a new cohort of patients with stroke.

METHODS

We enrolled 1,482 recombinant tissue plasminogen activator (rtPA)-treated patients with stroke in Spain and Finland from 2003 to 2016. Cohorts were analyzed on the basis of ethnicity and therapy: Spanish patients treated with IV rtPA within 4.5 hours of onset (cohort A and B) or rtPA in combination with mechanical thrombectomy within 6 hours of onset (cohort C) and Finnish participants treated with IV rtPA within 4.5 hours of onset (cohort D). The Genot-PA score was calculated, and hemorrhagic transformation (HT) and parenchymal hematoma (PH) risks were determined for each score stratum.

RESULTS

Genot-PA score was tested in 1,324 (cohort A, n = 726; B, n = 334; C, n = 54; and D, n = 210) patients who had enough information to complete the score. Of these, 213 (16.1%) participants developed HT and 85 (6.4%) developed PH. In cohorts A, B, and D, HT occurrence was predicted by the score (p = 2.02 × 10^-6, p = 0.023, p = 0.033); PH prediction was associated in cohorts A through C (p = 0.012, p = 0.034, p = 5.32 × 10^-4). Increased frequency of PH events from the lowest to the highest risk group was found (cohort A 4%-15.7%, cohort B 1.5%-18.2%, cohort C 0%-100%). The best odds ratio for PH prediction in the highest-risk group was obtained in cohort A (odds ratio 5.16, 95% confidence interval 1.46-18.08, p = 0.009).

CONCLUSION

The Genot-PA score predicts HT in patients with stroke treated with IV rtPA. Moreover, in an exploratory study, the score was associated with PH risk in mechanical thrombectomy-treated patients.

Evidence that Tenecteplase Is Noninferior to Alteplase for Acute Ischemic Stroke: Meta-Analysis of 5 Randomized Trials

Background and Purpose- TNK (tenecteplase), a newer fibrinolytic agent, has practical delivery advantages over ALT (alteplase) that would make it a useful agent if noninferior in acute ischemic stroke treatment outcome. Accordingly, the most recent US American Heart Association/American Stroke Association acute ischemic stroke guideline recognized TNK as an alternative to ALT, but only based on informal consideration, rather than formal meta-analysis, of completed randomized control trials. Methods- Systematic literature search and formal meta-analysis were conducted per PRISMA guidelines (Preferred Reporting Items for Systemic Reviews and Meta-Analyses), adapted to noninferiority analysis. The primary outcome of freedom from disability (modified Rankin Scale score, 0-1) outcome at 3 m, and additional efficacy and safety outcomes, were analyzed. Results- Systematic search identified 5 trials enrolling 1585 patients (828 TNK, 757 ALT). Across all trials, mean age was 70.8, 58.5% male, baseline National Institutes of Health Stroke Scale mean 7.0, and time from last known well to treatment start mean 148 minutes. All ALT patients received standard 0.9 mg/kg dosing, while TNK dosing was 0.1 mg/kg in 6.8%, 0.25 mg/kg in 24.6%, and 0.4 mg/kg in 68.6%. For the primary end point, crude cumulative rates of disability-free (modified Rankin Scale score, 0-1) 3 m outcome were TNK 57.9% versus ALT 55.4%. Informal, random-effects meta-analysis, the risk difference was 4% (95% CI, -1% to 8%). The lower 95% CI bound fell well within the prespecified noninferiority margin. Similar results were seen for the additional efficacy end points: functional independence (modified Rankin Scale score, 0-2): crude TNK 71.9% versus ALT 70.5%, risk difference 2% (95% CI, -3% to 6%); and modified Rankin Scale shift analysis, common odds ratio 1.21 (95% CI, 0.93-1.57). For safety end points, lower event rates reduced power, but point estimates were also consistent with noninferiority Conclusions- Accumulated clinical trial data provides strong evidence that TNK is noninferior to ALT in the treatment of acute ischemic stroke. These findings provide formal support for the recent guideline recommendation to consider TNK an alternative to ALT.

Latest developments in clinical stroke care

Stroke medicine has seen rapid developments in diagnosis and management, and consequently improved prognosis. Management of ischaemic stroke, in particular, has benefited from these advances. The approach to management has evolved from one of historical passivity to active intervention with time of the essence following stroke onset. The last decade has seen the comparative effectiveness of several pharmacological agents being tested, creating significant randomised controlled trial evidence to support the management of common clinical problems following acute stroke. While several of these interventions are widely available, some remain less accessible. This review will discuss the latest developments in clinical stroke medicine, based on a symposium presentation at the Royal College of Physicians of Edinburgh, and reference key randomised controlled trial evidence in an effort to provide a balanced perspective on our current understanding of acute ischaemic and haemorrhagic stroke.

Who will benefit more from low-dose alteplase in acute ischemic stroke?

OBJECTIVES

Controversy persists over the benefits of low-dose versus standard-dose intravenous alteplase for the treatment of acute ischemic stroke. We sought to determine individual patient factors that contribute to the risk-benefit balance of low-dose alteplase treatment.

METHODS

Observational study using data from the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED), an international, randomized, open-label, blinded-endpoint trial that assessed low-dose (0.6 mg/kg) versus standard-dose (0.9 mg/kg) intravenous alteplase in acute ischemic stroke patients. Logistic regression models were used to estimate the benefit of good functional outcome (scores 0 or 1 on the modified Rankin scale at 90 days) and risk (symptomatic intracerebral hemorrhage), under both regimens for individual patients. The net advantage for low-dose, relative to standard-dose, alteplase was calculated by dividing excess benefit by excess risk according to a combination of patient characteristics. The algorithms were externally validated in a nationwide acute stroke registry database in South Korea.

