Alteplase at 0.6 mg/kg for Acute Ischemic Stroke Within 3 Hours of Onset

The Impact of Discrepancy between Measured versus Stated Weight on Hemorrhagic Transformation and Clinical Outcomes after Intravenous Alteplase Thrombolysis

BACKGROUND

An accurate measurement of patient weight is important in determining the dosage for intravenous alteplase thrombolysis. In most emergency rooms, however, weight is not measured. We investigated the difference between stated and measured weight and its effect on hemorrhagic transformation and clinical outcomes.

METHODS

We enrolled 128 consecutive patients who had hyperacute stroke and were treated by alteplase. Alteplase dose was calculated using the weight provided by patient or guardian/caregiver, and the actual weight was measured after administration. Patients were classified into 2 groups: overused group (stated weight >measured weight) and underused group (measured weight ≥stated weight). The prevalence of hemorrhagic transformation on follow-up, determined by gradient-recalled echo MRI or non-enhanced CT, was compared between the 2 groups. The predictors for hemorrhage with progression, defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) by a value of 4 or more accompanied by hemorrhage, were determined using multivariable logistic regression analysis and included the overused or underused alteplase and baseline clinical and laboratory findings.

RESULTS

Sixty-six (51.6%) of 128 patients were in the underused group and 62 patients (48.4%) in the overused group. The median difference between the stated and measured weights was 1.5 (interquartile range 0.56-3.81) kg, with the largest difference being 25.6 kg. Although there were no significant difference in baseline clinical and laboratory findings between the 2 groups, the overused group showed a significantly higher prevalence of hemorrhagic transformation (p = 0.012) and hemorrhage with progression (p = 0.025). The multivariable logistic regression analysis demonstrated that overused alteplase (OR 7.26; 95% CI 1.24-42.45; p = 0.028), baseline glucose (>144 mg/dL; OR 5.03; 95% CI 1.00-25.26; p = 0.050), and initial NIHSS (OR 1.13 per 1-point NIHSS increase; 95% CI 1.00-1.27; p = 0.047) in model 1 that use alteplase overdose as a categorical variable and overused alteplase (OR 1.67 1-mg increase; 95% CI 1.05-2.66; p = 0.027) in model 2 that use an overused alteplase dose as numerical variable were significant predictors for hemorrhage with progression.

CONCLUSION

More alteplase usage than actual weight led to higher hemorrhagic transformation. As one of the predictors for clinical deterioration, it is important to administrate alteplase based on an accurately measured weight.

The Relationship between Functional Outcome and Prehospital Time Interval in Patients with Cerebral Infarction

BACKGROUND

When symptoms of cerebral infarction are recognized in a patient, he or she should be transported to a hospital and should be started on the appropriate treatments. The effectiveness of delayed treatment of cerebral infarction with respect to the initial diagnosis or perception of the disease is still unclear.

METHODS

We retrospectively investigated whether the functional outcomes would improve if patients with cerebral infarction were transported to the hospital with minimum delay. One-hundred twenty-two patients who were transported to Mishuku Hospital from January 2012 to August 2015 were included. We conducted multiple regression analyses. The criterion variable included the BI at discharge, and the explanatory variables were age, sex, days of hospital stay, the Barthel Index (BI) on admission, time from symptom onset to hospital arrival, time from emergency medical service perception to hospital arrival, recombinant tissue plasminogen activator (rt-PA) treatment, and the occluded artery type.

RESULTS

In all 122 cases, the BI at the time of discharge was not related to onset time (P = .453) but was significantly related to perception time (P = .026). BI scores at discharge were high for young patients (P = .002) and for patients with short hospital stays (P <.001). In the rt-PA group (52 cases), BI scores at discharge were also high when the perception time was short (P = .036).

CONCLUSIONS

A short interval between perception and hospital arrival improves the functional outcomes for patients with cerebral infarction. Thus, patients with cerebral infarctions must be treated with minimal delay after diagnosis of the condition.

Low risk of ICH after reperfusion therapy in acute stroke patients treated with direct oral anti-coagulant

BACKGROUND

The safety of intravenous thrombolysis (IVT) and endovascular therapy (EVT) in patients treated with DOAC is unclear. We investigated whether recanalization therapy in patients treated with DOAC is safe.

METHODS

A nationwide, multicenter, retrospective cohort questionnaire survey was conducted to investigate the: (1) frequency of intracerebral hemorrhage (ICH) after recanalization therapy in patients treated with DOAC; (2) independent factors related to ICH; (3) relationship between last intake time of DOAC and ICH; and (4) comparison of ICH frequency between patients treated with DOAC, vitamin K antagonist (VKA), and no-anticoagulation (no-ACT) (control).

RESULTS

One hundred eighteen stroke centers returned the questionnaire and 100 patients (56 IVT alone, 29 EVT alone, and 15 both IVT and EVT) on DOAC were registered. The frequency of asymptomatic and symptomatic (≥4-point NIHSS score increase) ICH within 24h in DOAC patients were 18% and 2%, and were not different compared with the VKA and no-ACT groups (p=0.728; and p=0.626). On multivariate analysis, systolic blood pressure (OR, 1.04; p<0.001) and blood glucose (OR, 1.02; p=0.019) were independent factors for ICH. Among the 52 patients with a known last intake time of DOAC, the rate of ICH was higher in patients ≤4h from last intake than those >4h (38% vs. 10%, p=0.033).

CONCLUSIONS

Risk of ICH after reperfusion therapy in patients treated with DOAC should be low. Systolic blood pressure, glucose level, and DOAC intake time appear to be factors for ICH.

