Eligibility for Intravenous Recombinant Tissue-Type Plasminogen Activator Within a Population: The Effect of the European Cooperative Acute Stroke Study (ECASS) III Trial

A Randomized Controlled Trial of Tenecteplase Versus Standard of Care for Minor Ischemic Stroke with Proven Occlusion (TEMPO-2): Rational and design of a multicenter, randomized open-label clinical trial

BACKGROUND

Almost half of acute ischemic stroke patients present with mild symptoms and there are large practice variations in their treatment globally. Individuals with an intracranial occlusion who present with minor stroke are at an increased risk of early neurological deterioration and poor outcomes. Individual patient data meta-analysis in the subgroup of patients with minor deficits showed benefit of alteplase in improving outcomes; however, this benefit has not been seen with intravenous alteplase in published randomized trials.

DESIGN

TEMPO-2 (A Randomized Controlled Trial of Tenecteplase Versus Standard of Care for Minor Ischemic Stroke With Proven Occlusion) is a prospective, open label with blinded outcome assessment, randomized controlled trial, designed to test the superiority of intravenous tenecteplase (0.25 mg/kg) over nonthrombolytic standard of care, with an estimated sample size of 1274 patients. Adult patients presenting with acute ischemic stroke with the National Institutes of Health Stroke Scale (NIHSS) ⩽ 5 and visible arterial occlusion or perfusion deficit within 12 h of onset are randomized to receive either tenecteplase (0.25 mg/kg) or standard of care. The primary outcome is return to baseline neurological functioning, measured by the modified Rankin scale (mRS) at 90 days. Safety outcomes include death and symptomatic hemorrhage (intra or extra-cranial). Other secondary outcomes include mRS 0-1, mRS 0-2, ordinal shift analysis of the mRS, partial, and full recanalization on follow-up computed tomography angiogram.

CONCLUSION

Results of this trial will aid in determining whether there is benefit of using tenecteplase (0.25 mg/kg) in treating patients presenting with minor stroke who are at high risk of developing poor outcomes due to presence of an intracranial occlusion.

DATA ACCESS STATEMENT

Data will be available upon reasonable request.

MRI-based microthrombi detection in stroke with polydopamine iron oxide

In acute ischemic stroke, even when successful recanalization is obtained, downstream microcirculation may still be obstructed by microvascular thrombosis, which is associated with compromised brain reperfusion and cognitive decline. Identifying these microthrombi through non-invasive methods remains challenging. We developed the PHySIOMIC (Polydopamine Hybridized Self-assembled Iron Oxide Mussel Inspired Clusters), a MRI-based contrast agent that unmasks these microthrombi. In a mouse model of thromboembolic ischemic stroke, our findings demonstrate that the PHySIOMIC generate a distinct hypointense signal on T2*-weighted MRI in the presence of microthrombi, that correlates with the lesion areas observed 24 hours post-stroke. Our microfluidic studies reveal the role of fibrinogen in the protein corona for the thrombosis targeting properties. Finally, we observe the biodegradation and biocompatibility of these particles. This work demonstrates that the PHySIOMIC particles offer an innovative and valuable tool for non-invasive in vivo diagnosis and monitoring of microthrombi, using MRI during ischemic stroke.

Racial Disparities in Blood Pressure at Time of Acute Ischemic Stroke Presentation: A Population Study

BACKGROUND

Hypertension is a stroke risk factor with known disparities in prevalence and management between Black and White patients. We sought to identify if racial differences in presenting blood pressure (BP) during acute ischemic stroke exist.

METHODS AND RESULTS

Adults with acute ischemic stroke presenting to an emergency department within 24 hours of last known normal during study epochs 2005, 2010, and 2015 within the Greater Cincinnati/Northern Kentucky Stroke Study were included. Demographics, histories, arrival BP, National Institutes of Health Stroke Scale score, and time from last known normal were collected. Multivariable linear regression was used to determine differences in mean BP between Black and White patients, adjusting for age, sex, National Institutes of Health Stroke Scale score, history of hypertension, hyperlipidemia, smoking, stroke, body mass index, and study epoch. Of 4048 patients, 853 Black and 3195 White patients were included. In adjusted analysis, Black patients had higher presenting systolic BP (161 mm Hg [95% CI, 159-164] versus 158 mm Hg [95% CI, 157-159], P<0.01), diastolic BP (86 mm Hg [95% CI, 85-88] versus 83 mm Hg [95% CI, 82-84], P<0.01), and mean arterial pressure (111 mm Hg [95% CI, 110-113] versus 108 mm Hg [95% CI, 107-109], P<0.01) compared with White patients. In adjusted subanalysis of patients <4.5 hours from last known normal, diastolic BP (88 mm Hg [95% CI, 86-90] versus 83 mm Hg [95% CI, 82-84], P<0.01) and mean arterial pressure (112 mm Hg [95% CI, 110-114] versus 108 mm Hg [95% CI, 107-109], P<0.01) were also higher in Black patients.

CONCLUSIONS

This population-based study suggests differences in presenting BP between Black and White patients during acute ischemic stroke. Further study is needed to determine whether these differences influence clinical decision-making, outcome, or clinical trial eligibility.

An Ultrasmall Cu/Cu2O Nanoparticle-Based Diselenide-Bridged Nanoplatform Mediating Reactive Oxygen Species Scavenging and Neuronal Membrane Enhancement for Targeted Therapy of Ischemic Stroke

Ischemic stroke is one of the major causes of death and disability worldwide, and an effective and timely treatment of ischemic stroke has been a challenge because of the narrow therapeutic window and the poor affinity with thrombus of the thrombolytic agent. In this study, rPZDCu, a multifunctional nanoparticle (NP) with the effects of thrombolysis, reactive oxygen species (ROS) scavenging, and neuroprotection, was synthesized based on an ultrasmall Cu4.6O NP, the thrombolytic agent rt-PA, and docosahexaenoic acid (DHA), which is a major component of the neuronal membrane. rPZDCu showed strong thrombus-targeting ability, which was achieved by the platelet cell membrane coating on the NP surface, and a good thrombolytic effect in both the common carotid artery clot model and embolic middle cerebral artery occlusion (MCAO) model of rats. Furthermore, rPZDCu exhibited a good escape from the phagocytosis of macrophages, effective promotion of the polarization of microglia, and efficient recovery of neurobiological and behavioral functions in the embolic MCAO model of rats. This is a heuristic report of (1) the Cu0/Cu+ NP for the treatments of brain diseases, (2) the integration of DHA and ROS scavengers for central nervous system therapies, and (3) diselenide-based ROS-responsive NPs for ischemic stroke treatments. This study also offers an example of cell membrane-camouflaged stimuli-responsive nanomedicine for brain-targeting drug delivery.

Neuroprotection during Thrombectomy for Acute Ischemic Stroke: A Review of Future Therapies

Stroke is a major cause of death and disability worldwide. Endovascular thrombectomy has been impactful in decreasing mortality. However, many clinical results continue to show suboptimal functional outcomes despite high recanalization rates. This gap in recanalization and symptomatic improvement suggests a need for adjunctive therapies in post-thrombectomy care. With greater insight into ischemia-reperfusion injury, recent preclinical testing of neuroprotective agents has shifted towards preventing oxidative stress through upregulation of antioxidants and downstream effectors, with positive results. Advances in multiple neuroprotective therapies, including uric acid, activated protein C, nerinetide, otaplimastat, imatinib, verapamil, butylphthalide, edaravone, nelonemdaz, ApTOLL, regional hypothermia, remote ischemic conditioning, normobaric oxygen, and especially nuclear factor erythroid 2-related factor 2, have promising evidence for improving stroke care. Sedation and blood pressure management in endovascular thrombectomy also play crucial roles in improved stroke outcomes. A hand-in-hand approach with both endovascular therapy and neuroprotection may be the key to targeting disability due to stroke.

Association of the Stroke Ready Community-Based Participatory Research Intervention With Incidence of Acute Stroke Thrombolysis in Flint, Michigan

Importance

Acute stroke treatment rates in the US lag behind those in other high-income nations.

Objective

To assess whether a hospital emergency department (ED) and community intervention was associated with an increased proportion of patients with stroke receiving thrombolysis.

Design, Setting, and Participants

This nonrandomized controlled trial of the Stroke Ready intervention took place in Flint, Michigan, from October 2017 to March 2020. Participants included adults living in the community. Data analysis was completed from July 2022 to May 2023.

Intervention

Stroke Ready combined implementation science and community-based participatory research approaches. Acute stroke care was optimized in a safety-net ED, and then a community-wide, theory-based health behavior intervention, including peer-led workshops, mailers, and social media, was conducted.

Main Outcomes and Measures

The prespecified primary outcome was the proportion of patients hospitalized with ischemic stroke or transient ischemic attack from Flint who received thrombolysis before and after the intervention. The association between thrombolysis and the Stroke Ready combined intervention, including the ED and community components, was estimated using logistic regression models, clustering at the hospital level and adjusting for time and stroke type. In prespecified secondary analyses, the ED and community intervention were explored separately, adjusting for hospital, time, and stroke type.