RESULTS

Patients with an estimated net advantage from low-dose alteplase, compared with without, were younger (mean age of 66 vs. 75 years), had lower systolic blood pressure (148 vs. 160 mm Hg), lower National Institute of Health Stroke Scale score (median of 8 vs. 16), and no atrial fibrillation (10.3% vs. 97.4%), diabetes mellitus (19.2% vs. 22.4%), or premorbid symptoms (defined by modified Rankin scale = 1) (16.3% vs. 37.8%).

CONCLUSION

Use of low-dose alteplase may be preferable in acute ischemic stroke patients with a combination of favorable characteristics, including younger age, lower systolic blood pressure, mild neurological impairment, and no atrial fibrillation, diabetes mellitus, or premorbid symptoms.

Low-dose versus standard-dose alteplase in acute ischemic stroke in Asian stroke registries: an individual patient data pooling study

OBJECTIVE

To investigate the comparative efficacy and safety of the low-dose versus standard-dose alteplase using real-world acute stroke registry data from Asian countries.

METHODS

Individual participant data were obtained from nine acute stroke registries from China, Japan, Philippines, Singapore, South Korea, and Taiwan between 2005 and 2018. Inverse probability of treatment weight was used to remove baseline imbalances between those receiving low-dose versus standard-dose alteplase. The primary outcome was death or disability defined by modified Rankin Scale scores of 2 to 6 at 90 days. Secondary outcomes were symptomatic intracerebral hemorrhage and death. Generalized linear mixed models with the individual registry as a random intercept were performed to determine associations of treatment with low-dose alteplase and outcomes.

RESULTS

Of the 6250 patients (mean age 66 years, 36% women) included in these analyses, 1610 (24%) were treated with low-dose intravenous alteplase. Clinical outcomes for low-dose alteplase were not significantly different to those for standard-dose alteplase, adjusted odds ratios for death or disability: 1.00 (0.85-1.19) and symptomatic intracerebral hemorrhage 0.87 (0.63-1.19), except for lower death with borderline significance, 0.77 (0.59-1.01).

CONCLUSIONS

The present analyses of real-world Asian acute stroke registry data suggest that low-dose intravenous alteplase has overall comparable efficacy for functional recovery and greater potential safety in terms of reduced mortality, to standard-dose alteplase for the treatment of acute ischemic stroke.

Patients on NOACs in the Emergency Room

PURPOSE OF REVIEW

Despite the increasing use of NOACs, there is still uncertainty on how to treat NOAC patients presenting with neurological emergencies. Initial assessment of coagulation status is challenging but essential in these patients to provide best-possible treatment in case of ischemic or hemorrhagic stroke. Meanwhile, anticoagulation reversal strategies have been suggested; yet, the optimal management is still unestablished. The current review aims to provide up-to-date information on (i) how to identify patients with NOAC intake, (ii) which therapies are feasible in the setting of ischemic and hemorrhagic stroke as well as traumatic intracranial hemorrhage, and (iii) how to proceed with patients requiring emergency lumbar puncture.

RECENT FINDINGS

Despite several expert opinions, there is still an ongoing debate which NOAC patients presenting with ischemic stroke may benefit from recanalizing strategies and whether these treatment approaches can be performed safely. Results from two phase IV trials investigating the efficacy of NOAC-specific reversal agents in case of major bleeding seem promising with regard to hemostatic parameters, but these antidotes have not been verified to clinically benefit patients, and approval by authorities in parts is still pending. Specific reversal agents are on the way and will provide new treatment options in patients with NOAC-related ischemic and hemorrhagic stroke. Up to now, the decision which patients should undergo recanalizing treatment for ischemic stroke, or which specific pharmacological reversal treatment in hemorrhagic stroke should be initiated, has to be made cautiously on an individual basis after assessing hemostatic parameters.

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.

Applicability of ENCHANTED trial results to current acute ischemic stroke patients eligible for intravenous thrombolysis in England and Wales: Comparison with the Sentinel Stroke National Audit Programme registry

BACKGROUND

Randomized controlled trials provide high-level evidence, but the necessity to include selected patients may limit the generalisability of their results.

METHODS

Comparisons were made of baseline and outcome data between patients with acute ischemic stroke (AIS) recruited into the alteplase-dose arm of the international, multi-center, Enhanced Control of Hypertension and Thrombolysis Stroke study (ENCHANTED) in the United Kingdom (UK), and alteplase-treated AIS patients registered in the UK Sentinel Stroke National Audit Programme (SSNAP) registry, over the study period June 2012 to October 2015.

RESULTS

There were 770 AIS patients (41.2% female; mean age 72 years) included in ENCHANTED at sites in England and Wales, which was 19.5% of alteplase-treated AIS patients registered in the SSNAP registry. Trial participants were significantly older, had lower baseline neurological severity, less likely Asian, and had more premorbid symptoms, hypertension and atrial fibrillation. Although ENCHANTED participants had higher rates of symptomatic intracerebral hemorrhage than those in SSNAP, there were no differences in onset-to-treatment time, levels of disability (assessed by the modified Rankin scale) at hospital discharge, and mortality over 90 days between groups.

CONCLUSIONS

Despite the high level of participation, equipoise over the dose of alteplase among UK clinician investigators favored the inclusion of older, frailer, milder AIS patients in the ENCHANTED trial.

CLINICAL TRIAL REGISTRATION

Clinical Trial Registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT01422616.

LncRNA-1810034E14Rik reduces microglia activation in experimental ischemic stroke

Background

Activation of microglial cells plays an important role in neuroinflammation after ischemic stroke. Inhibiting the activation of microglial cells has been suggested as a potential therapeutic approach in the treatment of ischemic stroke.

