Extending thrombolysis to 4·5-9 h and wake-up stroke using perfusion imaging: a systematic review and meta-analysis of individual patient data

Hyper-Acute Stroke Systems of Care and Workflow

PURPOSE OF REVIEW

Recent stroke treatment advances have necessitated agile, broad-scale healthcare system redesign, to achieve optimal patient outcomes and access equity. Optimised hyperacute stroke care requires integrated pre-hospital, emergency department, stroke specialist, radiology, neurosurgical and endovascular neurointervention services, guided by a population-wide needs analysis. In this review, we survey system integration efforts, providing case studies, and identify common elements of successful initiatives.

RECENT FINDINGS

Different regions and nations have evolved varied acute stroke systems depending on geography, population density and workforce. However, common facilitators to these solutions have included stroke unit care as a foundation, government-clinician synergy, pre-hospital pathway coordination, service centralisation, and stroke data guiding system improvement. Further technological advantages will minimize the geographical distance disadvantages and facilitate virtual expertise redistribution to remote areas. Continued treatment advances necessitate an integrated, adaptable, population-wide trans-disciplinary approach. A well-designed clinician-led and government-supported system can facilitate hyperacute care and scaffold future system enhancements.

Multi-grained contrastive representation learning for label-efficient lesion segmentation and onset time classification of acute ischemic stroke

Ischemic lesion segmentation and the time since stroke (TSS) onset classification from paired multi-modal MRI imaging of unwitnessed acute ischemic stroke (AIS) patients is crucial, which supports tissue plasminogen activator (tPA) thrombolysis decision-making. Deep learning methods demonstrate superiority in TSS classification. However, they often overfit task-irrelevant features due to insufficient paired labeled data, resulting in poor generalization. We observed that unpaired data are readily available and inherently carry task-relevant cues, but are less often considered and explored. Based on this, in this paper, we propose to fully excavate the potential of unpaired unlabeled data and use them to facilitate the downstream AIS analysis task. We first analyze the utility of features at the varied grain and propose a multi-grained contrastive learning (MGCL) framework to learn task-related prior representations from both coarse-grained and fine-grained levels. The former can learn global prior representations to enhance the location ability for the ischemic lesions and perceive the healthy surroundings, while the latter can learn local prior representations to enhance the perception ability for semantic relation between the ischemic lesion and other health regions. To better transfer and utilize the learned task-related representation, we designed a novel multi-task framework to simultaneously achieve ischemic lesion segmentation and TSS classification with limited labeled data. In addition, a multi-modal region-related feature fusion module is proposed to enable the feature correlation and synergy between multi-modal deep image features for more accurate TSS decision-making. Extensive experiments on the large-scale multi-center MRI dataset demonstrate the superiority of the proposed framework. Therefore, it is promising that it helps better stroke evaluation and treatment decision-making.

IV Thrombolysis for Acute Ischemic Stroke with Unknown Onset in Patients on Oral Anticoagulation

INTRODUCTION

IV thrombolysis (IVT) is established in the unknown or extended time window based on multimodal imaging. Further, increasing evidence exists regarding IVT in patients on oral anticoagulation including direct oral anticoagulants (DOACs). However, data on IVT in ischemic stroke patients on oral anticoagulation with unknown time of stroke onset are sparse.

METHODS

This study bases on the longitudinal cohort study Stroke Research Consortium in Northern Bavaria (STAMINA; ClinicalTrials.gov Identifier: NCT04357899). Acute ischemic stroke patients treated with IVT in the unknown or extended time window from January 2015 to December 2019 were included. Patient selection was based on multimodal CT or MRI. Patients on oral anticoagulation (vitamin-K antagonist [VKA] or DOAC within 48 h) were eligible for IVT based on INR measurement (VKA) or plasma levels (DOAC) according to an institutional protocol. Primary outcomes were the incidence of any and symptomatic intracranial hemorrhage.

RESULTS

Of 170 ischemic stroke patients treated with IVT in the unknown or extended time window, 151 had no oral anticoagulation at stroke onset and 19 were on oral anticoagulation (6 on VKA and 13 on DOAC). The risk of symptomatic ICH according to ECASS II criteria was similar between the patients with and without oral anticoagulation (1 [5.3%] vs. 4 [2.7%], p = 0.453). After adjustment for confounding factors, pre-medication with oral anticoagulation was not associated with symptomatic ICH (aOR 1.02 [0.09-11.02], p = 0.988).

CONCLUSION

IVT for ischemic stroke with unknown onset appeared safe in selected patients on oral anticoagulation with both DOAC and VKA.

Bridging thrombolysis before endovascular therapy is associated with better outcomes in patients with large infarction core

BACKGROUND

This study investigates the efficacy and safety of bridging intravenous thrombolysis (IVT) before endovascular therapy (EVT) compared with EVT alone in patients with large infarction core.

METHODS

We conducted a comprehensive search of PubMed, EMBASE, and the Cochrane Library from January 2015 to June 2024. Included studies involved patients with acute ischemic stroke with an Alberta Stroke Program Early CT Score of ≤5 or an ischemic core volume of ≥50 mL. Studies were required to provide either 90-day modified Rankin Scale (mRS) score, reperfusion, symptomatic intracranial hemorrhage (sICH), or 90-day mortality.

RESULTS

Nine observational studies with 2641 patients were analyzed. The IVT+EVT group had a higher rate of 90-day functional independence (mRS 0-2; OR 1.56, 95% CI 1.31 to 1.87; adjusted OR (aOR) 1.43, 95% CI 1.21 to 1.68) and 90-day functional outcome (mRS 0-3; OR 1.34, 95% CI 1.11 to 1.62; aOR 1.18, 95% CI 1.02 to 1.37) compared with EVT alone. There was no significant difference in successful reperfusion (OR 1.01, 95% CI 0.62 to 1.64; aOR 1.07, 95% CI 0.74 to 1.54) and 90-day mortality (OR 0.86, 95% CI 0.73 to 1.02; aOR 0.89, 95% CI 0.77 to 1.04) between the two groups. Moreover, patients who received IVT+EVT had a higher rate of sICH (OR 1.30, 95% CI 1.03 to 1.64; aOR 2.21, 95% CI 1.22 to 4.01).

CONCLUSIONS

In patients with large infarction core, bridging IVT before EVT is associated with favorable functional outcomes compared with EVT, even though bridging therapy entails a higher risk of sICH. Further trials are needed to confirm these findings.

Hyperacute ischemic stroke care-Current treatment and future directions

A decade on from the first positive thrombectomy trials, hyperacute therapies for ischemic stroke continue to rapidly advance. Effective treatments remain limited to reperfusion, although several cytoprotective approaches continue to be investigated. Intravenous fibrinolytics are now demonstrated to be beneficial up to 24 h in patients selected using perfusion imaging, but their role in patients with non-disabling symptoms appears very limited. Tenecteplase is superior to alteplase in meta-analysis of the latest trials, and adjuvant thrombolytics are an area of active investigation. Endovascular thrombectomy is beneficial in a wide range of anterior and posterior circulation large vessel occlusions up to 24 h after onset with the more distal occlusions, mild presentations, and >24 h window being the main frontiers to be tested in ongoing trials. Imaging parameters are prognostic but appear not to modify the relative treatment benefit of thrombectomy versus standard medical care. Therefore, deciding who not to treat with thrombectomy is a key clinical challenge that requires careful but rapid integration of clinical, imaging, and patient preference considerations. Systems of care to accelerate delivery of these highly effective therapies will maximize benefits for the greatest number of patients with stroke.

Days Alive and Out of Hospital as an Outcome Measure in Patients Receiving Hyperacute Stroke Intervention

BACKGROUND

Patient outcome after stroke is frequently assessed with clinical scales such as the modified Rankin Scale score (mRS). Days alive and out of hospital at 90 days (DAOH-90), which measures survival, time spent in hospital or rehabilitation settings, readmission and institutionalization, is an objective outcome measure that can be obtained from large administrative data sets without the need for patient contact. We aimed to assess the comparability of DAOH with mRS and its relationship with other prognostic variables after acute stroke reperfusion therapy.

METHODS AND RESULTS

Consecutive patients with ischemic stroke treated with intravenous thrombolysis or endovascular thrombectomy were analyzed. DAOH-90 was calculated from a national minimum data set, a mandatory nationwide administrative database. mRS score at day 90 (mRS-90) was assessed with in-person or telephone interviews. The study included 1278 patients with ischemic stroke (714 male, median age 70 [59-79], median National Institutes of Health Stroke Scale score 14 [9-20]). Median DAOH-90 was 71 [29-84] and median mRS-90 score was 3 [2-5]. DAOH-90 was correlated with admission National Institutes of Health Stroke Scale score (Spearman rho -0.44, P<0.001) and Alberta Stroke Program Early CT [Computed Tomography] Score (Spearman rho 0.24, P<0.001). There was a strong association between mRS-90 and DAOH-90 (Spearman rho correlation -0.79, P<0.001). Area under receiver operating curve for predicting mRS score >0 was 0.86 (95% CI, 0.84-0.88), mRS score >1 was 0.88 (95% CI, 0.86-0.90) and mRS score >2 was 0.90 (95% CI, 0.89-0.92).

