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Background and Purpose: Thrombus perviousness estimates residual flow along a thrombus in acute ischemic stroke, based on radiological images, and may influence the benefit of endovascular treatment for acute ischemic stroke. We aimed to investigate potential endovascular treatment (EVT) effect modification by thrombus perviousness. Methods: We included 443 patients with thin-slice imaging available, out of 1766 patients from the pooled HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke trials) data set of 7 randomized trials on EVT in the early window (most within 8 hours). Control arm patients (n=233) received intravenous alteplase if eligible (212/233; 91%). Intervention arm patients (n=210) received additional EVT (prior alteplase in 178/210; 85%). Perviousness was quantified by thrombus attenuation increase on admission computed tomography angiography compared with noncontrast computed tomography. Multivariable regression analyses were performed including multiplicative interaction terms between thrombus attenuation increase and treatment allocation. In case of significant interaction, subgroup analyses by treatment arm were performed. Our primary outcome was 90-day functional outcome (modified Rankin Scale score), resulting in an adjusted common odds ratio for a one-step shift towards improved outcome. Secondary outcomes were mortality, successful reperfusion (extended Thrombolysis in Cerebral Infarction score, 2B–3), and follow-up infarct volume (in mL). Results: Increased perviousness was associated with improved functional outcome. After adding a multiplicative term of thrombus attenuation increase and treatment allocation, model fit improved significantly ( P =0.03), indicating interaction between perviousness and EVT benefit. Control arm patients showed significantly better outcomes with increased perviousness (adjusted common odds ratio, 1.2 [95% CI, 1.1–1.3]). In the EVT arm, no significant association was found (adjusted common odds ratio, 1.0 [95% CI, 0.9–1.1]), and perviousness was not significantly associated with successful reperfusion. Follow-up infarct volume (12% [95% CI, 7.0–17] per 5 Hounsfield units) and chance of mortality (adjusted odds ratio, 0.83 [95% CI, 0.70–0.97]) decreased with higher thrombus attenuation increase in the overall population, without significant treatment interaction. Conclusions: Our study suggests that the benefit of best medical care including alteplase, compared with additional EVT, increases in patients with more pervious thrombi.

Background: It is not known if initial reductions in hospitalization for stroke and myocardial infarction early during the coronavirus disease–2019 pandemic were followed by subsequent increases. We describe the rates of emergency department visits for stroke and myocardial infarction through the pandemic phases. Methods: We used linked administrative data to compare the weekly age- and sex-standardized rates of visits for stroke and myocardial infarction in Ontario, Canada in the first 9 months of 2020 to the mean baseline rates (2015-2019) using rate ratios (RRs) and 95% confidence intervals (CIs). We compared care and outcomes by pandemic phases (pre-pandemic was January-March, lockdown was March-May, early reopening was May-July, and late reopening was July-September). Results: We identified 15,682 visits in 2020 for ischemic stroke (59.2%; n = 9279), intracerebral hemorrhage (12.2%; n = 1912), or myocardial infarction (28.6%; n = 4491). The weekly rates for stroke visits in 2020 were lower during the lockdown and early reopening than at baseline (RR 0.76, 95% CI [0.66, 0.87] for the largest weekly decrease). The weekly rates for myocardial infarction visits were lower during the lockdown only (RR 0.61, 95% CI [0.46, 0.77] for the largest weekly decrease), and there was a compensatory increase in visits following reopening. Ischemic stroke 30-day mortality was increased during the lockdown phase (11.5% pre-coronavirus disease; 12.2% during lockdown; 9.2% during early reopening; and 10.6% during late reopening, P = 0.015). Conclusion: After an initial reduction in visits for stroke and myocardial infarction, there was a compensatory increase in visits for myocardial infarction. The death rate after ischemic stroke was higher during the lockdown than in other phases. Résumé: Contexte: Nous ignorons si les réductions des taux d'hospitalisations pour un AVC et un infarctus du myocarde observées au début de la pandémie de coronavirus de 2019 ont été suivies d'une hausse de ces taux. Nous décrivons ici les taux de visites aux services des urgences pour un AVC et un infarctus du myocarde pendant toutes les phases de la pandémie. Méthodes: À partir de données administratives couplées, nous comparons les taux hebdomadaires de visites pour un AVC et un infarctus du myocarde, normalisés en fonction de l’âge et du sexe, en Ontario, au Canada, effectuées pendant les neuf premiers mois de 2020, avec les taux moyens de base (2015-2019), en utilisant des ratios des taux (RR) et des intervalles de confiance (IC) à 95 %. Nous avons comparé les soins et les issues selon les phases de la pandémie (avant la pandémie : de janvier à mars; confinement : de mars à mai; début de la réouverture : de mai à juillet; phase tardive de la réouverture : de juillet à septembre). Résultats: Nous avons répertorié 15 682 visites effectuées en 2020 pour un AVC ischémique (59,2 %; n = 9 279), une hémorragie intracérébrale (12,2 %; n = 1 912) ou un infarctus du myocarde (28,6 %; n = 4 491). Les taux hebdomadaires de visites pour un AVC effectuées en 2020 étaient inférieurs pendant la période de confinement et le début de la réouverture comparativement à la période de base (RR : 0,76; IC à 95 % : 0,66-0,87 pour la plus grande baisse hebdomadaire). Les taux hebdomadaires de visites pour un infarctus du myocarde étaient inférieurs pendant la période de confinement seulement (RR : 0,61; IC à 95 % : 0,46-0,77 pour la baisse hebdomadaire la plus importante); une hausse compensatrice du nombre de visites a été notée après la réouverture. Le taux de mortalité à 30 jours des suites d'un AVC ischémique était plus élevé pendant la période de confinement (11,5 % avant la pandémie de coronavirus; 12,2 % pendant le confinement; 9,2 % au début de la période de réouverture; 10,6 % pendant la phase tardive de la réouverture, p = 0,015). Conclusion: Après une réduction initiale du nombre de visites motivées par un AVC et un infarctus du myocarde, on a noté une hausse compensatrice du nombre de visites motivées par un infarctus du myocarde. Le taux de mortalité des suites d'un AVC ischémique était plus élevé pendant la période de confinement que pendant les autres périodes.

Endovascular thrombectomy (EVT) has significantly improved outcomes for patients with acute ischemic stroke due to large vessel occlusion. However, despite advances, more than half of patients remain functionally dependent 3 months after their initial stroke. Anesthetic strategy may influence both the technical success of the procedure and overall outcomes. Conventionally, general anesthesia (GA) has been widely used for neuroendovascular procedures, particularly for the distal intracranial circulation, because the complete absence of movement has been considered imperative for procedural success and to minimize complications. In contrast, in patients with acute stroke undergoing EVT, the optimal anesthetic strategy is controversial. Nonrandomized studies suggest GA negatively affects outcomes while the more recent anesthesia-specific RCTs report improved or unchanged outcomes in patients managed with versus without GA, although these findings cannot be generalized to other EVT capable centers due to a number of limitations. Potential explanations for these contrasting results will be addressed in this review including the effect of different anesthetic strategies on cerebral and systemic hemodynamics, revascularization times, and periprocedural complications.

Despite years of basic research and pioneering clinical work, ischemic stroke remains a major public health concern. Prior STAIR (Stroke Treatment Academic Industry Roundtable) conferences identified both failures of clinical trial design and failures in preclinical assessment in developing putative ischemic stroke treatments. At STAIR XI, participants in workshop no. 1 Top Priorities for Neuroprotection sought to redefine the neuroprotection paradigm and given the paucity of evidence underlying preclinical assessment, offer consensus-based recommendations. STAIR proposes the term brain cytoprotection or cerebroprotection to replace the term neuroprotection when the intention of an investigation is to demonstrate that a new, candidate treatment benefits the entire brain. Although “time is still brain,” tissue imaging techniques have been developed to identify patients with both predicted core injury and penumbral, salvageable brain tissue, regardless of time after stroke symptom onset. STAIR XI workshop participants called this imaging approach a tissue window to select patients for recanalization. Elements of the neurovascular unit show differential vulnerability evolving over differing time scales in different brain regions. STAIR proposes the term target window to suggest therapies that target the different elements of the neurovascular unit at different times. Based on contemporary principles of rigor and transparency, the workshop updated, revised, and enhanced the STAIR preclinical recommendations for developing new treatments in 2 phases: an exploratory qualification phase and a definitive validation phase. For new, putative treatments, investigators should carefully characterize the mechanism of action, the pharmacokinetics/pharmacodynamics, demonstrate target engagement, and confirm penetration through the blood-brain barrier. Before clinical trials, testing of candidate molecules in stroke models could proceed in a comprehensive manner using animals of both sexes and to include significant variables such as age and comorbid conditions. Comprehensive preclinical assessment might include multicenter, collaborative testing, for example, network trials. In the absence of a proven cerebroprotective agent to use as a gold standard, however, it remains speculative whether such comprehensive preclinical assessment can effectively predict clinical outcome.

