Minimal Clinically Important Difference for Safe and Simple Novel Acute Ischemic Stroke Therapies

Understanding physician preferences about combined thrombolysis and thrombectomy in patients with large vessel occlusion: An international cross-sectional survey

BACKGROUND

A recently published individual participant-level meta-analysis found that EVT alone was not non-inferior to combined intravenous thrombolysis (IVT) and EVT. Our aim was to determine factors that influence physicians' treatment choice of IVT-alone versus EVT-alone versus a combined approach.

METHODS

We performed an international, structured, invite-only survey among physicians treating patients presenting with AIS. Respondents were asked 16 multiple choice questions. Fourteen questions involved the respondent being provided with a clinical scenario. In each scenario, a patient was presenting with an AIS with LVO, varying a single clinical or imaging feature.

RESULTS

A total of 282 stroke physicians (mean age 46 years, 75 % males) participated in the survey. In LVO stroke, eligible for both IVT and EVT, without other qualifiers, 220 (85.9 %) respondents chose to pursue a combined approach. For age over 80 years, 191 (74 %) participants opted for combined approach, which decreased to 121 (48.2 %) with dementia and 148 (57.4 %) if the patient was on dual anti-platelet therapy (DAPT). Of respondents choosing combination therapy in a patient above the age of 80, only 105 (56.8 %) would pursue the same in a patient with dementia. For imaging factors, 177 (72.8 %) opted for a combined approach for intracranial carotid occlusion, which decreased to 160 (65.3 %) in tandem occlusions. Overall, 88 (38 %) respondents agreed to the statement "I am uncomfortable with uncertainty in patient care".

CONCLUSIONS

In a typical patient with AIS due to LVO, most respondents still choose a combined revascularization approach but discrepancy in decision-making increases in complex scenarios.

Tenecteplase versus alteplase for acute ischaemic stroke: a meta-analysis of phase III randomised trials

BACKGROUND

Tenecteplase (TNK) was found non-inferior to alteplase in recent clinical trials. We aimed to elucidate the efficacy and safety of TNK versus alteplase for acute ischaemic stroke (AIS).

METHODS

Systematic literature search and a meta-analysis of phase III clinical trials in ischaemic stroke patients with TNK use were conducted. The primary outcome was excellent functional outcome which was defined as modified Rankin Scale score of 0-1 at 90 days and safety outcomes included symptomatic intracerebral haemorrhage and death at 90 days. We used random-effects model to estimate the pooled risk difference and 95% CI in R package 'Meta'. The included trials were adapted to the non-inferiority analysis with a margin of -4%.

RESULTS

Three trials enrolling 4094 patients were identified by systematic search. All trials included AIS patients within 4.5 hours time window. Meta-analysis indicated that 1089 (53.0%) of 2056 patients in the TNK arm and 1016 (50.5%) of 2012 in the alteplase arm had excellent functional outcome at 90 days (0.03 (95% CI -0.00 to 0.06); I2=0%), meeting the prespecified non-inferiority threshold. And TNK thrombolysis was not correlated with increased risk of symptomatic intracerebral haemorrhage (0.00 (95% CI -0.01 to 0.01); I2=0%) or death (0.01 (95% CI -0.01 to 0.02); I2=0%) at 90 days. The sensitivity analysis with the 0.25 mg/kg trials exclusively showed similar results to the main analysis.

CONCLUSIONS

TNK was non-inferior to alteplase for achieving excellent functional outcome at 90 days without increasing the safety concern in treating patients with AIS. These findings suggest that TNK can be an alternative to alteplase.

PROSPERO REGISTRATION NUMBER

CRD42022354342.

Assessing Clinically Important Differences During Rehabilitation for Stroke: A Pilot Study Evaluating Anchor and Distribution Derived Estimates of Physical Function Change in Classically Summed and Rasch Models of Section GG of the Inpatient Rehabilitation Facility Patient Assessment Instrument

OBJECTIVE

To determine clinically important differences (CIDs) on Section GG physical functioning scores on the Centers for Medicare and Medicaid Services (CMS) Inpatient Rehabilitation Facility Assessment Instrument (IRF-PAI) for patients with stroke, using anchor and distribution-based approaches.

DESIGN

Pilot prospective observational cohort study.

SETTING

Inpatient rehabilitation facility.

PARTICIPANTS

Patients with stroke (N=208).

INTERVENTIONS

Physicians assessed improvements during rehabilitation using the modified Rankin scale (mRS). Improvements (≥1 point) on the mRS were used as the anchor for establishing CIDs.

MAIN OUTCOME MEASURES

Classically summed and Rasch transformed Section GG change scores associated with clinically important improvements on the mRS.

RESULTS

A total of 166 patients (79.8%) improved ≥1 point on the mRS. Change scores of 27, 9, and 16 on Section GG total physical functioning (self-care + mobility), self-care, and mobility/walk scales, respectively, had high sensitivity (0.82-0.85) but low specificity (0.52-0.69) in identifying patients improving on the mRS. Positive predictive values ranged from 0.87 to 0.91, and negative predictive values ranged from 0.42 to 0.52. Total physical functioning and selfcare anchor-derived change scores were similar to the reliable change index (RCI [2.77 × SEM]), calculated as 28 and 10 points, respectively, whereas anchor-derived mobility/walk scale change scores were equivalent to 1.96 × SEM. Exploratory Rasch modeling identified 3 Section GG subscales (R-Self-Care, R-Mobility, and R-Walking). Improvements on the R-Walking subscale were most correlated with mRS improvements (ρ=-0.47); however, accuracy of CID estimates was not improved.

CONCLUSIONS

Cut-off scores obtained using the mRS anchor aligned with more robust estimates of change, as estimated by distribution-based measures. While patients achieving anchor-derived cut-offs have a high probability of mRS improvement, change scores may fail to detect clinically meaningful improvements at these same thresholds. Alternative criteria for determining MCID/CIDs, should be explored. Rasch models require further validation.

Stroke reduction by cerebral embolic protection devices in transcatheter aortic valve implantation: a systematic review and Bayesian meta-analysis

OBJECTIVES

The use of cerebral embolic protection (CEP) during transcatheter aortic valve implantation (TAVI) has been studied in several randomised trials. We aimed to perform a systematic review and Bayesian meta-analysis of randomised CEP trials, focusing on a clinically relevant reduction in disabling stroke.

METHODS

A systematic search was applied to three electronic databases, including trials that randomised TAVI patients to CEP versus standard treatment. The primary outcome was the risk of disabling stroke. Outcomes were presented as relative risk (RR), absolute risk differences (ARDs), numbers needed to treat (NNTs) and the 95% credible intervals (CrIs). The minimal clinically important difference was determined at 1.1% ARD, per expert consensus (NNT 91). The principal Bayesian meta-analysis was performed under a vague prior, and secondary analyses were performed under two informed literature-based priors.

RESULTS

Seven randomised studies were included for meta-analysis (n=3996: CEP n=2126, control n=1870). Under a vague prior, the estimated median RR of CEP use for disabling stroke was 0.56 (95% CrI 0.28 to 1.19, derived ARD 0.56% and NNT 179, I2=0%). Although the estimated posterior probability of any benefit was 94.4%, the probability of a clinically relevant effect was 0-0.1% under the vague and informed literature-based priors. Results were robust across multiple sensitivity analyses.

CONCLUSION

There is a high probability of a beneficial CEP treatment effect, but this is unlikely to be clinically relevant. These findings suggest that future trials should focus on identifying TAVI patients with an increased baseline risk of stroke, and on the development of new generation devices.

PROSPERO REGISTRATION NUMBER

CRD42023407006.

How Do Quantitative Tissue Imaging Outcomes in Acute Ischemic Stroke Relate to Clinical Outcomes?

BACKGROUND AND PURPOSE

Infarct volume and other imaging markers are increasingly used as surrogate measures for clinical outcome in acute ischemic stroke research, but how improvements in these imaging surrogates translate into better clinical outcomes is currently unclear. We investigated how changes in infarct volume at 24 hours alter the probability of achieving good clinical outcome (modified Rankin Scale [mRS] 0-2).

METHODS

Data are from endovascular thrombectomy patients from the randomized controlled ESCAPE-NA1 (Efficacy and Safety of Nerinetide for the Treatment of Acute Ischaemic Stroke) trial. Infarct volume at 24 hours was manually segmented on non-contrast computed tomography or diffusion-weighted magnetic resonance imaging. Probabilities of achieving good outcome based on infarct volume were obtained from a multivariable logistic regression model. The probability of good outcome was plotted against infarct volume using linear spline regression.

RESULTS

A total of 1,099 patients were included in the analysis (median final infarct volume 24.9 mL [interquartile range: 6.6-92.2]). The relationship between total infarct volume and good outcome probability was nearly linear for infarct volumes between 0 mL and 250 mL. In this range, a 10% increase in the probability of achieving mRS 0-2 required a decrease in infarct volume of approximately 34.0 mL (95% confidence interval: -32.5 to -35.6). At infarct volumes above 250 mL, the probability of achieving mRS 0-2 probability was near zero. The relationships of tissue-specific infarct volumes and parenchymal hemorrhage volume generally showed similar patterns, although variability was high.