Results

In total, 5970 people received in-person stroke preparedness workshops, corresponding to 9.7% of the adult population in Flint. There were 3327 ischemic stroke and TIA visits (1848 women [55.6%]; 1747 Black individuals [52.5%]; mean [SD] age, 67.8 [14.5] years) among patients from Flint seen in the relevant EDs, including 2305 in the preintervention period from July 2010 to September 2017 and 1022 in the postintervention period from October 2017 to March 2020. The proportion of thrombolysis usage increased from 4% in 2010 to 14% in 2020. The combined Stroke Ready intervention was not associated with thrombolysis use (adjusted odds ratio [OR], 1.13; 95% CI, 0.74-1.70; P = .58). The ED component was associated with an increase in thrombolysis use (adjusted OR, 1.63; 95% CI, 1.04-2.56; P = .03), but the community component was not (adjusted OR, 0.99; 95% CI, 0.96-1.01; P = .30).

Conclusions and Relevance

This nonrandomized controlled trial found that a multilevel ED and community stroke preparedness intervention was not associated with increased thrombolysis treatments. The ED intervention was associated with increased thrombolysis usage, suggesting that implementation strategies in partnership with safety-net hospitals may increase thrombolysis usage.

Trial Registration

ClinicalTrials.gov Identifier: NCT036455900.

Increased fatty acid metabolism and decreased glycolysis are hallmarks of metabolic reprogramming within microglia in degenerating white matter during recovery from experimental stroke

The goal of this study was to evaluate changes in metabolic homeostasis during the first 12 weeks of recovery in a distal middle cerebral artery occlusion mouse model of stroke. To achieve this goal, we compared the brain metabolomes of ipsilateral and contralateral hemispheres from aged male mice up to 12 weeks after stroke to that of age-matched naïve and sham mice. There were 707 biochemicals detected in each sample by liquid chromatography-mass spectroscopy (LC-MS). Mitochondrial fatty acid β-oxidation, indicated by acyl carnitine levels, was increased in stroked tissue at 1 day and 4 weeks following stroke. Glucose and several glycolytic intermediates were elevated in the ipsilateral hemisphere for 12 weeks compared to the aged naïve controls, but pyruvate was decreased. Additionally, itaconate, a glycolysis inhibitor associated with activation of anti-inflammatory mechanisms in myeloid cells, was higher in the same comparisons. Spatial transcriptomics and RNA in situ hybridization localized these alterations to microglia within the area of axonal degeneration. These results indicate that chronic metabolic differences exist between stroked and control brains, including alterations in fatty acid metabolism and glycolysis within microglia in areas of degenerating white matter for at least 12 weeks after stroke.

Thromboinflammatory challenges in stroke pathophysiology

Despite years of encouraging translational research, ischemic stroke still remains as one of the highest unmet medical needs nowadays, causing a tremendous burden to health care systems worldwide. Following an ischemic insult, a complex signaling pathway emerges leading to highly interconnected thrombotic as well as neuroinflammatory signatures, the so-called thromboinflammatory cascade. Here, we thoroughly review the cell-specific and time-dependent role of different immune cell types, i.e., neutrophils, macrophages, T and B cells, as key thromboinflammatory mediators modulating the neuroinflammatory response upon stroke. Similarly, the relevance of platelets and their tight crosstalk with a variety of immune cells highlights the relevance of this cell-cell interaction during microvascular dysfunction, neovascularization, and cellular adhesion. Ultimately, we provide an up-to-date overview of therapeutic approaches mechanistically targeting thromboinflammation currently under clinical translation, especially focusing on phase I to III clinical trials.

Elevated NT-proBNP predicts unfavorable outcomes in patients with acute ischemic stroke after thrombolytic therapy

OBJECTIVE

Few studies correlated n-terminal pro-brain natriuretic peptide (NT-proBNP) with early neurological deterioration (END) and prognosis of acute ischaemic stroke (AIS) patients with rt-PA intravenous thrombolysis. Therefore this study aimed to investigate the relationship between NT-proBNP and END, and prognosis after intravenous thrombolysis in patients with AIS.

METHODS

A total of 325 patients with AIS were enrolled. We performed the natural logarithm transformation on the NT-proBNP [ln(NT-proBNP)]. Univariate and multivariate logistic regression analyses were performed to assess the relationship between ln(NT-proBNP) and END, and prognosis and receiver operating characteristic (ROC) curves were used to show the sensitivity and specificity of NT-proBNP.

RESULTS

After thrombolysis, among 325 patients with AIS, 43 patients (13.2%) developed END. In addition, three months follow-up showed a poor prognosis in 98 cases (30.2%) and a good prognosis in 227 cases (69.8%). Multivariate logistic regression analysis showed that ln(NT-proBNP) was an independent risk factor for END (OR = 1.450,95%CI:1.072 ~ 1.963, P = 0.016) and poor prognosis at three months follow-up (OR = 1.767, 95%CI: 1.347 ~ 2.317, P < 0.001) respectively. According to ROC curve analysis, ln(NT-proBNP) (AUC 0.735, 95%CI: 0.674 ~0.796, P < 0.001) had a good predictive value for poor prognosis, with a predictive value of 5.12 and sensitivity and specificity of 79.59% and 60.35% respectively. When combined with NIHSS to predict END(AUC 0.718, 95%CI: 0.631 ~ 0.805, P < 0.001) and poor prognosis(AUC 0.780, 95%CI: 0.724 ~ 0.836, P < 0.001), the predictive value of the model is further improved.

CONCLUSION

NT-proBNP is independently associated with END and poor prognosis in patients with AIS following intravenous thrombolysis and has a particular predictive value for END and poor prognosis.

Prothymosin α Plays Role as a Brain Guardian through Ecto-F1 ATPase-P2Y12 Complex and TLR4/MD2

Prothymosin alpha (ProTα) was discovered to be a necrosis inhibitor from the conditioned medium of a primary culture of rat cortical neurons under starved conditions. This protein carries out a neuronal cell-death-mode switch from necrosis to apoptosis, which is, in turn, suppressed by a variety of neurotrophic factors (NTFs). This type of NTF-assisted survival action of ProTα is reproduced in cerebral and retinal ischemia-reperfusion models. Further studies that used a retinal ischemia-reperfusion model revealed that ProTα protects retinal cells via ecto-F₁ ATPase coupled with the G_i-coupled P2Y₁₂ receptor and Toll-like receptor 4 (TLR4)/MD2 coupled with a Toll-IL-1 receptor domain-containing adaptor inducing IFN-β (TRIF). In cerebral ischemia-reperfusion models, ProTα has additional survival mechanisms via an inhibition of matrix metalloproteases in microglia and vascular endothelial cells. Heterozygous or conditional ProTα knockout mice show phenotypes of anxiety, memory learning impairment, and a loss of neurogenesis. There are many reports that ProTα has multiple intracellular functions for cell survival and proliferation through a variety of protein-protein interactions. Overall, it is suggested that ProTα plays a key role as a brain guardian against ischemia stress through a cell-death-mode switch assisted by NTFs and a role of neurogenesis.

Prothymosin α-derived hexapeptide prevents the brain damage and sequelae due to ischemia-hemorrhage

ProTα discovered as a necrosis-inhibitor from the conditioned medium of cortical culture also shows a potent survival action in brain and retinal ischemia/reperfusion models. The proposed mechanisms are the initial cell death mode switch from necrosis to apoptosis, which is subsequently inhibited by neurotrophic factors in vivo. It should be noted that ProTα and its derived hexapeptide P6Q completely suppress the cerebral hemorrhage induced by late tPA treatment (4.5 h) after the brain ischemia/reperfusion. Mechanisms underlying their beneficial actions may be related to the fact that ProTα inhibits the production of matrix metalloproteases (MMPs) in microglia and vascular endothelial cells. However, as P6Q inhibits MMPs in vascular endothelial cells, but not in microglia, the suppression of MMP production in endothelial cells seems to play major roles in the late tPA-induced hemorrhage. Although the tPA-treatments could enable the survival of patients with stroke, the post-stroke sequelae are the next clinical issues to be solved. The use of small peptide P6Q revealed the blockade of post-stroke pain, depression and memory-learning deficits in animal models. Furthermore, recent studies also showed that P6Q supplementation increased the viability of human induced pluripotent stem (iPS) cell-derived retinal pigment epithelium cell suspensions during the storage and P6Q attenuated the cisplatin-induced acute kidney injury.

Non-coding RNAs in stroke pathology, diagnostics, and therapeutics

Ischemic stroke is a leading cause of death and disability worldwide. Methods to alleviate functional deficits after ischemic stroke focus on restoration of cerebral blood flow to the affected area. However, pharmacological or surgical methods such as thrombolysis and thrombectomy have a narrow effective window. Harnessing and manipulating neurochemical processes of recovery may provide an alternative to these methods. Recently, non-coding RNA (ncRNA) have been increasingly investigated for their contributions to the pathology of diseases and potential for diagnostic and therapeutic applications. Here we will review several ncRNA - H19, MALAT1, ANRIL, NEAT1, pseudogenes, small nucleolar RNA, piwi-interacting RNA and circular RNA - and their involvement in stroke pathology. We also examine these ncRNA as potential diagnostic biomarkers, particularly in circulating blood, and as targets for therapeutic interventions. An important aspect of this is a discussion of potential methods of treatment delivery to allow for targeting of interventions past the blood-brain barrier, including lipid nanoparticles, polymer nanoparticles, and viral and non-viral vectors. Overall, several long non-coding RNA (lncRNA) discussed here have strong implications for the development of pathology and functional recovery after ischemic stroke. LncRNAs H19 and ANRIL show potential as diagnostic biomarkers, while H19 and MALAT1 may prove to be effective therapeutics for both minimising damage as well as promoting recovery. Other ncRNA have also been implicated in ischemic stroke but are currently too poorly understood to make inferences for diagnosis or treatment. Whilst the field of ncRNAs is relatively new, significant work has already highlighted that ncRNAs represent a promising novel investigative tool for understanding stroke pathology, could be used as diagnostic biomarkers, and as targets for therapeutic interventions.