Supplemental Digital Content is available in the text., Background and Purpose: Benefit of early endovascular treatment (EVT) for ischemic stroke varies considerably among patients. The MR PREDICTS decision tool, derived from MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), predicts outcome and treatment benefit based on baseline characteristics. Our aim was to externally validate and update MR PREDICTS with data from international trials and daily clinical practice. Methods: We used individual patient data from 6 randomized controlled trials within the HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) collaboration to validate the original model. Then, we updated the model and performed a second validation with data from the observational MR CLEAN Registry. Primary outcome was functional independence (defined as modified Rankin Scale score 0–2) 3 months after stroke. Treatment benefit was defined as the difference between the probability of functional independence with and without EVT. Discriminative performance was evaluated using a concordance (C) statistic. Results: We included 1242 patients from HERMES (633 assigned to EVT, 609 assigned to control) and 3156 patients from the MR CLEAN Registry (all of whom underwent EVT within 6.5 hours). The C-statistic for functional independence was 0.74 (95% CI, 0.72–0.77) in HERMES and, after model updating, 0.80 (0.78–0.82) in the Registry. Median predicted treatment benefit of routinely treated patients (Registry) was 10.3% (interquartile range, 5.8%–14.4%). Patients with low (

Background: Age and infarct volume are strong predictors of outcome in patients with ischemic stroke who underwent endovascular therapy (EVT). We aimed to investigate the impact of ischemic core volume (ICV) on stroke outcome after EVT in elderly. Methods: Using the HERMES (Highly Effective Reperfusion Using Multiple Endovascular Devices) collaboration, a patient-level meta-analysis of 7 randomized trials in which patients were enrolled from December 2010 to April 2015) dataset, we categorized patients into those aged Results: A total of 899 patients who had baseline ICV data, 247 patients aged ≥75 years, of which 118 were randomized in the EVT arm. Patients aged ≥75 years required smaller ICV to achieve mRS score ≤3 than those aged P Conclusions: Baseline ICV has an impact on stroke outcome after EVT in the elderly, but elderly patients with large ICV may still benefit from EVT if near-complete or complete reperfusion is achieved. Young patients seem to benefit from EVT regardless of ICV status.

In 2014, Hart et al. introduced the concept of "embolic stroke of undetermined source" (ESUS) to the clinical-research stroke community. The hypothesis underlying the development of the ESUS construct was that this potentially heterogenous group of stroke mechanisms were largely thromboembolic, and would thus benefit from anticoagulation over antiplatelet for secondary prevention. Since then, 2 large clinical trials have shown that, to date, there is not a clear uniform antithrombotic strategy for secondary prevention after ESUS as it was originally broadly defined. However, this work has yielded valuable information about the patient phenotypes that experience ESUS strokes, as well as hypothesis-generating substudies that have given rise to the next generation of secondary prevention trials aimed at more personalized approaches for different suspected mechanisms of embolic stroke. In parallel with the evolution of ESUS, several studies aimed at screening for atrial fibrillation in the secondary stroke prevention population have generated additional questions about the mechanistic relevance of atrial fibrillation detected after stroke, and how this should inform poststroke workup, and secondary prevention strategies. Herein, we provide a synthesis of the current understanding surrounding the patient phenotypes that experience ESUS strokes, and previous, ongoing, and anticipated clinical trials that will guide earlier and later secondary prevention strategies and poststroke cardiac investigations.

Dr. Michael Hill is President of the Canadian Neurology Federation and Director of the Stroke Unit for the Calgary Stroke Program. He is also a professor at the University of Calgary at the Department of Clinical Neurosciences. Dr. Hill has made outstanding contributions to the field of stroke research, particularly through the ESCAPE and ESCAPE-NA1 trials. Dr. Hill was a recipient of the Canadian Society for Clinical Investigation (CSCI) Distinguished Scientist Award in 2021—recognized as an expert and innovative leader in his research.

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. Copyright (C) 2022 Elsevier Ltd. All rights reserved.

Objective:We examined the return on investment (ROI) from the Endovascular Reperfusion Alberta (ERA) project, a provincially funded population-wide strategy to improve access to endovascular therapy (EVT), to inform policy regarding sustainability.Methods:We calculated net benefit (NB) as benefit minus cost and ROI as benefit divided by cost. Patients treated with EVT and their controls were identified from the ESCAPE trial. Using the provincial administrative databases, their health services utilization (HSU), including inpatient, outpatient, physician, long-term care services, and prescription drugs, were compared. This benefit was then extrapolated to the number of patients receiving EVT increased in 2018 and 2019 by the ERA implementation. We used three time horizons, including short (90 days), medium (1 year), and long-term (5 years).Results:EVT was associated with a reduced gross HSU cost for all the three time horizons. Given the total costs of ERA were $2.04 million in 2018 ($11,860/patient) and $3.73 million in 2019 ($17,070/patient), NB per patient in 2018 (2019) was estimated at −$7,313 (−$12,524), $54,592 ($49,381), and $47,070 ($41,859) for short, medium, and long-term time horizons, respectively. Total NB for the province in 2018 (2019) were −$1.26 (−$2.74), $9.40 ($10.78), and $8.11 ($9.14) million; ROI ratios were 0.4 (0.3), 5.6 (3.9) and 5.0 (3.5). Probabilities of ERA being cost saving were 39% (31%), 97% (96%), and 94% (91%), for short, medium, and long-term time horizons, respectively.Conclusion:The ERA program was cost saving in the medium and long-term time horizons. Results emphasized the importance of considering a broad range of HSU and long-term impact to capture the full ROI.

Background Intracranial hemorrhage is a known complication after endovascular treatment in patients with acute ischemic stroke due to large vessel occlusion, but the association between radiologic hemorrhage severity and outcome is controversial. Purpose To investigate the prevalence and impact on outcome of intracranial hemorrhage and hemorrhage severity after endovascular stroke treatment. Materials and Methods The Efficacy and Safety of Nerinetide for the Treatment of Acute Ischemic Stroke (ESCAPE-NA1) trial enrolled participants with acute large vessel occlusion stroke who underwent endovascular treatment from March 1, 2017, to August 12, 2019. Evidence of any intracranial hemorrhage, hemorrhage multiplicity, and radiologic severity, according to the Heidelberg classification (hemorrhagic infarction type 1 [HI1], hemorrhagic infarction type 2 [HI2], parenchymal hematoma type 1 [PH1], and parenchymal hematoma type 2 [PH2]) was assessed at CT or MRI 24 hours after endovascular treatment. Good functional outcome, defined as a modified Rankin score of 0-2 at 90 days, was compared between participants with intracranial hemorrhage and those without intracranial hemorrhage at follow-up imaging and between hemorrhage subtypes. Poisson regression was performed to obtain adjusted effect size estimates for the presence of any intracranial hemorrhage and hemorrhage subtypes at good functional outcome. Results Of 1097 evaluated participants (mean age, 69 years ± 14 [standard deviation]; 551 men), any degree of intracranial hemorrhage was observed in 372 (34%). Good outcomes were less often achieved among participants with hemorrhage than among those without hemorrhage at follow-up imaging (164 of 372 participants [44%] vs 500 of 720 [69%], respectively; P < .01). After adjusting for baseline variables and infarct volume, intracranial hemorrhage was not associated with decreased chances of good outcome (adjusted risk ratio [RR] = 0.91 [95% CI: 0.82, 1.02], P = .10), but there was a graded relationship of radiologic hemorrhage severity and outcomes, whereby PH1 (RR = 0.77 [95% CI: 0.61, 0.97], P = .03) and PH2 (RR = 0.41 [95% CI: 0.21, 0.81], P = .01) were associated with decreased chances of good outcome. Conclusion Any degree of intracranial hemorrhage after endovascular treatment was seen in one-third of participants. A graded association existed between radiologic hemorrhage severity and outcome. Hemorrhagic infarction was not associated with outcome, whereas parenchymal hematoma was strongly associated with poor outcome, independent of infarct volume. © RSNA, 2021 Clinical trial registration no. NCT01778335 Online supplemental material is available for this article.

