Urgent therapy for stroke. Part II. Pilot study of tissue plasminogen activator administered 91-180 minutes from onset

Safety and efficacy of active blood-pressure reduction to the recommended thresholds for intravenous thrombolysis in patients with acute ischaemic stroke in the Netherlands (TRUTH): a prospective, observational, cluster-based, parallel-group study

BACKGROUND

Intravenous thrombolysis is contraindicated in patients with ischaemic stroke with blood pressure higher than 185/110 mm Hg. Prevailing guidelines recommend to actively lower blood pressure with intravenous antihypertensive agents to allow for thrombolysis; however, there is no robust evidence for this strategy. Because rapid declines in blood pressure can also adversely affect clinical outcomes, several Dutch stroke centres use a conservative strategy that does not involve the reduction of blood pressure. We aimed to compare the clinical outcomes of both strategies.

METHODS

Thrombolysis and Uncontrolled Hypertension (TRUTH) was a prospective, observational, cluster-based, parallel-group study conducted across 37 stroke centres in the Netherlands. Participating centres had to strictly adhere to an active blood-pressure-lowering strategy or to a non-lowering strategy. Eligible participants were adults (≥18 years) with ischaemic stroke who had blood pressure higher than 185/110 mm Hg but were otherwise eligible for intravenous thrombolysis. The primary outcome was functional status at 90 days, measured using the modified Rankin Scale and assessed through telephone interviews by trained research nurses. Secondary outcomes were symptomatic intracranial haemorrhage, the proportion of patients treated with intravenous thrombolysis, and door-to-needle time. All ordinal logistic regression analyses were adjusted for age, sex, stroke severity, endovascular thrombectomy, and baseline imbalances as fixed-effect variables and centre as a random-effect variable to account for the clustered design. Analyses were done according to the intention-to-treat principle, whereby all patients were analysed according to the treatment strategy of the participating centre at which they were treated.

FINDINGS

Recruitment began on Jan 1, 2015, and was prematurely halted because of a declining inclusion rate and insufficient funding on Jan 5, 2022. Between these dates, we recruited 853 patients from 27 centres that followed an active blood-pressure-lowering strategy and 199 patients from ten centres that followed a non-lowering strategy. Baseline characteristics of participants from the two groups were similar. The 90-day mRS score was missing for 15 patients. The adjusted odds ratio (aOR) for a shift towards a worse 90-day functional outcome was 1·27 (95% CI 0·96-1·68) for active blood-pressure reduction compared with no active blood-pressure reduction. 798 (94%) of 853 patients in the active blood-pressure-lowering group were treated with intravenous thrombolysis, with a median door-to-needle time of 35 min (IQR 25-52), compared with 104 (52%) of 199 patients treated in the non-lowering group with a median time of 47 min (29-78). 42 (5%) of 852 patients in the active blood-pressure-lowering group had a symptomatic intracranial haemorrhage compared with six (3%) of 199 of those in the non-lowering group (aOR 1·28 [95% CI 0·62-2·62]).

INTERPRETATION

Insufficient evidence was available to establish a difference between an active blood-pressure-lowering strategy-in which antihypertensive agents were administered to reduce blood pressure below 185/110 mm Hg-and a non-lowering strategy for the functional outcomes of patients with ischaemic stroke, despite higher intravenous thrombolysis rates and shorter door-to-needle times among those in the active blood-pressure-lowering group. Randomised controlled trials are needed to inform the use of an active blood-pressure-lowering strategy.

FUNDING

Fonds NutsOhra.

Underrepresented and Underserved Populations in Neurological Research

Underserved and underrepresented populations have historically been excluded from neurological research. This lack of representation has implications for translation of research findings into clinical practice given the impact of social determinants of health on neurological disease risk, progression, and outcomes. Lack of inclusion in research is driven by individual-, investigator-, and study-level barriers as well as larger systemic injustices (e.g., structural racism, discriminatory practices). Although strategies to increase inclusion of underserved and underrepresented populations have been put forth, numerous questions remain about the most effective methodology. In this article, we highlight inclusivity patterns and gaps among the most common neurological conditions and propose best practices informed by our own experiences in engagement of local community organizations and collaboration efforts to increase underserved and underrepresented population participation in neurological research.

Specific inhibition on PAI-1 reduces the dose of Alteplase for ischemic stroke treatment

Administration of recombinant tPA (rtPA, or trade name Alteplase®) is an FDA-approved therapy for acute ischemic stroke (AIS), but poses the risk of hemorrhagic complications. Recombinant tPA can be rapidly inactivated by the endogenous inhibitor, plasminogen activator inhibitor 1 (PAI-1). In this work, we study a novel treatment approach that combines a PAI-1 inhibitor, PAItrap4, with a reduced dose of rtPA to address the hemorrhagic concern of rtPA. PAItrap4 is a highly specific and very potent protein-based inhibitor of PAI-1, comprising of a variant of uPA serine protease domain, human serum albumin, and a cyclic RGD peptide. PAItrap4 efficiently targets and inhibits PAI-1 on activated platelets, and also possesses a long half-life in vivo. Our results demonstrate that PAItrap4 effectively counteracts the inhibitory effects of PAI-1 on rtPA, preserving rtPA activity based on amidolytic and clot lysis assays. In an in vivo murine stroke model, PAItrap4, together with low-dose rtPA, enhances the blood perfusion in the stroke-affected areas, reduces infarct size, and promotes neurological recovery in mice. Importantly, such treatment does not increase the amount of cerebral hemorrhage, thus reducing the risk of cerebral hemorrhage. In addition, PAItrap4 does not compromise the normal blood coagulation function in mice, demonstrating its safety as a therapeutic agent. These findings highlight this combination therapy as a promising alternative for the treatment of ischemic stroke, offering improved safety and efficacy.

Thrombectomy in Stroke Patients With Low Alberta Stroke Program Early Computed Tomography Score: Is Modified Thrombolysis in Cerebral Infarction (mTICI) 2c/3 Superior to mTICI 2b?

BACKGROUND AND PURPOSE

Outcomes following mechanical thrombectomy (MT) are strongly correlated with successful recanalization, traditionally defined as modified Thrombolysis in Cerebral Infarction (mTICI) ≥2b. This retrospective cohort study aimed to compare the outcomes of patients with low Alberta Stroke Program Early Computed Tomography Score (ASPECTS; 2-5) who achieved mTICI 2b versus those who achieved mTICI 2c/3 after MT.

METHODS

This study utilized data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which combined databases from 32 thrombectomy-capable stroke centers between 2013 and 2023. The study included only patients with low ASPECTS who achieved mTICI 2b, 2c, or 3 after MT for internal carotid artery or middle cerebral artery (M1) stroke.