CONCLUSIONS

In patients with stroke treated with reperfusion therapies, DAOH-90 shows reasonable comparability to the more established outcome measure of mRS-90. DAOH-90 can be readily obtained from administrative databases and therefore has the potential to be used in large-scale clinical trials and comparative effectiveness studies.

Comparison of functional and safety outcomes between the extended versus early time window after intravenous thrombolysis and endovascular thrombectomy

INTRODUCTION

Based on recent trials regarding the early time window, omitting intravenous thrombolysis (IVT) before endovascular thrombectomy (EVT) in eligible patients seems unjustified. Whether this also concerns the extended time window, 4.5 to 9 h from last seen well, is yet unclear.

PATIENTS AND METHODS

All consecutive patients treated with IVT, EVT, or IVT plus EVT in the extended time window at Helsinki University Hospital (HUS) between 1/2021 and 12/2022 were compared with matched controls treated in the early time window between 1/2016 and 12/2020. Regression analysis was applied on functional outcome at 90 days, evaluated on modified Rankin Scale (mRS), and on the occurrence of symptomatic intracerebral hemorrhage (sICH), adjusted for potential confounders.

RESULTS

Altogether 134 patients and 134 matching controls were included. Functional outcomes did not significantly differ between the extended versus early time window. Among patients with IVT plus EVT, the adjusted odds ratio (aOR) for a favorable outcome shift on mRS was 1.15, 95% confidence interval (CI) 0.54-2.43. Although sICH occurred more frequently (2.2% versus 3.0%) in the extended time window, regression analysis did not show a significant difference, aOR 0.96, 95% CI 0.14-6.87.

DISCUSSION AND CONCLUSION

We found no significant differences in the functional or safety outcomes between the extended versus early time window among patients with either IVT, EVT, or IVT plus EVT. There were no signals indicating, that IVT or EVT should be avoided in eligible patients in the extended time window which aligns with the current clinical treatment guidelines of HUS.

Carotid artery transplantation of brain endothelial cells enhances neuroprotection and neurorepair in ischaemic stroke rats

Brain microvascular endothelial cells (BMECs), an important component of the neurovascular unit, can promote angiogenesis and synaptic formation in ischaemic mice after brain parenchyma transplantation. Since the therapeutic efficacy of cell-based therapies depends on the extent of transplanted cell residence in the target tissue and cell migration ability, the delivery route has become a hot research topic. In this study, we investigated the effects of carotid artery transplantation of BMECs on neuronal injury, neurorepair, and neurological dysfunction in rats after cerebral ischaemic attack. Purified passage 1 endothelial cells (P1-BMECs) were prepared from mouse brain tissue. Adult rats were subjected to transient middle cerebral artery occlusion (MCAO) for 30 min. Then, the rats were treated with 5 × 105 P1-BMECs through carotid artery infusion or tail vein injection. We observed that carotid artery transplantation of BMECs produced more potent neuroprotective effects than caudal injection in MCAO rats, including reducing infarct size and alleviating neurological deficits in behavioural tests. Carotid artery-transplanted BMECs displayed a wider distribution in the ischaemic rat brain. Immunostaining for endothelial progenitor cells and the mature endothelial cell markers CD34 and RECA-1 showed that carotid artery transplantation of BMECs significantly increased angiogenesis. Carotid artery transplantation of BMECs significantly increased the number of surviving neurons, decreased the cerebral infarction volume, and alleviated neurological deficits. In addition, we found that carotid artery transplantation of BMECs significantly enhanced ischaemia-induced hippocampal neurogenesis, as measured by doublecortin (DCX) and Ki67 double staining within 2 weeks after ischaemic injury. We conclude that carotid artery transplantation of BMECs can promote cerebral angiogenesis, neurogenesis, and neurological function recovery in adult rats after ischaemic stroke. Our results suggest that carotid injection of BMECs may be a promising new approach for treating acute brain injuries.

Reprint of: Fibrinolytic and Non-fibrinolytic Roles of Tissue-type Plasminogen Activator in the Ischemic Brain

The neurovascular unit (NVU) is assembled by endothelial cells (ECs) and pericytes, and encased by a basement membrane (BM) surveilled by microglia and surrounded by perivascular astrocytes (PVA), which in turn are in contact with synapses. Cerebral ischemia induces the rapid release of the serine proteinase tissue-type plasminogen activator (tPA) from endothelial cells, perivascular astrocytes, microglia and neurons. Owning to its ability to catalyze the conversion of plasminogen into plasmin, in the intravascular space tPA functions as a fibrinolytic enzyme. In contrast, the release of astrocytic, microglial and neuronal tPA have a plethora of effects that not always require the generation of plasmin. In the ischemic brain tPA increases the permeability of the NVU, induces microglial activation, participates in the recycling of glutamate, and has various effects on neuronal survival. These effects are mediated by different receptors, notably subunits of the N-methyl-D-aspartate receptor (NMDAR) and the low-density lipoprotein receptor-related protein-1 (LRP-1). Here we review data on the role of tPA in the NVU under non-ischemic and ischemic conditions, and analyze how this knowledge may lead to the development of potential strategies for the treatment of acute ischemic stroke patients.

Inhibition of NNMT enhances drug sensitivity in lung cancer cells through mediation of autophagy

Introduction

This study aimed to investigate the role of Nicotinamide N-methyltransferase (NNMT) in the drug sensitivity of non-small cell lung cancer (NSCLC) cells, with a focus on its impact on autophagy and resistance to the chemotherapeutic agent osimertinib. The study hypothesized that NNMT knockdown would enhance drug sensitivity by modifying autophagic processes, providing a potential new therapeutic target for overcoming chemoresistance in lung cancer.

Methods

Proteomic analysis was utilized to identify changes in protein expression following NNMT knockdown in H1975 and H1975 osimertinib resistance (H1975OR) lung cancer cell lines. Gene expression patterns and their correlation with NNMT expression in lung cancer patients were analyzed using The Cancer Genome Atlas (TCGA) dataset. Additionally, a predictive model for lung cancer survival was developed via lasso regression analysis based on NNMT-associated gene expression. Drug sensitivity was assessed using the IC50 values and apoptosis ratio, and autophagy was evaluated through Western blot and flow cytometric analysis.

Results

Significant variations in the expression of 1,182 proteins were observed following NNMT knockdown, with a significant association with autophagy-related genes. Analysis of gene expression patterns unveiled a significant correlation between NNMT expression and specific changes in gene expression in lung cancer. The predictive model successfully forecasted lung cancer patient survival outcomes, highlighting the potential of NNMT-associated genes in predicting patient survival. Knockdown of NNMT reversed osimertinib resistance in H1975 cells, as evidenced by altered IC50 values and apoptosis ratio, and changes were observed in autophagy markers.

Discussion

Knockdown of NNMT in lung cancer cells enhances drug sensitivity by modulating autophagy, providing a promising therapeutic target to overcome chemoresistance in NSCLC. The study underscores the importance of NNMT in lung cancer pathology and underscores its potential as a predictive marker for clinical outcomes. Additionally, the developed predictive model further supports the clinical relevance of NNMT-associated gene expression in improving the prognosis of lung cancer patients.

Fibrinolytic Agents in Thromboembolic Diseases: Historical Perspectives and Approved Indications

Fibrinolytic agents catalyze the conversion of the inactive proenzyme plasminogen into the active protease plasmin, degrading fibrin within the thrombus and recanalizing occluded vessels. The history of these medications dates to the discovery of the first fibrinolytic compound, streptokinase, from bacterial cultures in 1933. Over time, researchers identified two other plasminogen activators in human samples, namely urokinase and tissue plasminogen activator (tPA). Subsequently, tPA was cloned using recombinant DNA methods to produce alteplase. Several additional derivatives of tPA, such as tenecteplase and reteplase, were developed to extend the plasma half-life of tPA. Over the past decades, fibrinolytic medications have been widely used to manage patients with venous and arterial thromboembolic events. Currently, alteplase is approved by the U.S. Food and Drug Administration (FDA) for use in patients with pulmonary embolism with hemodynamic compromise, ST-segment elevation myocardial infarction (STEMI), acute ischemic stroke, and central venous access device occlusion. Reteplase and tenecteplase have also received FDA approval for treating patients with STEMI. This review provides an overview of the historical background related to fibrinolytic agents and briefly summarizes their approved indications across various thromboembolic diseases.

Outcomes of Bridging Intravenous Thrombolysis Versus Endovascular Therapy Alone in Late-Window Acute Ischemic Stroke

BACKGROUND

Studies comparing bridging intravenous thrombolysis (IVT) with direct endovascular therapy (EVT) in patients with acute ischemic stroke who present late are limited. We aimed to compare the clinical outcomes and safety of bridging IVT in patients with acute ischemic stroke due to anterior circulation large vessel occlusion who underwent EVT 6 to 24 hours after time last known well.