Background The effect of infarct pattern on functional outcome in acute ischemic stroke is incompletely understood. Purpose To investigate the association of qualitative and quantitative infarct variables at 24-hour follow-up noncontrast CT and diffusion-weighted MRI with 90-day clinical outcome. Materials and Methods The Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke, or ESCAPE-NA1, randomized controlled trial enrolled patients with large-vessel-occlusion stroke undergoing mechanical thrombectomy from March 1, 2017, to August 12, 2019. In this post hoc analysis of the trial, qualitative infarct variables (predominantly gray [vs gray and white] matter involvement, corticospinal tract involvement, infarct structure [scattered vs territorial]) and total infarct volume were assessed at 24-hour follow-up noncontrast CT or diffusion-weighted MRI. White and gray matter infarct volumes were assessed in patients by using follow-up diffusion-weighted MRI. Infarct variables were compared between patients with and those without good outcome, defined as a modified Rankin Scale score of 0-2 at 90 days. The association of infarct variables with good outcome was determined with use of multivariable logistic regression. Separate regression models were used to report effect size estimates with adjustment for total infarct volume. Results Qualitative infarct variables were assessed in 1026 patients (mean age ± standard deviation, 69 years ± 13; 522 men) and quantitative infarct variables were assessed in a subgroup of 358 of 1026 patients (mean age, 67 years ± 13; 190 women). Patients with gray and white matter involvement (odds ratio [OR] after multivariable adjustment, 0.19; 95% CI: 0.14, 0.25; P < .001), corticospinal tract involvement (OR after multivariable adjustment, 0.06; 95% CI: 0.04, 0.10; P < .001), and territorial infarcts (OR after multivariable adjustment, 0.22; 95% CI: 0.14, 0.32; P < .001) were less likely to achieve good outcome, independent of total infarct volume. Conclusion Infarct confinement to the gray matter, corticospinal tract sparing, and scattered infarct structure at 24-hour noncontrast CT and diffusion-weighted MRI were highly predictive of good 90-day clinical outcome, independent of total infarct volume. Clinical trial registration no. NCT02930018 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Mossa-Basha in this issue.

BACKGROUND AND PURPOSE: Infarct volume is an important predictor of clinical outcome in acute stroke. We hypothesized that the association of infarct volume and clinical outcome changes with the magnitude of infarct size. MATERIALS AND METHODS: Data were derived from the Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke (ESCAPE-NA1) trial, in which patients with acute stroke with large-vessel occlusion were randomized to endovascular treatment plus either nerinetide or a placebo. Infarct volume was manually segmented on 24-hour noncontrast CT or DWI. The relationship between infarct volume and good outcome, defined as mRS 0–2 at 90 days, was plotted. Patients were categorized on the basis of visual grouping at the curve shoulders of the infarct volume/outcome plot. The relationship between infarct volume and adjusted probability of good outcome was fitted with linear or polynomial functions as appropriate in each group. RESULTS: We included 1099 individuals in the study. Median infarct volume at 24 hours was 24.9 mL (interquartile range [IQR] = 6.6–92.2 mL). On the basis of the infarct volume/outcome plot, 4 infarct volume groups were defined (IQR = 0–15 mL, 15.1–70 mL, 70.1–200 mL, >200 mL). Proportions of good outcome in the 4 groups were 359/431 (83.3%), 219/337 (65.0%), 71/201 (35.3%), and 16/130 (12.3%), respectively. In small infarcts (IQR = 0–15 mL), no relationship with outcome was appreciated. In patients with intermediate infarct volume (IQR = 15–200 mL), there was progressive importance of volume as an outcome predictor. In infarcts of > 200 mL, outcomes were overall poor. CONCLUSIONS: The relationship between infarct volume and clinical outcome varies nonlinearly with the magnitude of infarct size. Infarct volume was linearly associated with decreased chances of achieving good outcome in patients with moderate-to-large infarcts, but not in those with small infarcts. In very large infarcts, a near-deterministic association with poor outcome was seen.

ObjectiveWe sought to evaluate the short- and long-term resource use and costs associated with intracerebral hemorrhage (ICH) taken from an entire population. We in addition sought to evaluate the association of oral anticoagulation (OAC) and health care costs.MethodsThis was a retrospective cohort study of adult patients (≥18 years) with ICH in the entire population of Ontario, Canada (2009–2017). We captured outcomes through linkage to health administrative databases. We used generalized linear models to identify factors associated with total cost. Analysis of OAC use was limited to patients ≥66 years of age. The primary outcome was total 1-year direct health care costs in 2020 US dollars.ResultsAmong 16,248 individuals with ICH (mean age 71.2 years, male 52.3%), 1-year mortality was 46.0%, and 24.2% required mechanical ventilation. The median total 1-year cost was $26,886 (interquartile range [IQR] $9,641–$62,907) with costs for those who died in hospital of $7,268 (IQR $4,031–$14,966) vs $44,969 (IQR $20,264–$82,414, p < 0.001) for survivors to discharge. OAC use (analysis limited to individuals ≥66 years old) was associated with higher total 1-year costs (cost ratio 1.06 [95% confidence interval 1.01–1.11]). Total 1-year costs for the entire cohort exceeded $120 million per year over the study period.ConclusionsICH is associated with significant health care costs, and the median cost of a patient with ICH is roughly 10 times the median inpatient cost in Ontario. Costs were higher among survivors than deceased patients. OAC use is independently associated with increased costs. To maximize cost-effectiveness, future therapies for ICH must aim to reduce disability, not only improve mortality.

Background Identification of therapies to prevent severe COVID-19 remains a priority. We sought to determine whether hydroxychloroquine treatment for outpatients with SARS-CoV-2 infection could prevent hospitalization, mechanical ventilation or death. Methods This randomized controlled trial was conducted in Alberta during the first wave of the COVID-19 pandemic without direct contact with participants. Community-dwelling individuals with confirmed SARS-CoV-2 infection (by reverse transcription polymerase chain reaction [RT-PCR] viral ribonucleic acid test) within the previous 4 days, and symptom onset within the previous 12 days, were randomly assigned to oral hydroxychloroquine or matching placebo for 5 days. Enrolment began Apr. 15, 2020. The primary outcome was the composite of hospitalization, invasive mechanical ventilation or death within 30 days. Secondary outcomes included symptom duration and disposition at 30 days. Safety outcomes, such as serious adverse events and mortality, were also ascertained. Outcomes were determined by telephone follow-up and administrative data. Results Among 4919 individuals with a positive RT-PCR test, 148 (10.2% of a planned 1446 patients) were randomly assigned, 111 to hydroxychloroquine and 37 to placebo. Of the 148 participants, 24 (16.2%) did not start the study drug. Four participants in the hydroxychloroquine group met the primary outcome (4 hospitalizations, 0 mechanical ventilation, 4 survived to 30 days) and none in the placebo group. Hydroxychloroquine did not reduce symptom duration (hazard ratio 0.77, 95% confidence interval 0.49-1.21). Recruitment was paused on May 22, 2020, when a since-retracted publication raised concerns about the safety of hydroxychloroquine for hospitalized patients with COVID-19. Although we had not identified concerns in a safety review, enrolment was slower than expected among those eligible for the study, and cases within the community were decreasing. Recruitment goals were deemed to be unattainable and the trial was not resumed, resulting in a study underpowered to assess the effect of treatment with hydroxychloroquine and safety. Interpretation There was no evidence that hydroxychloroquine reduced symptom duration or prevented severe outcomes among outpatients with proven COVID-19, but the early termination of our study meant that it was underpowered. Trial registration ClinicalTrials.gov, no. NCT04329611.