Methods

Oxygen-glucose deprivation in primary microglial cells and transient middle cerebral artery occlusion (MCAO) in C57BL/6 mice were used as the in vitro and in vivo ischemic stroke models. Microarray analysis was performed to investigate the overall impact of long non-coding RNAs (lncRNAs) on the inflammation status of microglial cells. RT-qPCR was used to evaluate the lncRNA levels and mRNA levels of cytokines and microglial cell markers. ELISA was taken to measure the level of cytokines. Immunofluorescence was used to observe the activation of microglial cells. Western blotting was performed to test the p65 phosphorylation.

Results

In this study, we showed that LncRNA-1810034E14Rik was significantly decreased in LPS-treated or oxygen-glucose deprivation-induced microglial cells. Overexpression of 1810034E14Rik decreased the infarct volume and alleviated brain damage in MCAO mice. 1810034E14Rik overexpression reduced the expression of inflammatory cytokines not only in ischemic stroke mice but also in oxygen-glucose deprivation-induced microglial cells. Moreover, 1810034E14Rik overexpression could suppress the activation of microglial cells and inhibit the phosphorylation of p65.

Conclusions

LncRNA-1810034E14Rik plays an anti-inflammatory role in ischemic stroke and regulates p65 phosphorylation, making it a potential target for stroke treatment.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1464-x) contains supplementary material, which is available to authorized users.

Use of Mortality as an Endpoint in Noninferiority Trials May Lead to Ethically Problematic Conclusions

BACKGROUND

Noninferiority trials are becoming more common. Their design often requires investigators to "trade" a secondary benefit for efficacy. Use of mortality as an outcome of interest leads to important ethical conflicts whereby researchers must establish a minimal clinically important difference for mortality, a process which has the potential to result in problematic conclusions.

OBJECTIVE

We sought to investigate the frequency of the use of mortality as an outcome in noninferiority trials, as well as to determine the average pre-specified noninferiority ("delta") values.

DESIGN

We searched MEDLINE for reports of parallel-group randomized controlled noninferiority trials published in five high-impact general medical journals.

MAIN OUTCOME MEASURES

Data abstracted from articles including trial design parameters, results, and interpretation of results based on CONSORT recommendations.

RESULTS

One hundred seventy-three manuscripts reporting 196 noninferiority comparisons were included in our analysis. Of these, over a third (67 trials) used mortality either as their sole endpoint (11 trials) or as part of a composite endpoint (56 trials). Nine trials were consort A, 21 trials consort B, 19 trials consort C, 12 were consort F, 4 consort G, and 2 were consort H. Four analyses showed statistically significant more deaths in the new treatment arm, while meeting consort criteria as "inconclusive" (consort G), (Behringer et al. in Lancet. 385(9976):1418-1427, 2015; Kaul et al. in N Engl J Med. 373(18):1709-1719, 2015; Bwakura-Dangarembizi et al. in N Engl J Med. 370(1):41-53, 2014) and thirteen trials utilizing mortality as an endpoint and had an absolute increase of > 3%, and six had an absolute increase of > 5%.

CONCLUSIONS

The use of mortality as an outcome in noninferiority trials is not rare and scenarios where the new treatment is statistically worse, but a conclusion of noninferiority or inconclusive do occur. We highlight these issues and propose simple steps to reduce the risk of ethically dubious conclusions.

The randomized study of endovascular therapy with versus without intravenous tissue plasminogen activator in acute stroke with ICA and M1 occlusion (SKIP study)

Rationale

Bridging therapy with endovascular therapy (EVT) and intravenous thrombolysis (IVT) has been reported to improve outcomes for acute stroke patients with large-vessel occlusion in the anterior circulation. While the IVT may increase the reperfusion rate, the risk of hemorrhagic complications increases. Whether EVT without IVT (direct EVT) is equally effective as bridging therapy in acute stroke remains unclear.

Aim

This randomized study of endovascular therapy with versus without intravenous tissue plasminogen activator for acute stroke with ICA and M1 occlusion aims to clarify the efficacy and safety of direct EVT compared with bridging therapy.

Methods and design

This is an investigator-initiated, multicenter, prospective, randomized, open-treatment, blinded-endpoint clinical trial. The target patient number is 200, comprising 100 patients receiving direct EVT and 100 receiving bridging therapy.

Study outcome

The primary efficacy endpoint is a modified Rankin Scale score of 0–2 at 90 days. Safety outcome measures are any intracranial hemorrhage at 24 h.

Discussion

This trial may help determine whether direct EVT should be recommended as a routine clinical strategy for ischemic stroke patients within 4.5 h from onset. Direct EVT would then become the choice of therapy in stroke centers with endovascular facilities.

Trial registration

UMIN000021488.

Local in situ fibrinolysis for recanalization of an occluded extracranial-intracranial bypass: Technical note

Extracranial-intracranial (EC-IC) bypass is a versatile technique to augment or preserve blood flow when treating cerebrovascular pathologies to prevent ischemic complications. Technical success and good patient outcomes rely on the successful establishment and maintenance of a patent bypass graft. Multiple modalities have been developed to confirm intraoperative graft patency. However, techniques and strategies to manage an occluded bypass are sparsely reported. The authors describe a novel technique for the in situ fibrinolysis utilizing recombinant tissue plasminogen activator (r-tPA) to recanalize an occluded EC-IC bypass following thrombus formation. This technique is feasible and effective in restoring long term EC-IC graft patency without requirement of additional vessel harvest or added ischemia time which may be tailored for use with other pharmacologic agents based on the acuity of an in-graft thrombosis.

Making a case for the right '-ase' in acute ischemic stroke: alteplase, tenecteplase, and reteplase

INTRODUCTION

Alteplase, reteplase, and tenecteplase are tissue plasminogen activators (TPA) approved for the management of acute myocardial infarction. Only alteplase is also approved for the treatment of acute ischemic stroke (AIS). The US Food and Drug Administration has received reports of accidental administration of tenecteplase or reteplase instead of alteplase in patients with AIS, which can result in failure to treat patients with the intended agent and lead to potential overdose.