Sex-dependent association analysis between serum uric acid and spontaneous hemorrhagic transformation in patients with ischemic stroke

Objective

The association between serum uric acid (UA) and spontaneous hemorrhagic transformation (HT) has been seldom studied, and the role of UA in spontaneous HT remains unclear. This study aims to investigate the sex-dependent association between UA and spontaneous HT in patients with ischemic stroke.

Method

We retrospectively included patients with ischemic stroke in a tertiary academic hospital between December 2016 and May 2020. Patients were included if they presented within 24 h after the onset of symptoms and did not receive reperfusion therapy. Spontaneous HT was determined by an independent evaluation of neuroimaging by three trained neurologists who were blinded to clinical data. A univariate analysis was performed to identify factors related to spontaneous HT. Four logistic regression models were established to adjust each factor and assess the association between UA and spontaneous HT.

Results

A total of 769 patients were enrolled (64.6% were male patients and 3.9% had HT). After adjusting the confounders with a P < 0.05 (model A) in the univariate analysis, the ratio of UA and its interquartile range (RUI) was independently associated with spontaneous HT in male patients (OR: 1.85; 95% CI: 1.07-3.19; P = 0.028), but not in female patients (OR: 1.39; 95% CI: 0.28-6.82; P = 0.685). In models B-D, the results remain consistent with model A after the adjustment for other potential confounders.

Conclusions

Higher serum UA was independently associated with a higher occurrence of spontaneous HT in male patients who were admitted within 24 h after the stroke onset without receiving reperfusion therapy.

Identification of immunogenic cell death-related gene classification patterns and immune infiltration characterization in ischemic stroke based on machine learning

Ischemic stroke (IS) accounts for more than 80% of strokes and is one of the leading causes of death and disability in the world. Due to the narrow time window for treatment and the frequent occurrence of severe bleeding, patients benefit less from early intravenous thrombolytic drug therapy. Therefore, there is an urgent need to explore the molecular mechanisms poststroke to drive the development of new therapeutic approaches. Immunogenic cell death (ICD) is a type of regulatory cell death (RCD) that is sufficient to activate the adaptive immune response of immunocompetent hosts. Although there is growing evidence that ICD regulation of immune responses and immune responses plays an important role in the development of IS, the role of ICD in the pathogenesis of IS has rarely been explored. In this study, we systematically evaluated ICD-related genes in IS. The expression profiles of ICD-related genes in IS and normal control samples were systematically explored. We conducted consensus clustering, immune infiltration analysis, and functional enrichment analysis of IS samples using ICD differentially expressed genes. The results showed that IS patients could be classified into two clusters and that the immune infiltration profile was altered in different clusters. In addition, we performed machine learning to screen nine signature genes that can be used to predict the occurrence of disease. We also constructed nomogram models based on the nine risk genes (CASP1, CASP8, ENTPD1, FOXP3, HSP90AA1, IFNA1, IL1R1, MYD88, and NT5E) and explored the immune infiltration correlation, gene-miRNA, and gene-TF regulatory network of the nine risk genes. Our study may provide a valuable reference for further elucidation of the pathogenesis of IS and provide directions for drug screening, personalized therapy, and immunotherapy for IS.

CaMKIIα as a Promising Drug Target for Ischemic Grey Matter

Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a major mediator of Ca2+-dependent signaling pathways in various cell types throughout the body. Its neuronal isoform CaMKIIα (alpha) centrally integrates physiological but also pathological glutamate signals directly downstream of glutamate receptors and has thus emerged as a target for ischemic stroke. Previous studies provided evidence for the involvement of CaMKII activity in ischemic cell death by showing that CaMKII inhibition affords substantial neuroprotection. However, broad inhibition of this central kinase is challenging because various essential physiological processes like synaptic plasticity rely on intact CaMKII regulation. Thus, specific strategies for targeting CaMKII after ischemia are warranted which would ideally only interfere with pathological activity of CaMKII. This review highlights recent advances in the understanding of how ischemia affects CaMKII and how pathospecific pharmacological targeting of CaMKII signaling could be achieved. Specifically, we discuss direct targeting of CaMKII kinase activity with peptide inhibitors versus indirect targeting of the association (hub) domain of CaMKIIα with analogues of γ-hydroxybutyrate (GHB) as a potential way to achieve more specific pharmacological modulation of CaMKII activity after ischemia.

Real-time monitoring of intravenous thrombolysis in acute ischemic stroke using rotational thromboelastometry: a feasibility pilot study

INTRODUCTION

Rotational thromboelastometry (ROTEM) records whole blood coagulation in vitro. Data on dynamic changes of clot patterns during intravenous thrombolysis (IVT) in acute ischemic stroke is scarce. We investigated the feasibility of ROTEM as a potential point-of-care assessment tool for IVT.

METHODS

In this prospective pilot study, patients with acute stroke symptoms received IVT. Whole blood coagulation was tracked on the ROTEM analyzer. Blood samples were analyzed before, and then 2, 15, 30 and 60 min after beginning IVT. In vitro clots (iCLs) were described by their maximum clot firmness (MCF), the time needed to reach MCF (MCF-t), as well as the area under the curve (AR10). National Institutes of Health Stroke Scale (NIHSS) was used as early clinical outcome parameter.

RESULTS

We analyzed 288 iCLs from 12 patients undergoing IVT. In all iCLs, an early fibrinolysis (91% within the first 10 min) was detected during IVT. Three different curve progression patterns were observed: a low-responder pattern with a continuous clot increase, a high-responder pattern with a sustained clot decrease or total clotting suppression and an intermediate-responder pattern with alternating clot characteristics. There was a difference among these groups in early clinical outcome (AR10 and MCF each p = 0.01, MCF-t p = 0.02, Kruskal-Wallis Test).

CONCLUSION

The fibrinolysis patterns determined using ROTEM allow for the monitoring of IVT in patients with acute ischemic stroke. This pilot study found a correlation between the in vitro fibrinolysis patterns and early clinical outcomes. These findings support a potential for individualization of IVT in the future.

Clinical Application of Thromboelastography in Acute Ischemic Stroke

Acute ischemic stroke (AIS), characterized by high morbidity and mortality, has imposed a considerable burden on society. Despite rapid development in the treatment of AIS, there is still a high risk of recurrence. Furthermore, there is a time delay in waiting for the results of conventional coagulation tests in candidate patients for intravenous thrombolysis therapy. Heterogeneous responses to antiplatelet, intravascular thrombolysis, and endovascular therapies also worsen the situation. Thromboelastography (TEG), as a global and portable detection method for hemostasis, facilitates clinicians in disease monitoring, treatment evaluation, and prognosis prediction in AIS. In this narrative review, we provided a comprehensive summary of the clinical application of TEG in ischemic stroke and gave insights to further studies.

Mechanical thrombectomy for acute ischemic stroke due to large vessel occlusion in Argentina: An economic analysis

OBJECTIVES

Mechanical thrombectomy (MT) after intravenous thrombolysis (IV-tPA) is an effective and cost-saving treatment for stroke due to large vessel occlusion. However, rates of MT use are low in Argentina. This study was designed to estimate the economic value and the budget impact of incorporating MT after thrombolysis, simulating scenarios from Argentinian compulsory social health insurance (Obras Sociales) and private insurances (Empresas de Medicina Prepaga).

MATERIALS AND METHODS

We adapted a previously published cost-utility and budget-impact (CUA and BIA) model to the Argentinian setting. The CUA was carried out for a lifetime horizon with efficacy inputs from the SWIFT PRIME clinical trial. For seven possible health states, we identified local costs (Argentinian Pesos AR$), utility (QALY), and transition/distribution probabilities (5% discounted rate) and performed deterministic and probabilistic sensitivity analyses. The BIA was based on a six-step approach and a static model for a five-year horizon, and two scenarios (staggered growth and no growth).

RESULTS

Despite higher incremental procedure costs, IV-tPA and MT was dominant over IV-tPA alone (AR$1,049,062 overall savings). Cost-effectiveness remained in the deterministic sensitivity analysis (100% probability of cost-effectiveness). Increased MT procedure volume resulted in savings in years three (0.96%), four (2.6%), and five (4.4%). By year five, 1,280 patients were treated with MT (versus 480) with overall savings of 1.8% (AR$817,244,417).

CONCLUSIONS

MT after IV-tPA is cost-effective in Argentina. Savings offset the incremental hospitalization and long-term costs from the third year onwards. With increased, access the superior efficacy of MT mitigates future disability and comorbidity, reducing overall expenses.