Magnetic resonance imaging (MRI) is often considered the gold-standard test for characterizing cardiac as well as noncardiac structure and function. However, many patients with cardiac implantable electronic devices (CIEDs) and/or severe renal dysfunction are unable to undergo this test because of safety concerns. In the past 10 years, newer-generation CIEDs and gadolinium-based contrast agents (GBCAs) as well as coordinated care between imaging and heart rhythm device teams have mitigated risk to patients and improved access to MRI at many hospitals. The purpose of this statement is to review published data on safety of MRI in patients with conditional and nonconditional CIEDs in addition to patient risks from older and newer GBCAs. This statement was developed through multidisciplinary collaboration of pan-Canadian experts after a relevant and independent literature search by the Canadian Agency for Drugs and Technologies in Health. All recommendations align with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Key recommendations include: (1) the development of standardized protocols for patients with a CIED undergoing MRI; (2) patients with MRI nonconditional pacemakers and pacemaker dependency should be programmed to asynchronous mode and those with MRI nonconditional transvenous defibrillators should have tachycardia therapies turned off during the scan; and (3) macrocyclic or newer linear GBCAs should be used in preference to older GBCAs because of their better safety profile in patients at higher risk of nephrogenic systemic fibrosis.

Background Inflammation contributes to unstable atherosclerotic plaque and stroke. In randomised trials in patients with coronary disease, canukinumab (an interleukin-1B antagonist) and colchicine (a tubulin inhibitor with pleiotropic anti-inflammatory effects) reduced recurrent vascular events. Hypothesis: Anti-inflammatory therapy with low-dose colchicine plus usual care will reduce recurrent vascular events in patients with non-severe, non-cardioembolic stroke and TIA compared with usual care alone. Design CONVINCE is a multi-centre international (in 17 countries) Prospective, Randomised Open-label, Blinded-Endpoint assessment (PROBE) controlled Phase 3 clinical trial in 3154 participants. The intervention is colchicine 0.5 mg/day and usual care versus usual care alone (antiplatelet, lipid-lowering, antihypertensive treatment, lifestyle advice). Included patients are at least 40 years, with non-severe ischaemic stroke (modified Rankin score ≤3) or high-risk TIA (ABCD2 > 3, or positive DWI, or cranio-cervical artery stenosis) within 72 hours-28 days of randomisation, with qualifying stroke/TIA most likely caused by large artery stenosis, lacunar disease, or cryptogenic embolism. Exclusions are stroke/TIA caused by cardio-embolism or other defined cause (e.g. dissection), contra-indication to colchicine (including potential drug interactions), or incapacity for participation in a clinical trial. The anticipated median follow-up will be 36 months. The primary analysis will be by intention-to-treat. Outcome The primary outcome is time to first recurrent ischaemic stroke, myocardial infarction, cardiac arrest, or hospitalisation with unstable angina (non-fatal or fatal). Summary CONVINCE will provide high-quality randomised data on the efficacy and safety of anti-inflammatory therapy with colchicine for secondary prevention after stroke. Schedule First-patient first-visit was December 2016. Recruitment to complete in 2021, follow-up to complete in 2023.

Perinatal arterial ischemic stroke (PAIS) is a focal brain injury in term neonates that is identified postnatally but is presumed to occur near the time of birth. Many pregnancy, delivery, and fetal factors have been associated with PAIS, but early risk detection is lacking; thus, targeted treatment and prevention efforts are currently limited.To develop and validate a diagnostic risk prediction model that uses common clinical factors to predict the probability of PAIS in a term neonate.In this diagnostic study, a prediction model was developed using multivariable logistic regression with registry-based case data collected between January 2003, and March 2020, from the Alberta Perinatal Stroke Project, Canadian Cerebral Palsy Registry, International Pediatric Stroke Study, and Alberta Pregnancy Outcomes and Nutrition study. Criteria for inclusion were term birth and no underlying medical conditions associated with stroke diagnosis. Records with more than 20% missing data were excluded. Variable selection was based on peer-reviewed literature. Data were analyzed in September 2021.Clinical pregnancy, delivery, and neonatal factors associated with PAIS as common data elements across the 4 registries.The primary outcome was the discriminative accuracy of the model predicting PAIS, measured by the concordance statistic (C statistic).Of 2571 term neonates in the initial analysis (527 [20%] case and 2044 [80%] control individuals; gestational age range, 37-42 weeks), 1389 (54%) were male, with a greater proportion of males among cases compared with controls (318 [60%] vs 1071 [52%]). The final model was developed using 1924 neonates, including 321 cases (17%) and 1603 controls (83%), and 9 clinical factors associated with risk of PAIS in term neonates: maternal age, tobacco exposure, recreational drug exposure, preeclampsia, chorioamnionitis, intrapartum maternal fever, emergency cesarean delivery, low 5-minute Apgar score, and male sex. The model demonstrated good discrimination between cases and controls (C statistic, 0.73; 95% CI, 0.69-0.76) and good model fit (Hosmer-Lemeshow P = .20). Internal validation techniques yielded similar C statistics (0.73 [95% CI, 0.69-0.77] with bootstrap resampling, 10-fold cross-validated area under the curve, 0.72 [bootstrap bias-corrected 95% CI, 0.69-0.76]), as did a sensitivity analysis using cases and controls from Alberta, Canada, only (C statistic, 0.71; 95% CI, 0.65-0.77).The findings suggest that clinical variables can be used to develop and internally validate a model to predict the risk of PAIS in term neonates, with good predictive performance and strong internal validity. Identifying neonates with a high probability of PAIS who could then be screened for early diagnosis and treatment may be associated with reductions in lifelong morbidity for affected individuals and their families.

Background and Purpose: Endovascular thrombectomy (EVT) reduces 90-day disability in patients following acute ischemic stroke due to large vessel occlusion. Patient-reported outcome measures after EVT, such as health-related quality of life and specific functional domains, are less well described. Methods: We report outcomes on the EuroQol-5D (EQ-5D) from the ESCAPE (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times) randomized controlled trial at 90 days after stroke. Death was assigned an index value of 0 for EQ-5D. We used quantile regression to evaluate the association between EVT and EQ-5D index scores and logistic regression for the association between EVT and symptom-free status among 90-day survivors for each EQ-5D dimension (self-care, usual activities, mobility, pain/discomfort, and anxiety/depression), assessing for modification by age or sex and adjusting for baseline factors including stroke severity, affected hemisphere, and receipt of alteplase. Lastly, the association between severe disability at 90 days and EQ-5D was evaluated with assessment for modification by EVT, age, and sex. Results: There were 165 patients randomized to EVT and 150 patients randomized to control. Median EQ-5D was significantly higher for those who received EVT compared with best medical management (0.80 versus 0.60; P Conclusions: Patients treated with EVT report substantially improved health-related quality of life, with relatively greater impact in older individuals and observed benefit across multiple dimensions.

Background and Purpose: Fast infarct progression in acute ischemic stroke has a severe impact on patient prognosis and benefit of endovascular thrombectomy. In this post hoc analysis of the ESCAPE trial (Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke), we identified acute ischemic stroke patients with rapid infarct growth and investigated their baseline clinical and imaging characteristics. Methods: Control arm patients were included if they had follow-up imaging at 2-8 hours without substantial recanalization, and if their baseline Alberta Stroke Program Early CT Score was ≥9. Fast infarct progression was defined as Alberta Stroke Program Early CT Score decay ≥3 points from baseline to 2- to 8-hour follow-up imaging. Clinical and imaging baseline characteristics were compared between fast progressors and other patients, and occlusion site and collateral flow patterns were assessed in detail. Results: Fast infarct progression occurred in 15 of 43 included patients (34.9%). Fast progressors had worse collaterals (poor in 3/15 [20%] versus 0/28 patients, P =0.021) and more carotid-T or -L occlusions (8/15 [53.4%] versus 3/28[10.7%], P =0.021). In 8 out of 15 (53.3%), occlusion site and circle of Willis configuration prevented collateral flow via the anterior or posterior cerebral artery. Conclusions: Most patients with fast infarct progression had terminal carotid occlusions and impaired collateral flow via the anterior or posterior cerebral artery, indicating that occlusion location and intracranial vascular anatomy are relevant for infarct progression.