The Chinese Stroke Association scientific statement: intravenous thrombolysis in acute ischaemic stroke

The most effective medical treatment for acute ischaemic stroke (AIS) is to offer intravenous thrombolysis during the ultra-early period of time after the onset. Even based on the Consensus of Chinese Experts on Intravenous Thrombolysis for AIS in 2012 and 2014 Chinese Guidelines on the Diagnosis and Treatment of AIS, the rate of thrombolysis for AIS in China remained around 2.4%, and the rate of intravenous tissue plasminogen activator usage was only about 1.6% in real world. The indication of thrombolysis for AIS has been expanded, and contraindications have been reduced with recently published studies. In order to facilitate the standardisation of treating AIS, improve the rate of thrombolysis and benefit patients who had a stroke, Chinese Stroke Association has organised and developed this scientific statement.

Outcome of stroke patients receiving different doses of recombinant tissue plasminogen activator

Background and purpose

Intravenous recombinant tissue plasminogen activator (tPA) at a dose of 0.9 mg/kg body weight is associated with a high hemorrhagic transformation (HT) rate. Low-dose tPA (0.6 mg/kg) may have a lower hemorrhage rate but the mortality and disability rates at 90 days cannot be confirmed as non-inferior to standard-dose tPA. Whether the doses 0.7 and 0.8 mg/kg have better efficacy and safety needs further investigation. Therefore, this study is to compare the efficacy and safety of each dose of tPA (0.6, 0.7, 0.8, and 0.9 mg/kg body weight) and to investigate the factors affecting early neurological improvement (ENI) and early neurological deterioration (END).

Methods

For this observational study, data were obtained from 274 patients who received tPA thrombolytic therapy in Chia-Yi Christian Hospital stroke unit. The tPA dose was given at the discretion of each physician. The definition of ENI was a >8 point improvement (compared with baseline) at 24 h following thrombolytic therapy or an improvement in the National Institutes of Health Stroke Score (NIHSS) to 0 or 1 toward the end of tPA infusion. The definition of END was a >4 point increase in NIHSS (compared with baseline) within 24 h of tPA infusion. The primary objective was to investigate whether 0.7 and 0.8 mg/kg of tPA have higher ENI rate, lower END rate, and better outcome at 6 months. Poor outcome was defined as having a modified Rankin Scale of 3 to 6 (range, 0 [no symptoms] to 6 [death]). The secondary objective was to investigate whether low-dose tPA has a lower risk of intracerebral HT than that with standard-dose tPA. We also investigated the factors affecting ENI, END, HT, and 6-month outcome.

Results

A total of 274 patients were included during the study period, of whom 260 were followed up for >6 months. There was a trend for the HT rate to increase as the dose increased (P=0.02). The symptomatic HT rate was not significantly different among the low-dose and standard-dose groups. The ENI and END (P=0.52) were not significantly different among the four dosage groups. The clinical functional outcome at 6 months after stroke onset was poorer in the standard-dose group (P=0.02). Stroke severity (P<0.01), stroke type (P=0.03), and diabetes mellitus (P=0.04) affected the functional outcome at 6 months.

Conclusion

Among the 274 patients receiving tPA thrombolytic therapy, the HT rate increased as dose increased. The symptomatic HT, ENI and END rates were not significantly different among the low-dose (0.6, 0.7, and 0.8 mg/kg) and standard-dose groups. Stroke severity (NIHSS >12), stroke type (cardioembolism and large artery atherosclerosis) and diabetes mellitus were associated with poor outcome at 6 months.

An uncovered risk factor of sonothrombolysis: Substantial fluctuation of ultrasound transmittance through the human skull

Sonothrombolysis is one of the most feasible methods for enhancing clot lysis with a recombinant tissue plasminogen activator (rt-PA) in cases of acute ischemic strokes. For safe and efficient clinical practices of sonothrombolysis, accurate estimation of ultrasound transmittance through the human skull is critical. Previously, we reported substantial and periodic fluctuation of ultrasound transmittance through a bone-phantom plate following changes to ultrasound frequency, the thickness of the bone-phantom plate, and the distance between a transducer and the bone-phantom plate. In the present study, we clarify the transmittance behavior of medium-frequency ultrasound (from 400kHz to 600kHz) through the human skull, and examine reduction of the transmittance fluctuation. For the study, we measured transmittance of sinusoidal ultrasound waves at 400kHz, 500kHz, and 600kHz at 13 temple spots on 3 human skulls by changing the distance between a transducer and the skull bone, and found substantial and periodic fluctuation in the transmittance behaviors for these sinusoidal voltage excitations. Degrees of the fluctuation varied depending on the measurement spots. A fluctuation ratio between the maximum transmittance and the minimum transmittance reached 3 in some spots. This large transmittance fluctuation is considered to be a risk factor for sonothrombolysis therapies. We examined a modulated ultrasound wave to reduce the fluctuation, and succeeded in obtaining considerable reduction. The average fluctuation ratios for 400-kHz, 500-kHz, and 600-kHz waves were 2.38, 2.38, and 2.07, respectively. We successfully reduced the ratio to 1.72 by using a periodic selection of random frequency (PSRF)-type of modulation wave. The thus obtained results indicate that attention to the fluctuation in ultrasound transmittance through the skull is necessary for safe and effective sonothrombolysis therapies, and that modulated ultrasound waves constitute a powerful method for reducing the risk of fluctuation.

Preceding Intravenous Thrombolysis in Patients Receiving Endovascular Therapy

Background: The beneficial effects of endovascular therapy (EVT) in acute ischemic stroke have been demonstrated in recent clinical trials using new-generation thrombectomy devices. However, the comparative effectiveness and safety of preceding intravenous thrombolysis (IVT) in this population has rarely been evaluated. Methods: From a prospective multicenter stroke registry database in Korea, we identified patients with acute ischemic stroke who were treated with EVT within 8 h of onset and admitted to 14 participating centers during 2008-2013. The primary outcome was a modified Rankin Scale (mRS) score at 3 months. Major secondary outcomes were successful recanalization defined as a modified Treatment in Cerebral Ischemia score of 2b-3, functional independence (mRS score 0-2), mortality at 3 months, and symptomatic hemorrhagic transformation (SHT) during hospitalization. Multivariable logistic regression analyses using generalized linear mixed models were performed to estimate the adjusted odds ratios (ORs) of preceding IVT. Results: Of the 639 patients (male, 61%; age 69 ± 12; National Institutes of Health Stroke Scale score of 15 [11-19]) who met the eligibility criteria, 458 received preceding IVT. These patients showed lower mRS scores (adjusted common OR, 1.38 [95% CI 0.98-1.96]). Preceding IVT was associated with successful recanalization (1.96 [1.23-3.11]) and reduced 3-month mortality (0.58 [0.35-0.97]) but not with SHT (0.96 [0.48-1.93]). Conclusion: In patients treated with EVT within 8 of acute ischemic stroke onset, preceding IVT may enhance survival and successful recanalization without additional risk of SHT, and mitigate disability at 3 months.