CONCLUSION

There seems to be a near-linear association between total infarct volume and probability of achieving good outcome for infarcts up to 250 mL, whereas patients with infarct volumes greater than 250 mL are highly unlikely to have a favorable outcome.

Combination therapy of Epidermal Growth Factor and Growth Hormone-Releasing Hexapeptide in acute ischemic stroke: a phase I/II non-blinded, randomized clinical trial

Objective

This study tested the hypothesis that a neuroprotective combined therapy based on epidermal growth factor (EGF) and growth hormone-releasing hexapeptide (GHRP6) could be safe for acute ischemic stroke patients, admitting up to 30% of serious adverse events (SAE) with proven causality.

Methods

A multi-centric, randomized, open-label, controlled, phase I-II clinical trial with parallel groups was conducted (July 2017 to January 2018). Patients aged 18-80 years with a computed tomography-confirmed ischemic stroke and less than 12 h from the onset of symptoms were randomly assigned to the study groups I (75 μg rEGF + 3.5 mg GHRP6 i.v., n=10), II (75 μg rEGF + 5 mg GHRP6 i.v., n=10), or III (standard care control, n=16). Combined therapy was given BID for 7 days. The primary endpoint was safety over 6 months. Secondary endpoints included neurological (NIHSS) and functional [Barthel index and modified Rankin scale (mRS)] outcomes.

Results

The study population had a mean age of 66 ± 11 years, with 21 men (58.3%), a baseline median NIHSS score of 9 (95% CI: 8-11), and a mean time to treatment of 7.3 ± 2.8 h. Analyses were conducted on an intention-to-treat basis. SAEs were reported in 9 of 16 (56.2%) patients in the control group, 3 of 10 (30%) patients in Group I (odds ratio (OR): 0.33; 95% CI: 0.06-1.78), and 2 of 10 (20%) patients in Group II (OR: 0.19; 95% CI: 0.03-1.22); only two events in one patient in Group I were attributed to the intervention treatment. Compliance with the study hypothesis was greater than 0.90 in each group. Patients treated with EGF + GHRP6 had a favorable neurological and functional evolution at both 90 and 180 days, as evidenced by the inferential analysis of NIHSS, Barthel, and mRS and by their moderate to strong effect size. At 6 months, proportion analysis evidenced a higher survival rate for patients treated with the combined therapy. Ancillary analysis including merged treated groups and utility-weighted mRS also showed a benefit of this combined therapy.

Conclusion

EGF + GHRP6 therapy was safe. The functional benefits of treatment in this study supported a Phase III study.

Clinical Trial Registration

RPCEC00000214 of the Cuban Public Registry of Clinical Trials, Unique identifier: IG/CIGB-845I/IC/1601.

Methylprednisolone as Adjunct to Endovascular Thrombectomy for Large-Vessel Occlusion Stroke: The MARVEL Randomized Clinical Trial

Importance

It is uncertain whether intravenous methylprednisolone improves outcomes for patients with acute ischemic stroke due to large-vessel occlusion (LVO) undergoing endovascular thrombectomy.

Objective

To assess the efficacy and adverse events of adjunctive intravenous low-dose methylprednisolone to endovascular thrombectomy for acute ischemic stroke secondary to LVO.

Design, Setting, and Participants

This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 82 hospitals in China, enrolling 1680 patients with stroke and proximal intracranial LVO presenting within 24 hours of time last known to be well. Recruitment took place between February 9, 2022, and June 30, 2023, with a final follow-up on September 30, 2023.

Interventions

Eligible patients were randomly assigned to intravenous methylprednisolone (n = 839) at 2 mg/kg/d or placebo (n = 841) for 3 days adjunctive to endovascular thrombectomy.

Main Outcomes and Measures

The primary efficacy outcome was disability level at 90 days as measured by the overall distribution of the modified Rankin Scale scores (range, 0 [no symptoms] to 6 [death]). The primary safety outcomes included mortality at 90 days and the incidence of symptomatic intracranial hemorrhage within 48 hours.

Results

Among 1680 patients randomized (median age, 69 years; 727 female [43.3%]), 1673 (99.6%) completed the trial. The median 90-day modified Rankin Scale score was 3 (IQR, 1-5) in the methylprednisolone group vs 3 (IQR, 1-6) in the placebo group (adjusted generalized odds ratio for a lower level of disability, 1.10 [95% CI, 0.96-1.25]; P = .17). In the methylprednisolone group, there was a lower mortality rate (23.2% vs 28.5%; adjusted risk ratio, 0.84 [95% CI, 0.71-0.98]; P = .03) and a lower rate of symptomatic intracranial hemorrhage (8.6% vs 11.7%; adjusted risk ratio, 0.74 [95% CI, 0.55-0.99]; P = .04) compared with placebo.

Conclusions and Relevance

Among patients with acute ischemic stroke due to LVO undergoing endovascular thrombectomy, adjunctive methylprednisolone added to endovascular thrombectomy did not significantly improve the degree of overall disability.

Trial Registration

ChiCTR.org.cn Identifier: ChiCTR2100051729.

Time to Treatment With Intravenous Thrombolysis Before Thrombectomy and Functional Outcomes in Acute Ischemic Stroke: A Meta-Analysis

Importance

The benefit of intravenous thrombolysis (IVT) for acute ischemic stroke declines with longer time from symptom onset, but it is not known whether a similar time dependency exists for IVT followed by thrombectomy.

Objective

To determine whether the benefit associated with IVT plus thrombectomy vs thrombectomy alone decreases with treatment time from symptom onset.

Design, Setting, and Participants

Individual participant data meta-analysis from 6 randomized clinical trials comparing IVT plus thrombectomy vs thrombectomy alone. Enrollment was between January 2017 and July 2021 at 190 sites in 15 countries. All participants were eligible for IVT and thrombectomy and presented directly at thrombectomy-capable stroke centers (n = 2334). For this meta-analysis, only patients with an anterior circulation large-vessel occlusion were included (n = 2313).

Exposure

Interval from stroke symptom onset to expected administration of IVT and treatment with IVT plus thrombectomy vs thrombectomy alone.

Main Outcomes and Measures

The primary outcome analysis tested whether the association between the allocated treatment (IVT plus thrombectomy vs thrombectomy alone) and disability at 90 days (7-level modified Rankin Scale [mRS] score range, 0 [no symptoms] to 6 [death]; minimal clinically important difference for the rates of mRS scores of 0-2: 1.3%) varied with times from symptom onset to expected administration of IVT.

Results

In 2313 participants (1160 in IVT plus thrombectomy group vs 1153 in thrombectomy alone group; median age, 71 [IQR, 62 to 78] years; 44.3% were female), the median time from symptom onset to expected administration of IVT was 2 hours 28 minutes (IQR, 1 hour 46 minutes to 3 hours 17 minutes). There was a statistically significant interaction between the time from symptom onset to expected administration of IVT and the association of allocated treatment with functional outcomes (ratio of adjusted common odds ratio [OR] per 1-hour delay, 0.84 [95% CI, 0.72 to 0.97], P = .02 for interaction). The benefit of IVT plus thrombectomy decreased with longer times from symptom onset to expected administration of IVT (adjusted common OR for a 1-step mRS score shift toward improvement, 1.49 [95% CI, 1.13 to 1.96] at 1 hour, 1.25 [95% CI, 1.04 to 1.49] at 2 hours, and 1.04 [95% CI, 0.88 to 1.23] at 3 hours). For a mRS score of 0, 1, or 2, the predicted absolute risk difference was 9% (95% CI, 3% to 16%) at 1 hour, 5% (95% CI, 1% to 9%) at 2 hours, and 1% (95% CI, -3% to 5%) at 3 hours. After 2 hours 20 minutes, the benefit associated with IVT plus thrombectomy was not statistically significant and the point estimate crossed the null association at 3 hours 14 minutes.

Conclusions and Relevance

In patients presenting at thrombectomy-capable stroke centers, the benefit associated with IVT plus thrombectomy vs thrombectomy alone was time dependent and statistically significant only if the time from symptom onset to expected administration of IVT was short.

Minimal Clinically Important Difference of Scales Reported in Stroke Trials: A Review

There is a growing awareness of the significance of using minimum clinically important differences (MCIDs) in stroke research. An MCID is the smallest change in an outcome measure that is considered clinically meaningful. This review is the first to provide a comprehensive summary of various scales and patient-reported outcome measures (PROMs) used in stroke research and their MCID values reported in the literature, including a concise overview of the concept of and methods for determining MCIDs in stroke research. Despite the controversies and limitations surrounding the estimation of MCIDs, their importance in modern clinical trials cannot be overstated. Anchor-based and distribution-based methods are recommended for estimating MCIDs, with patient self-evaluation being a crucial component in capturing the patient's perspective on their health. A combination of methods can provide a more comprehensive understanding of the clinical relevance of treatment effects, and incorporating the patient's perspective can enhance the care of stroke patients.

Clinically important effect sizes for clinical trials using infarct growth reduction as the primary outcome: a systematic review

BACKGROUND

Infarct growth on multimodal imaging is a common lead outcome in phase 2 proof-of-concept and dose-optimization neuroprotective agent stroke trials. However, the effect size in infarct growth reduction that correlates with clinically meaningful differences in clinical global disability outcomes has not been well delineated.