Background and Purpose Multiphase computed tomographic angiography (mCTA) provides time variant images of pial vasculature supplying brain in patients with acute ischemic stroke (AIS). To develop a machine learning (ML) technique to predict tissue perfusion and infarction from mCTA source images.Methods 284 patients with AIS were included from the Precise and Rapid assessment of collaterals using multi-phase CTA in the triage of patients with acute ischemic stroke for Intra-artery Therapy (Prove-IT) study. All patients had non-contrast computed tomography, mCTA, and computed tomographic perfusion (CTP) at baseline and follow-up magnetic resonance imaging/non-contrast-enhanced computed tomography. Of the 284 patient images, 140 patient images were randomly selected to train and validate three ML models to predict a pre-defined Tmax thresholded perfusion abnormality, core and penumbra on CTP. The remaining 144 patient images were used to test the ML models. The predicted perfusion, core and penumbra lesions from ML models were compared to CTP perfusion lesion and to follow-up infarct using Bland-Altman plots, concordance correlation coefficient (CCC), intra-class correlation coefficient (ICC), and Dice similarity coefficient.Results Mean difference between the mCTA predicted perfusion volume and CTP perfusion volume was 4.6 mL (limit of agreement [LoA], –53 to 62.1 mL; P=0.56; CCC 0.63 [95% confidence interval [CI], 0.53 to 0.71; P

Background and purpose: Endovascular treatment (EVT) is a powerful treatment for large vessel occlusion (LVO) stroke if reperfusion can be achieved, while in cases with failed reperfusion, EVT may cause harm, as procedure-related complications may occur. We hypothesized that EVT with failed recanalization does not result in worse outcomes compared to best medical management and compared clinical outcomes of LVO stroke patients who underwent EVT with failed reperfusion to those who were treated with best medical management. Methods: We included patients with failed reperfusion from the control (EVT-only) arm of the ESCAPE-NA1 trial and the EVT arm of the ESCAPE trial and patients of the ESCAPE control arm who were treated with best medical management. Failed reperfusion following EVT was defined as modified thrombolysis in cerebral infarction score 0–2a. Proportions of good outcome (modified Rankin scale 0–2) were compared between patients who did and did not undergo EVT, and adjusted effect size estimates for EVT on outcomes were obtained. Results: We included 260 patients (110 failed EVT and 150 non-EVT patients). Proportions of good outcome were 38/110 (34.6%) with failed EVT vs.43/147 (29.3%) without EVT (adjusted odds ratio[aOR]: 1.48 [95%CI: 0.81–2.68]). Mortality and proportions of sICH in the failed EVT group vs. patients treated with best medical management were 26/110 (23.6%) vs. 28/147 (19.1%), aOR: 1.12 (95%CI: 0.56–2.24), and 7/110 (6.4%) vs. 4/150 (2.7%), aOR: 2.34 (95%CI: 0.00–22.97). Conclusion: Clinical outcomes of EVT patients with failed reperfusion did not differ significantly from patients treated with best medical management.

Background: Subgroup analyses are widely used to evaluate the heterogeneity of treatment effects in randomized clinical trials. However, there is a limited investigation of the quality of prespecified and reported subgroup analyses in stroke trials. This study evaluated the credibility of subgroup analyses in stroke trials. Methods and analysis: We searched Medline/PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the Web of Science from inception to 24 March 2021. Three reviewers screened, extracted, and analyzed the data from the publications. Primary publications of stroke trials that reported at least one subgroup effect and had published corresponding study protocols were included. The Instrument for Assessing the Credibility of Effect Modification Analyses (ICEMAN) was used to examine the quality of the subgroup effects reported, with each subgroup effect assigned a credibility rating ranging from very low to high. Subgroup effects with two or more “definitely no” responses received a low credibility rating. The risk of bias was assessed using the Cochrane Risk-of-Bias tool for randomized trials version 2. Results: Seventy-four articles met the inclusion criteria and reported a combined total of 647 subgroup effects. The median sample size was 1264 (interquartile range (IQR): 380–3876), and the median number of subgroups prespecified in the protocol was 6 (IQR: 2–10). Sixty-one (82%) studies used the univariate test of interaction. Of the total 647 subgroup effects reported in these studies, 319 (49%) were reported in acute stroke trials, while 423 (65%) had low credibility. Conclusion: The quality of subgroup analysis reporting in stroke trials remains poor. More effort is needed to train trialists on the best methods for designing and performing subgroup analyses, and how to report the results. Trial registration number: We prospectively registered the review with International Prospective Register for Systematic Reviews (registration number: CRD42020223133)

Introduction: Precise risk of hemorrhagic transformation (HT) in acute ischemic stroke (AIS) remains unknown, leading to delays in anticoagulation initiation for secondary stroke prevention. We sought to assess the rate of HT associated with direct oral anticoagulant (DOAC) initiation within and beyond 48 h post-AIS. Methods: A pooled analysis of DOAC initiation within 14 days of AIS or transient ischemic attack (TIA) was conducted with six studies (four prospective open label treatment, blinded outcome studies and two randomized trials; NCT02295826 and NCT02283294). The primary endpoint was incident radiographic HT on follow-up imaging (days 7–30). Secondary endpoints included symptomatic HT, new parenchymal hemorrhage, recurrent ischemic events, extracranial hemorrhage, study period mortality, and follow-up modified Rankin Scale score. The results were reported as odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI). Results: We evaluated 509 patients; median infarct volume was 1.5 (0.1–7.8) ml, and median National Institutes of Health Stroke Scale was 2 (0–3). Incident radiographic HT was seen on follow-up scan in 34 (6.8%) patients. DOAC initiation within 48 h from index event was not associated with incident HT (adjusted OR 0.67, [0.30–1.50] P = 0.32). No patients developed symptomatic HT. Conversely, 31 (6.1%) patients developed recurrent ischemic events, 64% of which occurred within 14 days. Initiating a DOAC within 48 h of onset was associated with similar recurrent ischemic event rates compared with those in which treatment was delayed (HR: 0.42, [0.17–1.008] P = 0.052). In contrast to HT, recurrent ischemic events were associated with poor functional outcomes (OR = 6.8, [2.84–16.24], p Conclusions: In this pooled analysis, initiation of DOAC within 48 h post-stroke was not associated with increased incident risk of HT, and none developed symptomatic HT. The analysis was underpowered to determine the effect of early DOAC use upon recurrent ischemic events.

There are few data on the prevalence and impact of isolated deep grey matter infarction in acute stroke. In this study, we aimed to investigate the prevalence of isolated deep grey matter infarcts and their impact on the outcome. Infarcts on 24-h follow-up imaging (non-contrast head CT or diffusion-weighted MRI) in the ESCAPE-NA1 trial were categorized into predominantly deep grey matter infarcts vs. infarcts involving additional territories (“other infarcts”). Total infarct volume was manually segmented. Baseline characteristics and proportions of good outcome (primary outcome, defined as modified Rankin Score [mRS] 0–2 at 90 days), excellent outcome (mRS 0–1) and mortality were compared between patients with and without predominantly deep grey matter infarcts. Multivariable logistic regression with adjustment for baseline variables and total infarct volume was used to determine a possible association of predominantly deep grey matter infarcts and clinical outcome. Predominantly deep grey matter infarcts were seen in 316/1026 patients (30.8%). Compared to other patients, their ASPECTS was higher, collateral status and reperfusion quality were better and time to treatment was shorter. Good outcome was seen in 239/316 (75.6%) with vs. 374/704 (53.1%) without predominantly deep grey matter infarcts. After adjusting for baseline variables and total infarct volume, predominantly deep grey matter infarcts were independently associated with excellent outcome (adjOR: 1.45 [CI95: 1.04–2.02]), but not with good outcome (adjOR: 1.24 [CI95: 0.86–1.80]) or mortality (adjOR: 0.73 [CI95:0.39–1.35]) Predominantly deep grey matter infarct patterns were seen in 1/3rd of patients and were significantly associated with increased chances of excellent outcome, independent of patient baseline status and infarct size.