Functional Assessment of Stroke-Induced Regulation of miR-20a-3p and Its Role as a Neuroprotectant

MicroRNAs have gained popularity as a potential treatment for many diseases, including stroke. This study identifies and characterizes a specific member of the miR-17-92 cluster, miR-20a-3p, as a possible stroke therapeutic. A comprehensive microRNA screening showed that miR-20a-3p was significantly upregulated in astrocytes of adult female rats, which typically have better stroke outcomes, while it was profoundly downregulated in astrocytes of middle-aged females and adult and middle-aged males, groups that typically have more severe stroke outcomes. Assays using primary human astrocytes and neurons show that miR-20a-3p treatment alters mitochondrial dynamics in both cell types. To assess whether stroke outcomes could be improved by elevating astrocytic miR-20a-3p, we created a tetracycline (Tet)-induced recombinant adeno-associated virus (rAAV) construct where miR-20a-3p was located downstream a glial fibrillary acidic protein promoter. Treatment with doxycycline induced miR-20-3p expression in astrocytes, reducing mortality and modestly improving sensory motor behavior. A second Tet-induced rAAV construct was created in which miR-20a-3p was located downstream of a neuron-specific enolase (NSE) promoter. These experiments demonstrate that neuronal expression of miR-20a-3p is vastly more neuroprotective than astrocytic expression, with animals receiving the miR-20a-3p vector showing reduced infarction and sensory motor improvement. Intravenous injections, which are a therapeutically tractable treatment route, with miR-20a-3p mimic 4 h after middle cerebral artery occlusion (MCAo) significantly improved stroke outcomes including infarct volume and sensory motor performance. Improvement was not observed when miR-20a-3p was given immediately or 24 h after MCAo, identifying a unique delayed therapeutic window. Overall, this study identifies a novel neuroprotective microRNA and characterizes several key pathways by which it can improve stroke outcomes.

Prognostic value of the systemic inflammation response index in patients with acute ischemic stroke

OBJECTIVES

Inflammation plays an essential role in acute ischemic stroke (AIS). Recent studies have recognized the systemic inflammation response index (SIRI) as a useful index to indicate inflammation status and predict the prognosis of multiple diseases. However, the relationship between SIRI and AIS prognosis is unclear. Our study is aimed to investigate the association between SIRI and the prognosis of AIS.

METHODS

Our study prospectively recruited 287 consecutive patients with first-ever stroke within 72 h after stroke. Demographic and clinical information was collected at baseline. The functional prognosis was assessed 3 months after AIS using the modified Rankin Scale (mRS). A poor outcome was defined as mRS > 2. SIRI was calculated as neutrophil × monocyte/lymphocyte count. Univariate and multivariate analyses were introduced to identify the association between SIRI and AIS prognosis. Receiver operating characteristic curve and reclassification analyses were used to evaluate the predictive value of SIRI for AIS prognosis.

RESULTS

The patients with poor prognosis account for 27.5% of all participants. After fully adjusting for all covariates, each standard deviation increment of SIRI caused 58.9% additional risk for poor prognosis after AIS. When dividing SIRI into quartiles, the fourth quartile had a 6.152 times risk than the first quartile. Moreover, after adding SIRI into established clinical risk factors, AUC showed a significant improvement (0.829 vs. 0.790, p for comparison = .016). Consistently, category-free net reclassification index (NRI, 0.761, 95% CI: 0.517-1.004, p < .001) and integrated discrimination index (IDI, 0.093, 95% CI: 0.0512-0.134, p < .001) confirmed the improvement by SIRI to predict poor prognosis of AIS, CONCLUSION: SIRI is an independent prognostic indicator for AIS. Elevated SIRI is associated with poor functional outcome of AIS. Our findings suggest the usefulness of SIRI to refine the risk stratification of unfavorable prognosis of AIS.

Treatment and Outcomes of Thrombolysis Related Hemorrhagic Transformation: A Multi-Center Study in China

Objective

To investigate the current management of thrombolysis related hemorrhagic transformation (HT) in real-world practice, and whether these treatments would reduce the risk of 3-month death and hematoma expansion after HT.

Methods

A multicenter retrospective study was performed in three comprehensive stroke centers in China (West China Hospital, The First People’s Hospital of Ziyang, and Mianyang Central Hospital) between January 1st 2012 and December 31th 2020. Participants were patients diagnosed with HT after intravenous thrombolytics on brain computed tomography (CT) within 36 h after stroke onset. The treatment after thrombolysis related HT included aggressive therapy (procoagulant, neurosurgical treatment) and dehydration therapy (mannitol or glycerin and fructose). The primary clinical outcome was 3-month death. The primary radiographic outcome was hematoma expansion, defined as a 33% increase in the hematoma volume using the (A × B × C)/2 method on follow-up imaging.

Results

Of 538 patients with ischemic stroke receiving thrombolysis included during the study period, 94 patients (17.4%) were diagnosed with HT, 50% (47/94) of whom were symptomatic HT. The 3-month death was 31.5% (29/92), with two patients having been lost to follow up. A total of 68 patients (72.3%) had follow-up brain CT scans after HT detection for evaluating hematoma expansion, of whom 14.7% (10/68) had hematoma expansion. Among the 10 patients with hematoma expansion, 7 patients were from symptomatic HT group, and 3 patients were from the asymptomatic hematoma group. In regard to escalation in therapy, six patients received neurosurgical treatment and three patients had a fresh frozen plasma infusion. In addition, dehydration therapy was the most common management after HT diagnosis [87.2% (82 of 94)]. In the multivariable models, refusing any treatment after HT diagnosis was the sole factor associated with increased 3-month death (odds ratio, 13.6; 95% CI, 3.98–56.9) and hematoma expansion risk (odds ratio, 8.54; 95% CI, 1.33–70.1). In regard to the effects of aggressive therapy, a non-significant association of receiving hemostatic/neurosurgery therapy with a lower 3-month death and hematoma expansion risk was observed (all P > 0.05).

Conclusion

Refusing any treatment after HT detection had a significant trend of increasing 3-month death and hematoma expansion risk after HT. Our finding of hematoma expansion among patients with asymptomatic HT in non-western populations suggests an opportunity for intervention. Very few patients after thrombolysis related HT diagnosis received procoagulant or neurosurgical therapies. Large multicenter studies enrolling diverse populations are needed to examine the efficacy of these therapies on different HT subtypes.

Thromboinflammation in Brain Ischemia: Recent Updates and Future Perspectives

Despite decades of promising preclinical validation and clinical translation, ischemic stroke still remains as one of the leading causes of death and disability worldwide. Within its complex pathophysiological signatures, thrombosis and inflammation, that is, thromboinflammation, are highly interconnected processes leading to cerebral vessel occlusion, inflammatory responses, and severe neuronal damage following the ischemic event. Hence, we here review the most recent updates on thromboinflammatory-dependent mediators relevant after stroke focusing on recent discoveries on platelet modulation, a potential regulation of the innate and adaptive immune system in thromboinflammation, utterly providing a thorough up-to-date overview of all therapeutic approaches currently undergoing clinical trial.

Radiomics-based prediction of hemorrhage expansion among patients with thrombolysis/thrombectomy related-hemorrhagic transformation using machine learning

Introduction:

Patients with hemorrhagic transformation (HT) were reported to have hemorrhage expansion. However, identification these patients with high risk of hemorrhage expansion has not been well studied.

Objectives:

We aimed to develop a radiomic score to predict hemorrhage expansion after HT among patients treated with thrombolysis/thrombectomy during acute phase of ischemic stroke.

Methods:

A total of 104 patients with HT after reperfusion treatment from the West China hospital, Sichuan University, were retrospectively included in this study between 1 January 2012 and 31 December 2020. The preprocessed initial non-contrast-enhanced computed tomography (NECT) imaging brain images were used for radiomic feature extraction. A synthetic minority oversampling technique (SMOTE) was applied to the original data set. The after-SMOTE data set was randomly split into training and testing cohorts with an 8:2 ratio by a stratified random sampling method. The least absolute shrinkage and selection operator (LASSO) regression were applied to identify candidate radiomic features and construct the radiomic score. The performance of the score was evaluated by receiver operating characteristic (ROC) analysis and a calibration curve. Decision curve analysis (DCA) was performed to evaluate the clinical value of the model.

Results:

Among the 104 patients, 17 patients were identified with hemorrhage expansion after HT detection. A total of 154 candidate predictors were extracted from NECT images and five optimal features were ultimately included in the development of the radiomic score by using logistic regression machine-learning approach. The radiomic score showed good performance with high area under the curves in both the training data set (0.91, sensitivity: 0.83; specificity: 0.89), test data set (0.87, sensitivity: 0.60; specificity: 0.85), and original data set (0.82, sensitivity: 0.77; specificity: 0.78). The calibration curve and DCA also indicated that there was a high accuracy and clinical usefulness of the radiomic score for hemorrhage expansion prediction after HT.

Conclusions:

The currently established NECT-based radiomic score is valuable in predicting hemorrhage expansion after HT among patients treated with reperfusion treatment after ischemic stroke, which may aid clinicians in determining patients with HT who are most likely to benefit from anti-expansion treatment.

Temporal trends in reperfusion therapy for patients with acute ischemic stroke

OBJECTIVES

To analyze the temporal trends in thrombolysis rates after implementation of a regional emergency network for acute ischemic stroke (AIS).

METHODS

We conducted a retrospective study based on a prospective multicenter observational registry. The AIS benefited from reperfusion therapy included in 1 of the 5 primary stroke units or 1 comprehensive stroke center and 37 emergency departments were included using a standardized case report form. The population covers 3 million inhabitants.

RESULTS

In total, 32,319 AIS was reported in the regional hospitalization database of which 2215 thrombolyzed AIS patients were included in the registry and enrolled in this study. The annual incidence rate of thrombolysis continuously and significantly increased from 2010 to 2018 (10.2% to 17.3%, P-trend = 0.0013). The follow-up of the onset-to-door and the door-to-needle delays over the study period showed stable rates, as did the all-cause mortality rate at 3-months (13.2%).