METHODS

We enrolled patients with anterior circulation large vessel occlusion stroke and a National Institutes of Health Stroke Scale score of ≥6 from 20 centers across 10 countries in the multicenter retrospective CLEAR study (CT for Late Endovascular Reperfusion) between January 2014 and May 2022. We used inverse probability of treatment weighting modeling adjusted for clinical and imaging confounders to compare functional outcomes, reperfusion success, symptomatic intracranial hemorrhage, and mortality between EVT patients with and without prior IVT.

RESULTS

Of 5098 patients screened for eligibility, we included 2749 patients, of whom 549 received bridging IVT before EVT. The timing of IVT was not recorded. Witnessed stroke onset and transfer rates were higher in the bridging IVT group (25% versus 12% and 77% versus 55%, respectively, P value for both <0.0001), and time intervals between stroke onset and treatment were shorter (time last known well-start of EVT median 560 minutes [interquartile range, 432-791] versus 724 minutes [interquartile range, 544-912]; P<0.0001). After adjustment for confounders, there was no difference in functional outcome at 3 months (adjusted common odds ratio for modified Rankin Scale shift, 1.03 [95% CI, 0.89-1.19]; P=0.72) or successful reperfusion (adjusted odds ratio, 1.19 [95% CI, 0.81-1.75]; P=0.39). There were no safety concerns associated with bridging IVT versus direct EVT (symptomatic intracranial hemorrhage: adjusted odds ratio, 0.75 [95% CI, 0.38-1.48]; P=0.40; mortality: adjusted odds ratio, 1.14 [95% CI, 0.89-1.46]; P=0.31). Results were unchanged when the analysis was limited to patients who received IVT >6 hours after last known well.

CONCLUSIONS

In patients with an anterior circulation large vessel occlusion stroke who underwent EVT 6 to 24 hours from last known well, bridging IVT was not associated with a difference in outcomes compared with direct EVT.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04096248.

Improving acute stroke assessment in non-enhanced computed tomography: automated tool for early ischemic lesion volume detection

BACKGROUND AND OBJECTIVES

ASPECTs is a widely used marker to identify early stroke signs on non-enhanced computed tomography (NECT), yet it presents interindividual variability and it may be hard to use for non-experts. We introduce an algorithm capable of automatically estimating the NECT volumetric extension of early acute ischemic changes in the 3D space. We compared the power of this marker with ASPECTs evaluated by experienced practitioner in predicting the clinical outcome.

METHODS

We analyzed and processed neuroimaging data of 153 patients admitted with acute ischemic stroke. All patients underwent a NECT at admission and on follow-up. The developed algorithm identifies the early ischemic hypodense region based on an automatic comparison of the gray level in the images of the two hemispheres, assumed to be an approximate mirror image of each other in healthy patients.

RESULTS

In the two standard axial slices used to estimate the ASPECTs, the regions identified by the algorithm overlap significantly with those identified by experienced practitioners. However, in many patients, the regions identified automatically extend significantly to other slices. In these cases, the volume marker provides supplementary and independent information. Indeed, the clinical outcome of patients with volume marker = 0 can be distinguished with higher statistical confidence than the outcome of patients with ASPECTs = 10.

CONCLUSION

The volumetric extension and the location of acute ischemic region in the 3D-space, automatically identified by our algorithm, provide data that are mostly in agreement with the ASPECTs value estimated by expert practitioners, and in some cases complementary and independent.

Stroke

Stroke affects up to one in five people during their lifetime in some high-income countries, and up to almost one in two in low-income countries. Globally, it is the second leading cause of death. Clinically, the disease is characterised by sudden neurological deficits. Vascular aetiologies contribute to the most common causes of ischaemic stroke, including large artery disease, cardioembolism, and small vessel disease. Small vessel disease is also the most frequent cause of intracerebral haemorrhage, followed by macrovascular causes. For acute ischaemic stroke, multimodal CT or MRI reveal infarct core, ischaemic penumbra, and site of vascular occlusion. For intracerebral haemorrhage, neuroimaging identifies early radiological markers of haematoma expansion and probable underlying cause. For intravenous thrombolysis in ischaemic stroke, tenecteplase is now a safe and effective alternative to alteplase. In patients with strokes caused by large vessel occlusion, the indications for endovascular thrombectomy have been extended to include larger core infarcts and basilar artery occlusion, and the treatment time window has increased to up to 24 h from stroke onset. Regarding intracerebral haemorrhage, prompt delivery of bundled care consisting of immediate anticoagulation reversal, simultaneous blood pressure lowering, and prespecified stroke unit protocols can improve clinical outcomes. Guided by underlying stroke mechanisms, secondary prevention encompasses pharmacological, vascular, or endovascular interventions and lifestyle modifications.

Artificial intelligence for MRI stroke detection: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis aimed to assess the stroke detection performance of artificial intelligence (AI) in magnetic resonance imaging (MRI), and additionally to identify reporting insufficiencies.

METHODS

PRISMA guidelines were followed. MEDLINE, Embase, Cochrane Central, and IEEE Xplore were searched for studies utilising MRI and AI for stroke detection. The protocol was prospectively registered with PROSPERO (CRD42021289748). Sensitivity, specificity, accuracy, and area under the receiver operating characteristic (ROC) curve were the primary outcomes. Only studies using MRI in adults were included. The intervention was AI for stroke detection with ischaemic and haemorrhagic stroke in separate categories. Any manual labelling was used as a comparator. A modified QUADAS-2 tool was used for bias assessment. The minimum information about clinical artificial intelligence modelling (MI-CLAIM) checklist was used to assess reporting insufficiencies. Meta-analyses were performed for sensitivity, specificity, and hierarchical summary ROC (HSROC) on low risk of bias studies.

RESULTS

Thirty-three studies were eligible for inclusion. Fifteen studies had a low risk of bias. Low-risk studies were better for reporting MI-CLAIM items. Only one study examined a CE-approved AI algorithm. Forest plots revealed detection sensitivity and specificity of 93% and 93% with identical performance in the HSROC analysis and positive and negative likelihood ratios of 12.6 and 0.079.

CONCLUSION

Current AI technology can detect ischaemic stroke in MRI. There is a need for further validation of haemorrhagic detection. The clinical usability of AI stroke detection in MRI is yet to be investigated.

CRITICAL RELEVANCE STATEMENT

This first meta-analysis concludes that AI, utilising diffusion-weighted MRI sequences, can accurately aid the detection of ischaemic brain lesions and its clinical utility is ready to be uncovered in clinical trials.

KEY POINTS

There is a growing interest in AI solutions for detection aid. The performance is unknown for MRI stroke assessment. AI detection sensitivity and specificity were 93% and 93% for ischaemic lesions. There is limited evidence for the detection of patients with haemorrhagic lesions. AI can accurately detect patients with ischaemic stroke in MRI.

Treatment with intravenous alteplase in ischaemic stroke patients with onset time between 4.5 and 24 hours (HOPE): protocol for a randomised, controlled, multicentre study

BACKGROUND

While intravenous thrombolysis is recommended for patients who had an acute ischaemic stroke (AIS) within 4.5 hours of symptom onset, there are few randomised trials investigating the benefits of thrombolysis beyond this therapeutic window.

AIM

To determine whether patients who had an AIS selected with the presence of potentially salvageable tissue on CT perfusion at 4.5-24 hours after stroke onset (for stroke with unknown onset time, the midpoint of the time last known to be well and symptom recognition time; for wake-up stroke, the midpoint of the time last known to be well or sleep onset and wake up time) will benefit from intravenous thrombolysis.

DESIGN

HOPE is a prospective, multicentre, randomised, open-label blinded endpoint trial with the stage of phase III. The treatment allocation employs 1:1 randomisation. The treatment arm under investigation is alteplase with standard therapy, the control arm is standard therapy. Eligibility imaging criteria include ischaemic core volume ≤70 mL, penumbra ≥10 mL and mismatch ≥20%.

STUDY OUTCOMES

The primary outcome is non-disabled functional outcome (assessed as modified Rankin Scale score of 0-1 at 90 days).

DISCUSSION

HOPE is the first trial to investigate whether intravenous thrombolysis with alteplase offers benefits in patients who had an AIS presenting within 4.5-24 hours, which has the potential to extend time window and expand eligible population for thrombolysis therapy.

Endovascular thrombectomy with or without intravenous alteplase in large-core ischemic stroke: a systematic review and meta-analysis

The role of bridging intravenous thrombolysis (IVT) with alteplase before endovascular thrombectomy (EVT) in treating large core ischemic stroke remains uncertain. We aimed to compare clinical outcomes and safety of EVT with or without bridging IVT in patients with anterior circulation large vessel occlusion (ACLVO) and baseline Alberta Stroke Program Early CT Score (ASPECTS) ≤ 5. We systematically searched PubMed, Web of Science, Cochrane Library, and Embase from inception until November 2023. The primary outcome was 90-day functional independence (modified Rankin Scale [mRS] 0-2). Secondary outcomes included 90-day independent ambulation (mRS 0-3), successful recanalization, any intracranial hemorrhage (ICH), symptomatic ICH (sICH) and 90-day mortality. A random-effects model was used for data pooling. Five high-quality studies, incorporating 2124 patients (41% treated with bridging IVT), were included. Across both unadjusted and adjusted analyses, no significant differences were found between the bridging IVT and EVT-alone groups in terms of functional independence (odds ratios [OR] = 1.36, 95% confidence interval [CI]: 0.90-2.07, P = 0.14; adjusted OR [aOR] = 1.19, 95% CI: 0.68-2.09, P = 0.53) or independent ambulation (OR = 1.14, 95% CI: 0.80-1.62, P = 0.47; aOR = 1.18, 95% CI: 1.00-1.39, P = 0.05) at 90 days. Furthermore, no differences were observed in successful recanalization, any ICH, sICH, and 90-day mortality between the two treatment groups. Bridging IVT exhibits similar functional and safety outcomes compared to EVT alone in ACLVO patients with baseline ASPECTS ≤ 5. Further research is warranted to confirm these findings.