Background: During the Randomized Assessment of Rapid Endovascular Treatment (EVT) of Ischemic Stroke (ESCAPE) trial, patient-level micro-costing data were collected. We report a cost-effectiveness analysis of EVT, using ESCAPE trial data and Markov simulation, from a universal, single-payer system using a societal perspective over a patient’s lifetime. Methods: Primary data collection alongside the ESCAPE trial provided a 3-month trial-specific, non-model, based cost per quality-adjusted life year (QALY). A Markov model utilizing ongoing lifetime costs and life expectancy from the literature was built to simulate the cost per QALY adopting a lifetime horizon. Health states were defined using the modified Rankin Scale (mRS) scores. Uncertainty was explored using scenario analysis and probabilistic sensitivity analysis. Results: The 3-month trial-based analysis resulted in a cost per QALY of $201,243 of EVT compared to the best standard of care. In the model-based analysis, using a societal perspective and a lifetime horizon, EVT dominated the standard of care; EVT was both more effective and less costly than the standard of care (−$91). When the time horizon was shortened to 1 year, EVT remains cost savings compared to standard of care (∼$15,376 per QALY gained with EVT). However, if the estimate of clinical effectiveness is 4% less than that demonstrated in ESCAPE, EVT is no longer cost savings compared to standard of care. Conclusions: Results support the adoption of EVT as a treatment option for acute ischemic stroke, as the increase in costs associated with caring for EVT patients was recouped within the first year of stroke, and continued to provide cost savings over a patient’s lifetime. Clinical Trial Registration: NCT01778335

Background and Purpose: There is interest in what happens over time to the thrombus after intravenous alteplase. We study the effect of alteplase on thrombus structure and its impact on clinical outcome in patients with acute stroke. Methods: Intravenous alteplase treated stroke patients with intracranial internal carotid artery or middle cerebral artery occlusion identified on baseline computed tomography angiography and with follow-up vascular imaging (computed tomography angiography or first run of angiography before endovascular therapy) were enrolled from INTERRSeCT study (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography). Thrombus movement after intravenous alteplase was classified into complete recanalization, thrombus migration, thrombus fragmentation, and no change. Thrombus migration was diagnosed when occlusion site moved distally and graded according to degrees of thrombus movement (grade 0–3). Thrombus fragmentation was diagnosed when a new distal occlusion in addition to the primary occlusion was identified on follow-up imaging. The association between thrombus movement and clinical outcome was also evaluated. Results: Among 427 patients in this study, thrombus movement was seen in 54% with a median time of 123 minutes from alteplase administration to follow-up imaging, and sub-classified as marked (thrombus migration grade 2–3 + complete recanalization; 27%) and mild to moderate thrombus movement (thrombus fragmentation + thrombus migration grade 0–1; 27%). In patients with proximal M1/internal carotid artery occlusion, marked thrombus movement was associated with a higher rate of good outcome (90-day modified Rankin Scale, 0–2) compared with mild to moderate movement (52% versus 27%; adjusted odds ratio, 5.64 [95% CI, 1.72–20.10]). No difference was seen in outcomes between mild to moderate thrombus movement and no change. In M1 distal/M2 occlusion, marked thrombus movement was associated with improved 90-day good outcome compared with no change (70% versus 56%; adjusted odds ratio, 2.54 [95% CI, 1.21–5.51]). Conclusions: Early thrombus movement is common after intravenous alteplase. Marked thrombus migration leads to good clinical outcomes. Thrombus dynamics over time should be further evaluated in clinical trials of acute reperfusion therapy.

Background and Purpose: Quantitating the effect of intravenous alteplase on the technical outcome of early recanalization of large vessel occlusions aids understanding. We report the prevalence of early recanalization in patients with stroke because of large vessel occlusion treated with and without intravenous alteplase and endovascular thrombectomy, and its association with clinical outcome. Methods: Patients with acute ischemic stroke with large vessel occlusion from the ESCAPE trial (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times Trial) were included in this post hoc analysis. Outcomes of interest were the prevalence of early recanalization (1) and good outcome (2), defined as modified Rankin Scale score of 0 to 2 at 90 days. Results: Among 147 patients who did not receive endovascular thrombectomy, early recanalization occurred in 4/30 (13.3%) patients without and 48/117 (41.0%) patients with intravenous alteplase (adjusted risk ratios, 3.2 [95% CI, 1.2–8.1]). Good outcome was achieved by 34/116 (29.3%) of patients who received intravenous alteplase versus 10/29 (34.5%) who did not receive alteplase (adjusted risk ratios, 1.0 [95% CI, 0.6–1.5) and by 20/52 (38.5%) patients with versus 24/93 (25.8%) without early recanalization (adjusted risk ratios, 1.9 [95% CI, 1.2–2.9]). Conclusions: Early recanalization was confirmed as a strong predictor of good outcome in patients who did not undergo endovascular thrombectomy and was improved with intravenous alteplase, yet a majority of patients (59.0%) did not achieve early reperfusion. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01778335.

The AcT trial (Alteplase Compared to Tenecteplase) compares alteplase or tenecteplase for patients with acute ischemic stroke. All eligible patients are enrolled by deferral of consent. Although the use of deferral of consent in the AcT trial meets the requirements of Canadian policy, we sought to provide a more explicit and rigorous approach to the justification of deferral of consent organized around 3 questions. Ultimately, the approach we outline here could become the foundation for a general justification for deferral of consent.

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

Background : Intravenous thrombolysis with alteplase is widely used in acute ischemic stroke patients presenting early after symptom onset. Recent phase II trials have suggested that intravenous tenecteplase may be safer and associated with higher early reperfusion rates as compared to alteplase. This study investigates whether intravenous tenecteplase is non‐inferior to intravenous alteplase for the treatment of acute ischemic stroke. Methods : This is a pragmatic, registry‐linked, prospective, randomized (1:1) controlled, open‐label parallel group clinical trial with blinded endpoint assessment of 1600 patients to test if intravenous tenecteplase (0.25 mg/kg body weight, max dose 25 mg) is non‐inferior to intravenous alteplase (0.9 mg/kg body weight, max dose 90 mg) in patients with acute ischemic stroke eligible for intravenous thrombolysis in clinical routine. Patients are recruited from comprehensive and primary stroke centers and enrolled using deferral of consent. The proposed sample has at least 90% power with a non‐inferiority margin of 5%, assuming incidence of 90‐day mRS 0–1 is 38% in the tenecteplase and 35% in the alteplase groups, and a loss to follow‐up rate < 5%. Results : The blinded primary endpoint is the proportion of subjects achieving a 90‐day mRS (modified Rankin scale) of 0–1. Key safety outcomes include 24‐hour symptomatic intracerebral hemorrhage and 90‐day all‐cause mortality. All serious adverse events within 24‐hour period will be reported and coded using MedDRA. Outcomes are collected either centrally (primary, key secondary and safety endpoints) or through ongoing Canadian stroke registries. The primary analysis is a simple unadjusted comparison of proportions. Conclusion : Results from the trial will provide real‐world evidence of the effectiveness of intravenous tenecteplase vs. alteplase in patients with acute ischemic stroke presenting early after stroke onset. Clinical Trial Registration: NCT03889249 https://clinicaltrials.gov/ct2/show/NCT03889249 This article is protected by copyright. All rights reserved

BackgroundThe benefit of endovascular thrombectomy (EVT) in stroke patients with a low baseline Alberta Stroke Program Early CT Score (ASPECTS, ≤5) is uncertain. We aim to use random forest regression modeling to predict 90 day home time in patients with low ASPECTS.MethodsWe used the Quality Improvement and Clinical Research (QuICR) provincial stroke registry and administrative data from southern Alberta to identify patients who underwent EVT in our center from July 2015 to November 2020. Baseline ASPECTS on non-contrast CT and CT angiography data were scored by a two physician consensus. The primary outcome was the predicted 90 day home time (the number of nights a patient is back at their premorbid living situation without an increase in level of care within 90 days of the stroke) using random forests regression. Estimates were generated using 200 bootstrapped datasets. Covariate contribution to home time was determined using partial dependence plots.ResultsOf 657 EVT patients, 85 (12.9%) had baseline ASPECTS ≤5 (mean age 70.9 years, 44.7% women, 93.9% good–moderate collaterals, 60% M1–middle cerebral artery occlusion). Using partial dependence estimates, mean predicted home times were similar in the low ASPECTS (44.3 days) versus higher ASPECTS (43.1) groups. Factors predicting lower 90 day home time in this population were diabetes mellitus (−8.8 days), hypertension (−5.7 days), and atrial fibrillation (−3.6 days). There was no meaningful difference in predicted 90 day home time by sex, baseline National Institutes of Health Stroke Severity Scale score, occlusion site, tandem lesion, collateral grade or thrombolysis.ConclusionsPatients with low ASPECTS who are selected for EVT using demographic and clinical profiles similar to higher ASPECTS patients achieved comparable outcomes.