RESULTS

Of the 10,229 patients who underwent MT, 234 met the inclusion criteria. Of those, 98 (41.9%) achieved mTICI 2b, and 136 (58.1%) achieved mTICI 2c/3. There were no significant differences in baseline characteristics between the two groups. The 90-day favorable outcome (modified Rankin Scale score: 0-3) was significantly better in the mTICI 2c/3 group than in the mTICI 2b group (adjusted odds ratio 2.35; 95% confidence interval [CI] 1.18-4.81; P=0.02). Binomial logistic regression revealed that achieving mTICI 2c/3 was significantly associated with higher odds of a favorable 90-day outcome (odds ratio 2.14; 95% CI 1.07-4.41; P=0.04).

CONCLUSION

In patients with low ASPECTS, achieving an mTICI 2c/3 score after MT is associated with a more favorable 90-day outcome. These findings suggest that mTICI 2c/3 is a better target for MT than mTICI 2b in patients with low ASPECTS.

Management of hypertensive crisis: British and Irish Hypertension Society Position document

Patients with hypertensive emergencies, malignant hypertension and acute severe hypertension are managed heterogeneously in clinical practice. Initiating anti-hypertensive therapy and setting BP goal in acute settings requires important considerations which differ slightly across various diagnoses and clinical contexts. This position paper by British and Irish Hypertension Society, aims to provide clinicians a framework for diagnosing, evaluating, and managing patients with hypertensive crisis, based on the critical appraisal of available evidence and expert opinion.

Thrombus composition and thrombolysis resistance in stroke

A State of the Art lecture titled "Thrombus Composition and Thrombolysis Resistance in Stroke" was presented at the ISTH Congress in 2022. Intravenous thrombolysis (IVT) remains the only pharmacologic option to re-establish cerebral perfusion at the acute phase of ischemic stroke. IVT is based on the administration of recombinant tissue plasminogen activator with the objective of dissolving fibrin, the major fibrillar protein component of thrombi. Almost 30 years on from its introduction, although the clinical benefits of IVT have been clearly demonstrated, IVT still suffers from a relatively low efficacy, with a rate of successful early recanalization below 50% overall. Analyses of thrombectomy-recovered acute ischemic stroke (AIS) thrombi have shown that apart from occlusion site, thrombus length, and collateral status, AIS thrombus structure and composition are also important modulators of IVT efficacy. In this article, after a brief presentation of IVT principle and current knowledge on IVT resistance, we review recent findings on how compaction and structural alterations of fibrin together with nonfibrin thrombus components such as neutrophil extracellular traps and von Willebrand factor interfere with IVT in AIS. We further discuss how these new insights could soon result in the development of original adjuvant therapies for improved IVT in AIS. Finally, we summarize relevant new data presented during the 2022 ISTH Congress.

Intravenous Thrombolysis for Acute Ischemic Stroke

OBJECTIVE

This article reviews the history of IV thrombolysis, its current indications and implementation, the duality of the "time is brain" versus "tissue clock" approaches, the impact of endovascular thrombectomy on IV thrombolysis, the emergence of tenecteplase, and future research directions.

LATEST DEVELOPMENTS

The growing use of factor Xa inhibitors has increasingly caused patients with stroke to be excluded from treatment with IV thrombolysis. Important geographic, socioeconomic, sex, race, and ethnic disparities have been identified in the implementation of IV thrombolysis and need to be overcome. IV thrombolysis substantially improves outcomes when provided within the first golden hour after stroke onset in patients treated in mobile stroke units, supporting the "time is brain" concept and encouraging the possible value of more widespread implementation of the mobile stroke unit approach. At the same time, other studies have shown that IV thrombolysis can be successful in patients whose "tissue clock" is still ticking up to 9 hours after stroke onset or in patients who awaken with their stroke, as demonstrated by favorable imaging profiles. These considerations, along with the emergence of endovascular thrombectomy, have fostered examination of our care systems, including the "drip and ship" versus direct to comprehensive or endovascular thrombectomy stroke center approaches, as well as the possibility of skipping IV thrombolysis in certain patients treated with endovascular thrombectomy. Data suggesting that tenecteplase is at least noninferior to alteplase, as well as its more convenient dosing, has led to its increased use. Ongoing studies are evaluating newer thrombolytics and adding antithrombotic therapy to IV thrombolysis.

ESSENTIAL POINTS

IV thrombolysis remains the most common acute stroke treatment. Advances in acting faster to treat stroke have increased its efficacy, and advances in imaging have expanded its use. However, implementing these advances and overcoming disparities in IV thrombolysis use remain major challenges.

Recruitment in Acute Stroke Trials: Challenges and Potential Solutions

Randomized clinical trials of acute stroke have led to major advances in acute stroke therapy over the past decade. Despite these successes, recruitment in acute trials is often difficult. We outline challenges in recruitment for acute stroke trials and present potential solutions, which can increase the speed and decrease the cost of identifying new treatments for acute stroke. One of the largest opportunities to increase the speed of enrollment and make trials more generalizable is expansion of inclusion criteria whose impact on expected recruitment can be assessed by epidemiologic and registry databases. Another barrier to recruitment besides the number of eligible patients is availability of study investigators limited to business hours, which may be helped by financial support for after-hours call. The wider use of telemedicine has accelerated quicker stroke treatment at many hospitals and has the potential to accelerate research enrollment but requires training of clinical investigators who are often inexperienced with this approach. Other potential solutions to enhance recruitment include rapid prehospital notification of clinical investigators of potential patients, use of mobile stroke units, advances in the process of emergency informed consent, storage of study medication in the emergency department, simplification of study treatments and data collection, education of physicians to improve equipoise and enthusiasm for randomization of patients within a trial, and clear recruitment plans, and even potentially coenrollment, when there are competing trials at sites. Without successful recruitment, scientific advances and clinical benefit for acute stroke patients will lag.

Low-dose alteplase for the management of acute ischemic stroke in South Asians: A systematic review on cost, efficacy and safety

INTRODUCTION

South Asia is responsible for more than 40% of the stroke burden and stroke mortality in the developing world. South Asia, which is home to one-fourth of the world's population, is the most densely populated and one of the poorest regions. The majority of patients in this region are unable to afford intravenous thrombolysis (IVT) for acute ischemic stroke (AIS). If low-dose alteplase proves effective and safe in South Asians, it may be a more cost-effective treatment option.

METHODS

The study was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and meta-Analyses) guideline. Researchers searched PubMed, EMBASE, and Google Scholar for English literature from 2005 to 2021. END, ENI, good functional outcome, SICH, and all-cause mortality were used to assess efficacy and safety.

RESULTS

In the low-dose alteplase treated patients, different studies reported 32 to 57% ENI 24 h after IVT, and 7% to 9.7% END. At 3 months follow-up, good functional outcome was achieved by 48%-76.92% of low-dose alteplase treated patients. SICH rates ranged from 0% to 16.6% across studies. Asymptomatic ICH occurred in 5-14% of patients. The mortality rate in all included studies varied from none to 25%.