Intravenous tenecteplase for acute ischemic stroke between 4.5 and 6 h of onset (EXIT-BT2): Rationale and Design

RATIONALE

To date, the benefit of intravenous thrombolysis for acute ischemic stroke (AIS) patients without advanced neuroimaging selection is confined to within 4.5 h of onset. Our phase II EXIT-BT (Extending the tIme window of Thrombolysis by ButylphThalide up to 6 h after onset) trial suggested the safety, feasibility, and potential benefit of intravenous tenecteplase (TNK) in AIS between 4.5 and 6 h of onset. The EXIT-BT2 trial is a pivotal study undertaken to confirm or refute this signal.

AIM

To investigate the efficacy and safety of TNK for AIS between 4.5 and 6 h of onset with or without endovascular treatment.

SAMPLE SIZE ESTIMATES

A maximum of 1440 patients are required to test the superiority hypothesis with 80% power according to a two-sided 0.05 level of significance, stratified by age, sex, history of diabetes, location of vessel occlusion, baseline National Institute of Health stroke scale score, stroke etiology, and plan for endovascular treatment.

DESIGN

EXIT-BT2 is a prospective, randomized, open-label, blinded assessment of endpoint (PROBE), and multi-center study. Eligible AIS patients between 4.5 and 6 h of onset are randomly assigned 1:1 into a TNK group or control group. The TNK group will receive TNK (0.25 mg/kg, a single bolus over 5-10 s, maximum 25 mg). The control group will receive standard medical care in compliance with national guidelines for acute ischemic stroke. Both groups will receive standard stroke care from randomization to 90 days after stroke onset according to national guidelines.

OUTCOME

The primary efficacy endpoint is excellent functional outcome, defined as a modified Rankin Scale score 0-1 at 90 days after randomization, while the primary safety endpoint is symptomatic intracerebral hemorrhage, defined as National Institutes of Health Stroke Scale score increase ⩾4 caused by intracranial hemorrhage within 24 (-6/+12) h after randomization.

CONCLUSIONS

The results of EXIT-BT2 may determine whether intravenous TNK has a favorable risk/benefit profile in AIS between 4.5 and 6 h of onset.

Outcomes of wake-up stroke undergoing mechanical thrombectomy: A systematic review and meta-analysis

BACKGROUND

Wake-up stroke represents a significant challenge in acute treatment and care. Thrombolysis has been extensively studied in the wake-up stroke population. However, mechanical thrombectomy in wake-up stroke exclusively has not been well studied. We performed a systematic review and meta-analysis to assess the clinical and functional outcomes of patients undergoing mechanical thrombectomy for wake-up stroke.

METHODS

We performed a systematic review of the literature using publically accessible databases. Data extraction was completed using Nested Knowledge AutoLit software. Outcomes of interest included modified Rankin Scale (mRS) 0-2, mortality, symptomatic intracerebral hemorrhage (sICH), and thrombolysis in cerebral infarction (TICI) score 2b/3. Statistical analysis was performed using R software version 4.1.2.

RESULTS

A total of 12 studies were included in our study with a total of 510 patients included. Patients with wake-up stroke were found to have good functional outcome (mRS 0-2) in 46.2% of patients and successful reperfusion (TICI 2b/3) was seen in 83.5% of patients. Mortality was observed in 20.4% of patients with sICH seen in 8.3%.

CONCLUSION

Mechanical thrombectomy for patients with wake-up stroke was found to have favorable rates of good functional outcomes and relatively low rates of adverse events.

Current State of Evidence for Neuroimaging Paradigms in Management of Acute Ischemic Stroke

Stroke is the chief differential diagnosis in patient presenting to the emergency room with abrupt onset focal neurological deficits. Neuroimaging, including non-contrast computed tomography (CT), magnetic resonance imaging (MRI), vascular and perfusion imaging, is a cornerstone in the diagnosis and treatment decision-making. This review examines the current state of evidence behind the different imaging paradigms for acute ischemic stroke diagnosis and treatment, including current recommendations from the guidelines. Non-contrast CT brain, or in some centers MRI, can help differentiate ischemic stroke and intracerebral hemorrhage (ICH), a pivotal juncture in stroke diagnosis and treatment algorithm, especially for early window thrombolytics. Advanced imaging such as MRI or perfusion imaging can also assist making a diagnosis of ischemic stroke versus mimics such as migraine, Todd's paresis, or functional disorders. Identification of medium-large vessel occlusions with CT or MR angiography triggers consideration of endovascular thrombectomy (EVT), with additional perfusion imaging help identify salvageable brain tissue in patients who are likely to benefit from reperfusion therapies, particularly in the ≥6 h window. We also review recent advances in neuroimaging and ongoing trials in key therapeutic areas and their imaging selection criteria to inform the readers on potential future transitions into use of neuroimaging for stroke diagnosis and treatment decision making. ANN NEUROL 2024;95:1017-1034.

ACR Appropriateness Criteria® Cerebrovascular Diseases-Stroke and Stroke-Related Conditions

Cerebrovascular disease encompasses a vast array of conditions. The imaging recommendations for stroke-related conditions involving noninflammatory steno-occlusive arterial and venous cerebrovascular disease including carotid stenosis, carotid dissection, intracranial large vessel occlusion, and cerebral venous sinus thrombosis are encompassed by this document. Additional imaging recommendations regarding complications of these conditions including intraparenchymal hemorrhage and completed ischemic strokes are also discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Arterial Recanalization During Interhospital Transfer for Thrombectomy

BACKGROUND

Patients with acute ischemic stroke harboring a large vessel occlusion admitted to nonendovascular-capable centers often require interhospital transfer for thrombectomy. We evaluated the incidence and predictors of arterial recanalization during transfer, as well as the relationship between interhospital recanalization and clinical outcomes.

METHODS

We analyzed data from 2 cohorts of patients with an anterior circulation large vessel occlusion transferred for consideration of thrombectomy to a comprehensive center, with arterial imaging at the referring hospital and on comprehensive stroke center arrival. Interhospital recanalization was determined by comparison of the baseline and posttransfer arterial imaging and was defined as revised arterial occlusive lesion (rAOL) score 2b to 3. Pretransfer variables independently associated with interhospital recanalization were studied using multivariable logistic regression analysis.

RESULTS

Of the 520 included patients (Montpellier, France, n=237; Stanford, United States, n=283), 111 (21%) experienced interhospital recanalization (partial [rAOL=2b] in 77% and complete [rAOL=3] in 23%). Pretransfer variables independently associated with recanalization were intravenous thrombolysis (adjusted odds ratio, 6.8 [95% CI, 4.0-11.6]), more distal occlusions (intracranial carotid occlusion as reference: adjusted odds ratio, 2.0 [95% CI, 0.9-4.5] for proximal first segment of the middle cerebral artery, 5.1 [95% CI, 2.3-11.5] for distal first segment of the middle cerebral artery, and 5.0 [95% CI, 2.1-11.8] for second segment of the middle cerebral artery), and smaller clot burden (clot burden score 0-4 as reference: adjusted odds ratio, 3.4 [95% CI, 1.5-7.6] for 5-7 and 5.6 [95% CI, 2.4-12.7] for 8-9). Recanalization on arrival at the comprehensive center was associated with less interhospital infarct growth (rAOL, 0-2a: 11.6 mL; rAOL, 2b: 2.2 mL; rAOL, 3: 0.6 mL; Ptrend<0.001) and greater interhospital National Institutes of Health Stroke Scale score improvement (0 versus -5 versus -6; Ptrend<0.001). Interhospital recanalization was associated with reduced 3-month disability (adjusted common odds ratio, 2.51 [95% CI, 1.68-3.77]) with greater benefit from complete than partial recanalization.

CONCLUSIONS

Recanalization is frequently observed during interhospital transfer for thrombectomy and is strongly associated with favorable outcomes, even when partial. Broadening thrombolysis indications in primary centers, and developing therapies that increase recanalization during transfer, will likely improve clinical outcomes.

Artificial intelligence to predict individualized outcome of acute ischemic stroke patients: The SIBILLA project

INTRODUCTION

Formulating reliable prognosis for ischemic stroke patients remains a challenging task. We aimed to develop an artificial intelligence model able to formulate in the first 24 h after stroke an individualized prognosis in terms of NIHSS.