METHODS

A systematic literature search identified all endovascular thrombectomy randomized trials reporting magnitude of treatment effect on both infarct growth reduction and increase in functional independence (modified Rankin Scale (mRS) 0-2). Data aggregation determined the size of infarct growth reductions salient to four types of clinically meaningful effect sizes of increase in functional independence: (1) the minimal clinically important difference (MCID)-outcome specific; (2) the MCID-practice changing; (3) the realistic target difference; and (4) the reasonable comparability effect size.

RESULTS

A systematic search identified four trials enrolling 612 imaged participants. Across the trials, the amount of functional independence (mRS 0-2) increase associated with each 1 mL reduction in infarct growth was mean 2.3±0.6%. An infarct growth reduction of 0.57 mL correlated with the mRS 0-2 increase MCID of 1.3%. Infarct growth reductions of 2.27 mL, 4.35 mL, and 6.53 mL correlated with realistic effect and reasonable comparability effects sizes of mRS 0-2 increases of 5%, 10%, and 15%, respectively.

CONCLUSION

In formal meta-analysis of randomized treatment trials, every 1 mL reduction in infarct growth was associated with a 2.3% increase in functional independence (mRS 0-2) at 3 months. This conversion factor can inform selection of infarct growth effect size targets for phase 2 trials of neuroprotective agents.

Intensive vs Conventional Blood Pressure Lowering After Endovascular Thrombectomy in Acute Ischemic Stroke: The OPTIMAL-BP Randomized Clinical Trial

Importance

Optimal blood pressure (BP) control after successful reperfusion with endovascular thrombectomy (EVT) for patients with acute ischemic stroke is unclear.

Objective

To determine whether intensive BP management during the first 24 hours after successful reperfusion leads to better clinical outcomes than conventional BP management in patients who underwent EVT.

Design, Setting, and Participants

Multicenter, randomized, open-label trial with a blinded end-point evaluation, conducted across 19 stroke centers in South Korea from June 2020 to November 2022 (final follow-up, March 8, 2023). It included 306 patients with large vessel occlusion acute ischemic stroke treated with EVT and with a modified Thrombolysis in Cerebral Infarction score of 2b or greater (partial or complete reperfusion).

Interventions

Participants were randomly assigned to receive intensive BP management (systolic BP target <140 mm Hg; n = 155) or conventional management (systolic BP target 140-180 mm Hg; n = 150) for 24 hours after enrollment.

Main Outcomes and Measures

The primary outcome was functional independence at 3 months (modified Rankin Scale score of 0-2). The primary safety outcomes were symptomatic intracerebral hemorrhage within 36 hours and death related to the index stroke within 3 months.

Results

The trial was terminated early based on the recommendation of the data and safety monitoring board, which noted safety concerns. Among 306 randomized patients, 305 were confirmed eligible and 302 (99.0%) completed the trial (mean age, 73.0 years; 122 women [40.4%]). The intensive management group had a lower proportion achieving functional independence (39.4%) than the conventional management group (54.4%), with a significant risk difference (-15.1% [95% CI, -26.2% to -3.9%]) and adjusted odds ratio (0.56 [95% CI, 0.33-0.96]; P = .03). Rates of symptomatic intracerebral hemorrhage were 9.0% in the intensive group and 8.1% in the conventional group (risk difference, 1.0% [95% CI, -5.3% to 7.3%]; adjusted odds ratio, 1.10 [95% CI, 0.48-2.53]; P = .82). Death related to the index stroke within 3 months occurred in 7.7% of the intensive group and 5.4% of the conventional group (risk difference, 2.3% [95% CI, -3.3% to 7.9%]; adjusted odds ratio, 1.73 [95% CI, 0.61-4.92]; P = .31).

Conclusions and Relevance

Among patients who achieved successful reperfusion with EVT for acute ischemic stroke with large vessel occlusion, intensive BP management for 24 hours led to a lower likelihood of functional independence at 3 months compared with conventional BP management. These results suggest that intensive BP management should be avoided after successful EVT in acute ischemic stroke.

Trial Registration

ClinicalTrials.gov Identifier: NCT04205305.

Minimal Clinically Important Difference (MCID) in Patient-Reported Outcome Measures for Neurological Conditions: Review of Concept and Methods

The concept of the minimal clinically important difference (MCID) emerged from the recognition that statistical significance alone is not enough to determine the clinical relevance of treatment effects in clinical research. In many cases, statistically significant changes in outcomes may not be meaningful to patients or may not result in any tangible improvements in their health. This has led to a growing emphasis on the importance of measuring patient-reported outcome measures (PROMs) in clinical trials and other research studies, in order to capture the patient perspective on treatment effectiveness. MCID is defined as the smallest change in scores that is considered meaningful or important to patients. MCID is particularly important in fields such as neurology, where many of the outcomes of interest are subjective or based on patient-reported symptoms. This review discusses the challenges associated with interpreting outcomes of clinical trials based solely on statistical significance, highlighting the importance of considering clinical relevance and patient perception of change. There are two main approaches to estimating MCID: anchor-based and distribution-based. Anchor-based approaches compare change scores using an external anchor, while distribution-based approaches estimate MCID values based on statistical characteristics of scores within a sample. MCID is dynamic and context-specific, and there is no single 'gold standard' method for estimating it. A range of MCID thresholds should be defined using multiple methods for a disease under targeted intervention, rather than relying on a single absolute value. The use of MCID thresholds can be an important tool for researchers, neurophysicians and patients in evaluating the effectiveness of treatments and interventions, and in making informed decisions about care.

Effect of cerebellar transcranial magnetic stimulation with double-cone coil on dysphagia after subacute infratentorial stroke: A randomized, single-blinded, controlled trial

BACKGROUND

A 10-Hz cerebellar repetitive transcranial magnetic stimulation (rTMS) could increase corticobulbar tract excitability in healthy individuals. However, its clinical efficacy for poststroke dysphagia (PSD) remains unclear.

OBJECTIVE

To investigate the effectiveness of 10-Hz cerebellar rTMS in PSD patients with infratentorial stroke (IS).

METHODS

In this single-blinded, randomized controlled trial, 42 PSD patients with subacute IS were allocated to three groups: bilateral cerebellar rTMS (biCRB-rTMS), unilateral cerebellar rTMS (uniCRB-rTMS), or sham-rTMS. The stimulation parameters were 5 trains of 50 stimuli at 10 Hz with an interval of 10 s at 90% of the thenar resting motor threshold (RMT). The Functional Oral Intake Scale (FOIS) was assessed at T0 (baseline), T1 (day 0 after intervention), and T2 (day 14 after intervention), whereas the Dysphagia Outcome and Severity Scale (DOSS), Penetration Aspiration Scale (PAS), and neurophysiological parameters were evaluated at T0 and T1.

RESULTS

Significant time and intervention interaction effects were observed for the FOIS score (F = 3.045, p = 0.022). The changes in the FOIS scores at T1 and T2 were both significantly higher in the biCRB-rTMS group than in the sham-rTMS group (p < 0.05). The uniCRB-rTMS and biCRB-rTMS groups demonstrated greater changes in the DOSS and PAS at T1, compared with the sham-rTMS group (p < 0.05). Bilateral corticobulbar tract excitability partly increased in the biCRB-rTMS and uniCRB-rTMS groups at T1, compared with T0. The percent changes in corticobulbar tract excitability parameters at T1 showed no difference among three groups.

CONCLUSIONS

A 10-Hz bilateral cerebellar rTMS is a promising, noninvasive treatment for subacute infratentorial PSD.

Staged use of ordinal and linear disability scales: a practical approach to granular assessment of acute stroke outcome

Background

The modified Rankin Scale (mRS) assessment of global disability is the most common primary endpoint in acute stroke trials but lacks granularity (7 broad levels) and is ordinal (scale levels unknown distances apart), which constrains study power. Disability scales that are linear and continuous may better discriminate outcomes, but computerized administration in stroke patients is challenging. We, therefore, undertook to develop a staged use of an ordinal followed by a linear scale practical to use in multicenter trials.

Methods

Consecutive patients undergoing 3-month final visits in the NIH FAST-MAG phase 3 trial were assessed with the mRS followed by 15 mRS level-specific yes-no items of the Academic Medical Center Linear Disability Score (ALDS), a linear disability scale derived using item response theory.

Results

Among 55 patients, aged 71.2 (SD ± 14.2), 67% were men and the entry NIHSS was 10.7 (SD ± 9.5). At 90 days, the median mRS score was 3 (IQR, 1-4), and the median ALDS score was 78.8 (IQR, 3.3-100). ALDS scores correlated strongly with 90 days outcome measures, including the Barthel Index (r = 0.92), NIHSS (r = 0.87), and mRS (r = 0.94). ALDS scores also correlated modestly with entry NIHSS (r = 0.38). At 90 days, the ALDS showed greater scale granularity than the mRS, with fewer patients with identical values, 1.9 (SD ± 3.2) vs. 8.0 (SD ± 3.6), p < 0.001. When treatment effect magnitudes were small to moderate, projected trial sample size requirements were 2-12-fold lower when the ALDS rather than the mRS was used as the primary trial endpoint.