CONCLUSION

Although access to stroke thrombolysis has increased linearly since 2010, the 3-month functional outcome has not evolved as favorably. Further efforts must focus on reducing hospital delays.

Comprehensive Landscape of Immune Infiltration and Aberrant Pathway Activation in Ischemic Stroke

Ischemic stroke (IS) is a multifactorial disease caused by the interaction of multiple environmental and genetic risk factors, and it is the most common cause of disability. The immune microenvironment and inflammatory response participate in the whole process of IS occurrence and development. Therefore, the rational use of relevant markers or characteristic pathways in the immune microenvironment will become one of the important therapeutic strategies for the treatment of IS. We collected peripheral blood samples from 10 patients diagnosed with IS at the First Affiliated Hospital of Gannan Medical University and First Affiliated Hospital, Jinan" University, and from 10 normal people. The GSE16561 dataset was downloaded from the Gene Expression Omnibus (GEO) database. xCell, gene set enrichment analysis (GSEA), single-sample GSEA (ssGSEA) and immune-related gene analysis were used to evaluate the differences in the immune microenvironment and characteristic pathways between the IS and control groups of the two datasets. xCell analysis showed that the IS-24h group had significantly reduced central memory CD8+ T cell, effector memory CD8+ T cell, B cell and Th1 cell scores and significantly increased M1 macrophage and macrophage scores. GSEA showed that the IS-24h group had significantly increased inflammation-related pathway activity(myeloid leukocyte activation, positive regulation of tumor necrosis factor biosynthetic process, myeloid leukocyte migration and leukocyte chemotaxis), platelet-related pathway activity(platelet activation, signaling and aggregation; protein polymerization; platelet degranulation; cell-cell contact zone) and pathology-related pathway activity (ERBB signaling pathway, positive regulation of ERK1 and ERK2 cascade, vascular endothelial growth factor receptor signaling pathway, and regulation of MAP kinase activity). Immune-related signature analysis showed that the macrophage signature, antigen presentation-related signature, cytotoxicity-related signature, B cell-related signature and inflammation-related signature were significantly lower in the IS-24h group than in the control group. In this study, we found that there were significant differences in the immune microenvironment between the peripheral blood of IS patients and control patients, as shown by the IS group having significantly reduced CD8+ Tcm, CD8+ Tem, B cell and Th1 cell scores and significantly increased macrophage and M1 macrophage scores. Additionally, inflammation-related, pathological, and platelet-related pathway activities were significantly higher in the IS group than in the control group.

Acute Ischemic Stroke and Heart Failure: Stroke Risk Factors Associated with Exclusion from Thrombolytic Therapy

Objective: Acute ischemic stroke (AIS) patients with congestive heart failure (HF) that present with various risk factors are less likely to receive recombinant tissue plasminogen activator (rtPA). The risk factors associated with excluding AIS patients with congestive heart failure (AIS-HF) from rtPA therapy have not been fully established. Methods: Retrospective data for 5469 AIS patients comprised of 590 AIS patients with HF and 4879 AIS patients without HF were collected from a regional stroke registry between January 2010 and June 2016. Baseline risk factors were analyzed using logistic regression analysis to determine the risk factors associated with rtPA exclusion in AIS-HF patients. Results: In the adjusted analysis, AIS-HF patients that that did not receive rtPA were more likely to be older (OR = 0.982, 95% CI, 0.966-1, P = .020), presented with coronary artery disease (OR = 0.618, 95% CI, 0.391-0.98, P = .040), and with an elevated INR (OR = 0.326, 95% CI, 0.129-0.82, P = .018). AIS-HF patients that were included for rtPA therapy were more likely to show improvement in ambulatory status (OR = 1.69, 95% CI, 1.058-2.7, P = .028). The discriminating power of the model was strong with an area under the curve (AUROC) = 0.668 (95% CI, 0.611-0.724, P < .001). Conclusion: Our study establishes the associations between stroke risk factors and exclusion from rtPA therapy. This finding suggests the need to develop management strategies for older HF patients with carotid artery disease and an elevated INR to improve their eligibility for rtPA treatment following an acute ischemic stroke.

Dose-Response Relationship and Threshold Drug Dosage Identification for a Novel Hybrid Mechanical-Thrombolytic System with an Ultra-Low Dose Patch

Introduction

Ischemic stroke treatment has advanced in the last two decades and intravenous thrombolysis is now considered the standard of care for selected patients. Recanalization can also be achieved by mechanical endovascular treatment for patients with large vessel occlusions. Complicating treatment-related symptomatic intracerebral hemorrhage and prolonged needle-to-recanalization times have been identified as major determinants of poor three-month functional outcomes. A hybrid mechanical-thrombolytic system with a patch imbued with an ultra-low dose of thrombolytic agents loaded onto a stent-retriever has been developed.

Methods

In this study, the in situ dose-response relationship of the thrombolytic patch imbued with up to 1000 IU of urokinase plasminogen activator (uPA) was quantified using Raman spectroscopy.

Results

Thrombi of up to 400 μm thickness dissolved within 15 min when patches imbued with < 1% of the conventional thrombolysis therapy dosage were applied. The results demonstrated that low-dose thrombolytic patches can dissolve normal clots compressed in the blood vessel in a short time. 500 IU is the threshold uPA dosage in the thrombolytic patch that most effectively dissolves the clots.

Conclusion

This study suggests that a novel endovascular stent-retriever loaded with an ultra-low drug dose fibrinolytic patch may be a suitable treatment for patients who are ineligible for conventional thrombolytic therapy.

Increased Platelet-to-Lymphocyte Ratio is an Independent Predictor of Hemorrhagic Transformation and In-Hospital Mortality Among Acute Ischemic Stroke with Large-Artery Atherosclerosis Patients

Background

The platelet-to-lymphocyte ratio (PLR) is an inflammation marker of acute ischemic stroke, but its significance in patients with hemorrhage transformation (HT) after acute ischemic stroke with large-artery atherosclerosis (AIS-LAA) is unclear, and we also identified the relationship between PLR and in-hospital mortality of HT after AIS-LAA.

Methods

This was a retrospective analysis of patients with AIS-LAA. The PLR was calculated according to platelet and lymphocyte counts on admission. HT was defined on follow-up magnetic resonance imaging or computed tomography when neurologic deterioration worsened during hospitalization. The univariate analysis and multivariate logistic regression were performed to assess the association of PLR, HT and in-hospital mortality of HT after AIS-LAA.

Results

We included 328 Chinese AIS-LAA patients (mean age 67.2±11.1 years; 70.4% male). HT occurred in 38 patients (11.6%). After multivariate regression analyses, NRL (odds ratio [OR] 1.354, 95% confidence interval [CI] 1.176–1.559, P<0.001) and PLR (odds ratio [OR] 3.869, 95% confidence interval [CI] 2.233–5.702, P<0.001) were independently associated with HT after AIS-LAA. The area under the ROC curve (AUC) value of PLR (0.72, 95% CI (0.64–0.80), P<0.001) tested a greater discriminatory ability compared with neutrophil-lymphocyte ratio (NLR) (0.67, 95% CI (0.58–0.76), P<0.001). Meanwhile, PLR was found to be significantly related to HT after AIS-LAA, including in subtypes of artery-to-artery embolization (aOR 1.699, 95% CI 1.298–3.215, P<0.001), in-situ thrombosis (aOR4.499, 95% CI 1.344–9.054, P<0.001) and branch atheromatous disease (aOR3.239, 95% CI 1.098–8.354, P<0.001). Increased PLR predicts high in-hospital mortality of HT after AIS-LAA (OR 1.041, 95% CI (1.006–1.077), P=0.020; aOR 1.053, 95% CI (1.004–1.104), P=0.034).

Conclusion

High PLR is associated with greater risk of HT in AIS-LAA patients, including in artery-to-artery embolization, in-situ thrombosis and branch atheromatous disease. Meanwhile, increased PLR predicts high in-hospital mortality of HT after AIS-LAA.

Targeted Treatment of Ischemic Stroke by Bioactive Nanoparticle-Derived Reactive Oxygen Species Responsive and Inflammation-Resolving Nanotherapies

Stroke is a primary cause of death and disability worldwide, while effective and safe drugs remain to be developed for its clinical treatment. Herein, we report bioactive nanoparticle-derived multifunctional nanotherapies for ischemic stroke, which are engineered from a pharmacologically active oligosaccharide material (termed as TPCD) prepared by covalently conjugating a radical-scavenging compound (Tempol) and a hydrogen-peroxide-eliminating moiety of phenylboronic acid pinacol ester (PBAP) on β-cyclodextrin. Of note, combined functional moieties of Tempol and PBAP on β-cyclodextrin contribute to antioxidative and anti-inflammatory activities of TPCD. Cellularly, TPCD nanoparticles (i.e., TPCD NPs) reduced oxygen-glucose deprivation-induced overproduction of oxidative mediators, increased antioxidant enzyme expression, and suppressed microglial-mediated inflammation, thereby inhibiting neuronal apoptosis. After intravenous (i.v.) delivery, TPCD NPs could efficiently accumulate at the cerebral ischemic injury site of mice with middle cerebral artery occlusion (MCAO), showing considerable distribution in cells relevant to the pathogenesis of stroke. Therapeutically, TPCD NPs significantly decreased infarct volume and accelerated recovery of neurological function in MCAO mice. Mechanistically, efficacy of TPCD NPs is achieved by its antioxidative, anti-inflammatory, and antiapoptotic effects. Furthermore, TPCD NPs can function as a reactive oxygen species labile nanovehicle to efficiently load and triggerably release an inflammation-resolving peptide Ac2-26, giving rise to an inflammation-resolving nanotherapy (i.e., ATPCD NP). Compared to TPCD NP, ATPCD NP demonstrated notably enhanced in vivo efficacies, largely resulting from its additional inflammation-resolving activity. Consequently, TPCD NP-derived nanomedicines can be further developed as promising targeted therapies for stroke and other inflammation-associated cerebrovascular diseases.