PATIENTS AND METHODS

Seven hundred ninety four acute ischemic stroke patients were divided into a training (597) and testing (197) cohort. Clinical and instrumental data were collected in the first 24 h. We evaluated the performance of four machine-learning models (Random Forest, K-Nearest Neighbors, Support Vector Machine, XGBoost) in predicting NIHSS at discharge both in terms of variation between discharge and admission (regressor approach) and in terms of severity class namely NIHSS 0-5, 6-10, 11-20, >20 (classifier approach). We used Shapley Additive exPlanations values to weight features impact on predictions.

RESULTS

XGBoost emerged as the best performing model. The classifier and regressor approaches perform similarly in terms of accuracy (80% vs 75%) and f1-score (79% vs 77%) respectively. However, the regressor has higher precision (85% vs 68%) in predicting prognosis of very severe stroke patients (NIHSS > 20). NIHSS at admission and 24 hours, GCS at 24 hours, heart rate, acute ischemic lesion on CT-scan and TICI score were the most impacting features on the prediction.

DISCUSSION

Our approach, which employs an artificial intelligence based-tool, inherently able to continuously learn and improve its performance, could improve care pathway and support stroke physicians in the communication with patients and caregivers.

CONCLUSION

XGBoost reliably predicts individualized outcome in terms of NIHSS at discharge in the first 24 hours after stroke.

Rapid identification and prognosis evaluation by dual-phase computed tomography angiography for stroke patients with a large ischemic region in the anterior circulation treated with endovascular thrombectomy

Purpose

To investigate the value of dual-phase head-and-neck computed tomography angiography (CTA) in assessing advantages and risks associated with mechanical thrombectomy for stroke with a large ischemic region in the anterior circulation within 6 h of onset.

Methods

We retrospectively analyzed the data of patients with acute occlusion of the internal carotid artery or middle cerebral artery-M1 segment. Baseline dual-phase CTA was performed for collateral grading using the 4-point visual collateral score (0, 0% filling; 1, >0% and ≤50% filling; 2, >50 and <100% filling; 3, 100% filling). The rates of modified Rankin score (MRS) ≤ 3 at 90 days, any intracranial hemorrhage (ICH) within 48 h, malignant cerebral edema within 24 h, and all-cause 90-day mortality were analyzed.

Results

Among the 69 study patients, 15, 26, 17, and 11 patients had collateral grades of 0, 1, 2, and 3, respectively. At 90 days, the MRS was ≤3 in 0, 8.33, 29.41, and 36.36% of patients with grades 0, 1, 2, and 3, respectively. ICH incidence was 73.33, 57.69, 29.41, and 18.18% for grades 0, 1, 2, and 3, respectively, while the incidence of malignant brain edema was 100, 76.92, 35.29, and 0%, respectively. All-cause 90-day mortality was 53.33% for grade 0 and 30.77% for grade 1; no deaths occurred at grades 2 and 3.

Conclusion

Collateral grading based on dual-phase CTA enables simple and rapid preoperative evaluation prior to mechanical thrombectomy for acute anterior-circulation stroke with a large ischemic focus, particularly for patients presenting within the 6-h time window.

A systematic review of randomized controlled trials of endovascular therapy for stroke on mortality and disability

BACKGROUND

Endovascular treatment (EVT) has become standard of care for patients with anterior circulation large vessel occlusion (LVO) stroke, with indications having recently expanded to late time-window and large ischemic core patients. There is conflicting evidence on whether EVT reduces mortality or only disability. We performed a meta-analysis of randomized controlled trials (RCTs) to assess the effect of EVT on mortality and severe disability.

METHODS

We systematically searched PubMed, Web of Science, Scopus, and Embase on November 15, 2023, to identify phase 3 RCTs comparing EVT to best medical treatment (BMT) in patients with anterior circulation LVO stroke in a common effects meta-analysis. The primary outcome was mortality at 3 months. Secondary outcomes were moderately severe or severe disability (modified Rankin Scale (mRS) score 4-5) at 3 months.

RESULTS

18 studies comparing EVT to BMT were included, with a total of 4309 patients; 2159 that were treated with EVT, and 2150 treated with BMT. Mortality was significantly lower in the EVT group than in the BMT group (odds ratio (OR): 0.81, 95% CI: 0.70-0.94). Proportions of moderately severe or severe disability (OR: 0.55, 95% CI: 0.48-0.62) were also significantly lower in patients treated with EVT.

CONCLUSIONS

This meta-analysis suggests that EVT reduces both mortality and moderately severe or severe disability in patients with anterior circulation LVO stroke.

2.5-Minute Fast Brain MRI with Multiple Contrasts in Acute Ischemic Stroke

PURPOSE

To assess the performance of a 2.5-minute multi-contrast brain MRI sequence (NeuroMix) in diagnosing acute cerebral infarctions.

METHODS

Adult patients with a clinical suspicion of acute ischemic stroke were retrospectively included. Brain MRI at 3 T included NeuroMix and routine clinical MRI (cMRI) sequences, with DWI/ADC, T2-FLAIR, T2-weighted, T2*, SWI-EPI, and T1-weighted contrasts. Three radiologists (R1-3) independently assessed NeuroMix and cMRI for the presence of acute infarcts (DWI ↑, ADC = or ↓) and infarct-associated abnormalities on other image contrasts. Sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC) were calculated and compared using DeLong's test. Inter- and intra-rater agreements were studied with kappa statistics. Relative DWI (rDWI) and T2-FLAIR (rT2-FLAIR) signal intensity for infarctions were semi-automatically rendered, and the correlation between methods was evaluated.

RESULTS

According to the reference standard, acute infarction was present in 34 out of 44 (77%) patients (63 ± 17 years, 31 men). Other infarct-associated signal abnormalities were reported in similar frequencies on NeuroMix and cMRI (p > .08). Sensitivity for infarction detection was 94%, 100%, and 94% evaluated by R1, R2, R3, for NeuroMix and 94%, 100%, and 100% for cMRI. Specificity was 100%, 90%, and 100% for NeuroMix and 100%, 100%, and 100% for cMRI. AUC for NeuroMix was .97, .95, and .97 and .97, 1, and 1 for cMRI (DeLong p = 1, .32, .15), respectively. Inter- and intra-rater agreement was κ = .88-1. The correlation between NeuroMix and cMRI was R = .73 for rDWI and R = .83 for rT2-FLAIR.

CONCLUSION

Fast multi-contrast MRI NeuroMix has high diagnostic performance for detecting acute cerebral infarctions.

Intravenous thrombolysis for ischemic stroke in the posterior circulation: A systematic review and meta-analysis

OBJECTIVES

Intravenous thrombolysis (IVT) is recommended in patients with ischemic stroke in the anterior and posterior circulation. Neurological outcomes due to posterior circulation strokes (PCS) without treatment remain poor. Our aim was to overview the literature on outcomes of IVT and conservative treatment in PCS, based on a systematic review and meta-analysis.

METHODS

A systematic literature search was performed on February 27th 2023. Outcome measures included favorable functional outcome at 90 days (modified Rankin Scale [mRS] 0-2), mortality at 90 days, and symptomatic intracranial hemorrhages (sICH). Weighted averages with DerSimonian-Laird approach was used to analyze the data. Subgroup analyses by time window were performed: standard time window (<4.5 hours after symptom onset) and extended time window (>4.5 hours). Analyses were performed using R.

RESULTS

Eight prospective and four retrospective cohort studies were included (n = 1589 patients); no studies with conservative treatment were eligible. The pooled weighted probability regarding favorable functional outcome after IVT was 63 % (95 %CI:0.45-0.78), for mortality 19 % (95 %CI:0.11-0.30), and for sICH 4 % (95 %CI:0.02-0.07). Subgroup analyses showed higher probabilities on achieving favorable functional outcomes for patients treated in the standard (77 %; 95 %CI:0.62-0.88) compared to the extended time window (38 %; 95 %CI:0.29-0.48) with RR = 1.93 (95 %CI:1.66-2.24). Lower probabilities regarding mortality at 90 days and sICH were seen in patients treated in standard compared to extended time window (RR = 0.42, 95 %CI:0.34-0.51 and RR = 0.27, 95 %CI:0.16-0.45, respectively).

CONCLUSIONS

IVT in patients with PCS seems to be safe and effective in standard and extended time window. The effect of IVT is higher in the standard time window.

A systematic review and in silico analysis of studies investigating the ischaemic penumbra proteome in animal models of experimental stroke

Ischaemic stroke results in the formation of a cerebral infarction bordered by an ischaemic penumbra. Characterising the proteins within the ischaemic penumbra may identify neuro-protective targets and novel circulating markers to improve patient care. This review assessed data from studies using proteomic platforms to compare ischaemic penumbra tissues to controls following experimental stroke in animal models. Proteins reported to differ significantly between penumbra and control tissues were analysed in silico to identify protein-protein interactions and over-represented pathways. Sixteen studies using rat (n = 12), mouse (n = 2) or primate (n = 2) models were included. Heterogeneity in the design of the studies and definition of the penumbra were observed. Analyses showed high abundance of p53 in the penumbra within 24 hours of permanent ischaemic stroke and was implicated in driving apoptosis, cell cycle progression, and ATM- MAPK- and p53- signalling. Between 1 and 7 days after stroke there were changes in the abundance of proteins involved in the complement and coagulation pathways. Favourable recovery 1 month after stroke was associated with an increase in the abundance of proteins involved in wound healing. Poor recovery was associated with increases in prostaglandin signalling. Findings suggest that p53 may be a target for novel therapeutics for ischaemic stroke.