Recent advances in the management of acute ischemic stroke

In recent years, several landmark trials have transformed acute ischemic stroke care. The most dramatic results from the field of acute endovascular intervention demonstrate unequivocal benefit for a select group of patients with moderate to severe deficits presenting within 7 hours from onset and with occlusions of proximal arteries in the anterior circulation. In addition, technological advances and workflow efficiencies have facilitated more rapid delivery of acute stroke interventions. This review provides an overview of recent advances in the management of acute ischemic stroke.

An In Vitro Assay for Sonothrombolysis Based on the Spectrophotometric Measurement of Clot Thickness

OBJECTIVES

For improved thrombolysis therapy based on ultrasound irradiation, researchers and practitioners would strongly benefit from an easy and efficient in vitro assay system of thrombolysis activity involving irradiated ultrasound. For the present study, we designed a new in vitro sonothrombolysis assay system using a sheet-type clot.

METHODS

We designed a cell for clot assay, and we confirmed that this clot cell did not significantly intervene in the acoustic field. Using human plasma, we made a sheet-type clot in the cell. Clot thicknesses at 100 points along 4 directions were measured photometrically at a rate of approximately 4 points/s.

RESULTS

The sonothrombolysis effects at 13 levels of ultrasonic intensity were obtained with only one sheet-type clot. With this method, we used a clinically oriented probe at 0.7 and 0.3 W/cm² to confirm that sonothrombolysis took place.

CONCLUSIONS

We successfully established a new, easy, and efficient method for conducting in vitro sonothrombolysis assays. This method involves little intervention of either ultrasound reflection or standing waves in the clot cell. We believe that this new assay method is very useful for fundamental analyses of ultrasound's thrombolysis effects.

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.

Chronic kidney disease is independently associated with acute recurrent cerebral infarct in patients with atrial fibrillation

BACKGROUND AND PURPOSE

The present study aimed to determine the frequency and time of recurrent cerebral infarct (RCI) in patients with acute ischemic stroke (AIS) and atrial fibrillation (AF), and to clarify associated factors.

METHODS

We retrospectively assessed and compared the clinical features of 79 consecutive patients (male, n=56; median age, 75y; median baseline NIHSS, 4) who were hospitalized due to AIS accompanied by AF, and who did or did not develop RCI between January 2012 and March 2015.

RESULTS

Direct oral anticoagulants were administered to 59% of the patients after a median of two days from the onset of the index stroke. Stroke recurred in 10 (13%) of the 79 patients about 5days after admission. The proportion of men was lower (30% vs. 77%, P=0.005) and the patients were older (82vs. 75y, P=0.049) in the group with RCI. Chronic kidney disease was significantly more prevalent in the group with RCI (50% vs. 16%, P=0.025) and independently associated with RCI (OR, 6.59; 95%CI, 1.19-36.63; P=0.031).

CONCLUSIONS

We found that RCI frequently develops about 5days after admission in patients with AIS and AF and that chronic kidney disease is independently associated with RCI.

Edaravone-Encapsulated Agonistic Micelles Rescue Ischemic Brain Tissue by Tuning Blood-Brain Barrier Permeability

Thrombolysis has been a standard treatment for ischemic stroke. However, only 2-7% patients benefit from it because the thrombolytic agent has to be injected within 4.5 h after the onset of symptoms to avoid the increasing risk of intracerebral hemorrhage. As the only clinically approved neuroprotective drug, edaravone (EDV) rescues ischemic brain tissues by eradicating over-produced reactive oxygen species (ROS) without the limitation of therapeutic time-window. However, EDV's short circulation half-life and inadequate cerebral uptake attenuate its therapeutic efficacy. Here we developed an EDV-encapsulated agonistic micelle (EDV-AM) to specifically deliver EDV into brain ischemia by actively tuning blood-brain barrier (BBB) permeability. The EDV-AM actively up-regulated endothelial monolayer permeability in vitro. HPLC studies showed that EDV-AM delivered more EDV into brain ischemia than free EDV after intravenous injection. Magnetic resonance imaging also demonstrated that EDV-AM more rapidly salvaged ischemic tissue than free EDV. Diffusion tensor imaging indicated the highest efficiency of EDV-AM in accelerating axonal remodeling in the ipsilesional white matter and improving functional behaviors of ischemic stroke models. The agonistic micelle holds promise to improve the therapeutic efficiency of ischemic stroke patients who miss the thrombolytic treatment.

The High Cost of Stroke and Stroke Cytoprotection Research

Acute ischemic stroke is inadequately treated in the USA and worldwide due to a lengthy history of neuroprotective drug failures in clinical trials. The majority of victims must endure life-long disabilities that not only affect their livelihood, but also have an enormous societal economic impact. The rapid development of a neuroprotective or cytoprotective compound would allow future stroke victims to receive a treatment to reduce disabilities and further promote recovery of function. This opinion article reviews in detail the enormous costs associated with developing a small molecule to treat stroke, as well as providing a timely overview of the cell-death time-course and relationship to the ischemic cascade. Distinct temporal patterns of cell-death of neurovascular unit components provide opportunities to intervene and optimize new cytoprotective strategies. However, adequate research funding is mandatory to allow stroke researchers to develop and test their novel therapeutic approach to treat stroke victims.