CONCLUSION

Our systematic review demonstrates that the use of low-dose alteplase for AIS in the South Asians offer comparable efficacy and reduced risk of SICH at a significantly lower cost than standard alteplase dose. Future well-randomized clinical trials are necessary to validate the findings of our study.

Fifty Years of Acute Ischemic Stroke Treatment: A Personal History

BACKGROUND

It has been 50 years since the first explorations of the physiology of cerebral ischemia by measuring cerebral blood flow (CBF), and 25 years since the approval of tissue plasminogen activator for treating acute ischemic stroke. My personal career began and matured during those eras. Here, I provide my perspective on the evolution of acute stroke research and treatment from 1971 to the present, with some in-depth discussion of the National Institutes of Neurologic Disease and Stroke (NINDS) tissue-type plasminogen activator (tPA) stroke trial and development of mobile stroke units.

SUMMARY

Studies of CBF and metabolism in acute stroke patients revealed graded tissue injury that was dependent on the duration of ischemia. Subsequent animal research unraveled the biochemical cascade of events occurring at the cellular level after cerebral ischemia. After a decade of failed translation, the development of a relatively safe thrombolytic allowed us to achieve reperfusion and apply the lessons from earlier research to achieve positive clinical results. The successful conduct of the NINDS tPA stroke study coupled with positive outcomes from companion tPA studies around the world created the specialty of vascular neurology. This was followed by an avalanche of research in imaging, a focus on enhancing reperfusion through thrombectomy, and improving delivery of faster treatment culminating in mobile stroke units. Key Messages: The last half century has seen the birth and evolution of successful acute stroke treatment. More research is needed in developing new drugs and catheters to build on the advances we have already made with reperfusion and also in evolving our systems of care to get more patients treated more quickly in the prehospital setting. The history of stroke treatment over the last 50 years exemplifies that medical "science" is an evolving discipline worth an entire career's dedication. What was impossible 50 years ago is today's standard of care, what we claim as dogma today will be laughed at a decade from now, and what appears currently impossible will be tomorrow's realities.

Adapting Clinical Practice of Thrombolysis for Acute Ischemic Stroke Beyond 4.5 Hours: A Review of the Literature

Several clinical trials have demonstrated that advanced neuroimaging can select patients for recanalization therapy in an extended time window. The favorable functional outcomes and safety profile of these studies have led to the incorporation of neuroimaging in endovascular treatment guidelines, and most recently, also extended to decision making on thrombolysis. Two randomized clinical trials have demonstrated that patients who are not amenable to endovascular thrombectomy within 4.5 hours from symptoms discovery or beyond 4.5 hours from the last-known-well time may also be safely treated with intravenous thrombolysis and have a clinical benefit above the risk of safety concerns. With the growing aging population, increased stroke incidence in the young, and the impact of evolving medical practice, healthcare and stroke systems of care need to adapt continuously to provide evidence-based care efficiently. Therefore, understanding and incorporating appropriate screening strategies is critical for the prompt recognition of potentially eligible patients for extended-window intravenous thrombolysis. Here we review the clinical trial evidence for thrombolysis for acute ischemic stroke in the extended time window and provide a review of new enrolling clinical trials that include thrombolysis intervention beyond the 4.5 hour window.

Dosing Tissue Plasminogen Activator on a Mobile Stroke Unit: Comparison Between Estimated and Hospital-Measured Weights

ABSTRACT

BACKGROUND: Prehospital tissue plasminogen activator dosing in a mobile stroke unit (MSU) is estimated by the paramedic and nurse. We aimed to determine the accuracy of the estimated weight method compared with the actual weight of patients treated with tissue plasminogen activator on the MSU. METHODS: We prospectively collected the estimated weight used on the MSU for treatment and the first-documented hospital-measured weight (bed scale) within 24 hours of hospital arrival. Median absolute and percent difference in weights were calculated; less than 10% of difference in weights was considered acceptable. To compare the estimated and measured weights, we conducted a Wilcoxon signed rank test and Fisher exact test to explore the association between weight difference of greater than 10% and patient outcomes. RESULTS: Among 337 patients, median estimated and hospital-measured weights were 79.0 kg (interquartile range [IQR], 66.0-94.5) and 78.5 kg (IQR, 65.0-91.7), respectively. The median of the absolute value of the difference in estimated versus measured weight was 2.7 kg (IQR, 0.6-7.6; P < .0001). The median percent difference in weight was 3.6% (IQR, 0.8%-9.4%). The median difference between the tissue plasminogen activator dosage administered on the MSU and the recommended dose based on the actual weight was 1.3 mg (IQR, 0.06-4.8) in absolute value. In 56 patients (16.6% of the entire sample) with overestimation of weight by greater than 10%, there were no symptomatic intracerebral hemorrhages. There was no association between weight difference and discharge modified Rankin score (P = .59). CONCLUSION: Weight estimation on an MSU can lead to similar tissue plasminogen activator dosing for 83.4% of subjects compared with if dosing were determined based on actual weight. Weight overestimation or underestimation had no detected impact on tissue plasminogen activator outcomes.

Maximum intravenous alteplase dose for obese stroke patients is not associated with greater likelihood of worse outcomes

BACKGROUND

IV alteplase is a primary treatment for acute ischemic stroke (AIS) at a weight-based dose (WBD) of 0.9 mg/kg and maximum dose (MD) of 90 mg. There are conflicting data regarding outcomes for those weighing ≥100 kg. There is also a paucity of data in Hispanics. The prevalence of adult obesity in the US has progressively increased; hence, the percentage of patients receiving the maximum dose also is expected to rise. We examined differences between patients treated with WBD vs. MD.

METHODS

A retrospective review of our center's Get With The Guidelines-Stroke database was performed for IV alteplase cases between October 2013-February 2017. Selection criteria included age ≥18 years, IV alteplase administration, and a recorded measured weight. Patients were dichotomized into WBD group weighing <100 kg and MD group weighing ≥100 kg. Categorical variables were analyzed using Chi square tests and continuous variables were analyzed using independent samples t-tests. Multivariable logistic regression analysis was performed to determine whether MD in combination with other variables was associated with poor outcomes.

RESULTS

There were 328 patients included in the study, 38 (11.6%) received MD. Proportions of younger, male, and non-Hispanic were higher in the MD group. There were no statistically significant differences for initial NIHSS, discharge modified Rankin Scale (mRS), 90-day mRS, symptomatic intracerebral hemorrhage (sICH), or systemic hemorrhage between groups.

CONCLUSION

One in ten patients thrombolysed for the treatment of AIS received MD. In a predominantly Hispanic population, those who received MD and WBD had similar rates of sICH, discharge disposition, and functional outcome (mRS) at discharge and at 90 days. Limitations include small sample size and attrition for the 90-day mRS.