Fibrinolytic and Non-fibrinolytic Roles of Tissue-type Plasminogen Activator in the Ischemic Brain

The neurovascular unit (NVU) is assembled by endothelial cells (ECs) and pericytes, and encased by a basement membrane (BM) surveilled by microglia and surrounded by perivascular astrocytes (PVA), which in turn are in contact with synapses. Cerebral ischemia induces the rapid release of the serine proteinase tissue-type plasminogen activator (tPA) from endothelial cells, perivascular astrocytes, microglia and neurons. Owning to its ability to catalyze the conversion of plasminogen into plasmin, in the intravascular space tPA functions as a fibrinolytic enzyme. In contrast, the release of astrocytic, microglial and neuronal tPA have a plethora of effects that not always require the generation of plasmin. In the ischemic brain tPA increases the permeability of the NVU, induces microglial activation, participates in the recycling of glutamate, and has various effects on neuronal survival. These effects are mediated by different receptors, notably subunits of the N-methyl-D-aspartate receptor (NMDAR) and the low-density lipoprotein receptor-related protein-1 (LRP-1). Here we review data on the role of tPA in the NVU under non-ischemic and ischemic conditions, and analyze how this knowledge may lead to the development of potential strategies for the treatment of acute ischemic stroke patients.

Tenecteplase for Stroke at 4.5 to 24 Hours with Perfusion-Imaging Selection

BACKGROUND

Thrombolytic agents, including tenecteplase, are generally used within 4.5 hours after the onset of stroke symptoms. Information on whether tenecteplase confers benefit beyond 4.5 hours is limited.

METHODS

We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving patients with ischemic stroke to compare tenecteplase (0.25 mg per kilogram of body weight, up to 25 mg) with placebo administered 4.5 to 24 hours after the time that the patient was last known to be well. Patients had to have evidence of occlusion of the middle cerebral artery or internal carotid artery and salvageable tissue as determined on perfusion imaging. The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death) at day 90. Safety outcomes included death and symptomatic intracranial hemorrhage.

RESULTS

The trial enrolled 458 patients, 77.3% of whom subsequently underwent thrombectomy; 228 patients were assigned to receive tenecteplase, and 230 to receive placebo. The median time between the time the patient was last known to be well and randomization was approximately 12 hours in the tenecteplase group and approximately 13 hours in the placebo group. The median score on the modified Rankin scale at 90 days was 3 in each group. The adjusted common odds ratio for the distribution of scores on the modified Rankin scale at 90 days for tenecteplase as compared with placebo was 1.13 (95% confidence interval, 0.82 to 1.57; P = 0.45). In the safety population, mortality at 90 days was 19.7% in the tenecteplase group and 18.2% in the placebo group, and the incidence of symptomatic intracranial hemorrhage was 3.2% and 2.3%, respectively.

CONCLUSIONS

Tenecteplase therapy that was initiated 4.5 to 24 hours after stroke onset in patients with occlusions of the middle cerebral artery or internal carotid artery, most of whom had undergone endovascular thrombectomy, did not result in better clinical outcomes than those with placebo. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by Genentech; TIMELESS ClinicalTrials.gov number, NCT03785678.).

Safranal acts as a neurorestorative agent in rats with cerebral ischemic stroke via upregulating SIRT1

Safranal is an active ingredient of saffron (Crocus sativus L.). Its neuroprotective role in ischemic stroke (IS) through reducing oxidative stress damage has been widely reported. However, the neurorestorative mechanisms of safranal are still in the preliminary stage of exploration. the present study is aimed to discuss the effects of safranal on the recovery of neural function after IS. A middle cerebral artery occlusion/reperfusion (MCAO/R) rat model and an oxygen-glucose deprivation/reoxygenation (OGD/R) model in rat brain microvascular endothelial cells (RBMEC) were established to explore the effects of safranal on IS in vivo and in vitro. It was found that safranal dramatically reduced infarct size and Nissl's body loss in rats subjected to MCAO/R. Safranal also promoted neuron survival, stimulated neurogenesis, induced angiogenesis and increased SIRT1 expression in vivo and in vitro. Silencing of SIRT1 reversed the above effects of safranal on OGD/R-induced RBMEC. The present study indicated that safranal was a promising compound to exert neurorestorative effect in IS via upregulating SIRT1 expression. These results offer insight into developing new mechanisms in the recovery of neural function after safranal treatment of IS.

CHinese Acute Tissue-Based Imaging Selection for Lysis In Stroke Tenecteplase II (CHABLIS-T II): rationale and design

BACKGROUND AND PURPOSE

Tenecteplase (TNK) has demonstrated non-inferiority to alteplase in patients who had an acute ischaemic stroke presenting within 4.5 hours from symptom onset. The trial is aimed to explore the efficacy and safety of TNK in Chinese patients who had an acute ischaemic stroke with large/medium vessel occlusion in an extended time window.

METHODS AND DESIGN

Chinese Acute Tissue-Based Imaging Selection for Lysis In Stroke Tenecteplase II (CHABLIS-T II) is a multicentre, prospective, block-randomised, open-label, blinded-endpoint, phase IIb study. Eligible patients are 1:1 randomised into two groups: 0.25 mg/kg TNK versus best medical management (excluding TNK). The safety and efficacy of 0.25 mg/kg TNK are assessed through reperfusion status and presence of symptomatic intracranial haemorrhage (sICH).

STUDY OUTCOMES

The primary outcome is major reperfusion without sICH at 24-48 hours after randomisation. Major reperfusion is defined as restoration of blood flow to greater than 50% of the involved ischaemic territory assessed by catheter angiography or repeated perfusion imaging. Secondary outcomes include post-thrombolytic recanalisation, neurological improvements, change in the National Institutes of Health Stroke Scale score, haemorrhagic transformation at 24-48 hours, systematic bleeding at discharge, modified Rankin Scale (mRS) 0-1, mRS 0-2, mRS 5-6, mRS distribution and Barthel index at 90 days.

DISCUSSION

CHABLIS-T II will provide important evidence of intravenous thrombolysis with TNK for patients who had an acute stroke in an extended time window.

Does imaging of the ischemic penumbra have value in acute ischemic stroke with large vessel occlusion?

PURPOSE OF REVIEW

In this review, we summarize current evidence regarding potential benefits and limitations of using perfusion imaging to estimate presence and extent of irreversibly injured ischemic brain tissue ('core') and severely ischemic yet salvageable tissue ('penumbra') in acute stroke patients with large vessel occlusion (LVO).

RECENT FINDINGS

Core and penumbra volumes are strong prognostic biomarkers in LVO patients. Greater benefits of both intravenous thrombolysis and endovascular therapy (EVT) are observed in patients with small core and large penumbra volumes. However, some current definitions of clinically relevant penumbra may be too restrictive and exclude patients who may benefit from reperfusion therapies. Alongside other clinical and radiological factors, penumbral imaging may enhance the discussion regarding the benefit/risk ratio of EVT in common clinical situations, such as patients with large core - for whom EVT's benefit is established but associated with a high rate of severe disability -, or patients with mild symptoms or medium vessel occlusions - for whom EVT's benefit is currently unknown. Beyond penumbral evaluation, perfusion imaging is clinically relevant for optimizing patient's selection for neuroprotection trials.

SUMMARY

In an emerging era of precision medicine, perfusion imaging is a valuable tool in LVO-related acute stroke.

Perioperative stroke

Ischaemic or haemorrhagic perioperative stroke (that is, stroke occurring during or within 30 days following surgery) can be a devastating complication following surgery. Incidence is reported in the 0.1-0.7% range in adults undergoing non-cardiac and non-neurological surgery, in the 1-5% range in patients undergoing cardiac surgery and in the 1-10% range following neurological surgery. However, higher rates have been reported when patients are actively assessed and in high-risk populations. Prognosis is significantly worse than stroke occurring in the community, with double the 30-day mortality, greater disability and diminished quality of life among survivors. Considering the annual volume of surgeries performed worldwide, perioperative stroke represents a substantial burden. Despite notable differences in aetiology, patient populations and clinical settings, existing clinical recommendations for perioperative stroke are extrapolated mainly from stroke in the community. Perioperative in-hospital stroke is unique with respect to the stroke occurring in other settings, and it is essential to apply evidence from other settings with caution and to identify existing knowledge gaps in order to effectively guide patient care and future research.