Edaravone with and without .6 Mg/Kg Alteplase within 4.5 Hours after Ischemic Stroke: A Prospective Cohort Study (PROTECT4.5)

BACKGROUND

Edaravone is widely used to treat acute ischemic stroke (AIS) within 24 hours of onset. We aimed to evaluate current edaravone treatment practices and the efficacy and safety of edaravone used with recombinant tissue plasminogen activator (tPA) in AIS patients within 4.5 hours of onset. The results were compared with those of the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Registry (SITS-ISTR) study.

METHODS

PROTECT4.5 was a prospective observational study conducted from April 2010 to March 2013 in Japan. The primary end points were favorable outcomes (modified Rankin Scale score [mRS] 0-1) at 3 months after onset and incidence of symptomatic intracranial hemorrhage (sICH) within 36 hours of treatment. For comparison with SITS-ISTR, patients were categorized based on the time from onset to treatment (within 3 hours of and 3-4.5 hours after onset) and baseline National Institutes of Health Stroke Scale score (NIHSS).

RESULTS

Among the 11,384 registered patients, 11,126 and 8274 patients were included in the safety and efficacy analysis populations, respectively. The proportions of patients with mRS 0-1 receiving edaravone alone and edaravone + tPA were 51.3% (95% confidence interval, 49.7%-52.8%) and 39.0% (37.6%-40.5%), respectively. The incidence of sICH within 36 hours after tPA treatment (edaravone + tPA group) was 1.6% (1.3%-2.0%). When compared with the SITS-ISTR results, those treated with edaravone + tPA appeared to show better outcomes in patients with NIHSS score ≥16.

CONCLUSIONS

The efficacy and safety of edaravone combined with tPA and administered within 4.5 hours of AIS onset were demonstrated with numerically lower incidence of sICH and better outcomes.

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.

Efficiency of the Penumbra 5MAX ACE Reperfusion Catheter in Acute Ischemic Stroke Patients

OBJECTIVE

This study was performed to investigate whether the Penumbra 5MAX ACE is superior to other Penumbra systems.

MATERIALS AND METHODS

We performed a retrospective, single center analysis of patients with acute ischemic stroke with occlusion of the internal carotid artery or middle cerebral artery (M1 segment) who underwent endovascular therapy using a Penumbra system. The reperfusion success rate, puncture-to-revascularization time, and number of passes were assessed. Multivariate regression analysis was conducted to evaluate independent factors related to revascularization within 60 minutes. Successful revascularization was defined by a thrombolysis in cerebral infarction score ≥2b.

RESULTS

The Penumbra 5MAX ACE was used in 24 of the 40 patients (60%). Although the revascularization success rate was similar between patient groups (P = .229), the number of passes was significantly lower (1.5 ± .8 versus 2.6 ± 1.3, P = .006) and the puncture-to-revascularization time was shorter (50 ± 26 minutes versus 116 ± 69 minutes, P = .002) in patients treated with the Penumbra 5MAX ACE. The Penumbra 5MAX ACE was identified as an independent factor for early revascularization (odds ratio, 5.80; P = .041). Among patients with a premorbid modified Rankin Scale score of 0-1, a modified Rankin Scale score of 0-2 at 3 months was observed in 15 of the 19 patients (79%) treated with the Penumbra 5MAX ACE and in 8 of the 16 (50%) who were not (P = .072).

CONCLUSION

Acute revascularization therapy using the Penumbra 5MAX ACE can achieve rapid successful recanalization and tend to improve clinical outcomes.

Update on the effects of treatment with recombinant tissue-type plasminogen activator (rt-PA) in acute ischemic stroke

INTRODUCTION

Acute ischemic stroke (AIS) represents a major cause of death and disability all over the world. The recommended therapy aims at dissolving the clot to re-establish quickly the blood flow to the brain and reduce neuronal injury. Intravenous administration of recombinant tissue-type plasminogen activator (rt-PA) is clinically used with this goal.

AREAS COVERED

A description of beneficial and detrimental effects of rt-PA treatment is addressed. An overview of new therapies against AIS, such as new thrombolytics, sonolysis and sonothrombolysis, endovascular procedures, and association therapies is provided. Updates on the pathophysiological process leading to intracranial hemorrhage (ICH) is also discussed.

EXPERT OPINION

rt-PA treatment in AIS patients is beneficial to recovery outcomes. To weaken risks and improve benefits, it might be relevant to consider: i) a definitive identification of risk factors for symptomatic ICH; ii). a better organization of the health care system to reduce time-to-treatment and enhance discharge management. The pharmacological improvement of new thrombolytic drugs (such as tenecteplase and desmoteplase) targeting harmful and maximally exploiting beneficial effects might further reduce mortality and disability in AIS.

A Retrospective Study of thrombolysis with 0.6 mg/kg Recombinant Tissue Plasminogen Activator (rt-PA) in Mild Stroke

We sought to assess the safety, effectiveness and cost of 0.6 mg/kg rt-PA treatment for patients with acute mild stroke and to compare that with 0.9 mg/kg. We retrospectively analyzed consecutive acute ischemic stroke patients who had a NIHSS score ≤5 at admission and who were treated with rt-PA within 4.5 hours of symptom onset. The demographic data, clinical outcomes and hospitalization cost were analyzed. A total of 108 patients were included. Forty six patients (42.6%) received a 0.6 mg/kg dosage of rt-PA. The baseline characteristics of the two groups were well matched (p > 0.05). Regarding the safety and effectiveness, the 0.6 mg/kg dosage group had a comparable proportion of symptomatic intracranial hemorrhage (sICH) (0.6 mg/kg, 4.3% vs 0.9 mg/kg, 4.8%; p > 0.05), early neurological deterioration (END) (19.6% vs 17.7%; p > 0.05), in-hospital mortality (4.3% vs 1.6%; p > 0.05), and a similar rate of favorable functional outcome (mRS score 0–1) at 3 months (73.9% vs 71.0%; p > 0.05) to those who received the standard dosage. However, the hospital cost was markedly lower in the 0.6 mg/kg group (0.6  mg/kg, 3,401.7 USD vs 0.9  mg/kg, 4,157.4 USD; p < 0.01). Our study suggest that 0.6 mg/kg rt-PA shared similar effectiveness and safety profile compared with that of 0.9 mg/kg in treating mild stroke, but cost less.