European Stroke Organisation (ESO) guidelines on blood pressure management in acute ischaemic stroke and intracerebral haemorrhage

The optimal blood pressure (BP) management in acute ischaemic stroke (AIS) and acute intracerebral haemorrhage (ICH) remains controversial. These European Stroke Organisation (ESO) guidelines provide evidence-based recommendations to assist physicians in their clinical decisions regarding BP management in acute stroke.The guidelines were developed according to the ESO standard operating procedure and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. The working group identified relevant clinical questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and made specific recommendations. Expert consensus statements were provided where insufficient evidence was available to provide recommendations based on the GRADE approach. Despite several large randomised-controlled clinical trials, quality of evidence is generally low due to inconsistent results of the effect of blood pressure lowering in AIS. We recommend early and modest blood pressure control (avoiding blood pressure levels >180/105 mm Hg) in AIS patients undergoing reperfusion therapies. There is more high-quality randomised evidence for BP lowering in acute ICH, where intensive blood pressure lowering is recommended rapidly after hospital presentation with the intent to improve recovery by reducing haematoma expansion. These guidelines provide further recommendations on blood pressure thresholds and for specific patient subgroups. There is ongoing uncertainty regarding the most appropriate blood pressure management in AIS and ICH. Future randomised-controlled clinical trials are needed to inform decision making on thresholds, timing and strategy of blood pressure lowering in different acute stroke patient subgroups.

Current approach to acute stroke management

There have been marked improvements in the management of stroke in Australia over the past two decades. The greatest benefit has accrued from public health measures including reduced smoking rates and treatment of hypertension and hypercholesterolaemia. Recent advances in recanalisation therapy offer the chance of recovery to a subset of people who have a stroke. For many patients, stroke remains an illness with a devastating impact on their quality of life. Reducing the burden of stroke requires intervention across the health system from primary prevention through diagnosis, acute treatment, rehabilitation and secondary prevention. In this review, we will cover the changes in the epidemiology of stroke, public health measures in primary prevention of stroke, and acute management and secondary prevention of ischaemic stroke and primary intracerebral haemorrhage.

IV tPA is associated with increase in rates of intracerebral hemorrhage and length of stay in patients with acute stroke treated with endovascular treatment within 4.5 hours: should we bypass IV tPA in large vessel occlusion?

BACKGROUND

Endovascular treatment (EVT) is a widely proved method to treat patients diagnosed with intracranial large vessel occlusions (LVOs); however, there has been controversy about the safety and efficacy of incorporating intravenous tissue plasminogen activator (IV tPA) as pretreatment for EVT.

OBJECTIVE

To compare the outcomes of all patients with LVO treated with IV tPA +EVT versus EVT alone within 4.5 hours of stroke onset.

METHODS

A prospectively collected endovascular database at a comprehensive stroke center between 2012 and 2019 was used to examine variables such as demographics, comorbid conditions, symptomatic/asymptomatic intracerebral hemorrhage (ICH), mortality rate, and good/poor outcomes as shown by the modified Thrombolysis in Cerebral Infarction score and modified Rankin Scale (mRS) assessment at discharge. The outcomes between patients receiving IV tPA+EVT on admission and patients who underwent EVT alone were compared.

RESULTS

Of 588 patients with acute ischemic stroke treated with EVT, a total of 189 met the criteria for the study (average age 70.44±12.90 years, 42.9% women). Analysis of 109 patients from the group receiving EVT+IV tPA (average age 68.17±14.28 years, 41.3% women), and 80 patients from the EVT alone group was performed (average age 73.54±9.84 years, 45.0% women). Four patients (5.0%) in the EVT alone group experienced symptomatic ICH versus 15 patients (13.8%) in the IV tPA+EVT group (p=0.0478); significant increases were also noted in the length of stay for patients treated with IV tPA (8.2 days vs 11.0 days; p=0.0056).

CONCLUSION

IV tPA in addition to EVT was associated with an increase in the rate of ICH in patients with LVO treated within 4.5 hours and in patients' length of stay. Further research is required to determine whether EVT treatment alone in patients with LVO treated within 4.5 hours is a more effective option.

Who may benefit from lower dosages of intravenous tissue plasminogen activator? Results from a cluster data analysis

Background

The risk of symptomatic intracranial haemorrhage (sICH) after thrombolysis is low but severe. Lower dose of alteplase may reduce the risk of sICH. We aim to identify subsets of patients who could benefit from lower dose of alteplase compared with standard dose.

Methods

Data from two observational registries were pooled together. A total of 3479 patients who had acute ischaemic stroke were entered into the interaction tree model. The response variable was the rate of sICH per the definition of the National Institute of Neurological Disorders and Stroke Study. Clinical improvement was measured by the National Institutes of Health Stroke Scale (NIHSS) and defined as NIHSS 0 or 1 or an improvement of more than 4 points (within 7 days or at discharge). Rare event logistic regression was performed to analyse the OR of safety outcome.

Results

To optimise the interaction effect between tissue plasminogen activator (tPA) dosage (standard/lower) and patient subgroups, three subgroups based on the severity of stroke were identified: (1) NIHSS ≤4, (2) NIHSS between 5 and 14, and (3) NIHSS ≥15. The estimated difference of OR of having sICH was 2.71 (95% CI 0.80 to 7.69, p=0.10) for mild, 0.13 (95% CI 0.02 to 0.68, p=0.01) for moderate, and 0.65 (95% CI 0.19 to 2.55, p=0.52) for severe, respectively. In addition, patients who had moderate stroke treated with lower dose had comparable efficacy outcome (OR 1.23, 95% CI 0.71 to 2.13, p=0.45).

Conclusion

Our analysis demonstrated that in patients who had moderate stroke, lower doses of alteplase are associated with significant sICH reduction and non-inferior performance in efficacy, compared with those in the standard dose group.

Trial registration number

The TIMS-China was a national prospective stroke registry on thrombolytic therapy using intravenous tPA in patients who had acute ischaemic stroke. The results were initially published in 2012 without a clinical trial registration number. The Shanghai Stroke Service System was registered at www.clinicaltrial.gov (NCT02735226).

The Impact of Loading Dose on Outcome in Stroke Patients Receiving Low-Dose Tissue Plasminogen Activator Thrombolytic Therapy

Background

Intravenous tissue plasminogen activator (tPA) (0.9 mg/kg, maximum 90 mg) with a bolus of 10% of the total dose given within 1–2 mins is the standard therapy for patients receiving thrombolytic therapy. Low-dose (0.6 mg/kg) tPA is also approved for thrombolytic therapy for ischemic stroke patients. Low-dose tPA is associated with a low bolus dose. It is unknown whether increasing the bolus dose in patients receiving low-dose tPA thrombolysis may improve outcomes or increase the risk of hemorrhagic transformation (HT).

Aim

This study investigated the impact of the bolus dose on the outcome in ischemic stroke patients receiving low-dose tPA thrombolytic therapy.