BackgroundThe DAWN and DEFUSE-3 trials showed the benefit of endovascular treatment (EVT) in acute ischemic stroke patients presenting beyond 6 hours from last known well (LKW) and selected by perfusion imaging criteria. The ESCAPE NA1-trial selected patients based on non-contrast CT (NCCT) Alberta Stroke Program Early CT Score (ASPECTS) and multiphase CT angiography (CTA) collateral status. This study compares baseline characteristics, workflow, and outcomes in the EVT arms of DAWN and DEFUSE-3 with late-window patients from the EVT-only arm of ESCAPE-NA1.MethodsAggregate data on baseline characteristics, workflow, reperfusion quality, final infarct volume, and clinical outcomes (modified Rankin Score [mRS] at 90 days) in subjects enrolled in the DAWN and DEFUSE-3 EVT arms were compared with similar data from the ESCAPE-NA1 control arm (EVT-only arm) presenting beyond 6 hours from LKW using descriptive statistics.ResultsBaseline characteristics among late-window patients in the ESCAPE NA1 trial were similar to those in the DAWN and DEFUSE-3 EVT arms. Median time from LKW-to-puncture in subjects enrolled in the ESCAPE NA1 trial was 9 hrs (IQR: 7.5–11 hours) when compared with DAWN (n=107; 12.8 hours, IQR: 10.6–16.7 hours) and DEFUSE-3 (n=92; 11.5 hours, IQR: 9.2–12.8 hours). Median post-treatment infarct-volume was largest in the ESCAPE NA1-patients (47 mL [IQR: 19–146] vs median 8 mL [IQR: 0–48] in the DAWN group and 35 mL [IQR: 18–82] in DEFUSE-3), while % mRS 0–2 at 90 days were similar across the three trials (ESCAPE NA1: 50/111 [45%], DAWN: 52/107 [49%], DEFUSE-3: 41/92 [45%]).ConclusionPatients enrolled beyond 6 hours from LKW in the ESCAPE-NA1 trial based on NCCT-ASPECTS and mCTA had similar clinical outcomes when compared with patients selected by perfusion imaging in the DAWN and DEFUSE-3 trials.

Background and Purpose: Available data on the clinical course of patients with acute ischemic stroke due to medium vessel occlusion (MeVO) are mostly limited to those with M2 segment occlusions. Outcomes are generally better compared with more proximal occlusions, but many patients will still suffer from severe morbidity. We aimed to determine the clinical course of acute ischemic stroke due to MeVO with and without intravenous alteplase treatment. Methods: Patients with MeVO (M2/M3/A2/A3/P2/P3 occlusion) from the INTERRSeCT (The Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography) and PRoveIT (Precise and Rapid Assessment of Collaterals Using Multi-Phase CTA in the Triage of Patients With Acute Ischemic Stroke for IA Therapy) studies were included. Baseline characteristics and clinical outcomes were summarized using descriptive statistics. The primary outcome was a modified Rankin Scale score of 0 to 1 at 90 days, describing excellent functional outcome. Secondary outcomes were the common odds ratio for a 1-point shift across the modified Rankin Scale and functional independence, defined as modified Rankin Scale score of 0 to 2. We compared outcomes between patients with versus without intravenous alteplase treatment and between patients who did and did not show recanalization on follow-up computed tomography angiography. Logistic regression was used to provide adjusted effect-size estimates. Results: Among 258 patients with MeVO, the median baseline National Institutes of Health Stroke Scale score was 7 (interquartile range: 5–12). A total of 72.1% (186/258) patients were treated with intravenous alteplase and in 41.8% (84/201), recanalization of the occlusion (revised arterial occlusive lesion score 2b/3) was seen on follow-up computed tomography angiography. Excellent functional outcome was achieved by 50.0% (129/258), and 67.4% (174/258) patients gained functional independence, while 8.9% (23/258) patients died within 90 days. Recanalization was observed in 21.4% (9/42) patients who were not treated with alteplase and 47.2% (75/159) patients treated with alteplase ( P =0.003). Early recanalization (adjusted odds ratio, 2.29 [95% CI, 1.23–4.28]) was significantly associated with excellent functional outcome, while intravenous alteplase was not (adjusted odds ratio, 1.70 [95% CI, 0.88–3.25]). Conclusions: One of every 2 patients with MeVO did not achieve excellent clinical outcome at 90 days with best medical management. Early recanalization was strongly associated with excellent outcome but occurred in

Background:Acute ischemic stroke may affect women and men differently. We aimed to evaluate sex differences in outcomes of endovascular treatment (EVT) for ischemic stroke due to large vessel occlusion in a population-based study in Alberta, Canada.Methods and Results:Over a 3-year period (April 2015–March 2018), 576 patients fit the inclusion criteria of our study and constituted the EVT group of our analysis. The medical treatment group of the ESCAPE trial had 150 patients. Thus, our total sample size was 726. We captured outcomes in clinical routine using administrative data and a linked database methodology. The primary outcome of our study was home-time. Home-time refers to the number of days that the patient was back at their premorbid living situation without an increase in the level of care within 90 days of the index stroke event. In adjusted analysis, EVT was associated with an increase of 90-day home-time by an average of 6.08 (95% CI −2.74–14.89, p-value 0.177) days in women compared to an average of 11.20 (95% CI 1.94–20.46, p-value 0.018) days in men. Further analysis revealed that the association between EVT and 90-day home-time in women was confounded by age and onset-to-treatment time.Conclusions:We found a nonsignificant nominal reduction of 90-day home-time gain for women compared to men in this province-wide population-based study of EVT for large vessel occlusion, which was only partially explained by confounding.

BACKGROUND: In studies showing associations between ambient air pollution and myocardial infarction (MI), data have been lacking on the inherent spatial variability of air pollution. The aim of this study was to determine whether the long-term spatial distribution of air pollution influences short-term temporal associations between air pollution and admission to hospital for MI. METHODS: We identified adults living in Calgary who were admitted to hospital for an MI between 2004 and 2012. We evaluated associations between short-term exposure to air pollution (ozone [O(3)], nitrogen dioxide [NO(2)], sulfur dioxide [SO(2)], carbon monoxide [CO], particulate matter < 10 μm in diameter [PM(10)] and particulate matter < 2.5 μm in diameter [PM(2.5)]), and hospital admissions for MI using a time-stratified, case-crossover study design. Air Quality Health Index (AQHI) scores were calculated from a composition of O(3), NO(2) and PM(2.5). Conditional logistic regression models were stratified by low, medium and high levels of neighbourhood NO(2) concentrations derived from land use regression models; results of these analyses are presented as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: From 2004 to 2012, 6142 MIs were recorded in Calgary. Individuals living in neighbourhoods with higher long-term air pollution concentrations were more likely to be admitted to hospital for MI after short-term elevations in air pollution (e.g., 5-day average NO(2): OR 1.20, 95% CI 1.03–1.40, per interquartile range [IQR]) as compared with regions with lower air pollution (e.g., 5-day average NO(2): OR 0.90, 95% CI 0.78–1.04, per IQR). In high NO(2) tertiles, the AQHI score was associated with MI (e.g., 5-day average OR 1.13, 95% CI 1.02–1.24, per IQR; 3-day average OR 1.13, 95% CI 1.04–1.23, per IQR). INTERPRETATION: Our results show that the effect of air pollution on hospital admissions for MI was stronger in areas with higher NO(2) concentrations than that in areas with lower NO(2) concentrations. Individuals living in neighbourhoods with higher traffic-related pollution should be advised of the health risks and be attentive to special air quality warnings.