Timing of Symptomatic Infarct Swelling Following Intravenous Thrombolysis in Acute Middle Cerebral Artery Infarction: A Case–Control Study

Background:

The risk of symptomatic infarct swelling has been reported to be higher in patients treated with recombinant tissue plasminogen activator (rt-PA). The aim of this study was to evaluate the timing of symptomatic infarct swelling after rt-PA treatment.

Methods:

We retrospectively analyzed 14 868 patients with acute ischemic stroke from a stroke registry databank. We recruited patients with massive middle cerebral artery (MCA) infarction and symptomatic infarct swelling and excluded those with parenchymal or symptomatic hemorrhage. Multiple linear regression and multivariate logistic regression analyses were used to estimate the impact of rt-PA on the timing of symptomatic infarct swelling.

Results:

A total of 23 patients with rt-PA treatment and 117 patients without rt-PA treatment were included. The rt-PA treatment group had a lower rate of coronary artery disease (8.7% vs 32.5%; P = .023), lower severity of baseline National Institutes of Health Stroke Scale score (19 vs 23; P = .014), shorter duration of infarct swelling (27.6 vs 45.4 hours; P < .001), and higher rate of hemicraniectomy surgery (65.2% vs 28.2%; P =.001) than those without rt-PA treatment. After adjusting for variables in multiple linear regression analysis, rt-PA treatment and an elevated C-reactive protein level were associated with early symptomatic infarct swelling ( P = .014 and P = .041, respectively). The rt-PA treatment was an independent factor related to early symptomatic infarct swelling within 36 hours ( P = .005; odds ratio [OR]: 5.3; confidence interval [CI]: 1.65-17.0) or 48 hours ( P = .009; OR: 16.4; CI: 2.00-134).

Conclusion:

Intravenous rt-PA treatment may hasten the onset of cerebral edema and subsequent cerebral herniation in large MCA territory infarction.

Clinical efficacy and safety of hypernormal shortened door to needle time (DNT) plus individualized low-dose alteplase therapy in treating acute ischemic stroke

OBJECTIVE

This study aims to observe the clinical efficacies of hyper-early low-dose alteplase thrombolysis in treating acute ischemic stroke (AIS).

METHODS

Two hundred twenty AIS patients were randomly divided into group A (90 cases), group B (90 cases), and group C (40 cases). The National Institutes of Health Stroke Scale (NIHSS) scores, mRS score-evaluated prognosis, intracranial hemorrhage, and mortality of the three groups were observed before and after the treatment.

RESULTS

The NIHSS scores of the three groups were significantly reduced after the treatment (P<0.05), among which the NIHSS score of group A was the lowest (P<0.05); and the difference between group B and C was not significant (P>0.05). The incidence of such complications as cerebral hemorrhage in the three groups was low, and there was no significant difference among the groups (P>0.05). The modified Rankin Scale (mRS)scores of the three groups showed that group A had much better prognosis than group B and C, while the difference between group B and group C was not significant.

CONCLUSIONS

The hyper-early low-dose alteplase thrombolysis was safe and effective in Acute ischemic stroke (AIS).

Stroke and Thrombolysis in Developing Countries

Summary of review

The epidemiology of stroke is well investigated in the developed world; however, in the developing world stroke is less well documented. Most of the available stroke data from these countries are hospital-based. Stroke thrombolysis is currently used in few developing countries like Brazil, Argentina, Senegal, Iran, Pakistan, China, Thailand, and India. The two main barriers for implementation of thrombolysis therapy in developing countries are the high cost of tissue plasminogen activator and lack of proper infrastructure. Most of the centers with the infrastructure to deliver thrombolysis for stroke are predominantly private sector, and only available in urban areas.

Conclusion

Until a more cost-effective thrombolytic agent and the proper infrastructure for widespread use of thrombolysis therapy are available, developing nations should focus on primary and secondary stroke prevention strategies and the establishment of stroke units wherever possible. Such multi-faceted approaches will be more cost-effective for developing countries than the use of thrombolysis.

Drip-and-Ship Thrombolytic Therapy Supported by the Telestroke System for Acute Ischemic Stroke Patients Living in Medically Under-served Areas

There are a few stroke specialists in medically under-served areas in Japan. Consequently, in remote area patients may not receive thrombolysis with intravenous recombinant tissue plasminogen activator (iv rt-PA), the standard treatment for acute ischemic stroke. Using a mobile telestroke support system (TSS) that accesses the internet via a smart phone, we implemented iv rt-PA infusion therapy under a drip-and-ship protocol to treat the stroke patients in medically under-served areas. The physicians at the Tokushima Prefectural Kaifu Hospital (TPKH), located in rural Japan, can relay CT or MRI scans and other patient data via their smart phone to off-site stroke specialists. In the course of 34 months, we used the TSS in 321 emergencies. A total of 9 of 188 (4.8%) with acute ischemic stroke, received iv rt-PA infusion therapy using a mobile TSS; in 5 among these (55.6%), we obtained partial or complete recanalization of occluded arteries. None suffered post-treatment hemorrhage and their average NIH stroke score fell from 14.6 at the time of admission to 6.8 at 24 h post-infusion. The drip-and-ship protocol contributed to the safe and effective treatment of the stroke patients living in medically under-served rural areas.

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

BACKGROUND

Thrombolytic therapy for acute ischemic stroke with a lower-than-standard dose of intravenous alteplase may improve recovery along with a reduced risk of intracerebral hemorrhage.