AREAS COVERED

This review compares the molecular and clinical features of alteplase, reteplase, and tenecteplase (TNK), identifies factors contributing to medication errors among these agents, and provides steps to reduce medication errors.

EXPERT OPINION

Primary factors contributing to medication errors among tissue plasminogen activators include the use of the abbreviations 'TPA,' 'tPA,' or 'TNK' in written or verbal orders and use of these agents in similar settings (e.g. emergency departments and critical care areas). Steps to reduce the likelihood of accidental substitution of tenecteplase or reteplase for alteplase in patients with AIS include the use of full brand or generic names and inclusion of the indication in written and verbal orders, the addition of alerts in automated dispensing machines and ordering systems and use of stroke boxes containing alteplase and materials for administration.

Mathematical Modelling of Intravenous Thrombolysis in Acute Ischaemic stroke: Effects of Dose Regimens on Levels of Fibrinolytic Proteins and Clot Lysis Time

Thrombolytic therapy is one of the medical procedures in the treatment of acute ischaemic stroke (AIS), whereby the tissue plasminogen activator (tPA) is intravenously administered to dissolve the obstructive blood clot. The treatment of AIS by thrombolysis can sometimes be ineffective and it can cause serious complications, such as intracranial haemorrhage (ICH). In this study, we propose an efficient mathematical modelling approach that can be used to evaluate the therapeutic efficacy and safety of thrombolysis in various clinically relevant scenarios. Our model combines the pharmacokinetics and pharmacodynamics of tPA with local clot lysis dynamics. By varying the drug dose, bolus-infusion delay time, and bolus-infusion ratio, with the FDA approved dosing protocol serving as a reference, we have used the model to simulate 13 dose regimens. Simulation results are compared for temporal concentrations of fibrinolytic proteins in plasma and the time that is taken to achieve recanalisation. Our results show that high infusion rates can cause the rapid degradation of plasma fibrinogen, indicative of increased risk for ICH, but they do not necessarily lead to fast recanalisation. In addition, a bolus-infusion delay results in an immediate drop in plasma tPA concentration, which prolongs the time to achieve recanalisation. Therefore, an optimal administration regimen should be sought by keeping the tPA level sufficiently high throughout the treatment and maximising the lysis rate while also limiting the degradation of fibrinogen in systemic plasma. This can be achieved through model-based optimisation in the future.

Intensive blood pressure reduction with intravenous thrombolysis therapy for acute ischaemic stroke (ENCHANTED): an international, randomised, open-label, blinded-endpoint, phase 3 trial

BACKGROUND

Systolic blood pressure of more than 185 mm Hg is a contraindication to thrombolytic treatment with intravenous alteplase in patients with acute ischaemic stroke, but the target systolic blood pressure for optimal outcome is uncertain. We assessed intensive blood pressure lowering compared with guideline-recommended blood pressure lowering in patients treated with alteplase for acute ischaemic stroke.

METHODS

We did an international, partial-factorial, open-label, blinded-endpoint trial of thrombolysis-eligible patients (age ≥18 years) with acute ischaemic stroke and systolic blood pressure 150 mm Hg or more, who were screened at 110 sites in 15 countries. Eligible patients were randomly assigned (1:1, by means of a central, web-based program) within 6 h of stroke onset to receive intensive (target systolic blood pressure 130-140 mm Hg within 1 h) or guideline (target systolic blood pressure <180 mm Hg) blood pressure lowering treatment over 72 h. The primary outcome was functional status at 90 days measured by shift in modified Rankin scale scores, analysed with unadjusted ordinal logistic regression. The key safety outcome was any intracranial haemorrhage. Primary and safety outcome assessments were done in a blinded manner. Analyses were done on intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT01422616.

FINDINGS

Between March 3, 2012, and April 30, 2018, 2227 patients were randomly allocated to treatment groups. After exclusion of 31 patients because of missing consent or mistaken or duplicate randomisation, 2196 alteplase-eligible patients with acute ischaemic stroke were included: 1081 in the intensive group and 1115 in the guideline group, with 1466 (67·4%) administered a standard dose among the 2175 actually given intravenous alteplase. Median time from stroke onset to randomisation was 3·3 h (IQR 2·6-4·1). Mean systolic blood pressure over 24 h was 144·3 mm Hg (SD 10·2) in the intensive group and 149·8 mm Hg (12·0) in the guideline group (p<0·0001). Primary outcome data were available for 1072 patients in the intensive group and 1108 in the guideline group. Functional status (mRS score distribution) at 90 days did not differ between groups (unadjusted odds ratio [OR] 1·01, 95% CI 0·87-1·17, p=0·8702). Fewer patients in the intensive group (160 [14·8%] of 1081) than in the guideline group (209 [18·7%] of 1115) had any intracranial haemorrhage (OR 0·75, 0·60-0·94, p=0·0137). The number of patients with any serious adverse event did not differ significantly between the intensive group (210 [19·4%] of 1081) and the guideline group (245 [22·0%] of 1115; OR 0·86, 0·70-1·05, p=0·1412). There was no evidence of an interaction of intensive blood pressure lowering with dose (low vs standard) of alteplase with regard to the primary outcome.

INTERPRETATION

Although intensive blood pressure lowering is safe, the observed reduction in intracranial haemorrhage did not lead to improved clinical outcome compared with guideline treatment. These results might not support a major shift towards this treatment being applied in those receiving alteplase for mild-to-moderate acute ischaemic stroke. Further research is required to define the underlying mechanisms of benefit and harm resulting from early intensive blood pressure lowering in this patient group.

FUNDING

National Health and Medical Research Council of Australia; UK Stroke Association; Ministry of Health and the National Council for Scientific and Technological Development of Brazil; Ministry for Health, Welfare, and Family Affairs of South Korea; Takeda.