The impact of antihypertensive use in the treatment of acute ischemic stroke in patients receiving alteplase

BACKGROUND

Treatment of acute ischemic stroke (AIS) with intravenous alteplase within 4.5 h of symptom onset is associated with neurologic improvement. High baseline blood pressure (BP) and BP variability during the first 24 h of AIS is associated with increased early adverse events and death. The purpose of this study is to characterize the incidence of poor neurologic outcome in patients treated with alteplase for AIS who received antihypertensive medications prior to and within the first 24 h following alteplase administration compared with patients who did not.

METHODS

This was a multicenter, retrospective cohort of patients >18 years diagnosed with AIS from January 1, 2011 through December 31, 2015 who received one or more antihypertensive medication in the first 24 h of AIS in patients receiving alteplase compared to controls. The primary endpoint was poor neurologic outcome at 90 days, according to modified Rankin Scale ≥3. Univariate analysis was conducted using Chi-square, Fisher's exact test, or Mann-Whitney U test. Multivariable logistic regression was conducted to determine independent predictors of poor outcome.

RESULTS

Of the 587 patients evaluated, 351 (59.7%) were included, of which 127 (36.2%) received antihypertensive(s). More patients in the antihypertensive treatment group had a history of hypertension (88.2% vs. 69.6%, p < 0.01), diabetes (37% vs. 25.5%, p = 0.03) and chronic kidney disease (19.7% vs. 8.5%, p < 0.01). Intravenous push labetalol was most commonly administered (81.2%), followed by nicardipine (44.1%), and hydralazine (22%). More patients in the antihypertensive treatment group experienced poor neurologic outcome at 90 days (53.5% vs. 38.8%, p < 0.01), however, this finding was not observed after multivariable logistic regression.

CONCLUSION

Antihypertensive treatment in the first 24 h of AIS was associated with poor neurologic outcomes at 90 days. However, after controlling for other clinical factors in a multivariable logistic regression, this association was no longer observed.

Four Decades of Ischemic Penumbra and Its Implication for Ischemic Stroke

The ischemic penumbra defined four decades ago has been the main battleground of ischemic stroke. The evolving ischemic penumbra concept has been providing insight for the development of vascular and cellular approaches as well as diagnostic tools for the treatment of ischemic stroke. rt-PA thrombolytic therapy to prevent the transition of ischemic penumbra to core has been approved for acute ischemic stroke within 3 h and was later recommended to extend to 4.5 h after symptom onset. Mechanical thrombectomy was introduced for the treatment of acute ischemic stroke with a therapeutic window of up to 24 h after stroke onset. Multiple modalities brain imaging techniques have been developed that provide guidance to define ischemic penumbra for reperfusion therapy in clinical practice. Cellular and molecular dissection of ischemic penumbra has been providing targets for the development of neuroprotective therapy for ischemic stroke. However, the dynamic nature of ischemic penumbra implicates that infarct core eventually expands into penumbra over time without reperfusion, dictating relative short therapeutic windows and limiting the impact of current reperfusion intervention. Entering the 5^th decade since the introduction, ischemic penumbra remains the main focus of ischemic stroke research and clinical practice. In this review, we summarized the evolving ischemic penumbra concept and its implication in the development of vascular and cellular interventions as well as diagnostic tools for acute ischemic stroke. In addition, we discussed future perspectives on expansion of the campaign beyond ischemic penumbra to develop treatment for ischemic stroke.

Prediction of Hemorrhagic Transformation After Ischemic Stroke: Development and Validation Study of a Novel Multi-biomarker Model

Objectives: We aimed to develop and validate a novel multi-biomarker model for predicting hemorrhagic transformation (HT) risk after acute ischemic stroke (AIS).

Methods: We prospectively included patients with AIS admitted within 24 h of stroke from January 1st 2016 to January 31st 2019. A panel of 17 circulating biomarkers was measured and analyzed in this cohort. We assessed the ability of individual circulating biomarkers and the combination of multiple biomarkers to predict any HT, symptomatic HT (sHT) and parenchymal hematoma (PH) after AIS. The strategy of multiple biomarkers in combination was then externally validated in an independent cohort of 288 Chinese patients.

Results: A total of 1207 patients with AIS (727 males; mean age, 67.2 ± 13.9 years) were included as a derivation cohort, of whom 179 patients (14.8%) developed HT. The final multi-biomarker model included three biomarkers [platelets, neutrophil-to-lymphocyte ratios (NLR), and high-density lipoprotein (HDL)] from different pathways, showing a good performance for predicting HT in both the derivation cohort (c statistic = 0·64, 95% CI 0·60–0·69), and validation cohort (c statistic = 0·70, 95% CI 0·58–0·82). Adding these three biomarkers simultaneously to the basic model with conventional risk factors improved the ability of HT reclassification [net reclassification improvement (NRI) 65.6%, P < 0.001], PH (NRI 64.7%, P < 0.001), and sHT (NRI 71.3%, P < 0.001).

Conclusion: This easily applied multi-biomarker model had a good performance for predicting HT in both the derivation and external validation cohorts. Incorporation of biomarkers into clinical decision making may help to identify patients at high risk of HT after AIS and warrants further consideration.

Management of Acute Ischemic Stroke

Objectives:

Concise “synthetic” review of the state of the art of management of acute ischemic stroke.

Data Sources:

Available literature on PubMed.

Study Selection:

We selected landmark studies, recent clinical trials, observational studies, and professional guidelines on the management of stroke including the last 10 years.

Data Extraction:

Eligible studies were identified and results leading to guideline recommendations were summarized.

Data Synthesis:

Stroke mortality has been declining over the past 6 decades, and as a result, stroke has fallen from the second to the fifth leading cause of death in the United States. This trend may follow recent advances in the management of stroke, which highlight the importance of early recognition and early revascularization. Recent studies have shown that early recognition, emergency interventional treatment of acute ischemic stroke, and treatment in dedicated stroke centers can significantly reduce stroke-related morbidity and mortality. However, stroke remains the second leading cause of death worldwide and the number one cause for acquired long-term disability, resulting in a global annual economic burden.

Conclusions:

Appropriate treatment of ischemic stroke is essential in the reduction of mortality and morbidity. Management of stroke involves a multidisciplinary approach that starts and extends beyond hospital admission.

Impact of onset-to-door time on outcomes and factors associated with late hospital arrival in patients with acute ischemic stroke

Background and purpose

Previous studies have reported that early hospital arrival improves clinical outcomes in patients with acute ischemic stroke; however, whether early arrival is associated with favorable outcomes regardless of reperfusion therapy and the type of stroke onset time is unclear. Thus, we investigated the impact of onset-to-door time on outcomes and evaluated the predictors of pre-hospital delay after ischemic stroke.

Methods

Consecutive acute ischemic stroke patients who arrived at the hospital within five days of onset from September 2019 to May 2020 were selected from the prospective stroke registries of Seoul National University Hospital and Chung-Ang University Hospital of Seoul, Korea. Patients were divided into early (onset-to-door time, ≤4.5 h) and late (>4.5 h) arrivers. Multivariate analyses were performed to assess the effect of early arrival on clinical outcomes and predictors of late arrival.

Results

Among the 539 patients, 28.4% arrived early and 71.6% arrived late. Early hospital arrival was significantly associated with favorable outcomes (three-month modified Rankin Scale [mRS]: 0−2, adjusted odds ratio [aOR]: 2.03, 95% confidence interval: [CI] 1.04–3.96) regardless of various confounders, including receiving reperfusion therapy and type of stroke onset time. Furthermore, a lower initial National Institute of Health Stroke Scale (NIHSS) score (aOR: 0.94, 95% CI: 0.90–0.97), greater pre-stroke mRS score (aOR: 1.58, 95% CI: 1.18–2.13), female sex (aOR: 1.71, 95% CI: 1.14–2.58), unclear onset time, and ≤6 years of schooling (aOR: 1.76, 95% CI: 1.03–3.00 compared to >12 years of schooling) were independent predictors of late arrival.

Conclusions

Thus, the onset-to-door time of≤4.5 h is crucial for better clinical outcome, and lower NIHSS score, greater pre-stroke mRS score, female sex, unclear onset times, and ≤6 years of schooling were independent predictors of late arrival. Therefore, educating about the importance of early hospital arrival after acute ischemic stroke should be emphasized. More strategic efforts are needed to reduce the prehospital delay by understanding the predictors of late arrival.