Conclusion

Among patients enrolled in an acute neuroprotective stroke trial, the ALDS showed strong convergent validity and superior discrimination characteristics compared with the modified Rankin Scale and increased projected trial power to detect clinically meaningful treatment benefits.

Perceived acceptable uncertainty regarding comparability of endovascular treatment alone versus intravenous thrombolysis plus endovascular treatment

BACKGROUND

Most trials comparing endovascular treatment (EVT) alone versus intravenous thrombolysis with alteplase (IVT) + EVT in directly admitted patients with a stroke are non-inferiority trials. However, the margin based on the level of uncertainty regarding non-inferiority of the experimental treatment that clinicians are willing to accept to incorporate EVT alone into clinical practice remains unknown.

OBJECTIVE

To characterize what experienced stroke clinicians would consider an acceptable level of uncertainty for hypothetical decisions on whether to administer IVT or not before EVT in patients admitted directly to EVT-capable centers.

METHODS

A web-based, structured survey was distributed to a cross-section of 600 academic neurologists/neurointerventionalists. For this purpose, a response framework for a hypothetical trial comparing IVT+EVT (standard of care) with EVT alone (experimental arm) was designed. In this trial, a similar proportion of patients in each arm achieved functional independence at 90 days. Invited physicians were asked at what level of certainty they would feel comfortable skipping IVT in clinical practice, considering these hypothetical trial results.

RESULTS

There were 180 respondents (response rate: 30%) and 165 with complete answers. The median chosen acceptable uncertainty suggesting reasonable comparability between both treatments was an absolute difference in the rate of day 90 functional independence of 3% (mode 5%, IQR 1-5%), with higher chosen margins observed in interventionalists (aOR 2.20, 95% CI 1.06 to 4.67).

CONCLUSION

Physicians would generally feel comfortable skipping IVT before EVT at different certainty thresholds. Most physicians would treat with EVT alone if randomized trial data suggested that the number of patients achieving functional independence at 90 days was similar between the two groups, and one could be sufficiently sure that no more than 3 out of 100 patients would not achieve functional independence at 90 days due to skipping IVT.

European Stroke Organisation (ESO) expedited recommendation on tenecteplase for acute ischaemic stroke

Within the last year, four randomised-controlled clinical trials (RCTs) have been published comparing intravenous thrombolysis (IVT) with tenecteplase and alteplase in acute ischaemic stroke (AIS) patients with a non-inferiority design for three of them. An expedited recommendation process was initiated by the European Stroke Organisation (ESO) and conducted according to ESO standard operating procedure based on the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework. We identified three relevant Population, Intervention, Comparator, Outcome (PICO) questions, performed systematic reviews of the literature and meta-analyses, assessed the quality of the available evidence, and wrote evidence-based recommendations. Expert consensus statements were provided if insufficient evidence was available to provide recommendations based on the GRADE approach. For patients with AIS of <4.5 h duration who are eligible for IVT, tenecteplase 0.25 mg/kg can be used as a safe and effective alternative to alteplase 0.9 mg/kg (moderate evidence, strong recommendation). For patients with AIS of <4.5 h duration who are eligible for IVT, we recommend against using tenecteplase at a dose of 0.40 mg/kg (low evidence, strong recommendation). For patients with AIS of <4.5 h duration with prehospital management with a mobile stroke unit who are eligible for IVT, we suggest tenecteplase 0.25 mg/kg over alteplase 0.90 mg/kg (low evidence, weak recommendation). For patients with large vessel occlusion (LVO) AIS of <4.5 h duration who are eligible for IVT, we recommend tenecteplase 0.25 mg/kg over alteplase 0.9 mg/kg (moderate evidence, strong recommendation). For patients with AIS on awakening from sleep or AIS of unknown onset who are selected with non-contrast CT, we recommend against IVT with tenecteplase 0.25 mg/kg (low evidence, strong recommendation). Expert consensus statements are also provided. Tenecteplase 0.25 mg/kg may be favoured over alteplase 0.9 mg/kg for patients with AIS of <4.5 h duration in view of comparable safety and efficacy data and easier administration. For patients with LVO AIS of <4.5 h duration who are IVT-eligible, IVT with tenecteplase 0.25 mg/kg is preferable over skipping IVT before MT, even in the setting of a direct admission to a thrombectomy-capable centre. IVT with tenecteplase 0.25 mg/kg may be a reasonable alternative to alteplase 0.9 mg/kg for patients with AIS on awakening from sleep or AIS of unknown onset and who are IVT-eligible after selection with advanced imaging.

EMAGINE-Study protocol of a randomized controlled trial for determining the efficacy of a frequency tuned electromagnetic field treatment in facilitating recovery within the subacute phase following ischemic stroke

Stroke is a leading cause of disability with limited effective interventions that improve recovery in the subacute phase. This protocol aims to evaluate the safety and efficacy of a non-invasive, extremely low-frequency, low-intensity, frequency-tuned electromagnetic field treatment [Electromagnetic Network Targeting Field (ENTF) therapy] in reducing disability and promoting recovery in people with subacute ischemic stroke (IS) with moderate-severe disability and upper extremity (UE) motor impairment. Following a sample-size adaptive design with a single interim analysis, at least 150 and up to 344 participants will be recruited to detect a 0.5-point (with a minimum of 0.33 points) difference on the modified Rankin Scale (mRS) between groups with 80% power at a 5% significance level. This ElectroMAGnetic field Ischemic stroke-Novel subacutE treatment (EMAGINE) trial is a multicenter, double-blind, randomized, sham-controlled, parallel two-arm study to be conducted at approximately 20 United States sites, and enroll participants with subacute IS and moderate-severe disability with UE motor impairment. Participants will be assigned to active (ENTF) or sham treatment, initiated 4-21 days after stroke onset. The intervention, applied to the central nervous system, is designed for suitability in multiple clinical settings and at home. Primary endpoint is change in mRS score from baseline to 90 days post-stroke. Secondary endpoints: change from baseline to 90 days post-stroke on the Fugl-Meyer Assessment - UE (lead secondary endpoint), Box and Block Test, 10-Meter Walk, and others, to be analyzed in a hierarchical manner. EMAGINE will evaluate whether ENTF therapy is safe and effective at reducing disability following subacute IS.

Trial registration

www.ClinicalTrials.gov, NCT05044507 (14 September 2021).

Credibility and Generalization of the Minimally Important Difference Concept in Dermatology: A Scoping Review

Importance

The minimally important difference (MID) represents the point at which a difference in an outcome measure (eg, Dermatology Life Quality Index) is important enough that it warrants a change in treatment, and, to the authors' knowledge, the robustness and limitations of MIDs have not been thoroughly evaluated in skin diseases. The MID is increasingly used in clinical trials to demonstrate that an intervention is worthwhile for patients; furthermore, MIDs also contribute to sample size calculations in clinical trials, influence treatment guidelines, and can guide clinicians to modify treatment.

Objective

To evaluate the credibility and generalization of MIDs for patient-reported outcome measures (PROMs) in skin disorders.

Evidence Review

A systematic search was conducted in PubMed and Embase for all original articles using the MID concept for skin disorders from inception to December 29, 2021. The credibility of MIDs obtained via an anchor-based approach (eg, global rating of change scale) was assessed with a previously developed credibility instrument. The validity of generalizing established MIDs to other patient groups was evaluated based on the diagnosis and the patient characteristics.

Findings

A total of 126 articles were selected, and 84 different MIDs were identified for PROMs. A total of 13 of 84 MIDs (15.5%) for PROMs displayed acceptable credibility. The anchors used had varying capacity to assess minimal important changes from a patient's perspective and were deemed inappropriate for this purpose in 52 of 84 cases (61.9%). Correlations between the anchors and PROMs were frequently not determined (39 of 84; 46.4%). The time interval for anchor questions assessing a change in the experienced disease burden was not optimal for 10 of 32 transition anchors (>3 months), introducing potential recall bias. Previously reported MIDs were widely used to examine relevant changes in other study populations. However, the diagnosis and disease severity were different from the original MID population in 39 of 70 (55.7%) and 45 of 70 (64.3%) cases, respectively.

Conclusions and Relevance

In this scoping review, only a minority of MIDs for PROMs demonstrated sufficient credibility in dermatology. Inappropriate generalization of previously reported MIDs to patient populations with different disease characteristics was found to be a major concern. Furthermore, the study supported the use of multiple anchors and encouraged consistent reporting of the correlation between changes in the anchor and changes in the outcome measures.

RESCUE BT 2, a multicenter, randomized, double-blind, double-dummy trial of intravenous tirofiban in acute ischemic stroke: study rationale and design

BACKGROUND

Tirofiban is a glycoprotein IIb/IIIa receptor inhibitor that has been shown to be effective in the treatment of acute coronary syndromes. However, it remains unknown whether it improves outcomes in patients with acute ischemic stroke.

OBJECTIVE

This trial investigates the efficacy and safety of tirofiban compared with aspirin for acute ischemic stroke within 24 hours after symptom onset.