Management of Acute Ischemic Stroke

The treatment of acute ischemic stroke includes both intravenous (IV) thrombolysis and mechanical thrombectomy. Important advances regarding both treatment modalities have occurred recently that all physicians who see patients at risk for or who have had a stroke should be aware of. This review will focus on recent clinical trials of IV thrombolysis both positive and negative. Additionally, the results of a large number of early and late time window thrombectomy trials will be presented that demonstrate the remarkable efficacy of this treatment for appropriately selected patients.

Low-dose rt-PA may not decrease the incidence of symptomatic intracranial haemorrhage in patients with high risk of symptomatic intracranial haemorrhage

BACKGROUND

Recombinant tissue plasminogen activator (rt-PA) has been used as the standard treatment for acute ischemic stroke (AIS). The following study investigates whether low-dose rt-PA can decrease the incidence of symptomatic intracranial haemorrhage (sICH) in AIS patients with high-risk sICH compared to standard-dose rt-PA.

MATERIALS AND METHODS

Data from the Thrombolysis Implementation and Monitor of Acute Ischemic Stroke in China (TIMS-China) studies were assessed to explore risk factors for sICH after intravenous thrombolysis. For high-risk sICH patients (age ≧70 years old, or with diabetes, or serum glucose on admission >9.0 mmol/L, or NIHSS on admission>20, or with cardioembolism), standard-dose rt-PA (0.85 to 0.95 mg/kg) and low- dose rt-PA (0.5 to 0.7 mg/kg) were compared. Primary outcome measure was the incidence of sICH, and the secondary outcome measures were 7-day mortality and 90-day functional independence outcome (modified Rankin scale, 0-2).

RESULTS

A total of 554 patients were enrolled (60 cases for low dose, and 494 cases for standard dose). Median rt-PA doses were 0.63 and 0.90 mg, respectively. After adjustment for the baseline variables, low-dose rt-PA did not decrease the incidence of sICH (per SITS-MOST criteria, 3.33% versus 2.23%, P = 0.3467) compared to low dose. The low-dose group revealed less functional independence outcomes (modified Rankin scale, 0-2) compared to standard-dose group (36.67% versus 52.43%; odds ratio = 0.49; p = 0.0204) at 90 days.

CONCLUSIONS

Our study suggests that low-dose intravenous rt-PA for high-risk sICH stroke in Chinese patients may not decrease the incidence of sICH, and concomitant with a poor outcome compared to standard-dose rt-PA.

ABBREVIATIONS

rt-PA: recombinant tissue plasminogen activator; AIS: acute ischemic stroke; sICH: symptomatic intracranial haemorrhage.

The National Institute for Health Research Hyperacute Stroke Research Centres and the ENCHANTED trial: the impact of enhanced research infrastructure on trial metrics and patient outcomes

BACKGROUND

The English National Institute for Health Research Clinical Research Network first established Hyperacute Stroke Research Centres (HSRCs) in 2010 to support multicentre hyperacute (< 9 h) and complex stroke research. We assessed the impact of this investment on research performance and patient outcomes in a post-hoc analysis of country-specific data from a large multicentre clinical trial.

METHODS

Comparisons of baseline, outcome and trial metric data were made for participants recruited to the alteplase-dose arm of the international Enhanced Control of Hypertension and Thrombolysis Stroke study (ENCHANTED) at National Institute for Health Research Clinical Research Network HSRCs and non-HSRCs between June 2012 and October 2015.

RESULTS

Among 774 ENCHANTED United Kingdom participants (41% female; mean age 72 years), 502 (64.9%) were recruited from nine HSRCs and 272 (35.1%) from 24 non-HSRCs. HSRCs had higher monthly recruitment rates (median 1.5, interquartile interval 1.4-2.2 vs. 0.7, 0.5-1.3; p = 0.01) and shorter randomisation-to-treatment times (2.6 vs. 3.1 min; p = 0.01) compared to non-HSRCs. HSRC participants were younger and had milder stroke severity, but clinically important between-group differences in 90-day death or disability outcomes remained after adjustment for minimisation criteria and important baseline variables at randomisation, whether defined by ordinal modified Rankin scale score shift (adjusted OR 0.82, 95% CI 0.62-1.08; p = 0.15), scores 2 to 6 (adjusted OR 0.71, 95% CI 0.50-1.01; p = 0.05), or scores 3 to 6 (adjusted OR 0.82, 95% CI 0.57-1.17; p = 0.27). There was no significant difference in symptomatic intracerebral haemorrhage, nor heterogeneity in the comparative treatment effects between low- and standard-dose alteplase by HSRCs or non-HSRCs.

CONCLUSIONS

Infrastructure investment in HSRCs was associated with improved research performance metrics, particularly recruitment and time to treatment with clinically important, though not statistically significant, improvements in patient outcomes.

TRIAL REGISTRATION

Unique identifier: NCT01422616 .

Low-dose versus standard-dose intravenous alteplase for octogenerian acute ischemic stroke patients: A multicenter prospective cohort study

BACKGROUND AND PURPOSE

The optimal dose of alteplase for acute ischemic stroke among geriatric patients is unclear. We aimed to assess the efficacy and safety of a low-dose (0.6 mg/kg) and standard-dose (0.9 mg/kg) alteplase for varying severity of Asian geriatric stroke patients.

METHODS

The favorable functional outcome on day 90 after stroke onset, and the symptomatic intracranial hemorrhage (SICH) rate following 24-36 h of intravenous alteplase were measured. The baseline NIHSS of 4-8, 9-13, ≥14 were defined as mild, moderate, and high severity, respectively.

RESULTS

Totally, 249 geriatric patients treated with low-dose (n = 108) and standard-dose (n = 141) alteplase. Compared to standard-dose alteplase, low-dose alteplase had decrease in favorable functional outcome (22.2% versus 34.8%), and no difference in SICH rates was observed. For mild severity patients, the mortality was significantly increased with standard-dose alteplase (the NNT/NNH = 22.9/8.0 for mild severity, the NNT/ NNH = 15.0/14.7 for moderate severity, and the NNT/NNH = 13.5/19.6 for high severity).