METHODS

Using a 2-by-2 quasi-factorial open-label design, we randomly assigned 3310 patients who were eligible for thrombolytic therapy (median age, 67 years; 63% Asian) to low-dose intravenous alteplase (0.6 mg per kilogram of body weight) or the standard dose (0.9 mg per kilogram); patients underwent randomization within 4.5 hours after the onset of stroke. The primary objective was to determine whether the low dose would be noninferior to the standard dose with respect to the primary outcome of death or disability at 90 days, which was defined by scores of 2 to 6 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]). Secondary objectives were to determine whether the low dose would be superior to the standard dose with respect to centrally adjudicated symptomatic intracerebral hemorrhage and whether the low dose would be noninferior in an ordinal analysis of modified Rankin scale scores (testing for an improvement in the distribution of scores). The trial included 935 patients who were also randomly assigned to intensive or guideline-recommended blood-pressure control.

RESULTS

The primary outcome occurred in 855 of 1607 participants (53.2%) in the low-dose group and in 817 of 1599 participants (51.1%) in the standard-dose group (odds ratio, 1.09; 95% confidence interval [CI], 0.95 to 1.25; the upper boundary exceeded the noninferiority margin of 1.14; P=0.51 for noninferiority). Low-dose alteplase was noninferior in the ordinal analysis of modified Rankin scale scores (unadjusted common odds ratio, 1.00; 95% CI, 0.89 to 1.13; P=0.04 for noninferiority). Major symptomatic intracerebral hemorrhage occurred in 1.0% of the participants in the low-dose group and in 2.1% of the participants in the standard-dose group (P=0.01); fatal events occurred within 7 days in 0.5% and 1.5%, respectively (P=0.01). Mortality at 90 days did not differ significantly between the two groups (8.5% and 10.3%, respectively; P=0.07).

CONCLUSIONS

This trial involving predominantly Asian patients with acute ischemic stroke did not show the noninferiority of low-dose alteplase to standard-dose alteplase with respect to death and disability at 90 days. There were significantly fewer symptomatic intracerebral hemorrhages with low-dose alteplase. (Funded by the National Health and Medical Research Council of Australia and others; ENCHANTED ClinicalTrials.gov number, NCT01422616.).

Feasibility and efficacy of thrombolysis in acute ischemic stroke: A study from National Institute of Neurological and Allied Sciences, Kathmandu, Nepal

Background:

Stroke is the major cause of morbidity and mortality worldwide. The number of stroke patients receiving recombinant tissue plasminogen activator (rt-PA), also known as Alteplase, in the developing world is extremely low. We aim to study the feasibility and efficacy of thrombolysis for the 1^st time in our country.

Materials and Methods:

In this retrospective study (July 2012-August 2015), acute ischemic stroke patients who were thrombolyzed within 3 h of stroke onset were included. Their demographic profiles, clinical profiles, risk factors, type of thrombolytic used, and outcomes were systematically recorded and analyzed.

Results:

A total of 9 patients were thrombolyzed. The mean time from the onset of stroke symptoms to first dose of rt-PA (onset to treatment) was 1.2 h. Six patients had good neurological outcome as measured by modified Rankin Scale (mRS). The median mRS at discharge was 3. Thrombolysis-related post treatment complication was noted in 44.4%, of which nonfatal intracranial bleed occurred only in 2 patients (22.2%). None of the patients receiving intravenous tenecteplase had thrombolysis-related complications, and none of the patients had fatal intracranial bleed.

Conclusion:

This study clearly demonstrates the beginning of a feasible and effective thrombolysis in the treatment of acute ischemic stroke in Nepal.

Thrombectomy using Trevo ProVue Stent Retriever Devices after Recombinant Tissue Plasminogen Activator Thrombolysis for Acute Basilar Artery Occlusion during Vertebral Artery Dissection

A 41-year-old woman was admitted due to a sudden-onset severe headache, left hemiparesis and dysarthria. Diffusion-weighted magnetic resonance imaging showed an acute infarct in the bilateral pons, and magnetic resonance angiography revealed basilar artery (BA) occlusion resulting from dissection of the right vertebral artery (VA). She was treated with intravenous recombinant tissue plasminogen activator (rt-PA) 110 minutes after symptom onset. Subsequently, brain angiography was performed along with mechanical thrombolysis using Trevo ProVue retriever devices. The BA was successfully recanalized 240 minutes after the onset of symptoms. Thrombectomy is a promising treatment strategy for cases of VA dissection resistant to intravenous rt-PA thrombolysis.

Direct Microsurgical Embolectomy for Acute Occlusion of the Internal Carotid Artery and Middle Cerebral Artery

BACKGROUND

Surgical embolectomy is the most promising therapy for physically removing emboli from major cerebral arteries. However, it requires an experienced surgical team, time-consuming steps, and is not incorporated into acute stroke therapy.

METHODS

We established seamless collaboration between services, refined surgical techniques, and conducted a prospective trial of emergency surgical embolectomy. Surgical indications included the presence of acute hemispheric symptoms, absence of low-density area on computed tomography, evidence of internal carotid artery terminus or proximal middle cerebral artery occlusion, and availability of resources to start surgery within 3 hours of symptom onset. The indications were confirmed by an interdisciplinary team. We assessed revascularization rates, time from admission to surgery and from surgery to recanalization, procedural complications, and clinical outcomes.

RESULTS

Between 2005 and 2014, 14 consecutive patients with acute proximal middle cerebral artery or internal carotid artery terminus occlusion underwent emergency surgical embolectomy. All patients showed complete recanalization. Twelve patients survived and 7 had fair functional outcome (Rankin Scale score, ≤3). No significant procedural adverse events occurred. The mean times from admission to start of surgery, from surgery to recanalization, and from onset to recanalization were 14 minutes, 79 minutes, and 223 minutes, respectively.

CONCLUSIONS

Our results suggest that microsurgical embolectomy can rapidly, safely, and effectively retrieve clots and deserves reappraisal, although the choice largely depends on local institutional expertise.