METHODS AND DESIGN

The Efficacy and Safety of Tirofiban Compared with Aspirin in the Treatment of Acute Ischemic Stroke (RESCUE BT 2) Trial is an investigator-initiated, prospective, randomized, double-blind, double-dummy, multicenter clinical trial. Up to 1158 eligible patients will be consecutively randomized to receive antiplatelet therapy with tirofiban or aspirin in 1:1 ratio across approximately 100 stroke centers in China.

OUTCOMES

The primary endpoint is the proportion of patients with excellent functional outcome defined as modified Rankin scale score of 0 to 1 at 90 days after randomization. Lead safety endpoints include symptomatic intracerebral hemorrhage at 48 hours and mortality at 90 days. Trial registry number: ChiCTR2000029502 (www.chictr.org.cn).

The Meaning and Reliability of Minimal Important Differences (MIDs) for Clinician-Reported Outcome Measures (ClinROMs) in Dermatology-A Scoping Review

Background: Clinician-reported outcome measures (ClinROMs) are frequently used in clinical trials and daily practice to evaluate the disease status and evolution of skin disorders. The minimal important difference (MID) represents the smallest difference that decreases the disease impact enough to make a treatment change worthwhile for patients. As no clear guidance exists on the preferred method to calculate MIDs for ClinROMs, we evaluated how the published values for different skin disorders should be interpreted. Methods: A systematic search was performed for MIDs of ClinROMs that focus on skin disorders and/or symptoms. The results of the questions in the credibility instrument for MIDs of Devji et al., 2020 were analyzed to gain insights into the meaning of these MIDs. Results: 29 MIDs were identified. The most common skin diseases were atopic dermatitis/eczema, followed by bullous disorders and psoriasis. A minimal important difference from the patients’ perspective was determined in 31% of the cases. However, in 41.4% of the cases, it concerned a substantial rather than a minimal difference in disease severity rated by physicians. Over half (55.1%) of the studies contained an inadequate number of patients (n < 150). MID values increased substantially in patients with severe compared to mild disease. Conclusions: MIDs of ClinROMs for skin disorders should be carefully interpreted due to the substantial differences in methodology between the studies. There is an urgent need for a consensus method to report reliable MIDs. Otherwise, this lack of uniformity could not only affect the design and conclusion of clinical trials but also skew treatment decisions.

Intravenous tenecteplase compared with alteplase for acute ischaemic stroke in Canada (AcT): a pragmatic, multicentre, open-label, registry-linked, randomised, controlled, non-inferiority trial

BACKGROUND

Intravenous thrombolysis with alteplase bolus followed by infusion is a global standard of care for patients with acute ischaemic stroke. We aimed to determine whether tenecteplase given as a single bolus might increase reperfusion compared with this standard of care.

METHODS

In this multicentre, open-label, parallel-group, registry-linked, randomised, controlled trial (AcT), patients were enrolled from 22 primary and comprehensive stroke centres across Canada. Patients were eligible for inclusion if they were aged 18 years or older, with a diagnosis of ischaemic stroke causing disabling neurological deficit, presenting within 4·5 h of symptom onset, and eligible for thrombolysis per Canadian guidelines. Eligible patients were randomly assigned (1:1), using a previously validated minimal sufficient balance algorithm to balance allocation by site and a secure real-time web-based server, to either intravenous tenecteplase (0·25 mg/kg to a maximum of 25 mg) or alteplase (0·9 mg/kg to a maximum of 90mg; 0·09 mg/kg as a bolus and then a 60 min infusion of the remaining 0·81 mg/kg). The primary outcome was the proportion of patients who had a modified Rankin Scale (mRS) score of 0-1 at 90-120 days after treatment, assessed via blinded review in the intention-to-treat (ITT) population (ie, all patients randomly assigned to treatment who did not withdraw consent). Non-inferiority was met if the lower 95% CI of the difference in the proportion of patients who met the primary outcome between the tenecteplase and alteplase groups was more than -5%. Safety was assessed in all patients who received any of either thrombolytic agent and who were reported as treated. The trial is registered with ClinicalTrials.gov, NCT03889249, and is closed to accrual.

FINDINGS

Between Dec 10, 2019, and Jan 25, 2022, 1600 patients were enrolled and randomly assigned to tenecteplase (n=816) or alteplase (n=784), of whom 1577 were included in the ITT population (n=806 tenecteplase; n=771 alteplase). The median age was 74 years (IQR 63-83), 755 (47·9%) of 1577 patients were female and 822 (52·1%) were male. As of data cutoff (Jan 21, 2022), 296 (36·9%) of 802 patients in the tenecteplase group and 266 (34·8%) of 765 in the alteplase group had an mRS score of 0-1 at 90-120 days (unadjusted risk difference 2·1% [95% CI - 2·6 to 6·9], meeting the prespecified non-inferiority threshold). In safety analyses, 27 (3·4%) of 800 patients in the tenecteplase group and 24 (3·2%) of 763 in the alteplase group had 24 h symptomatic intracerebral haemorrhage and 122 (15·3%) of 796 and 117 (15·4%) of 763 died within 90 days of starting treatment INTERPRETATION: Intravenous tenecteplase (0·25 mg/kg) is a reasonable alternative to alteplase for all patients presenting with acute ischaemic stroke who meet standard criteria for thrombolysis.

FUNDING

Canadian Institutes of Health Research, Alberta Strategy for Patient Oriented Research Support Unit.

Thrombectomy alone versus intravenous alteplase plus thrombectomy in patients with stroke: an open-label, blinded-outcome, randomised non-inferiority trial

BACKGROUND

Whether thrombectomy alone is equally as effective as intravenous alteplase plus thrombectomy remains controversial. We aimed to determine whether thrombectomy alone would be non-inferior to intravenous alteplase plus thrombectomy in patients presenting with acute ischaemic stroke.

METHODS

In this multicentre, randomised, open-label, blinded-outcome trial in Europe and Canada, we recruited patients with stroke due to large vessel occlusion confirmed with CT or magnetic resonance angiography admitted to endovascular centres. Patients were randomly assigned (1:1) via a centralised web server using a deterministic minimisation method to receive stent-retriever thrombectomy alone or intravenous alteplase plus stent-retriever thrombectomy. In both groups, thrombectomy was initiated as fast as possible with any commercially available Solitaire stent-retriever revascularisation device (Medtronic, Irvine, CA, USA). In the combined treatment group, intravenous alteplase (0·9 mg/kg bodyweight, maximum dose 90 mg per patient) was administered as early as possible after randomisation for 60 min with 10% of the calculated dose given as an initial bolus. Personnel assessing the primary outcome were masked to group allocation; patients and treating physicians were not. The primary binary outcome was a score of 2 or less on the modified Rankin scale at 90 days. We assessed the non-inferiority of thrombectomy alone versus intravenous alteplase plus thrombectomy in all randomly assigned and consenting patients using the one-sided lower 95% confidence limit of the Mantel-Haenszel risk difference, with a prespecified non-inferiority margin of 12%. The main safety endpoint was symptomatic intracranial haemorrhage assessed in all randomly assigned and consenting participants. This trial is registered with ClinicalTrials.gov, NCT03192332, and is closed to new participants.

FINDINGS

Between Nov 29, 2017, and May 7, 2021, 5215 patients were screened and 423 were randomly assigned, of whom 408 (201 thrombectomy alone, 207 intravenous alteplase plus thrombectomy) were included in the primary efficacy analysis. A modified Rankin scale score of 0-2 at 90 days was reached by 114 (57%) of 201 patients assigned to thrombectomy alone and 135 (65%) of 207 patients assigned to intravenous alteplase plus thrombectomy (adjusted risk difference -7·3%, 95% CI -16·6 to 2·1, lower limit of one-sided 95% CI -15·1%, crossing the non-inferiority margin of -12%). Symptomatic intracranial haemorrhage occurred in five (2%) of 201 patients undergoing thrombectomy alone and seven (3%) of 202 patients receiving intravenous alteplase plus thrombectomy (risk difference -1·0%, 95% CI -4·8 to 2·7). Successful reperfusion was less common in patients assigned to thrombectomy alone (182 [91%] of 201 vs 199 [96%] of 207, risk difference -5·1%, 95% CI -10·2 to 0·0, p=0·047).

INTERPRETATION

Thrombectomy alone was not shown to be non-inferior to intravenous alteplase plus thrombectomy and resulted in decreased reperfusion rates. These results do not support omitting intravenous alteplase before thrombectomy in eligible patients.

FUNDING

Medtronic and University Hospital Bern.

Minimal clinically important difference of the Berg Balance Scale and comfortable walking speed in patients with acute stroke: A multicenter, prospective, longitudinal study

OBJECTIVE

To determine the minimal clinically important difference between the Berg Balance Scale and comfortable walking speed in acute-phase stroke patients.

DESIGN

Multicenter, prospective, longitudinal study.

SETTING

Inpatient acute stroke rehabilitation.

SUBJECTS

Seventy-five patients with acute stroke, mean (SD) age 71.7 (12.2) years.

INTERVENTION

Inpatients with acute stroke were assessed with the Berg Balance Scale and comfortable walking speed before and after rehabilitation. Physiotherapy was conducted to improve balance and gait over a 2-week period: an average of 40 min/day on weekdays and 20 min/day on weekends and holidays.