CONCLUSIONS

Standard-dose and low-dose alteplase were comparable in reducing major disability, but low-dose alteplase for mild stroke showed much reduced mortality on day 90 for octogenarians.

The safety and efficacy of tPA intravenous thrombolysis for treating acute ischemic stroke patients with a history of cerebral hemorrhage

Alteplase (tPA) intravenous thrombolysis is an effective treatment for acute ischemic stroke (AIS) when administered within 4.5 h of initial stroke symptoms. Here, its safety and efficacy were evaluated among AIS patients with a previous history of cerebral hemorrhage. Patients who arrived at the hospital within 4.5 h of initial stroke symptoms and who were treated with tPA intravenous thrombolysis or conventional therapies were analyzed. The 90-day modified Rankin scale (90-d mRS) was used alongside mortality and incidence of symptomatic intracerebral hemorrhage (SICH) rates to evaluate the curative effect of these therapies. Among 1,694 AIS patients, 805 patients were treated with intravenous thrombolysis, including patients with (n=793) or without (n=12) a history of cerebral hemorrhage, and the rate of incidence of SICH significantly differed between them (8.3 vs 4.3%, P=0.039). No significant difference was found in 90-d mRS measurements (41.7 vs 43.6%, P=0.530) and 90-d mortality rates (8.3 vs 6.5%, P=0.946). A total of 76 AIS patients with a history of cerebral hemorrhage received tPA thrombolytic therapy (n=12) or conventional therapy (n=64), and a significant difference was noted in the 90-d mRS scores between the two groups (41.7 vs 23.4%, P=0.029), while no significant difference was found in SICH measurements (8.3 vs 4.6%, P=0.610) and 90-d mortality rates (8.3 vs 9.4%, P=0.227). A history of cerebral hemorrhage is not an absolute contraindication for thrombolytic therapy; tPA intravenous thrombolysis does not increase SICH measurements and mortality rates in patients with a history of cerebral hemorrhage, and they may benefit from thrombolytic therapy.

rt-PA with remote ischemic postconditioning for acute ischemic stroke

Objective

To investigate the feasibility and safety of remote ischemic postconditioning (RIPC) in acute ischemic stroke patients after intravenous recombinant tissue plasminogen activator (rt‐PA) thrombolysis (IVT).

Methods

We performed a pilot randomized trial involving acute ischemic stroke patients with IVT. The patients were randomized 1:1 to receive RIPC or standard medical therapy. In the RIPC group, the participants underwent instant RIPC within 2 h of IVT, followed by repeated RIPC therapy for 7 days. The feasibility end point was the completion of RIPC and time from the first RIPC to finishing IVT in the RIPC group. The safety end point included tissue and neurovascular injury resulting from RIPC, changes in vital signs, level of plasma myoglobin, any hemorrhagic transformation, and other adverse events.

Results

Thirty patients (15 RIPC and 15 Control) were recruited after IVT. The mean age was 65.7 ± 10.2 years, with a National Institutes of Health Stroke Scale (NIHSS) score of 6.5 (4.0–10.0). The completion rate for RIPC was 97.0%. The mean time from first RIPC to completing IVT was 66.0 (25.0–75.0) min in the RIPC group. One case of hemorrhagic transformation was observed in the RIPC group. No significant difference was found in the level of myoglobin between the two groups (P > 0.05).

Interpretation

RIPC is effective and safe for AIS patients after intravenous rt‐PA thrombolysis.

Innovations in Acute Stroke Reperfusion Strategies

Vascular neurology is witnessing unprecedented innovations in the management of acute ischemic stroke, especially in reperfusion strategies. The emergence of mechanical thrombectomy with new generation devices has revolutionized the treatment of acute ischemic stroke with large vessel occlusion. The reperfusion strategies are evolving with the extension of the window period for thrombolysis and endovascular therapy through the concept of “tissue clock” in addition to the established “time clock.” The newer generation of thrombolytic drugs like tenecteplase are promising exciting times ahead in acute stroke care. In this “viewpoint,'” the evolution of reperfusion therapy in acute ischemic stroke will be discussed followed by recent innovations in reperfusion strategies.

Intravenous Thrombolysis in Acute Ischemic Stroke After Idarucizumab Reversal of Dabigatran Effect: Analysis of the Cases From Taiwan

BACKGROUND

Asians with atrial fibrillation carry a higher risk of ischemic stroke than non-Asians even under treatment of nonvitamin K antagonist oral anticoagulants. The purpose of the study was to observe the feasibility of intravenous thrombolytic therapy after administering a reversal agent, idarucizumab, in dabigatran-treated patients with acute ischemic stroke in Taiwan.

METHODS

Dabigatran-treated patients with acute ischemic stroke who received intravenous recombinant tissue plasminogen activator (rt-PA) after idarucizumab reversal were enrolled in the retrospective nationwide study. The clinical data, treatment course, and outcomes were recorded. Stroke severity was evaluated using the National Institutes of Health Stroke Scale (NIHSS) score. Any intracerebral hemorrhage (ICH) after rt-PA was detected by neuroimaging studies.

RESULTS

Ten dabigatran-treated patients (6 men, mean age 71.10 ± 7.96 years) with acute ischemic stroke were included. Before stroke, the mean CHA₂DS₂-VASc score was 4.50 ± 1.57 and 8 patients (80%) received dabigatran 110 mg twice daily. All patients were treated with 5 g idarucizumab, following which the activated partial thromboplastin time normalized. Intravenous rt-PA (mean dose .78 mg/kg) was initiated a mean time of 11.11 minutes after idarucizumab infusion. The NIHSS score improved significantly after thrombolysis (16.0 ± 6.67 at admission to 9.38 ± 4.75 at discharge, P = .016). ICH developed in 3 patients (30%). Two of them were asymptomatic and 1 patient suffered from symptomatic ICH leading to mortality.