Determining acute ischemic stroke onset time using machine learning and radiomics features of infarct lesions and whole brain

Accurate determination of the onset time in acute ischemic stroke (AIS) patients helps to formulate more beneficial treatment plans and plays a vital role in the recovery of patients. Considering that the whole brain may contain some critical information, we combined the Radiomics features of infarct lesions and whole brain to improve the prediction accuracy. First, the radiomics features of infarct lesions and whole brain were separately calculated using apparent diffusion coefficient (ADC), diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) sequences of AIS patients with clear onset time. Then, the least absolute shrinkage and selection operator (Lasso) was used to select features. Four experimental groups were generated according to combination strategies: Features in infarct lesions (IL), features in whole brain (WB), direct combination of them (IW) and Lasso selection again after direct combination (IWS), which were used to evaluate the predictive performance. The results of ten-fold cross-validation showed that IWS achieved the best AUC of 0.904, which improved by 13.5% compared with IL (0.769), by 18.7% compared with WB (0.717) and 4.2% compared with IW (0.862). In conclusion, combining infarct lesions and whole brain features from multiple sequences can further improve the accuracy of AIS onset time.

Factors influencing the reliability of a CT angiography-based deep learning method for infarct volume estimation

Objectives

CT angiography (CTA)-based machine learning methods for infarct volume estimation have shown a tendency to overestimate infarct core and final infarct volumes (FIV). Our aim was to assess factors influencing the reliability of these methods.

Methods

The effect of collateral circulation on the correlation between convolutional neural network (CNN) estimations and FIV was assessed based on the Miteff system and hypoperfusion intensity ratio (HIR) in 121 patients with anterior circulation acute ischaemic stroke using Pearson correlation coefficients and median volumes. Correlation was also assessed between successful and futile thrombectomies. The timing of individual CTAs in relation to CTP studies was analysed.

Results

The strength of correlation between CNN estimated volumes and FIV did not change significantly depending on collateral status as assessed with the Miteff system or HIR, being poor to moderate (r = 0.09-0.50). The strongest correlation was found in patients with futile thrombectomies (r = 0.61). Median CNN estimates showed a trend for overestimation compared to FIVs. CTA was acquired in the mid arterial phase in virtually all patients (120/121).

Conclusions

This study showed no effect of collateral status on the reliability of the CNN and best correlation was found in patients with futile thrombectomies. CTA timing in the mid arterial phase in virtually all patients can explain infarct volume overestimation.

Advances in knowledge

CTA timing seems to be the most important factor influencing the reliability of current CTA-based machine learning methods, emphasizing the need for CTA protocol optimization for infarct core estimation.

Ultrasound biomicroscopy in the quantification of brain perfusion parameters of a rat stroke model: Analysis of contrast agent bolus kinetic dynamics

BACKGROUND

Ischemic stroke represents a significant global health concern, necessitating thorough investigations and the utilization of stroke animal models to explore novel treatment modalities and diagnostic imaging techniques.

NEW METHOD

Ultrasound biomicroscopy (BMU), operating at a center frequency of 21 MHz, along with ultrasound contrast agents (UCAs), was used to quantify microcirculation cerebral blood flow in a rat model of ischemic stroke. The microcirculation parameters were derived from time intensity curve (TIC) plots obtained based on UCA-bolus kinetics.

RESULTS

Semiquantitative perfusion-related parameters were assessed. The TIC curves showed differences in amplitude when compared intra-animal between the left and right sides, and three situations were observed: normal perfusion, hypoperfusion, and nonperfusion. ROC analysis of delays between the left and right time intensity peak (TIP) for regions of interest (ROIs) in the control and stroke-hypoperfusion groups revealed an optimal cutpoint of 0.39 s to indicate when hypoperfusion is occurring in rats, with a sensitivity of 93.33 % and a specificity of 80 %.

COMPARISON WITH EXISTING METHOD(S)

Ultrasound perfusion imaging through the temporal bone window has been clinically applied to stroke patients using a UCA bolus for TIC analysis. TIC parameters were correlated with MRI- and CT-based measurements.

CONCLUSIONS

This investigation quantified cerebral blood flow in a rat model of ischemic stroke by measuring microcirculation parameters. The study demonstrated the efficacy of this approach as a valuable tool for conducting preclinical studies.

Prevalence of stroke-related risk factors in Albania: a single-center experience

Introduction

Stroke, a prominent global cause of mortality and disability, is broadly categorized into ischemic and hemorrhagic types. An epidemiological survey of stroke and its risk factors can help identify individuals at higher risk and therefore promote stroke prevention strategies. The aim of this study was to estimate the current prevalence of stroke and evaluate stroke-associated risk factors in Albania.

Material and methods

This was a single-center retrospective analysis conducted in Albania for the period from May 2015 to September 2021. Data were collected retrospectively through hospital records. Stroke was defined as sudden onset of a nonconvulsive and focal neurological deficit, and ischemic stroke was diagnosed using brain computed tomography (CT), magnetic resonance (MR) imaging, or both. We examined patient history characteristics encompassing demographics, stroke history, conventional vascular risk factors, and lifestyle-related risk factors.

Results

The mean age of the 3860 patients was 74.6 ±10.4 years, and 73.5% were men. The prevalence of carotid stenosis, arrhythmia, obesity, and hypertension was significantly higher in males than in females (p < 0.001). Out of the 3860 patients in the study cohort, 641 (16.6%) subjects died, while 335 (8.7%) patients achieved complete recovery. Hemiparesis was observed in 386 (10%) patients and hemiplegia in 868 (22.4%) patients.

Conclusions

Our analysis underscores the male predominance (2.2 : 1) in stroke cases. Carotid and vertebral artery stenosis is a significant factor, emphasizing the life-saving potential of early intervention. Social and economic factors in Albania pose challenges, demanding comprehensive strategies. Prospective trials are crucial to explore intervention efficacy, and timing, and address socioeconomic impacts on timely stroke management.

Computed tomography hypoperfusion-hypodensity mismatch vs. automated perfusion mismatch to identify stroke patients eligible for thrombolysis

Background and purpose

Automated perfusion imaging can detect stroke patients with unknown time of symptom onset who are eligible for thrombolysis. However, the availability of this technique is limited. We, therefore, established the novel concept of computed tomography (CT) hypoperfusion-hypodensity mismatch, i.e., an ischemic core lesion visible on cerebral perfusion CT without visible hypodensity in the corresponding native cerebral CT. We compared both methods regarding their accuracy in identifying patients suitable for thrombolysis.

Methods

In a retrospective analysis of the MissPerfeCT observational cohort study, patients were classified as suitable or not for thrombolysis based on established time window and imaging criteria. We calculated predictive values for hypoperfusion-hypodensity mismatch and automated perfusion imaging to compare accuracy in the identification of patients suitable for thrombolysis.

Results

Of 247 patients, 219 (88.7%) were eligible for thrombolysis and 28 (11.3%) were not eligible for thrombolysis. Of 197 patients who were within 4.5 h of symptom onset, 190 (96.4%) were identified by hypoperfusion-hypodensity mismatch and 88 (44.7%) by automated perfusion mismatch (p < 0.001). Of 22 patients who were beyond 4.5 h of symptom onset but were eligible for thrombolysis, 5 patients (22.7%) were identified by hypoperfusion-hypodensity mismatch. Predictive values for the hypoperfusion-hypodensity mismatch vs. automated perfusion mismatch were as follows: sensitivity, 89.0% vs. 50.2%; specificity, 71.4% vs. 100.0%; positive predictive value, 96.1% vs. 100.0%; and negative predictive value, 45.5% vs. 20.4%.

Conclusion

The novel method of hypoperfusion-hypodensity mismatch can identify patients suitable for thrombolysis with higher sensitivity and lower specificity than established techniques. Using this simple method might therefore increase the proportion of patients treated with thrombolysis without the use of special automated software.The MissPerfeCT study is a retrospective observational multicenter cohort study and is registered with clinicaltrials.gov (NCT04277728).

Definition, prediction, prevention and management of patients with severe ischemic stroke and large infarction

ABSTRACT

Severe ischemic stroke carries a high rate of disability and death. The severity of stroke is often assessed by the degree of neurological deficits or the extent of brain infarct, defined as severe stroke and large infarction, respectively. Critically severe stroke is a life-threatening condition that requires neurocritical care or neurosurgical intervention, which includes stroke with malignant brain edema, a leading cause of death during the acute phase, and stroke with severe complications of other vital systems. Early prediction of high-risk patients with critically severe stroke would inform early prevention and treatment to interrupt the malignant course to fatal status. Selected patients with severe stroke could benefit from intravenous thrombolysis and endovascular treatment in improving functional outcome. There is insufficient evidence to inform dual antiplatelet therapy and the timing of anticoagulation initiation after severe stroke. Decompressive hemicraniectomy (DHC) <48 h improves survival in patients aged <60 years with large hemispheric infarction. Studies are ongoing to provide evidence to inform more precise prediction of malignant brain edema, optimal indications for acute reperfusion therapies and neurosurgery, and the individualized management of complications and secondary prevention. We present an evidence-based review for severe ischemic stroke, with the aims of proposing operational definitions, emphasizing the importance of early prediction and prevention of the evolution to critically severe status, summarizing specialized treatment for severe stroke, and proposing directions for future research.