Methods

In this retrospective, observational study, we enrolled 214 ischemic stroke patients receiving low-dose tPA thrombolytic therapy. Of these 214 patients, 107 patients received 10% of the total dose as a bolus dose, and 107 patients received 15% of the total dose as a bolus dose. The National Institutes of Health Stroke Score (NIHSS) were evaluated before tPA infusion, 24 h after thrombolytic therapy, and at discharge. Stroke severity was categorized as mild (0–5), moderate (6–14), severe (15–24), or very severe (≥25). Neurological improvement (NI) was defined as an improvement of 6 or more points in the NIHSS, and no response (NR) was defined as an increase in the NIHSS of ≤4 points or a decrease ≤6 points. Neurological deterioration (ND) was defined as an increase in the NIHSS >4 points. A good outcome was defined as a modified Ranking Score (mRS) of 0 or 1. We compared the NI, NR, and ND rates at 24 hrs after thrombolytic therapy and discharge between the 15% and 10% bolus dose groups.

Results

In patients with mild and moderate stroke, there was no significant difference in the NI, NR, ND, and HT rates and 6-month outcomes between the 15% and 10% bolus groups. In patients with severe and very severe stroke, outcomes at 6 months were significantly better in the 15% bolus group than in the 10% bolus group. The factors affecting the outcomes of severe and very severe stroke patients are hypertension and bolus dose.

Conclusion

In severe and very severe stroke patients receiving low-dose tPA thrombolytic therapy, a bolus dose of 15% of the total dose can improve outcomes.

Thrombolysis related symptomatic intracranial hemorrhage in estimated versus measured body weight

BACKGROUND AND AIM

In acute ischemic stroke, under- or overestimation of body weight can lead to dosing errors of recombinant tissue plasminogen activator with consequent reduced efficacy or increased risk of hemorrhagic complications. Measurement of body weight is more accurate than estimation of body weight but potentially leads to longer door-to-needle times. Our aim was to assess if weight modality (estimation of body weight versus measurement of body weight) is associated with (i) symptomatic intracranial hemorrhage rate, (ii) clinical outcome, and (iii) door-to-needle times.

METHODS

Consecutive patients treated with intravenous thrombolysis between 2009 and 2016 from 14 hospitals were included. Baseline characteristics and outcome parameters were retrieved from medical records. We defined symptomatic intracranial hemorrhage according to the European Cooperative Acute Stroke Study (ECASS)-III definition and clinical outcome was assessed with the modified Rankin Scale. The association of weight modality and outcome parameters was estimated with regression analyses.

RESULTS

A total of 4801 patients were included. Five hospitals used measurement of body weight (n = 1753), six hospitals used estimation of body weight (n = 2325), and three hospitals (n = 723) changed from estimation of body weight to measurement of body weight during the study period. In 2048 of the patients (43%), measurement of body weight was used and in 2753 (57%), estimation of body weight. In the measurement of body weight group, an inbuilt weighing bed was used in 1094 patients (53%) and a patient lift scale in 954 patients (47%). In the estimation of body weight group, policy regarding estimation was similar. Estimation of body weight was not associated with increased symptomatic intracranial hemorrhage risk (adjusted odds ratio = 1.16; 95% confidence interval 0.83-1.62) or favorable outcome (adjusted odds ratio = 0.99; 95% confidence interval 0.82-1.21), but it was significantly associated with longer door-to-needle times compared to measurement of body weight using an inbuilt weighing bed (adjusted B = 3.57; 95% confidence interval 1.33-5.80) and shorter door-to-needle times compared to measurement of body weight using a patient lift scale (-3.96; 95% confidence interval -6.38 to -1.53).

CONCLUSION

We did not find evidence that weight modality (estimation of body weight versus measurement of body weight) to determine recombinant tissue plasminogen activator dose in intravenous thrombolysis eligible patients is associated with symptomatic intracranial hemorrhage or clinical outcome. We did find that estimation of body weight leads to longer door-to-needle times compared to measurement of body weight using an inbuilt weighing bed and to shorter door-to-needle times compared to measurement of body weight using a patient lift scale.

Fixed Dose IV rt-PA and Clinical Outcome in Ischemic Stroke Patients With Body Weight >100 kg: Pooled Data From 3 Randomized Clinical Trials

BACKGROUND AND PURPOSE

The ASA/AHA guidelines recommend a fixed dose of 90 mg of intravenous (IV) recombinant tissue plasminogen activator (rt-PA) for acute stroke patients weighing more than 100 kg. We aimed to determine if body weight >100 kg (and receiving <0.9 mg/kg dose) independently influence patient clinical outcomes following IV rt-PA treatment.

METHODS

We pooled data from IV rt-PA treatment arms from 3 randomized controlled clinical trials; NINDS IV rt-PA study, Interventional Management of Stroke 3 and ALIAS (part 1 and 2). Baseline characteristic, hospital course and 90-day mRS were compared between patients >100 kg and those ≤100 kg body weight. Multivariate logistic regression model was used to identify the independent effect of >100 kg body weight on favorable 90-day outcome (defined as mRS 0-2), the rate of symptomatic intracranial hemorrhage, and poor 90-day outcome (mRS 4-6).

RESULTS

Among 873 patients treated with IV rt-PA, a total of 105 (12%) subjects had body weight >100 kg. Compared with patients having ≤100 kg body weight, the rate of favorable outcome at 90 days was not significantly different among patients with >100 kg body weight (OR: 0.99; 95% CI: 0.91-1.01; p=0.91) , after adjusting for potential confounders. The ordinal analysis did not show any significant shift in the distribution of 90-day mRS score in patients with >100 kg body weight (OR, 0.93; 95% CI, 0.64-1.37; P = 0.74) CONCLUSIONS: There was no reduction in the rate of favorable outcome in patients with acute ischemic stroke with body weight >100 kg who received <0.9 mg/kg dose of IV rt-PA. Our results support the current recommendations in the ASA/AHA guidelines.

Different doses of tenecteplase vs alteplase in thrombolysis therapy of acute ischemic stroke: evidence from randomized controlled trials

Background

Recent studies showed inconsistent results of tenecteplase vs alteplase for acute ischemic stroke (AIS) with safety and efficacy.

Methods

A meta-analysis was performed to explore the value of tenecteplase and alteplase in AIS treatment. Medline, Embase, and Cochrane Library from January 2001 to April 2018 were searched for randomized controlled trials (RCTs) with tenecteplase vs alteplase for AIS.

Results

The primary outcomes were early neurological improvement at 24 h and functional outcome at 3 months. We pooled 1,390 patients from four RCTs. Tenecteplase showed a significant early neurological improvement (P=0.035) compared with alteplase. In addition, tenecteplase showed a neutral effect on excellent outcome (P=0.309), good functional outcome (P=0.275), and recanalization (P=0.3). No significant differences in safety outcomes were demonstrated. In subgroup analysis, 0.25 mg/kg dose of tenecteplase showed a significantly increased early neurological improvement (P<0.001). In serious stroke at baseline (National Institutes of Health Stroke Scale [NIHSS] >12) subgroup, tenecteplase showed a dramatic early neurological improvement (P=0.002) and low risks of any intracranial hemorrhage (ICH) (P=0.027).