The use of transcranial ultrasound and clinical assessment to diagnose ischaemic stroke due to large vessel occlusion in remote and rural areas

Rapid endovascular thrombectomy, which can only be delivered in specialist centres, is the most effective treatment for acute ischaemic stroke due to large vessel occlusion (LVO). Pre-hospital selection of these patients is challenging, especially in remote and rural areas due to long transport times and limited access to specialist clinicians and diagnostic facilities. We investigated whether combined transcranial ultrasound and clinical assessment (“TUCA” model) could accurately triage these patients and improve access to thrombectomy. We recruited consecutive patients within 72 hours of suspected stroke, and performed non-contrast transcranial colour-coded ultrasonography within 24 hours of brain computed tomography. We retrospectively collected clinical information, and used hospital discharge diagnosis as the “gold standard”. We used binary regression for diagnosis of haemorrhagic stroke, and an ordinal regression model for acute ischaemic stroke with probable LVO, without LVO, transient ischaemic attacks (TIA) and stroke mimics. We calculated sensitivity, specificity, positive and negative predictive values and performed a sensitivity analysis. We recruited 107 patients with suspected stroke from July 2017 to December 2019 at two study sites: 13/107 (12%) with probable LVO, 50/107 (47%) with acute ischaemic stroke without LVO, 18/107 (17%) with haemorrhagic stroke, and 26/107 (24%) with stroke mimics or TIA. The model identified 55% of cases with probable LVO who would have correctly been selected for thrombectomy and 97% of cases who would not have required this treatment (sensitivity 55%, specificity 97%, positive and negative predictive values 75% and 93%, respectively). Diagnostic accuracy of the proposed model was superior to the clinical assessment alone. These data suggest that our model might be a useful tool to identify pre-hospital patients requiring mechanical thrombectomy, however a larger sample is required with the use of CT angiogram as a reference test.

Sex differences in stroke co-morbidities

Males and females possess distinct biological differences that manifest in diverse risk profiles for acute and chronic diseases. A well-documented example of this is ischemic stroke. It has been demonstrated that older females have greater prevalence of, and worse outcome after, ischemic stroke than do males and younger females. Loss of estrogen after menopause is heavily implicated as a contributing factor for this phenomenon; however, there is mounting evidence to suggest that certain risk factors tend to occur more often in older females, such as hypertension and atrial fibrillation, while others more adversely affect females than they do males, such as diabetes and smoking. Sex-specific risk factors, such as oral contraceptive use and menopause, could also contribute to the discrepancy in stroke prevalence and outcome. Additionally, there is evidence to suggest that females tend to present with more nontraditional symptoms of acute stroke than do males, making it more difficult for clinicians to correctly identify the occurrence of a stroke, which may delay the administration of thrombolytic intervention. Finally, certain sociodemographic factors, such as the fact that females were more likely to live alone prior to stroke, may contribute to poorer recovery in females. This review will explore the various co-morbidities and sociodemographic factors that contribute to the greater prevalence of and poorer outcome after stroke in older females and will highlight the critical need for considering sex as a predisposing biological variable in stroke studies.

Increased intracranial hemorrhage of mechanical thrombectomy in acute ischemic stroke patients with atrial fibrillation

The impact of atrial fibrillation (AF) on outcomes of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) is controversial, and with a paucity of evidence base. This study aimed to investigate the potential association between AF and outcomes after MT in AIS patients. A post-hoc analysis of a multi-center prospective clinical trial was conducted. Before and after propensity score matching (PSM), the clinical features were compared between patients with and without AF. Multivariable logistic regression and mediation analyses were performed to assess the relationship between AF and ICH. Of the total 245 patients, 123 patients were included in the AF group. After PSM, the AF group showed more retrieval attempts (P = 0.004), comparable favorable outcome (P = 0.493), and mortality (P = 0.362) at 90 days. Multivariate analysis revealed that AF was significantly associated with increased risk for ICH (OR 2.198; 95%CI 1.099-4.395; P = 0.026). INR and retrieval attempts were found to act as partial mediations. In the subgroup with lower INR, AF still had a significant association with ICH (OR 2.496; 95%CI 1.331-4.679; P = 0.004). In AIS patients undergoing MT, AF was associated with more retrieval attempts and higher risk of any ICH. Of note, the effect of AF on the increased risk of ICH was partly attributable to the adjusted anticoagulation status and more retrieval attempts. It is crucial to elaborately prevent ICH after thrombectomy for stroke patients with AF.

AST to ALT ratio and risk of hemorrhagic transformation in patients with acute ischemic stroke

BACKGROUND

Hemorrhagic transformation (HT) is a common complication of ischemic stroke. We performed this study to determine whether aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio (AAR) was related to HT, as well as compare the predictive values of AAR, ALT and AST for HT in patients with ischemic stroke.

METHODS

We included ischemic stroke patients within 7 days of onset. HT was identified by a follow-up imaging examination. Univariate and multivariate logistic regression models were performed to assess the association between AAR and HT. Net reclassification index (NRI) was calculated to assess the ability of AAR, AST and ALT to reclassify risks of HT.

RESULTS

A total of 2042 (median age: 69 years; 63.2% males) patients were included in this study, of whom 232 (11.4%) were identified as HT. The receiver-operating characteristic curve analysis showed that the optimal cut-off value for AAR to predict HT was 1.22. Higher AAR (≥1.22) was an independent predictor associated with HT (OR 1.44, 95%CI 1.06-1.97, P = 0.02) after adjusting for covariates. A U-shaped dose-effect relationship was found between AAR level and HT in logistic regression model with restricted cubic splines. In addition, adding AAR to a model containing conventional risk factors significantly improved predictive power for HT (NRI: 15.4%, P = 0.027), but not for ALT (NRI: 10.3%, P = 0.141) or AST (NRI: 8.3%, P = 0.237).

CONCLUSIONS

Higher AAR was associated with an increased risk of HT after ischemic stroke. In addition, AAR might be a better biomarker for predicting HT than ALT or AST.

Worse prognosis in women, compared with men, after thrombolysis: An individual patient data pooling study of Asian acute stroke registries

BACKGROUND AND PURPOSE

To examine sex differences in disease profiles and short-term outcomes after acute ischemic stroke treated with recombinant tissue plasminogen activator.

METHODS

Eight national and regional stroke registries contributed individual participant data from mainland China, Japan, Philippines, Singapore, South Korea and Taiwan in 2005-2018. The primary outcome was ordinal-modified Rankin scale at 90 days. Key safety outcome was symptomatic intracerebral hemorrhage (sICH).

RESULTS

Of 4453 patients included in the analyses, 1692 (36.3%) were women who were older, more likely to have a more severe neurological deficit, history of hypertension and atrial fibrillation, and a cardioembolic stroke compared to men. Women were more likely than men to have unfavorable shift of modified Rankin scale (fully adjusted odds ratio) (women vs. men) 1.14, 95% confidence interval 1.02-1.28). There was no significant sex difference for death 1.05 (0.84-1.31) or sICH (1.17, 0.89-1.54). Women were more likely to have unfavorable functional outcome with increasing age (P = 0.022 for interaction). In the age groups 70-80 and ≥80 years, women had a worse functional outcome compared to men (1.22, 1.02-1.47 and 1.43, and 1.06-1.92, respectively).

CONCLUSION

In this pooled data from Asian acute stroke registries, women had poorer prognosis than men after receiving recombinant tissue plasminogen activator for acute ischemic stroke, which worsened with age. Women older than 70 appear to have a worse outcome than men which could be explained by greater stroke severity, more AF, and cardioembolic stroke.

Health Utility Weighting of the Modified Rankin Scale: A Systematic Review and Meta-analysis

IMPORTANCE

The utility-weighted modified Rankin Scale (UW-mRS) has been proposed as a patient-centered alternative primary outcome for stroke clinical trials. However, to date, there is no clear consensus on an approach to weighting the mRS.

OBJECTIVE

To characterize the between-study variability in utility weighting of the mRS in a population of patients who experienced stroke and its implications when applied to the results of a clinical trial.

DATA SOURCES

In this systematic review and meta-analysis, MEDLINE, Embase, and PsycINFO were searched from January 1987 through May 2019 using major search terms for stroke, health utility, and mRS.

STUDY SELECTION

Original research articles published in English were reviewed. Included were studies with participants 18 years or older with ischemic or hemorrhagic stroke, transient ischemic attack, or subarachnoid hemorrhage, with mRS scores and utility weights evaluated concurrently. A total of 5725 unique articles were identified. Of these, 283 met criteria for full-text review, and 24 were included in the meta-analysis.

DATA EXTRACTION AND SYNTHESIS

PRISMA guidelines for systematic review were followed. Data extraction was performed independently by multiple researchers. Data were pooled using mixed models.

MAIN OUTCOMES AND MEASURES

The mean utility weights and 95% CIs were calculated for each mRS score and health utility scale. Geographic differences in weighting for the EuroQoL 5-dimension (EQ-5D) and Stroke Impact Scale-based UW-mRS were explored using inverse variance-weighted linear models. The results of 18 major acute stroke trials cited in current guidelines were then reanalyzed using the UW-mRS weighting scales identified in the systematic review.

RESULTS

The meta-analysis included 22 389 individuals; the mean (SD) age of participants was 65.9 (4.0) years, and the mean (SD) proportion of male participants was 58.2% (7.5%). For all health utility scales evaluated, statistically significant differences were observed between the mean utility weights by mRS score. For studies using an EQ-5D-weighted mRS, between-study variance was higher for worse (mRS 2-5) compared with better (mRS 0-1) scores. Of the 18 major acute stroke trials with reanalyzed results, 3 had an unstable outcome when using different UW-mRSs.

CONCLUSIONS AND RELEVANCE

Multiple factors, including cohort-specific characteristics and health utility scale selection, can influence mRS utility weighting. If the UW-mRS is selected as a primary outcome, the approach to weighting may alter the results of a clinical trial. Researchers using the UW-mRS should prospectively and concurrently obtain mRS scores and utility weights to characterize study-specific outcomes.