MAIN MEASURES

The patients' Berg Balance Scale, comfortable walking speed, Global Rating of Change scale (patient-rated and physiotherapist-rated), and motor score of the Functional Independence Measure were obtained. Minimal clinically important differences were estimated using both anchor- (receiver operating characteristic curves and change difference) and distribution-based approaches (minimal detectable change and 0.5× the change score [SD]).

RESULTS

The baseline scores were 31.2 (18.9) for the Berg Balance Scale and 0.79 (0.35) m/s for comfortable walking speed. The minimal clinically important difference in the Berg Balance Scale was 6.5-12.5 points by the anchor-based approach and 2.3-4.9 points by the distribution-based approach. The minimal clinically important difference in comfortable walking speed was 0.18-0.25 m/s by the anchor-based and 0.13-0.15 m/s by the distribution-based approach.

CONCLUSIONS

A change of 6.5-12.5 points in the Berg Balance Scale and 0.18-0.25 m/s in the comfortable walking speed is required in these measurements' anchor-based minimal clinically important differences to be beyond measurement error, and to be perceptible by both patients and clinicians.

IV thrombolysis with tenecteplase for the treatment of acute ischemic stroke

OBJECTIVE

Intravenous thrombolysis (IVT) with tenecteplase has been associated with better clinical outcomes in acute ischemic stroke (AIS) patients with confirmed large vessel occlusions compared to IVT with alteplase. However, the utility of tenecteplase for the treatment of all AIS patients eligible for IVT has not been established.

METHODS

We compared the safety and efficacy of tenecteplase vs. alteplase in AIS patients by analysing propensity score matched data from 20 centres participating in the SITS-ISTR registry. Patients receiving IVT with tenecteplase were matched with up to three patients receiving alteplase from the same centre. The primary outcome of interest was the distribution of 3-month functional outcomes. Secondary outcomes included the rates of patients with symptomatic intracranial hemorrhage (SICH) in the first 24 hours, excellent (mRS-scores of 0-1) or good (mRS-scores of 0-2) functional outcome, and all-cause mortality at 3 months.

RESULTS

A total of 331 tenecteplase-treated AIS patients were matched to 797 patients treated with alteplase [median age of 70 years; 43.9% women; median NIHSS-score: 11 (IQR: 6-17)]. Patients treated with tenecteplase had better three-month functional outcomes (common OR=1.54,95%CI:1.18-2.00) with higher odds of good functional outcome (OR=2.00,95%CI:1.45-2.77) and a lower likelihood of all-cause mortality (OR=0.43,95%CI:0.27-0.67) at three months, compared to alteplase-treated patients. No difference was found in the likelihood of the three-month excellent functional outcomes (OR=1.31,95%CI:0.96-1.78) and 24-hour SICH (1.0% vs. 1.3%; OR=0.72,95%CI:.20-2.64).

INTERPRETATION

IVT with tenecteplase was associated with better three-month clinical outcomes compared to IVT with alteplase in AIS patients, with no increased risk of symptomatic intracranial bleeding. This article is protected by copyright. All rights reserved.

European Stroke Organisation - European Society for Minimally Invasive Neurological Therapy expedited recommendation on indication for intravenous thrombolysis before mechanical thrombectomy in patients with acute ischaemic stroke and anterior circulation large vessel occlusion

Six randomized controlled clinical trials have assessed whether mechanical thrombectomy (MT) alone is non-inferior to intravenous thrombolysis (IVT) plus MT within 4.5 hours of symptom onset in patients with anterior circulation large vessel occlusion (LVO) ischaemic stroke and no contraindication to IVT. An expedited recommendation process was initiated by the European Stroke Organisation (ESO) and conducted with the European Society of Minimally Invasive Neurological Therapy (ESMINT) according to ESO standard operating procedure based on the GRADE system. We identified two relevant Population, Intervention, Comparator, Outcome (PICO) questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence and wrote evidence-based recommendations. Expert opinion was provided if insufficient evidence was available to provide recommendations based on the GRADE approach. For stroke patients with anterior circulation LVO directly admitted to a MT-capable centre ('mothership') within 4.5 hours of symptom onset and eligible for both treatments, we recommend IVT plus MT over MT alone (moderate evidence, strong recommendation). MT should not prevent the initiation of IVT, nor should IVT delay MT. In stroke patients with anterior circulation LVO admitted to a centre without MT facilities and eligible for IVT ≤4.5 hrs and MT, we recommend IVT followed by rapid transfer to a MT capable-centre ('drip-and-ship') in preference to omitting IVT (low evidence, strong recommendation). Expert consensus statements on ischaemic stroke on awakening from sleep are also provided. Patients with anterior circulation LVO stroke should receive IVT in addition to MT if they have no contraindications to either treatment.

European Stroke Organisation (ESO)-European Society for Minimally Invasive Neurological Therapy (ESMINT) expedited recommendation on indication for intravenous thrombolysis before mechanical thrombectomy in patients with acute ischemic stroke and anterior circulation large vessel occlusion

Six randomized controlled clinical trials have assessed whether mechanical thrombectomy (MT) alone is non-inferior to intravenous thrombolysis (IVT) plus MT within 4.5 hours of symptom onset in patients with anterior circulation large vessel occlusion (LVO) ischemic stroke and no contraindication to IVT. An expedited recommendation process was initiated by the European Stroke Organisation (ESO) and conducted with the European Society of Minimally Invasive Neurological Therapy (ESMINT) according to ESO standard operating procedure based on the GRADE system. We identified two relevant Population, Intervention, Comparator, Outcome (PICO) questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote evidence-based recommendations. Expert opinion was provided if insufficient evidence was available to provide recommendations based on the GRADE approach.For stroke patients with anterior circulation LVO directly admitted to a MT-capable center ('mothership') within 4.5 hours of symptom onset and eligible for both treatments, we recommend IVT plus MT over MT alone (moderate evidence, strong recommendation). MT should not prevent the initiation of IVT, nor should IVT delay MT. In stroke patients with anterior circulation LVO admitted to a center without MT facilities and eligible for IVT ≤4.5 hours and MT, we recommend IVT followed by rapid transfer to a MT capable-center ('drip-and-ship') in preference to omitting IVT (low evidence, strong recommendation). Expert consensus statements on ischemic stroke on awakening from sleep are also provided. Patients with anterior circulation LVO stroke should receive IVT in addition to MT if they have no contraindications to either treatment.

Direct Endovascular Thrombectomy Alone vs. Bridging Thrombolysis for Patients with Acute Ischemic Stroke : A Meta-analysis

PURPOSE

Although the current guidelines recommend bridging thrombolysis (BT) therapy, which is intravenous thrombolysis (IVT) followed by endovascular thrombectomy (EVT), for patients with acute ischemic stroke from large vessel occlusion (AIS-LVO), the effectiveness and safety of IVT remain controversial. We performed a meta-analysis to demonstrate the non-inferiority of direct EVT alone (DEVT) compared to BT for the efficacy and safety in patients with AIS-LVO who were eligible for IVT.

METHODS

The literature was searched in big databases between 1 January 1990 and 1 April 2021. The search included both randomized clinical trials (RCTs) and nonrandomized studies (NRSs) that compared DEVT with BT for patients with AIS-LVO who were eligible for IVT (time from stroke onset ≤ 4.5 h). Only NRSs with good intergroup variable matching were included in the study. Outcomes measured included 90-day functional independence, mortality, symptomatic intracranial hemorrhage (sICH), and successful recanalization. The noninferiority margin for risk difference was set at 5% from the literature review.

RESULTS

Three RCTs (n = 1094) and four NRSs (n = 1366) were included in the meta-analysis. There were 1227 patients (49.9%) in the DEVT group and 1233 patients (50.1%) in the BT group. A statistically significant noninferiority of DEVT compared to BT was concluded in 90-day functional independence, mortality and successful reperfusion. Even in the sICH rate, DEVT group showed a superiority (risk difference, -2%; 95% confidence interval, -4 to -0.002%).

CONCLUSION

Evidence from RCTs and observational NRSs supports the use of DEVT (without IVT) as the first choice for treatment of patients with AIS-LVO within a time span of 4.5 h or less from stroke onset.

Prospective, Multicenter, Controlled Trial of Mobile Stroke Units

BACKGROUND

Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied.

METHODS

In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients.

RESULTS

We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group.

CONCLUSIONS

In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).

How to Establish the Outer Limits of Reperfusion Therapy

Reperfusion therapy with intravenous alteplase and endovascular therapy are effective treatments for selected patients with acute ischemic stroke. Guidelines for treatment are based upon randomized trials demonstrating substantial treatment effects for highly selected patients based on time from stroke onset and imaging features. However, patients beyond the current established guidelines might benefit with lesser but still clinically significant treatment effects. The STAIR (Stroke Treatment Academic Industry Roundtable) XI meeting convened a workgroup to consider the "outer limits" of reperfusion therapy by defining the current boundaries, and exploring optimal parameters and methodology for determining the outer limits. In addition to statistical significance, the minimum clinically important difference should be considered in exploring the limits of reperfusion therapy. Societal factors and quality of life considerations should be incorporated into assessment of treatment efficacy. The threshold for perception of benefit in the medical community may differ from that necessary for the Food and Drug Administration approval. Data from alternative sources such as platform trials, registries and large pragmatic trials should supplement randomized controlled trials to improve generalizability to routine clinical practice. Further interactions between industry and academic centers should be encouraged.