Conclusion

Tenecteplase provided better early neurological improvement than alteplase. The 0.25 mg/kg dose of tenecteplase subgroup specially showed better early neurological improvement and lower any ICH tendency than that of alteplase. In addition, in serious stroke at baseline subgroup, tenecteplase showed a lower risk of any ICH.

Prediction of thrombus resolution after intravenous thrombolysis assessed by CT-based thrombus imaging

The degree of thrombus resolution directly indicates the effectiveness of a thrombolytic drug. We investigated the degree of thrombus resolution and factors associated with thrombus resolution after intravenous (IV) recombinant tissue plasminogen activator (rt-PA) using thin-section noncontrast computed tomography (NCT). Thin-section NCTs were performed before and immediately after IV rt-PA infusion in acute stroke patients. The thrombus volume and Hounsfield unit were measured using three-dimensional imaging software. Immediate recanalisation was assessed immediately after IV rt-PA infusion using CT angiography. During a three-year study period, 130 patients were prospectively enrolled. On baseline thin-section NCT, no thrombi were found in 30 patients (23%). Among the 100 patients with confirmed thrombus, the median volume decreased by 20% on the follow-up NCT. The thrombus was completely resolved in 8%. Of note, an increase in thrombus volume was observed in 20 patients. Independent predictors of thrombus resolution were total rt-PA dose, thrombus location in the M2 segment of the middle cerebral artery, and time from baseline to follow-up NCT. Thrombus resolution increased by 9% per each 10-mg increase in rt-PA (p = 0.045). Immediate complete recanalisation was achieved in 12% of patients. Total dose of rt-PA was independently associated with complete recanalisation [odds ratio [OR] 4.52, 95% confidence interval [CI] 1.345–15.184) and good functional outcome at three months (modified Rankin scale score <3, OR 2.34, 95% CI 1.104–4.962). In conclusion, rt-PA dose was associated with the degree of thrombus resolution, immediate complete recanalisation, and good outcome at three months. CT-based thrombus imaging may be helpful in determining thrombolysis effectiveness.

Efficacy and safety of low dose alteplase for intravenous thrombolysis in Asian stroke patients: a meta-analysis

Whether low dose alteplase is comparable to standard dose in efficacy and safety for intravenous thrombolysis (IVT) in Asian stroke patients remains unverified. PubMed, EMBASE, and Cochrane Library Database from the beginning to June 30, 2017 were searched. IVT efficacy was measured by favorable outcome (modified Rankin Scale scores of 0–1) at 3 months, and safety measured by mortality within 3 months and symptomatic intracerebral hemorrhage (SICH). Pooled estimates were conducted using fixed- or random-effects model depending on heterogeneity. For SICH, studies were pooled separately according to different definitions. Twelve studies involving 7,905 participants were included. No association was found between alteplase dose and favorable outcome (OR = 0.94, 95% CI 0.78–1.14, P = 0.5; heterogeneity: P_hetero = 0.01, I² = 57.3%) and mortality (OR = 0.87, 95% CI 0.74–1.02, P = 0.08; P_hetero = 0.83, I² = 0) using random- and fixed-effects models, respectively. Low dose alteplase was associated with lower SICH as defined by the National Institute of Neurological Disorders and Stroke study (OR = 0.79, 95% CI 0.64–0.99, P = 0.04; P_hetero = 0.57, I² = 0) using fixed-effects model. Subgroup and sensitivity analysis could change the results significantly. Current limited evidence was insufficient to support the speculation that low dose alteplase was comparable to standard dose in thrombolytic efficacy and safety in Asian stroke patients.

The need for a population-based, dose optimization study for recombinant tissue plasminogen activator in acute ischemic stroke: A study from a tertiary care teaching hospital from South India

Context:

The guideline recommended dose of intravenous (i.v) recombinant tissue-type plasminogen activator (rt-PA) for acute ischemic stroke is 0.9 mg/kg in the European and American populations. In Asiatic population, some studies have shown that a lower dose of i.v rt-PA is equally efficacious.

Aims:

To assess if there is a need for a dose optimization for i.v rt-PA study among Indians.

Setting and Design:

A prospective, observational database of acute stroke cases that presented to a tertiary care institute over a period of 1 year was made.

Methods:

The data procured using a prestructured elaborate pro forma. Based on the dose of rt-PA received, the individuals were divided into three groups; Group 1 (0.6–0.7 mg/kg), Group 2 (0.7–0.8 mg/kg), and Group 3 (0.8–0.9 mg/kg). Improvement was assessed in each group and between the thrombolysed and nonthrombolysed individuals.

Statistical Analysis Used:

The nonparametric Mann–Whitney U-test (Wilcoxon rank-sum test) was applied for assessing improvement of National Institutes of Health Stroke Scale score with significance level of α < 0.05 (P < 0.012) and compliance level at 95%.

Results:

Between the thrombolysed (n = 46) and nonthrombolysed (n = 113) group, there was a statistically significant neurological improvement in the thrombolysed group. Clinical improvement was noted in 75%, 85.7%, and 66.7% of individuals receiving rt-PA in Groups 1, 2, and 3, respectively. Four out of the five who developed a clinically significant intracranial hemorrhage were thrombolysed at a dose of 0.8–0.9 mg/kg rt-PA (Group 3).

Conclusion:

There is a need for a properly randomized, dose optimization study of i.v rt-PA in the Indian subcontinent.

Neurorestoration after stroke

Recent advancements in stem cell biology and neuromodulation have ushered in a battery of new neurorestorative therapies for ischemic stroke. While the understanding of stroke pathophysiology has matured, the ability to restore patients' quality of life remains inadequate. New therapeutic approaches, including cell transplantation and neurostimulation, focus on reestablishing the circuits disrupted by ischemia through multidimensional mechanisms to improve neuroplasticity and remodeling. The authors provide a broad overview of stroke pathophysiology and existing therapies to highlight the scientific and clinical implications of neurorestorative therapies for stroke.

Low-dose intravenous tissue plasminogen activator for acute ischaemic stroke: an alternative or a new standard?

BACKGROUND

With the recent publication of a large clinical trial on the use of a lower dose of intravenous (IV) tissue plasminogen activator (tPA) for acute ischaemic stroke (AIS), the concept of using a different dose has been debated. We intend to review the literature on using a lower dose of IV tPA and gain a better understanding of the impact of different IV doses on the treatment of patients with AIS.