BACKGROUND AND PURPOSE: Infarct core volume measurement using CTP (CT perfusion) is a mainstay paradigm for stroke treatment decision-making. Yet, there are several downfalls with cine CTP technology that can be overcome by adopting the simple perfusion reconstruction algorithm (SPIRAL) derived from multiphase CTA. We compare SPIRAL with CTP parameters for the prediction of 24-hour infarction. MATERIALS AND METHODS: Seventy-two patients had admission NCCT, multiphase CTA, CTP, and 24-hour DWI. All patients had successful/quality reperfusion. Patient-level and cohort-level receiver operator characteristic curves were generated to determine accuracy. A 10-fold cross-validation was performed on the cohort-level data. Infarct core volume was compared for SPIRAL, CTP–time-to-maximum, and final DWI by Bland-Altman analysis. RESULTS: When we compared the accuracy in patients with early and late reperfusion for cortical GM and WM, there was no significant difference at the patient level (0.83 versus 0.84, respectively), cohort level (0.82 versus 0.81, respectively), or the cross-validation (0.77 versus 0.74, respectively). In the patient-level receiver operating characteristic analysis, the SPIRAL map had a slightly higher, though nonsignificant (P

ObjectiveTo undertake an effectiveness and safety analysis of EVT in patients with LVO and NIH Stroke Scale (NIHSS) score ≤6 using datasets of multicenter and multinational nature.MethodsWe pooled patients with anterior circulation occlusion from 3 prospective international cohorts. Patients were eligible if presentation occurred within 12 hours from last known well and baseline NIHSS ≤6. Primary outcome was modified Rankin Scale (mRS) score 0–1 at 90 days. Secondary outcomes included neurologic deterioration at 24 hours (change in NIHSS of ≥2 points), mRS 0–2 at 90 days, and 90-day all-cause mortality. We used propensity score matching to adjust for nonrandomized treatment allocation.ResultsAmong 236 patients who fit inclusion criteria, 139 received EVT and 97 received medical management. Compared to medical management, the EVT group was younger (65 vs 72 years; p < 0.001), had more proximal occlusions (p < 0.001), and less frequently received concurrent IV thrombolysis (57.7% vs 71.2%; p = 0.04). After propensity score matching, clinical outcomes between the 2 groups were not significantly different. EVT patients had an 8.6% (95% confidence interval [CI] −8.8% to 26.1%) higher rate of excellent 90-day outcome, despite a 22.3% (95% CI, 3.0%–41.6%) higher risk of neurologic deterioration at 24 hours.ConclusionsEVT for LVO in patients with low NIHSS score was associated with increased risk of neurologic deterioration at 24 hours. However, both EVT and medical management resulted in similar proportions of excellent clinical outcomes at 90 days.Classification of evidenceThis study provides Class III evidence that for patients with acute anterior circulation ischemic strokes and LVO with NIHSS < 6, EVT and medical management result in similar outcomes at 90 days.

Background and Purpose: We investigated the effect of higher therapeutic exercise doses on walking during inpatient rehabilitation, typically commencing 1 to 4 weeks poststroke. Methods: This phase II, blinded-assessor, randomized controlled trial recruited from 6 Canadian inpatient rehabilitation units, between 2014 and 2018. Subjects (n=75; 25/group) were randomized into: control (usual care) physical therapy: typically, 1 hour, 5 days/week; Determining Optimal Post-Stroke Exercise (DOSE1): 1 hour, 5 days/week, more than double the intensity of Control (based on aerobic minutes and walking steps); and DOSE2: 2 hours, 5 days/week, more than quadruple the intensity of Control, each for 4 weeks duration. The primary outcome, walking endurance at completion of the 4-week intervention (post-evaluation), was compared across these groups using linear regression. Secondary outcomes at post-evaluation, and longitudinal outcomes at 6 and 12-month evaluations, were also analyzed. Results: Both DOSE1 (mean change 61 m [95% CI, 9–113], P =0.02) and DOSE2 (mean change 58 m, 6–110, P =0.03) demonstrated greater walking endurance compared with Control at the post-evaluation. Significant improvements were also observed with DOSE2 in gait speed (5-m walk), and both DOSE groups in quality of life (EQ-5D-5 L) compared with Control. Longitudinal analyses revealed that improvements in walking endurance from the DOSE intervention were retained during the 1-year follow-up period over usual care. Conclusions: This study provides the first preliminary evidence that patients with stroke can improve their walking recovery and quality of life with higher doses of aerobic and stepping activity within a critical time period for neurological recovery. Furthermore, walking endurance benefits achieved from a 4-week intervention are retained over the first-year poststroke. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01915368.

Background and Purpose: The prognosis of medium vessel occlusions (MeVOs), that is, M2/3 middle cerebral artery, A2/3 anterior cerebral artery, and P2/3 posterior cerebral artery occlusions, is generally better compared with large vessel occlusions, since brain ischemia is less extensive. However, in some MeVO patients, infarcts are seen outside the territory of the occluded vessel (MeVO with discrepant infarcts). This study aims to determine the prevalence and clinical impact of discrepant infarct patterns in acute ischemic stroke due to MeVO. Methods: We pooled data of MeVO patients from INTERRSeCT (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography) and PRove-IT (Precise and Rapid Assessment of Collaterals Using Multi-Phase CTA in the Triage of Patients With Acute Ischemic Stroke for IA Therapy)—2 prospective cohort studies of patients with acute ischemic stroke. The combination of occlusion location on baseline computed tomography angiography and infarct location on follow-up computed tomography/magnetic resonance imaging was used to identify MeVOs with discrepant infarct patterns. Two definitions for discrepant infarcts were applied; one was more restrictive and purely based on infarct patterns of the basal ganglia, whereas the second one took cortical infarct patterns into account. Clinical outcomes of patients with versus without discrepant infarcts were summarized using descriptive statistics. Logistic regression was performed to obtain adjusted effect size estimates for the association of discrepant infarcts and good outcome, defined as a modified Rankin Scale score of 0 to 2, and excellent outcome (modified Rankin Scale score 0–1). Results: Two hundred sixty-two patients with MeVO were included in the analysis. The prevalence of discrepant infarcts was 39.7% (definition 1) and 21.0% (definition 2). Patients with discrepant infarcts were less likely to achieve good outcome (definition 1: adjusted odds ratio, 0.48 [95% CI, 0.25–0.91]; definition 2: adjusted odds ratio, 0.47 [95% CI, 0.22–0.99]). When definition 1 was applied, patients with discrepant infarcts were also less likely to achieve excellent outcome (definition 1: adjusted odds ratio, 0.55 [95% CI, 0.31–0.99]; definition 2: adjusted odds ratio, 0.62 [95% CI, 0.31–1.25]). Conclusions: MeVO patients with discrepant infarcts are common, and they are associated with more severe deficits and poor outcomes.

Background. Understanding potential sex differences in stroke recovery is important for prognosis, ensuring appropriate allocation of health care resources, and for stratification in research studies. Previously, functional measures have shown poorer outcomes for females, however, little is known about sex differences that may exist in specific motor and sensory impairments. Objective. The aim of this study was to utilize robotic assessments of motor and sensory impairments to determine if there are sex differences at the impairment level in stroke recovery over the first 6 months poststroke. Methods. We used robotic and clinical assessments of motor and sensory impairments at 1, 6, 12, and 26 weeks poststroke in 108 males and 52 females. Linear mixed models were used to examine the effect of sex on recovery poststroke, controlling for age and lesion volume. Results. In general, we did not find significant sex differences across a range of assessments. The exception to this was a sex × age interaction for the Purdue Pegboard Assessment, where we found that females had better performance than males at younger ages (