Non-immunogenic recombinant staphylokinase versus alteplase for patients with acute ischaemic stroke 4·5 h after symptom onset in Russia (FRIDA): a randomised, open label, multicentre, parallel-group, non-inferiority trial

BACKGROUND

Non-immunogenic staphylokinase is modified recombinant staphylokinase with low immunogenicity, high thrombolytic activity, and selectivity to fibrin. We aimed to assess the safety and efficacy of a single intravenous bolus of non-immunogenic staphylokinase compared with alteplase in patients with acute ischaemic stroke within 4·5 h after symptom onset.

METHODS

We did a randomised, open-label, multicentre, parallel-group, non-inferiority trial in 18 clinical sites in Russia. We included patients aged 18 years and older with a diagnosis of acute ischaemic stroke (up to 25 points on the National Institutes of Health Stroke Scale). The study drug had to be administered within 4·5 h after the onset of symptoms. Patients were randomly assigned to receive either non-immunogenic staphylokinase (10 mg) or alteplase (0·9 mg/kg, maximum 90 mg), both administered intravenously. The randomisation sequence was created by an independent biostatistician using computer-generated random numbers. 84 blocks (block size of four) of opaque sealed envelopes were numbered sequentially from 1 to 336 and were opened in numerical order. Patients were unaware of their assigned treatment and were assessed by the study investigators who were also unaware of the treatment assignment on all trial days. Emergency department staff, who administered the assigned drug and opened the envelopes, were not masked to treatment. The primary efficacy endpoint was a favourable outcome, defined as a modified Rankin scale (mRS) score of 0-1 on day 90. The margin of non-inferiority was established as 16% for the difference in mRS score of 0-1 on day 90. Non-inferiority was tested using Welch's t-test for the primary outcome only. Endpoints were analysed in the per-protocol population, which comprised all randomly assigned patients who completed treatment without any protocol violations; this population was identical to the intention-to-treat population. This trial is completed and registered at ClinicalTrials.gov, NCT03151993.

FINDINGS

Of 385 patients recruited from March 18, 2017, to March 23, 2019, 336 (87%) were included in the trial. 168 (50%) patients were randomly assigned to receive non-immunogenic staphylokinase and 168 (50%) to receive alteplase. The median duration of follow-up was 89 days (IQR 89-89). 84 (50%) of 168 patients in the non-immunogenic staphylokinase group had a favourable outcome at day 90 compared with 68 (40%) of 168 patients in the alteplase group (odds ratio [OR] 1·47, 95% CI 0·93 to 2·32; p=0·10). The difference in the rate of favourable outcome at day 90 was 9·5% (95% CI -1·7 to 20·7) and the lower limit did not cross the margin of non-inferiority (p_{non-inferiority} <0·0001). Symptomatic intracranial haemorrhage occurred in five (3%) patients in the non-immunogenic staphylokinase group and in 13 (8%) patients in the alteplase group (p=0·087). On day 90, 17 (10%) patients in the non-immunogenic staphylokinase group and 24 (14%) patients in the alteplase group had died (p=0·32). 22 (13%) patients in the non-immunogenic staphylokinase group had serious adverse events, compared with 37 (22%) patients in the alteplase group (p=0·044).

INTERPRETATION

Non-immunogenic staphylokinase was non-inferior to alteplase for patients with acute ischaemic stroke. Mortality, symptomatic intracranial haemorrhage, and serious adverse events did not differ significantly between groups. Future studies are needed to continue to assess the safety and efficacy of non-immunogenic staphylokinase in patients with acute ischaemic stroke within the 4·5 h time window, and to assess the drug in patients with acute ischaemic stroke outside this time window with reperfusion CT or magnetic resonance angiography followed by thrombectomy if necessary.

FUNDING

The Russian Academy of Sciences.

Endovascular thrombectomy without versus with intravenous thrombolysis in acute ischemic stroke: a non-inferiority meta-analysis of randomized clinical trials

OBJECTIVE

To conduct a meta-analysis of randomized trials to comprehensively compare the effect of endovascular thrombectomy (EVT) versus intravenous thrombolysis (IVT) plus EVT on functional independence (modified Rankin Scale (mRS) 0-2) after acute ischemic stroke due to large vessel occlusions (AIS-LVO).

METHODS

We searched Pubmed, EMBASE, CENTRAL, and clinicaltrials.gov from January 2000 to February 2021 and abstracts presented at the International Stroke Conference in March 2021 to identify trials comparing EVT alone versus IVT plus EVT in AIS-LVO. Five non-inferiority margins established in the literature were assessed: -15%, -10%, -6.5%, -5%, and -1.3% for the risk difference for functional independence at 90 days.

RESULTS

Four trials met the selection criteria, enrolling 1633 individuals, with 817 participants randomly assigned to EVT alone and 816 to IVT plus EVT. Crude cumulative rates of 90-day functional independence were 46.0% with EVT alone versus 45.5% with IVT plus EVT. Pooled results showed the risk difference of functional independence was 1% (95% CI -4% to 5%) between EVT alone versus IVT plus EVT. The lower 95% CI bound of -4% fell within the non-inferiority margins of -15%, -10%, -6.5%, and -5%, but not -1.3%. Pooled results also showed the risk difference between EVT alone versus IVT plus EVT was 1% (95% CI -3% to 5%) for mRS 0-1, and 1% (95% CI -1% to 3%) for symptomatic intracranial hemorrhage.

CONCLUSIONS

This meta-analysis suggests that EVT alone is non-inferior to IVT plus EVT for several, but not the most stringent, non-inferiority margins.

Direct mechanical thrombectomy without intravenous thrombolysis versus bridging therapy for acute ischemic stroke: A meta-analysis of randomized controlled trials

BACKGROUND

Direct mechanical thrombectomy may result in similar outcomes compared to a bridging approach with intravenous thrombolysis (IVT + MT) in acute ischemic stroke. Recent randomized controlled trials have varied in their design and noninferiority margin.

AIM

We sought to meta-analyze accumulated trial data to assess the difference and non-inferiority in clinical and procedural outcomes between direct mechanical thrombectomy and bridging therapy.

SUMMARY OF REVIEW

We conducted a systematic review of electronic databases following the preferred reporting items for systematic reviews and meta-analyses guidelines. Random effects meta-analyses were conducted for the pooled data. The primary outcome was good functional outcome at 90 days (modified Rankin scale (mRS) ≤ 2). Secondary outcomes included excellent functional outcome (mRS ≤ 1), mortality, any intracranial hemorrhage, symptomatic intracranial hemorrhage, successful reperfusion (thrombolysis in cerebral infarction ≥ 2 b), and procedure-related complications. Four randomized controlled trials comprising 1633 patients (817 direct mechanical thrombectomy, 816 bridging therapy) were included. There were no statistical differences for the 90-day good functional outcome (OR = 1.02, 95% CI 0.84-1.25, p = 0.54, I²= 0%), and the absolute risk difference was 1% (95% CI: -4% to 5%). The lower 95% CI falls within the strictest noninferiority margin of -10% among included randomized control trials. Direct mechanical thrombectomy reduced the odds of successful reperfusion (OR = 0.76, 95% CI: 0.60-0.97, p = 0.03, I²= 0%) and any intracranial hemorrhage (OR = 0.65, 95% CI: 0.49-0.86, p = 0.003, I²= 38%). There was no difference in the remaining secondary outcomes. The risk of bias for all studies was low.

CONCLUSION

The combined trial data assessing direct mechanical thrombectomy versus bridging therapy showed no difference in improving good functional outcome. The wide noninferiority thresholds set by individual trials are in contrast with the clinical consensus on minimally important differences. However, our pooled analysis indicates noninferiority of direct mechanical thrombectomy with a 4% margin of confidence. The application of these findings is limited to patients presenting directly to mechanical thrombectomy-capable centers and real-world workflow times may differ against those achieved in a trial setting.

Clinical trials in critical care: can a Bayesian approach enhance clinical and scientific decision making?

Recent Bayesian reanalyses of prominent trials in critical illness have generated controversy by contradicting the initial conclusions based on conventional frequentist analyses. Many clinicians might be sceptical that Bayesian analysis, a philosophical and statistical approach that combines prior beliefs with data to generate probabilities, provides more useful information about clinical trials than the frequentist approach. In this Personal View, we introduce clinicians to the rationale, process, and interpretation of Bayesian analysis through a systematic review and reanalysis of interventional trials in critical illness. In the majority of cases, Bayesian and frequentist analyses agreed. In the remainder, Bayesian analysis identified interventions where benefit was probable despite the absence of statistical significance, where interpretation depended substantially on choice of prior distribution, and where benefit was improbable despite statistical significance. Bayesian analysis in critical care medicine can help to distinguish harm from uncertainty and establish the probability of clinically important benefit for clinicians, policy makers, and patients.