METHODS

A comprehensive literature search of the related topics in PubMed, EMBASE, Web of Science and MEDLINE was carried out. Key words used include low dose IV tPA, thrombolysis, Alteplace and tPA for AIS. Findings were tabulated according to the size of the cohort studied, outcome, adverse event and level of evidence. The results of all studies using lower doses were analysed for efficacy and adverse events.

RESULTS

From 1992 to 2016, there were 23 trials that included 10 950 patients published on the use of lower doses of IV tPA for AIS. Doses ranged from 0.5, 0.6, 0.75 to 0.85 mg/kg. Most were observational, retrospective and registry studies. One was a prospective open-label randomised controlled trial. 13 trials combined lower doses of IV tPA with a glycoprotein IIb/IIIa inhibitor or thrombectomy. Patients treated with lower doses of IV tPA showed a trend of lower rate of symptomatic intracranial haemorrhage and mortality at 3 months but slightly more disability.

CONCLUSIONS

Lower doses of IV tPA showed less haemorrhagic events but were not more effective compared with the standard dose. The optimal low dose of IV tPA remains unclear. Patients with AIS with a high risk of developing sypmtomatic intracranial haemorrhage might benefit from lower dose IV tPA, such as 0.6 mg/kg.

History, Evolution, and Importance of Emergency Endovascular Treatment of Acute Ischemic Stroke

More than 800,000 people in North America suffer a stroke each year, with ischemic stroke making up the majority of these cases. The outcomes of ischemic stroke range from complete functional and cognitive recovery to severe disability and death; outcome is strongly associated with timely reperfusion treatment. Historically, ischemic stroke has been treated with intravenous thrombolytic agents with moderate success. However, five recently published positive trials have established the efficacy of endovascular treatment in acute ischemic stroke. In this review, we will discuss the history of stroke treatments moving from various intravenous thrombolytic drugs to intra-arterial thrombolysis, early mechanical thrombectomy devices, and finally modern endovascular devices. Early endovascular therapy failures, recent successes, and implications for current ischemic stroke management and future research directions are discussed.

Ultrasound Enhanced Thrombolysis for Stroke

In the pivotal clinical trials of intravenous tissue plasminogen activator (TPA) therapy, a low rate of early arterial recanalization was suspected because only a few stroke patients may have had early dramatic clinical improvement. Tissue plasminogen activator activity can be enhanced with ultrasound, including 2 MHz transcranial Doppler (TCD). Transcranial Doppler identifies residual blood flow signals around thrombi, and, by delivering mechanical pressure waves, exposes more thrombus surface to circulating TPA. For the first time in clinical medicine, the international multicenter CLOTBUST trial showed that ultrasound enhances the thrombolytic activity of a drug in humans, thereby confirming multidisciplinary experimental research conducted worldwide for the past 30 years. In the CLOTBUST trial, the dramatic clinical recovery from stroke coupled with complete recanalization within 2 h after TPA bolus occurred in 25% of patients treated with TPA+TCD compared with 8% who received TPA alone ( P = 0·02). Complete clearance of a thrombus and dramatic recovery of brain functions during treatment are feasible goals for ultrasound-enhanced thrombolysis that can lead to sustained recovery. An early boost in brain perfusion seen in the target CLOTBUST group resulted in a trend of 13% more patients achieving favorable outcome at 3 months. To further enhance the ability of TPA to break up thrombi, current ongoing clinical trials include phase II studies of 2 MHz TCD with ultrasound contrast agents or (microbubbles): TCD+TPA+Levovist; TCD+TPA+MRX nano-platform (C3F8). Intra-arterial TPA delivery can be enhanced with 1·7–2·1 MHz pulsed wave ultrasound (EKOS catheter, IMS trial). Dose escalation studies of microbubbles, ultrasound exposure, and the development of an operator-independent ultrasound device are underway.

Tenecteplase versus alteplase in stroke thrombolysis: An individual patient data meta-analysis of randomized controlled trials

Background

Tenecteplase, a modified plasminogen activator with higher fibrin specificity and longer half-life, may have advantages over alteplase in acute ischemic stroke thrombolysis.

Aims

We undertook an individual patient data meta-analysis of randomized controlled trials that compared alteplase with tenecteplase in acute stroke.

Methods

Eligible studies were identified by a MEDLINE search, and individual patient data were acquired. We compared clinical outcomes including modified Rankin Scale at three months, early neurological improvement at 24 h, intracerebral hemorrhage, symptomatic intracerebral hemorrhage, and mortality at three months between all dose tiers of tenecteplase and alteplase.

Results

Three relevant studies (Haley et al., Parsons et al., and ATTEST) included 291 patients and investigated three doses of tenecteplase (0.1, 0.25, 0.4 mg/kg). There were no differences between any dose of tenecteplase and alteplase for either efficacy or safety end points. Tenecteplase 0.25 mg/kg had the greatest odds to achieve early neurological improvement (OR [95%CI] 3.3 [1.5, 7.2], p = 0.093), excellent functional outcome (modified Rankin Scale 0–1) at three months (OR [95%CI] 1.9 [0.8, 4.4], p = 0.28), with reduced odds of intracerebral hemorrhage (OR [95%CI] 0.6 [0.2, 1.8], P = 0.43) compared with alteplase. Only 19 patients were treated with tenecteplase 0.4 mg/kg, which showed increased odds of symptomatic intracerebral hemorrhage compared with alteplase (OR [95% CI] 6.2 [0.7, 56.3]).

Conclusions

While no significant differences between tenecteplase and alteplase were found, point estimates suggest potentially greater efficacy of 0.25 and 0.1 mg/kg doses with no difference in symptomatic intracerebral hemorrhage, and potentially higher symptomatic intracerebral hemorrhage risk with the 0.4 mg/kg dose. Further investigation of 0.25 mg/kg tenecteplase is warranted.

Low-Dose Versus Standard-Dose Tissue Plasminogen Activator in Acute Ischemic Stroke in Asian Populations: A Meta-Analysis

Recent studies have investigated the most efficacious dose of intravenous tissue plasminogen activator (IV-tPA) for acute ischemic stroke (AIS) patients. There remains no definitive consensus concerning the superior efficacious IV-tPA dose (standard- vs. low-dose), prompting us to perform a meta-analysis comparing the efficacy and safety profile of standard- versus low-dose IV-tPA.We identified relevant studies pertaining to the specific aim of our meta-analysis by searching PubMed and EMBASE (January 1990-September 2015) Either a fixed- or random-effects model was employed (dependent upon data heterogeneity) to analyze the efficacy and safety outcome.Ten cohort studies involving 4389 sum patients were included in the meta-analysis. By using the random-effects model, the meta-analysis indicated no statistically significant difference in favorable functional outcome (modified Rankin scale 0-1) at 3 months (heterogeneity: χ = 17.45, P = 0.04, I = 48%; OR: 0.88 [95% CI: 0.71-1.11]; P = 0.28) and incidence of symptomatic intracranial hemorrhage (SICH) (heterogeneity: χ = 14.41, P = 0.11, I = 38%; OR: 1.19 [95% CI: 0.76 to 1.87]; P = 0.45) between the standard- and low-dose groups. The fixed-effects model demonstrated no significant difference in mortality within 3 months (heterogeneity: χ = 6.73, P = 0.57, I = 0%; OR: 0.91 [95% CI: 0.73-1.12]; P = 0.37) between the standard- and low-dose groups.Low-dose IV-tPA is comparable to standard-dose IV-tPA in both efficacy (favorable functional outcome) and safety (SICH and mortality). Confirmation of these findings through randomized trials is warranted.