CONCLUSION

Our data reconfirmed the feasibility of intravenous rt-PA for Asian stroke patients after reversal of dabigatran effect with idarucizumab.

Effect of Clot Stiffness on Recombinant Tissue Plasminogen Activator Lytic Susceptibility in Vitro

The lytic recombinant tissue plasminogen activator (rt-PA) is the only drug approved by the Food and Drug Administration for treating ischemic stroke. Less than 40% of patients with large vessel occlusions who are treated with rt-PA have improved blood flow. However, up to 6% of all patients receiving rt-PA develop intracerebral hemorrhage. Predicting the efficacy of rt-PA treatment a priori could help guide therapeutic decision making, such that rt-PA is administered only to those individuals who would benefit from this treatment. Clot composition and structure affect the lytic efficacy of rt-PA and have an impact on elasticity. However, the relationship between clot elasticity and rt-PA lytic susceptibility has not been adequately investigated. The goal of this study was to quantify the relationship between clot elasticity and rt-PA susceptibility in vitro. Human and porcine highly retracted and mildly retracted clots were fabricated in glass pipettes. The rt-PA lytic susceptibility was evaluated in vitro using the percent clot mass loss. The Young's moduli of the clots were estimated using ultrasound-based single-track-location shear wave elasticity imaging. The percent mass loss in mildly retracted porcine and human clots (28.9 ± 6.1% and 45.2 ± 7.1%, respectively) was significantly higher (p < 0.05) than in highly retracted porcine and human clots (10.9 ± 2.1% and 25.5 ± 10.0%, respectively). Furthermore, the Young's moduli of highly retracted porcine and human clots (5.33 ± 0.92 and 3.21 ± 1.97 kPa, respectively) were significantly higher (p < 0.05) than those of mildly retracted porcine and human clots (2.66 ± 0.55 and 0.79 ± 0.21 kPa, respectively). The results revealed an inverse relationship between the percent clot mass loss and Young's modulus. These findings motivate continued investigation of ultrasound-based methods to assess clot stiffness in order to predict rt-PA thrombolytic efficacy.

Predictors of functional outcome in patients with stroke thrombolysis in a tertiary hospital in Malaysia

INTRODUCTION

Intravenous (IV) thrombolysis with alteplase (rt-PA) is effective in ischaemic stroke. The primary objective was to evaluate predictors of functional outcome in acute ischaemic stroke (AIS) patients treated with IV rt-PA. The secondary objective was to assess the outcome with the modified Rankin scale (mRS). We also examined the predictive value of the Totaled Health Risks in Vascular Events (THRIVE) score.

METHODS

AIS patients treated with IV rt-PA from February 2012 to August 2016 were recruited. Demographic data, National Institutes of Health Stroke Scale (NIHSS) scores, timing and neuroradiological findings were recorded. Patients received a dose of 0.9 mg/kg IV rt-PA within 4.5 hours of symptom onset. mRS score was evaluated at discharge and three months, and good and poor clinical outcomes were defined as scores of 0-2 and 3-6, respectively. Baseline THRIVE scores were assessed.

RESULTS

36 patients received IV rt-PA. 20 (55.6%) patients had an mRS score of 0-2 at three months. Based on THRIVE score, 86.1% had a good or moderately good prognosis. On univariate analysis, poor outcome was associated with NIHSS score before rt-PA (p = 0.03), THRIVE score (p = 0.02), stroke subtype (p = 0.049) and diabetes mellitus (DM; p = 0.06). Multiple logistic regression showed that outcome was significantly associated with NIHSS score before rt-PA (p = 0.032) and DM (p = 0.010).

CONCLUSION

Our newly developed Malaysian IV rt-PA service is safe, with similar outcomes to the published literature. Functional outcome after thrombolysis was associated with baseline NIHSS score and DM.

Hemoglobin level and three-month clinical outcomes among ischemic stroke patients with elevated systolic blood pressure

BACKGROUND

Previous studies have reported that extreme low and high hemoglobin levels are positively associated with the risk of ischemic stroke. However, there are few reports on the relationship between hemoglobin at acute phase and clinical outcomes after ischemic stroke and the results of their association to date are inconsistent. We aimed to investigate the association between them in a large prospective cohort of ischemic stroke patients.

METHODS

Baseline hemoglobin levels were measured in 3881 patients with acute ischemic stroke. The primary outcome was defined as composite outcome of major disability and death (modified Rankin Scale score ≥ 3) at 3 months after stroke onset. Secondary outcomes were separately those of major disability and death.

RESULTS

Compared with the lowest quartile of hemoglobin, the multivariate adjusted odds ratios (95% confidence intervals) associated with the highest quartile were 1.38 (1.03-1.86), 1.49 (1.11-1.99), 0.79 (0.41-1.52) for primary outcome, major disability and death, respectively. Multiple-adjusted spline regression model showed linear associations of hemoglobin levels with primary outcome (P for linearity =0.037) and major disability (P for linearity =0.004). Subgroup analyses further confirmed the positive association between high hemoglobin and poor prognosis of ischemic stroke.

CONCLUSIONS

Elevated hemoglobin levels in the acute phase were associated with poor prognosis at 3 months after ischemic stroke. Further prospective studies from other samples of ischemic stroke patients are needed to validate our findings.