Tissue Plasminogen Activator Prescription and Administration Errors within a Regional Stroke System

BACKGROUND

Intravenous (IV) tissue plasminogen activator (tPA) utilization in acute ischemic stroke (AIS) requires weight-based dosing and a standardized infusion rate. In our regional network, we have tried to minimize tPA dosing errors. We describe the frequency and types of tPA administration errors made in our comprehensive stroke center (CSC) and at community hospitals (CHs) prior to transfer.

METHODS

Using our stroke quality database, we extracted clinical and pharmacy information on all patients who received IV tPA from 2010-11 at the CSC or CH prior to transfer. All records were analyzed for the presence of inclusion/exclusion criteria deviations or tPA errors in prescription, reconstitution, dispensing, or administration, and for association with outcomes.

RESULTS

We identified 131 AIS cases treated with IV tPA: 51% female; mean age 68; 32% treated at the CSC, and 68% at CHs (including 26% by telestroke) from 22 CHs. tPA prescription and administration errors were present in 64% of all patients (41% CSC, 75% CH, P < .001), the most common being incorrect dosage for body weight (19% CSC, 55% CH, P < .001). Of the 27 overdoses, there were 3 deaths due to systemic hemorrhage or ICH. Nonetheless, outcomes (parenchymal hematoma, mortality, modified Rankin Scale score) did not differ between CSC and CH patients nor between those with and without errors.

CONCLUSION

Despite focus on minimization of tPA administration errors in AIS patients, such errors were very common in our regional stroke system. Although an association between tPA errors and stroke outcomes was not demonstrated, quality assurance mechanisms are still necessary to reduce potentially dangerous, avoidable errors.

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.

Effects of a Public Education Campaign on the Association Between Knowledge of Early Stroke Symptoms and Intention to Call an Ambulance at Stroke Onset: The Acquisition of Stroke Knowledge (ASK) Study

Background

An immediate ambulance call offers the greatest opportunity for acute stroke therapy. Effectively using ambulance services requires strengthening the association between knowledge of early stroke symptoms and intention to call an ambulance at stroke onset, and encouraging the public to use ambulance services.

Methods

The present study utilized data from the Acquisition of Stroke Knowledge (ASK) study, which administered multiple-choice, mail-in surveys regarding awareness of early stroke symptoms and response to a stroke attack before and after a 2-year stroke education campaign in two areas subject to intensive and moderate intervention, as well as in a control area, in Japan. In these three areas, 3833 individuals (1680, 1088 and 1065 participants in intensive intervention, moderate intervention, and control areas, respectively), aged 40 to 74 years, who responded appropriately to each survey were included in the present study.

Results

After the intervention, the number of correctly identified symptoms significantly associated with intention to call an ambulance (P < 0.05) increased (eg, from 4 to 5 correctly identified symptoms), without increasing choice of decoy symptoms in the intensive intervention area. Meanwhile, in other areas, rate of identification of not only correct symptoms but also decoy symptoms associated with intention to call an ambulance increased. Furthermore, the association between improvement in the knowledge of stroke symptoms and intention to call an ambulance was observed only in the intensive intervention area (P = 0.009).

Conclusions

Our results indicate that intensive interventions are useful for strengthening the association between correct knowledge of early stroke symptoms and intention to call an ambulance, without strengthening the association between incorrect knowledge and intention to call an ambulance.

Predictors of a Favorable Outcome after Recanalization in Patients with Cerebral Major Vessel Occlusion

BACKGROUND

Although tissue plasminogen activator and endovascular treatment were reported to be useful for recanalization in patients with major vessel occlusion (MVO), the outcome in some patients with recanalization was unfavorable. We could detect prolongation of the ipsilateral posterior cerebral artery (PCA) to the ischemic side on magnetic resonance angiography in some patients (ipsilateral-PCA sign). We investigated the predictors including radiological findings for a favorable outcome after successful recanalization.

METHODS

We included 76 patients with MVO of the anterior circulation and documented recanalization by treatment. We divided our patients into 2 groups: group F (modified Rankin scale [mRS] score = 0-2) and group UF (mRS score = 3-6). We compared biomarkers between the groups.

RESULTS

National Institutes of Health Stroke Scale (NIHSS) score before treatment in group F (8.5) was lower than that in group UF (16.0; P <.001). Sensitivity of the ipsilateral-PCA sign was commonly associated with group F (67.5% versus 19.4%, P <.001), and specificity of the sign was 80.6%. Absence of infarcts in the anterior cerebral artery (ACA) territory and ACA occlusion were also associated with a favorable outcome. In multivariate analysis, the ipsilateral-PCA sign and NIHSS score (≤ 10) were independent predictors of favorable outcome (odds ratio = 9.92, 95% confidence interval [CI] 2.71-36.23, P = .001; and odds ratio = 9.15, 95% CI 2.44-34.36, P = .001, respectively)

CONCLUSIONS

The ipsilateral-PCA sign and low NIHSS score (≤ 10) were predictors of a favorable outcome in patients with MVO and documented recanalization by treatments.

Safety and Tolerability of Desmoteplase Within 3 to 9 Hours After Symptoms Onset in Japanese Patients With Ischemic Stroke

Background and Purpose—

This study investigated the safety and tolerability of desmoteplase administered within 3 to 9 hours after stroke symptoms onset in Japanese patients with acute ischemic stroke.

Methods—

Patients were randomized to treatment with either desmoteplase or placebo in a 2:1 ratio in 2 consecutive cohorts (70 μg/kg and then 90 μg/kg). Included patients had a baseline National Institutes of Health Stroke Scale score of 4 to 24 and occlusion or high-grade stenosis in the middle cerebral artery segment M1 or M2 on magnetic resonance angiography. The incidence of symptomatic intracranial hemorrhage (≤72 hours) was defined as the primary end point. The occurrence of asymptomatic ICH, symptomatic cerebral edemas, and adverse events were other safety outcomes of special interest.