Intravenous Thrombolysis for Acute Ischemic Stroke Within 3 Hours Versus Between 3 and 4.5 Hours of Symptom Onset

Data from randomized clinical trials have supported the safety and efficacy of intravenous tissue-type plasminogen activator (IV tPA) for acute ischemic stroke when administered within 3 hours of symptom onset, and regulatory approvals for this indication have been in place for almost 20 years. However, recent clinical trials have provided evidence that IV tPA may be safe and effective in selected patients up to 4.5 hours after symptom onset, thereby increasing the proportion of patients that may be eligible for treatment. Although professional organizations in the United States and many regulatory agencies internationally have supported this expanded time window for IV tPA, the US Food and Drug Administration has declined to approve this expanded indication and so this use of IV tPA has remained off-label in the United States. Here we review the current evidence for IV tPA in the standard and the expanded time windows and the data on current clinical practice in the United States as it relates to IV tPA treatment for acute stroke within 3 to 4.5 hours of symptom onset.

Statistical analysis plan for evaluating low- vs. standard-dose alteplase in the ENhanced Control of Hypertension and Thrombolysis strokE stuDy (ENCHANTED)

Background

The ENhanced Control of Hypertension And Thrombolysis strokE stuDy trial is a 2 × 2 quasi‐factorial active‐comparison, prospective, randomized, open, blinded endpoint clinical trial that is evaluating in thrombolysis‐eligible acute ischemic stroke patients whether: (1) low‐dose (0·6 mg/kg body weight) intravenous alteplase has noninferior efficacy and lower risk of symptomatic intracerebral hemorrhage compared with standard‐dose (0·9 mg/kg body weight) intravenous alteplase; and (2) early intensive blood pressure lowering (systolic target 130–140 mmHg) has superior efficacy and lower risk of any intracerebral hemorrhage compared with guideline‐recommended blood pressure control (systolic target <180 mmHg).

Objective

To outline in detail the predetermined statistical analysis plan for the ‘alteplase dose arm’ of the study.

Methods

All data collected by participating researchers will be reviewed and formally assessed. Information pertaining to the baseline characteristics of patients, their process of care, and the delivery of treatments will be classified, and for each item, appropriate descriptive statistical analyses are planned with appropriate comparisons made between randomized groups. For the trial outcomes, the most appropriate statistical comparisons to be made between groups are planned and described.

Results

A statistical analysis plan was developed for the results of the alteplase dose arm of the study that is transparent, available to the public, verifiable, and predetermined before completion of data collection.

Conclusions

We have developed a predetermined statistical analysis plan for the ENhanced Control of Hypertension And Thrombolysis strokE stuDy alteplase dose arm which is to be followed to avoid analysis bias arising from prior knowledge of the study findings.

Treatment of acute ischemic stroke: from fibrinolysis to neurointervention

Thrombolytic therapy with intravenous recombinant tissue plasminogen activator is well established as a beneficial treatment for patients presenting with acute ischemic stroke (AIS). The odds of a favorable clinical outcome (living independently) increase as the time between stroke onset and treatment with IV thrombolysis decreases. However, many patients present with a large clot burden that seldom responds to systemic fibrinolysis. Alternative options include new and emerging endovascular therapies that have recently proven effectiveness at restoring cerebral blood flow to the ischemic brain parenchyma. This review article will briefly outline some of the key evidence for intravenous thrombolysis as well as endovascular therapy for AIS.

Rationale, Design, and Progress of the ENhanced Control of Hypertension ANd Thrombolysis Stroke Study (ENCHANTED) Trial: An International Multicenter 2 × 2 Quasi-Factorial Randomized Controlled Trial of Low- vs. Standard-Dose rt-PA and Early Intensive vs. Guideline-Recommended Blood Pressure Lowering in Patients with Acute Ischaemic Stroke Eligible for Thrombolysis Treatment

Rationale

Controversy exists over the optimal dose of intravenous (iv) recombinant tissue plasminogen activator (rt-PA) and degree of blood pressure (BP) control in acute ischaemic stroke (AIS). Asian studies suggest low-dose (0·6 mg/kg) is more efficacious than standard-dose (0·9 mg/kg) iv rt-PA, and guidelines recommend reducing systolic BP to <185 mmHg before and <180 mmHg after use of iv rt-PA, despite observational studies indicating better outcomes at much lower (<140 mmHg) systolic BP levels in this patient group.

Aims

The study aims to assess in thrombolysis-eligible AIS patients whether: (i) low-dose (0·6 mg/kg body weight; maximum 60 mg) iv rt-PA has non-inferior efficacy and lower risk of symptomatic intracerebral haemorrhage (sICH) compared to standard-dose (0·9 mg/kg body weight; maximum 90 mg) iv rt-PA; and (ii) early intensive BP lowering (systolic target 130–140 mmHg) has superior efficacy and lower risk of any ICH compared to guideline-recommended BP control (systolic target < 180 mmHg).

Design

The ENhanced Control of Hypertension And Thrombolysis strokE stuDy (ENCHANTED) trial is an independent, 2 × 2 quasi-factorial, active-comparison, prospective, randomized, open blinded endpoint (PROBE), clinical trial that is evaluating Arm [A] ‘rt-PA dose’ and/or Arm [B] ‘BP control’, using central Internet randomization and data collection in patients fulfilling local criteria for thrombolysis and clinician uncertainty over the study treatments. The treatment arms will be analyzed separately.

Study outcomes

The primary study outcome in both trial Arms is death or disability according to the modified Rankin scale (mRS, scores 2–6) assessed at 90 days. Secondary outcomes include sICH, any ICH, a shift (‘improvement’) in function across mRS scores, separately on death and disability, early neurological deterioration, recurrent major vascular events, health-related quality of life, length of hospital stay, need for permanent residential care, and health care costs.

Results

Following launch of the trial in February 2012, the study has recruited more than 2500 patients across a global network of approximately 100 sites in 15 countries. The required sample sizes are 3300 for Arm [A] and 2300 for Arm [B], which will provide >90% power to detect non-inferiority of low-dose iv rt-PA and superiority of intensive BP lowering on the primary clinical outcome, respectively.

Conclusions

Low-dose iv rt-PA and early intensive BP lowering could provide more affordable and safer use of thrombolysis treatment for patients with AIS worldwide.