The Minimal Clinically Important Difference for Achievement of Substantial Reperfusion With Endovascular Thrombectomy Devices in Acute Ischemic Stroke Treatment

Background and Purpose: Recent noninferiority clinical trials of novel endovascular thrombectomy devices for acute ischemic stroke have used substantial reperfusion as the primary outcome of achievement. Determining the minimal clinically important difference (MCID) is an essential step for the design of noninferiority clinical trials. Materials and Methods: We surveyed international neuro-interventionalist and noninterventional vascular neurologist investigators. The questionnaire included demographic characteristics, level of clinical experience, and their MCID clinical scenario-based judgment regarding the MCID for the outcome substantial reperfusion (thrombolysis in cerebral infarction score 2b-3) within 3 passes. Results: Survey responses were received from 58 of 200 experts. Among responders, 75.9% were neuro-interventionalists (most commonly interventional neuroradiologists and interventional neurologists, followed by endovascular neurosurgeons), and 24.1% were noninterventional vascular neurologists; 87.9% had been in practice for more than 5 years, and 67.3% devoted more than half of their practice to stroke care. Responder-nonresponder and continuum of resistance analysis indicated responders were representative of the full expert population. Among experts, the median MCID for substantial reperfusion was 3.1-5% (interquartile range 1.1-3% to 5.1-10%). MCID distributions did not differ among neuro-interventionalists and noninterventional vascular neurologists. Conclusions: Neuro-interventionl and noninterventional stroke experts judged that the minimal clinically important difference in comparing thrombectomy devices for achieving substantial reperfusion is 3.1-5%. This MCID, lower than noninferiority margins used in several recent clinical trials, can inform trial designs and clinical development.

Psychometric assessment and validation of the dysphagia severity rating scale in stroke patients

Post stroke dysphagia (PSD) is common and associated with poor outcome. The Dysphagia Severity Rating Scale (DSRS), which grades how severe dysphagia is based on fluid and diet modification and supervision requirements for feeding, is used for clinical research but has limited published validation information. Multiple approaches were taken to validate the DSRS, including concurrent- and predictive criterion validity, internal consistency, inter- and intra-rater reliability and sensitivity to change. This was done using data from four studies involving pharyngeal electrical stimulation in acute stroke patients with dysphagia, an individual patient data meta-analysis and unpublished studies (NCT03499574, NCT03700853). In addition, consensual- and content validity and the Minimal Clinically Important Difference (MCID) were assessed using anonymous surveys sent to UK-based Speech and Language Therapists (SLTs). Scores for consensual validity were mostly moderate (62.5-78%) to high or excellent (89-100%) for most scenarios. All but two assessments of content validity were excellent. In concurrent criterion validity assessments, DSRS was most closely associated with measures of radiological aspiration (penetration aspiration scale, Spearman rank rs = 0.49, p < 0.001) and swallowing (functional oral intake scale, FOIS, rs = -0.96, p < 0.001); weaker but statistically significant associations were seen with impairment, disability and dependency. A similar pattern of relationships was seen for predictive criterion validity. Internal consistency (Cronbach's alpha) was either "good" or "excellent". Intra and inter-rater reliability were largely "excellent" (intraclass correlation >0.90). DSRS was sensitive to positive change during recovery (medians: 7, 4 and 1 at baseline and 2 and 13 weeks respectively) and in response to an intervention, pharyngeal electrical stimulation, in a published meta-analysis. The MCID was 1.0 and DSRS and FOIS scores may be estimated from each other. The DSRS appears to be a valid tool for grading the severity of swallowing impairment in patients with post stroke dysphagia and is appropriate for use in clinical research and clinical service delivery.

Protocol for outcome reporting and follow-up in the Targeted Hypothermia versus Targeted Normothermia after Out-of-Hospital Cardiac Arrest trial (TTM2)

AIMS

The TTM2-trial is a multi-centre randomised clinical trial where targeted temperature management (TTM) at 33 °C will be compared with normothermia and early treatment of fever (≥37.8 °C) after Out-of-Hospital Cardiac Arrest (OHCA). This paper presents the design and rationale of the TTM2-trial follow-up, where information on secondary and exploratory outcomes will be collected. We also present the explorative outcome analyses which will focus on neurocognitive function and societal participation in OHCA-survivors.

METHODS

Blinded outcome-assessors will perform follow-up at 30-days after the OHCA with a telephone interview, including the modified Rankin Scale (mRS) and the Glasgow Outcome Scale Extended (GOSE). Face-to-face meetings will be performed at 6 and 24-months, and include reports on outcome from several sources of information: clinician-reported: mRS, GOSE; patient-reported: EuroQol-5 Dimensions-5 Level responses version (EQ-5D-5L), Life satisfaction, Two Simple Questions; observer-reported: Informant Questionnaire on Cognitive Decline in the Elderly-Cardiac Arrest version (IQCODE-CA) and neurocognitive performance measures: Montreal Cognitive Assessment, (MoCA), Symbol Digit Modalities Test (SDMT). Exploratory analyses will be performed with an emphasis on brain injury in the survivors, where the two intervention groups will be compared for potential differences in neuro-cognitive function (MoCA, SDMT) and societal participation (GOSE). Strategies to increase inter-rater reliability and decrease missing data are described.

DISCUSSION

The TTM2-trial follow-up is a pragmatic yet detailed pre-planned and standardised assessment of patient's outcome designed to ensure data-quality, decrease missing data and provide optimal conditions to investigate clinically relevant effects of TTM, including OHCA-survivors' neurocognitive function and societal participation.

Effect of ivabradine on major adverse cardiovascular events and mortality in critically ill patients: a systematic review and meta-analyses of randomised controlled trials with trial sequential analyses

BACKGROUND

Ivabradine lowers heart rate (HR) without affecting contractility or vascular tone. It is licensed for HR control in chronic heart diseases. We performed a systematic review and meta-analyses to examine whether ivabradine could decrease major adverse cardiovascular events (MACE) and mortality in critically ill patients.

METHODS

We searched Medline, Embase, Cochrane Library, and Web of Science for RCTs. Trial quality was assessed using the Cochrane risk of bias tool. Random-effects meta-analyses were performed if at least three trials or 100 patients were available. Results are reported as weighted mean difference (WMD), odds ratio (OR), and 95% confidence intervals (CIs). Trial sequential analyses were performed to estimate the sample size needed to reach definitive conclusions of efficacy or futility.

RESULTS

We included 13 RCTs (n=1497 patients). We found no evidence of an impact of ivabradine on MACE (three RCTs, 819 patients; OR=0.77; 95% CI, 0.53-1.11) or mortality (10 RCTs, 1356 patients; OR=1.07; 95% CI, 0.63-1.82), but sample sizes were not reached to allow definitive conclusions. Compared with placebo or standard care, ivabradine reduced HR (eight RCTs, 464 patients; WMD, -9.5 beats min^-1; 95% CI, -13.3 to -5.8). Risk of bradycardia was not different between ivabradine and control (five RCTs, 434 patients; OR=1.2; 95% CI, 0.60-2.38). Risk of bias was overall high or unclear.

CONCLUSIONS

Ivabradine reduces HR compared with placebo or standard care. The effect on MACE or mortality in acute care remains unclear. Further RCTs powered to detect changes in clinically relevant outcomes are warranted.

CLINICAL TRIAL REGISTRATION

Prospero CRD42018086109.

Noninferiority Margins in Trials of Thrombectomy Devices for Acute Ischemic Stroke

Background and Purpose—

Novel endovascular thrombectomy (EVT) devices for acute ischemic stroke are often cleared by regulatory agencies on the basis of noninferiority trials. The relation between the noninferiority margins used in trials and the minimal clinically important differences (MCIDs) determined by experts have not been systematically investigated.

Methods—

Systematic searches were performed to identify (1) all noninferiority design or noninferiority-presented stroke-EVT trials for acute ischemic stroke, (2) all studies determining the MCIDs for the same outcomes, and (3) all noninferiority coronary revascularization trials. Stroke-EVT trial results were reanalyzed using the broad noninferiority margins originally used and narrower noninferiority margins derived from formal MCID studies.

Results—

We identified 7 noninferiority-designed or noninferiority-interpreted stroke-EVT controlled trials, enrolling 1766 patients, variously comparing coil retrievers, first- and second-generation stent retrievers, and aspiration devices. In 6 trials, the primary outcome was achievement of reperfusion, using noninferiority margins of 15% (3 trials), 10% (2 trials), and 8% (1 trial). In contrast, a stroke expert survey identified the MCID for reperfusion as 3.1% to 5%, and cardiac trials used noninferiority margins of 3.5% to 4.4%. In one stroke-EVT trial, the primary outcome was functional independence, using a noninferiority margin of 15%. However, 2 stroke expert survey studies identified MCIDs for functional independence as having lower values, 5% and 1% to 1.5%. For both reperfusion and functional independence outcomes, all 7 trials demonstrated noninferiority with the broadest noninferiority margin, but only 4 and 3 trials demonstrated noninferiority with actual expert-derived margins for reperfusion and functional independence, respectively.

Conclusions—

Noninferiority margins used in EVT device trials have regularly exceeded the MCIDs determined by stroke experts, as well as margins used for cardiac devices. New approaches, such as the use of reasonably adequate performance margins, rather than noninferiority margins, are needed to optimize stroke-EVT trial design integrity and trial performance feasibility.

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

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