Management of acute ischemic stroke

Ischemic stroke is a serious neurological condition that requires urgent attention. As a time-dependent disease, acute stroke management must be coordinated and effective to provide the best treatment as early as possible. The treatment of the acute phase of ischemic stroke includes general measures to ensure patient hemodynamic stability, the use of reperfusion therapies (intravenous thrombolytics and mechanical thrombectomy), improving cerebral protection by monitoring the homeostasis of certain variables as blood pressure, glycemia, temperature, or oxygenation, as well as preventing cerebral and systemic complications. Also, it is necessary an early planning of comprehensive rehabilitation. To prevent early recurrences, control of vascular risk factors and antithrombotic treatment is recommended. The management of patients with acute ischemic stroke aims to reverse initial symptoms, to prevent further brain damage, improve functional outcomes and avoid ischemic recurrences.

Automated advanced imaging in acute ischemic stroke. Certainties and uncertainties

The purpose of this is study was to review pearls and pitfalls of advanced imaging, such as computed tomography perfusion and diffusion-weighed imaging and perfusion-weighted imaging in the selection of acute ischemic stroke (AIS) patients suitable for endovascular treatment (EVT) in the late time window (6-24 h from symptom onset). Advanced imaging can quantify infarct core and ischemic penumbra using specific threshold values and provides optimal selection parameters, collectively called target mismatch. More precisely, target mismatch criteria consist of core volume and/or penumbra volume and mismatch ratio (the ratio between total hypoperfusion and core volumes) with precise cut-off values. The parameters of target mismatch are automatically calculated with dedicated software packages that allow a quick and standardized interpretation of advanced imaging. However, this approach has several limitations leading to a misclassification of core and penumbra volumes. In fact, automatic software platforms are affected by technical artifacts and are not interchangeable due to a remarkable vendor-dependent variability, resulting in different estimate of target mismatch parameters. In addition, advanced imaging is not completely accurate in detecting infarct core, that can be under- or overestimated. Finally, the selection of candidates for EVT remains currently suboptimal due to the high rates of futile reperfusion and overselection caused by the use of very stringent inclusion criteria. For these reasons, some investigators recently proposed to replace advanced with conventional imaging in the selection for EVT, after the demonstration that non-contrast CT ASPECTS and computed tomography angiography collateral evaluation are not inferior to advanced images in predicting outcome in AIS patients treated with EVT. However, other authors confirmed that CTP and PWI/DWI postprocessed images are superior to conventional imaging in establishing the eligibility of patients for EVT. Therefore, the routine application of automatic assessment of advanced imaging remains a matter of debate. Recent findings suggest that the combination of conventional and advanced imaging might improving our selection criteria.

Speech-language pathologists' perspectives of dysphagia following reperfusion therapies: An Australian mixed-methods study

PURPOSE

To investigate speech-language pathologists' (SLPs) perceptions and clinical experiences of dysphagia management following reperfusion therapies.

METHOD

A multi-staged mixed approach involving a two-phase cross-sectional design was used. Data generated during phase 1 (a purpose-built, online survey) guided the development of phase 2 (semi-structured interviews). Sixty-two SLPs participated in phase 1 and six SLPs participated in phase 2.

RESULT

SLPs in both phases reported perceived changes in dysphagia presentation according to the success of reperfusion therapy administered and had concerns regarding worsened dysphagia following unsuccessful procedures. Fluctuations in dysphagia were more frequently reported in the acute stage post-stroke. SLPs reported increased workload demands due to increased interhospital transfers between ECR/thrombolysis centres and referring facilities. The optimal timing for swallowing screening and assessment was not identified, with initial SLP involvement ranging from during the administration of thrombolysis to up to 24 hours post-reperfusion therapy.

CONCLUSION

Preliminary evidence suggests that SLPs perceive that the presentation of post-stroke dysphagia is changing, with increasing fluctuations and complexities in the acute stage of post-stroke care, within the context of increasing use of reperfusion therapies. There is a critical need for research investigating the trajectory of dysphagia in the acute stage to inform dysphagia management within this patient population.

Pragmatic solutions to reduce the global burden of stroke: a World Stroke Organization-Lancet Neurology Commission

Stroke is the second leading cause of death worldwide. The burden of disability after a stroke is also large, and is increasing at a faster pace in low-income and middle-income countries than in high-income countries. Alarmingly, the incidence of stroke is increasing in young and middle-aged people (ie, age <55 years) globally. Should these trends continue, Sustainable Development Goal 3.4 (reducing the burden of stroke as part of the general target to reduce the burden of non-communicable diseases by a third by 2030) will not be met.

In this Commission, we forecast the burden of stroke from 2020 to 2050. We project that stroke mortality will increase by 50%—from 6·6 million (95% uncertainty interval [UI] 6·0 million–7·1 million) in 2020, to 9·7 million (8·0 million–11·6 million) in 2050—with disability-adjusted life-years (DALYs) growing over the same period from 144·8 million (133·9 million–156·9 million) in 2020, to 189·3 million (161·8 million–224·9 million) in 2050. These projections prompted us to do a situational analysis across the four pillars of the stroke quadrangle: surveillance, prevention, acute care, and rehabilitation. We have also identified the barriers to, and facilitators for, the achievement of these four pillars. Disability-adjusted life-years (DALYs) The sum of the years of life lost as a result of premature mortality from a disease and the years lived with a disability associated with prevalent cases of the disease in a population. One DALY represents the loss of the equivalent of one year of full health

On the basis of our assessment, we have identified and prioritised several recommendations. For each of the four pillars (surveillance, prevention, acute care, and rehabilitation), we propose pragmatic solutions for the implementation of evidence-based interventions to reduce the global burden of stroke. The estimated direct (ie, treatment and rehabilitation) and indirect (considering productivity loss) costs of stroke globally are in excess of US$891 billion annually. The pragmatic solutions we put forwards for urgent implementation should help to mitigate these losses, reduce the global burden of stroke, and contribute to achievement of Sustainable Development Goal 3.4, the WHO Intersectoral Global Action Plan on epilepsy and other neurological disorders (2022–2031), and the WHO Global Action Plan for prevention and control of non-communicable diseases.

Reduction of the global burden of stroke, particularly in low-income and middle-income countries, by implementing primary and secondary stroke prevention strategies and evidence-based acute care and rehabilitation services is urgently required. Measures to facilitate this goal include: the establishment of a framework to monitor and assess the burden of stroke (and its risk factors) and stroke services at a national level; the implementation of integrated population-level and individual-level prevention strategies for people at any increased risk of cerebrovascular disease, with emphasis on early detection and control of hypertension; planning and delivery of acute stroke care services, including the establishment of stroke units with access to reperfusion therapies for ischaemic stroke and workforce training and capacity building (and monitoring of quality indicators for these services nationally, regionally, and globally); the promotion of interdisciplinary stroke care services, training for caregivers, and capacity building for community health workers and other health-care providers working in stroke rehabilitation; and the creation of a stroke advocacy and implementation ecosystem that includes all relevant communities, organisations, and stakeholders.

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The efficacy and safety of general anesthesia vs. conscious sedation for endovascular treatment in patients with acute ischemic stroke: a systematic review and meta-analysis

Background

Endovascular thrombectomy (EVT) is an important treatment for patients with acute ischemic stroke (AIS). A number of studies have suggested that anesthesia type (conscious sedation vs. general anesthesia) during intra-arterial treatment for acute ischemic stroke has implications for patient outcomes.

Methods

PubMed, EMBASE, Cochrane Library and clinicaltrials.gov were searched for randomized controlled trials (RCTs) that were performed to evaluate general anesthesia (GA) and conscious sedation (CS) up to May 30, 2023. Review Manager 5.3 software was used to assess the data. The risk ratio (RR) and mean difference (MD) were analyzed and calculated with a fixed effect model.

Results

We pooled 930 patients from seven RCTs. We conducted a meta-analysis comparing the outcomes of GA and CS in the included trials. The rate of functional independence in the GA group was higher than that in the CS group (RR: 1.17, 95% CI: 1.00-1.35; P = 0.04; I2 = 16%). The GA group had a higher successful recanalization rate than the CS group (RR: 1.15, 95% CI: 1.08-1.22; P < 0.0001; I2 = 26%). The GA group had a higher pneumonia rate than the CS group (RR: 1.69, 95% CI: 1.22-2.34; P = 0.002; I2 = 26%). In addition, there was no significant difference between GA and CS with respect to the National Institutes of Health Stroke Scale (NIHSS) score at 24 h (P = 0.62), Modified Rankin Scale (mRS) score at 90 days (P = 0.25), intracerebral hemorrhage (P = 0.54), and mortality at 3 months (P = 0.61).

Conclusion

GA demonstrated superiority over CS in achieving successful recanalization and functional independence at 3 months when performing EVT in AIS patients. However, it was also associated with a higher risk of pneumonia. Further studies, particularly those with long-term follow-ups, are necessary to identify precise strategies for selecting the appropriate anesthetic modality in EVT patients.

Systematic review registration

INPLASY202370116.