The role of plasminogen activators in stroke treatment: fibrinolysis and beyond

Although recent technical advances in thrombectomy have revolutionised acute stroke treatment, prevalence of disability and death related to stroke remain high. Therefore, plasminogen activators-eukaryotic, bacterial, or engineered forms that can promote fibrinolysis by converting plasminogen into active plasmin and facilitate clot breakdown-are still commonly used in the acute treatment of ischaemic stroke. Hence, plasminogen activators have become a crucial area for clinical investigation for their ability to recanalise occluded arteries in ischaemic stroke and to accelerate haematoma clearance in haemorrhagic stroke. However, inconsistent results, insufficient evidence of efficacy, or reports of side-effects in trial settings might reduce the use of plasminogen activators in clinical practice. Additionally, the mechanism of action for plasminogen activators could extend beyond the vessel lumen and involve plasminogen-independent processes, which would suggest that plasminogen activators have also non-fibrinolytic roles. Understanding the complex mechanisms of action of plasminogen activators can guide future directions for therapeutic interventions in patients with stroke.

NIHSS cut point for predicting outcome in supra- vs infratentorial acute ischemic stroke

OBJECTIVE

To determine the optimal cut point on the NIH Stroke Scale (NIHSS) for predicting poor 90-day clinical outcome in patients with supratentorial and infratentorial acute ischemic stroke (AIS).

METHODS

Data are from participants of the alteplase-dose arm of the randomized controlled trial, Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED). Associations between baseline characteristics of clinically defined supratentorial and infratentorial AIS patients and poor functional outcome, defined by scores 3-6 on the modified Rankin Scale, were evaluated in logistic regression models, with area under the curve (AUC) receiver operating characteristics defining the optimal NIHSS predictor cut point.

RESULTS

Patients with infratentorial AIS (n = 289) had lower baseline NIHSS scores than those with supratentorial AIS (n = 2,613) (median 7 vs 9; p < 0.001). NIHSS cut points for poor outcome were 10 (AUC 76, sensitivity 65%, specificity 73%) and 6 (AUC 69, sensitivity 72%, specificity 56%) in supratentorial and infratentorial AIS, respectively. There was no significant difference in functional outcome or symptomatic intracranial hemorrhage between AIS types.

CONCLUSIONS

In thrombolysis-eligible AIS patients, the NIHSS may underestimate clinical severity for infratentorial compared to supratentorial lesions for a similar prognosis for recovery. Because thrombolysis treatment has low effect on stroke outcome in patients with infratentorial AIS when baseline NIHSS score is more than 6, additional treatment such as endovascular treatment should be considered to improve stroke outcome.

CLINICALTRIALSGOV IDENTIFIER

NCT01422616.

Ordinal vs dichotomous analyses of modified Rankin Scale, 5-year outcome, and cost of stroke

Objective

To compare how 3 common representations (ordinal vs dichotomized as 0–1/2–6 or 0–2/3–6) of the modified Rankin Scale (mRS)—a commonly used trial outcome measure—relate to long-term outcomes, and quantify trial ineligibility rates based on premorbid mRS.

Methods

In consecutive patients with ischemic stroke in a population-based, prospective, cohort study (Oxford Vascular Study; 2002–2014), we related 3-month mRS to 1-year and 5-year disability and death (logistic regressions), and health/social care costs (generalized linear model), adjusted for age/sex, and compared goodness-of-fit values (C statistic, mean absolute error). We also calculated the proportion of patients in whom premorbid mRS score >1 or >2 would result in exclusion from trials using dichotomous analysis.

Results

Among 1,607 patients, the ordinal mRS was more strongly related to 5-year mortality than both the 0–1/2–6 and 0–2/3–6 dichotomies (all p < 0.0001). Results were similar for 5-year disability, and 5-year care costs were also best captured by the ordinal model (change in mean absolute error vs age/sex: −$3,059 for ordinal, −$2,805 for 0–2/3–6, −$1,647 for 0–1/2–6). Two hundred forty-four (17.1%) 3-month survivors had premorbid mRS score >2 and 434 (30.5%) had mRS score >1; both proportions increased with female sex, socioeconomic deprivation, and age (all p < 0.0001).

Conclusion

The ordinal form of the 3-month mRS relates better to long-term outcomes and costs in survivors of ischemic stroke than either dichotomy. This finding favors using ordinal approaches in trials analyzing the mRS. Exclusion of patients with higher premorbid disability by use of dichotomous primary outcomes will also result in unrepresentative samples.

Diabetes mellitus inhibits complete recanalization in patients with middle cerebral artery occlusion

Methods: This was a retrospective cohort study. Data from 165 patients, with middle cerebral occlusion before t-PA therapy (from the YAMATO study databank), were retrospectively evaluated. Patients were classified into diabetic (D) or non-diabetic (ND) groups based on the history of diabetes mellitus (DM) or hemoglobin A1c levels of ≥ 6.5%. Arterial recanalization was assessed using magnetic resonance angiography or digital subtraction angiography at 2 points: 1) early recanalization, within 2 h; 2) delayed complete recanalization at 24 h. Good clinical outcome was defined as modified Rankin Scale score 0-2 at 3 months. Results: A total of 33 (21%) were classified into the D and 127 (79%) in the ND groups. Early recanalization was similarly in the D and ND groups (61% vs. 52%, p = 0.434). However, complete recanalization at 24 h was infrequent in the D group (13% vs. 43%, p = 0.002). Among patients with early recanalization, 4 (22%) of 18 patients in the D group and 32 (56%) of 57 patients in the ND group had complete recanalization at 24 h (p = 0.015); while among those without early recanalization, 17 (30%) in the ND and none in the D groups had complete recanalization at 24 h (p = 0.028). Multivariate regression analysis showed DM was one of the independent negative factors for complete recanalization at 24 h (odds ratio 0.113, 95%CI: 0.027-0.472, p = 0.003). At 3 months, group with complete recanalization at 24 h achieved higher frequency of good outcome (67% vs. 49%, p = 0.046). Conclusion: Diabetes might be a risk factor of incomplete recanalization at 24 h regardless of early recanalization.