Results—

Symptomatic intracranial hemorrhage was observed within 72 hours in 2 patients treated with placebo and in 1 patient treated with 70 μg/kg desmoteplase. Any ICH (symptomatic or asymptomatic ICH) within 72 hours were observed in 7 (43.8%) patients treated with placebo, in 8 (50%) patients treated with 70 μg/kg desmoteplase, and in 9 (56.3%) patients treated with 90 μg/kg desmoteplase. Desmoteplase treatment with 70 or 90 μg/kg was not associated with an increased risk of symptomatic cerebral edema compared with placebo. There were no other serious safety concerns associated with desmoteplase.

Conclusions—

Desmoteplase in both 70 and 90 μg/kg doses had a favorable safety profile and was well tolerated in Japanese patients with acute ischemic stroke when administered 3 to 9 hours after stroke symptoms onset.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01104467.

Timing of recanalization and outcome in ischemic-stroke patients treated with recombinant tissue plasminogen activator

BACKGROUND

Intravenous administration of recombinant tissue plasminogen activator (rtPA) is approved treatment for acute ischemic stroke <3 h of symptom onset.

PURPOSE

To determine the impact of the timing and degree of recanalization on clinical outcome after rtPA infusion in patients.

MATERIAL AND METHODS

Seventy-five patients with ischemic stroke in the middle cerebral artery territory treated with intravenous rtPA within 3 h were studied consecutively. Magnetic resonance imaging (MRI), including magnetic resonance angiography (MRA), before, 6 h, and 24 h after thrombolytic therapy was undertaken. Depending on the MRA results acquired 6 h after rtPA infusion, recanalization was graded as: early recanalization (ER), delayed recanalization (DR), and no recanalization (NR). Clinical outcome was assessed using the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS).

RESULTS

Of patients in the ER, DR and NR groups, 71.4% (15/21), 13.3% (2/15), and 30.7% (12/39), respectively, showed dramatic improvement in NIHSS score 7 days after rtPA administration compared with those scores upon hospital admission. The 6-h and 24-h NIHSS scores and 3-month mRS scores of ER patients were significantly lower than those of the other two groups (P < 0.05). The 24-h, 7-d NHISS and mRS scores of DR patients were significantly higher than NR patients (P = 0.001, 0.002, 0.049, respectively). Three patients in the DR group died during follow-up.

CONCLUSION

These data suggest that DR is associated with clinical deterioration. Patients treated with rtPA thrombolysis should be under close observation for 6-24 h. Corresponding treatment should be considered once DR appears.

Management of Postthrombolysis Hemorrhagic and Orolingual Angioedema Complications

Intravenous recombinant tissue plasminogen activator was first approved for the treatment of acute ischemic stroke in the United States in 1996. Thrombolytic therapy has been proven to be effective in acute ischemic stroke treatment and shown to improve long-term functional outcomes. Its use is associated with an increased risk of symptomatic intracerebral hemorrhage as well as orolingual angioedema. Our goal is to outline the management strategies for these postthrombolysis complications.

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.

Low-Versus Standard-Dose Alteplase for Ischemic Strokes Within 4.5 Hours: A Comparative Effectiveness and Safety Study

BACKGROUND AND PURPOSE

The low-dose (0.6 mg/kg) alteplase strategy to treat acute ischemic stroke patients became widespread in East Asian countries, without rigorous testing against standard-dose (0.9 mg/kg) alteplase treatment. Our aim was to investigate the comparative effectiveness and safety of the low-dose versus standard-dose intravenous alteplase strategy.

METHODS

A total of 1526 acute ischemic stroke patients who qualified for intravenous alteplase and treated within 4.5 hours were identified from a prospective, multicenter, and nationwide stroke registry database. Primary outcomes were a modified Rankin scale score of 0 to 1 at 3 months after stroke and occurrence of symptomatic hemorrhagic transformation. Inverse probability of low-dose alteplase weighting by propensity scores was used to remove baseline imbalances between the 2 groups, and variation among centers were also accounted using generalized linear mixed models with a random intercept.

RESULTS

Low-dose intravenous alteplase was given to 450 patients (29.5%) and standard-dose intravenous alteplase to 1076 patients (70.5%). Low-dose alteplase treatment was comparable to standard-dose therapy according to the following adjusted outcomes and odds ratios (95% confidence intervals): modified Rankin scale score 0 to 1 at 3 months and 0.95 (0.68-1.32); modified Rankin scale 0 to 2 at 3 months and 0.84 (0.62-1.15); symptomatic hemorrhagic transformation and 1.05 (0.65-1.70); and 3-month mortality and 0.54 (0.35-0.83). The associations were unchanged when the analysis was limited to those without endovascular recanalization.

CONCLUSIONS

The low-dose alteplase strategy was comparable to the standard-dose treatment in terms of the effectiveness and safety.

Substantial fluctuation of acoustic intensity transmittance through a bone-phantom plate and its equalization by modulation of ultrasound frequency

For safe and efficient sonothrombolysis therapies, accurate estimation of ultrasound transmittance through the human skull is essential. The present study clarifies uncertainty surrounding this transmittance and experimentally verifies the equalization of transmittance through the modulation of ultrasound frequency. By changing three factors (ultrasound frequency, the thickness of a bone-phantom plate, and the distance between a transducer and a bone-phantom plate), we measured the intensity of ultrasound passing through the plate. Two activating methods, sinusoidal waves at 500 kHz and modulated waves, were compared. When we changed (1) the distance between a transducer and a bone-phantom plate and (2) the thickness of the bone-phantom plate, ultrasound transmittance through the plates substantially fluctuated. The substantial fluctuation in transmittance was observed also for a cut piece of human temporal skull bone. This fluctuation significantly declined for the modulated wave. In conclusion, modulation of ultrasound frequency can equalize the transmittance with an approximately 30-65% fluctuation drop and an approximately 40% fluctuation drop for a bone-phantom plate and for a cut piece of skull bone, respectively. By using modulated waves, we can develop safer and more effective sonothrombolysis therapies.

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.