Local Leukocyte Invasion during Hyperacute Human Ischemic Stroke

OBJECTIVE

Bridging the gap between experimental stroke and patients by ischemic blood probing during the hyperacute stage of vascular occlusion is crucial to assess the role of inflammation in human stroke and for the development of adjunct treatments beyond recanalization.

METHODS

We prospectively observed 151 consecutive ischemic stroke patients with embolic large vessel occlusion of the anterior circulation who underwent mechanical thrombectomy. In all these patients, we attempted microcatheter aspiration of 3 different arterial blood samples: (1) within the core of the occluded vascular compartment and controlled by (2) carotid and (3) femoral samples obtained under physiological flow conditions. Subsequent laboratory analyses comprised leukocyte counting and differentiation, platelet counting, and the quantification of 13 proinflammatory human chemokines/cytokines.

RESULTS

Forty patients meeting all clinical, imaging, interventional, and laboratory inclusion criteria could be analyzed, showing that the total number of leukocytes significantly increased under the occlusion condition. This increase was predominantly driven by neutrophils. Significant increases were also apparent for lymphocytes and monocytes, accompanied by locally elevated plasma levels of the T-cell chemoattractant CXCL-11. Finally, we found evidence that short-term clinical outcome (National Institute of Health Stroke Scale at 72 hours) was negatively associated with neutrophil accumulation.

INTERPRETATION

We provide the first direct human evidence that neutrophils, lymphocytes, and monocytes, accompanied by specific chemokine upregulation, accumulate in the ischemic vasculature during hyperacute stroke and may affect outcome. These findings strongly support experimental evidence that immune cells contribute to acute ischemic brain damage and indicate that ischemic inflammation initiates already during vascular occlusion. Ann Neurol 2020;87:466-479.

Selective retrograde cerebral cooling in complete cerebral circulatory arrest

BACKGROUND AND PURPOSE:

Cerebral hypothermia is a known neuroprotectant with promising applications in the treatment of ischemic events. Although systemic cooling is standard in post-cardiac arrest care, the deleterious effects of whole-body cooling have precluded it from translation into a viable treatment option for acute ischemic stroke (AIS). Selective cerebral cooling has been proposed as a method to minimize these risks while granting the neuroprotection of therapeutic hypothermia in AIS.

METHODS:

In a porcine model (n = 3), the efficacy of selective retrograde cerebral cooling through the internal jugular vein was evaluated in the setting of complete cerebral circulatory arrest. Furthermore, a novel endovascular device and cooling system enabling selective retrograde cerebral cooling were studied in a normothermic perfused cadaver.

RESULTS AND CONCLUSION:

Neurologic assessment of animals receiving this therapy reflected substantial neuroprotection in animals undergoing both 15 min and 30 min of otherwise catastrophic complete cerebral circulatory arrest. The novel endovascular device and cooling system were validated in human anatomy, demonstrating successful cerebral cooling, and feasibility of this mechanism of selective retrograde cerebral cooling.

Prothymosin alpha and its mimetic hexapeptide improve delayed tissue plasminogen activator-induced brain damage following cerebral ischemia

Tissue plasminogen activator (tPA) administration beyond 4.5 h of stroke symptoms is beneficial for patients but has an increased risk of cerebral hemorrhage. Thus, increasing the therapeutic window of tPA is important for stroke recovery. We previously showed that prothymosin alpha (ProTα) or its mimetic hexapeptide (P6Q) has anti-ischemic activity. Here, we examined the beneficial effects of ProTα or P6Q against delayed tPA-induced brain damage following middle cerebral artery occlusion (MCAO) or photochemically induced thrombosis in mice. Brain hemorrhage was observed by tPA administration during reperfusion at 4.5 and 6 h after MCAO. Co-administration of ProTα with tPA at 4.5 h inhibited hemorrhage and motor dysfunction 2-4 days, but not 7 days after MCAO. ProTα administration at 2 and 4.5 h after MCAO significantly inhibited tPA (4.5 h)-induced motor dysfunction and death more than 7 days. Administration of tPA caused the loss of tight junction proteins, zona occulden-1 and occludin, and up-regulation of matrix metalloproteinase-2/9, in a ProTα-reversible manner. P6Q administration abolished tPA (4.5 h)-induced hemorrhage and reversed tPA (6 h)-induced vascular damage and matrix metalloproteinase-2 and 9 up-regulation. Twice administrations of P6Q at 2 h alone and 6 h with tPA significantly improved motor dysfunction more than 7 days. In photochemically induced thrombosis ischemia, similar vascular leakage and neuronal damage (infarction and motor dysfunction) by late tPA (4.5 or 6 h) were also inhibited by P6Q. Thus, these studies suggest that co-administration with ProTα or P6Q would be beneficial to inhibit delayed tPA-induced hemorrhagic mechanisms in acute ischemic stroke.

Intravenous thrombolysis for suspected ischemic stroke with seizure at onset

OBJECTIVE

Seizure at onset (SaO) has been considered a relative contraindication for intravenous thrombolysis (IVT) in patients with acute ischemic stroke, although this appraisal is not evidence based. Here, we investigated the prognostic significance of SaO in patients treated with IVT for suspected ischemic stroke.

METHODS

In this multicenter, IVT-registry-based study we assessed the association between SaO and symptomatic intracranial hemorrhage (sICH, European Cooperative Acute Stroke Study II definition), 3-month mortality, and 3-month functional outcome on the modified Rankin Scale (mRS) using unadjusted and adjusted logistic regression, coarsened exact matching, and inverse probability weighted analyses.

RESULTS

Among 10,074 IVT-treated patients, 146 (1.5%) had SaO. SaO patients had significantly higher National Institutes of Health Stroke Scale score and glucose on admission, and more often female sex, prior stroke, and prior functional dependence than non-SaO patients. In unadjusted analysis, they had generally less favorable outcomes. After controlling for confounders in adjusted, matched, and weighted analyses, all associations between SaO and any of the outcomes disappeared, including sICH (odds ratio [OR]_unadjusted = 1.53 [95% confidence interval (CI) = 0.74-3.14], OR_adjusted = 0.52 [95% CI = 0.13-2.16], OR_matched = 0.68 [95% CI = 0.15-3.03], OR_weighted = 0.95 [95% CI = 0.39-2.32]), mortality (OR_unadjusted = 1.49 [95% CI = 1.00-2.24], OR_adjusted = 0.98 [95% CI = 0.5-1.92], OR_matched = 1.13 [95% CI = 0.55-2.33], OR_weighted = 1.17 [95% CI = 0.73-1.88]), and functional outcome (mRS ≥ 3/ordinal mRS: OR_unadjusted = 1.33 [95% CI = 0.96-1.84]/1.35 [95% CI = 1.01-1.81], OR_adjusted = 0.78 [95% CI = 0.45-1.32]/0.78 [95% CI = 0.52-1.16], OR_matched = 0.75 [95% CI = 0.43-1.32]/0.45 [95% CI = 0.10-2.06], OR_weighted = 0.87 [95% CI = 0.57-1.34]/1.00 [95% CI = 0.66-1.52]). These results were consistent regardless of whether patients had an eventual diagnosis of ischemic stroke (89/146) or stroke mimic (57/146 SaO patients).

INTERPRETATION

SaO was not an independent predictor of poor prognosis. Withholding IVT from patients with assumed ischemic stroke presenting with SaO seems unjustified. ANN NEUROL 2019;86:770-779.

Serum Uric Acid and Risk of Hemorrhagic Transformation in Patients with Acute Ischemic Stroke

Uric acid (UA) is an antioxidant with neuroprotective effects in experimental stroke models. Whether serum UA plays a role in hemorrhagic transformation (HT) remains unclear. We aimed to explore the association between serum UA and HT in patients with acute ischemic stroke (AIS). AIS patients within 7 days after stroke onset were consecutively enrolled between January 2016 and October 2017. Patients were categorized into three groups according to serum UA tertiles by sex. HT was detected by follow-up CT or MRI within 7 days after admission. The multivariate logistic analysis was performed to assess the association of serum UA with HT. We included 1230 patients (mean age 64.1 years, 63.5% males) and 133 (10.8%) patients experienced HT. After adjusting confounders, patients in the second and third UA tertiles showed a significant decrease in HT compared with those in the lowest tertile (OR 0.432, 95% CI 0.266-0.702; OR 0.033, 95% CI 0.013-0.086, respectively). Similar results were observed for sex-based subgroups. Males with higher UA had lower risk of HT compared with the lowest UA tertile (OR 0.332, 95% CI 0.170-0.651; OR 0.008, 95% CI 0.001-0.070, respectively). In females, the highest UA tertile was inversely associated with HT (OR 0.148, 95% CI 0.058-0.376). Multiple-adjusted spline regression analyses further confirmed the dose-response relationship between UA levels and HT. Higher serum UA is independently associated with lower HT following stroke. More studies are needed to elucidate the potential neuroprotective mechanism of serum UA and its link to HT.

Stem cell transplantation for ischemic stroke

BACKGROUND

Stroke is a leading cause of morbidity and mortality worldwide, with very large healthcare and social costs, and a strong demand for alternative therapeutic approaches. Preclinical studies have shown that stem cells transplanted into the brain can lead to functional improvement. However, to date, evidence for the benefits of stem cell transplantation in people with ischemic stroke is lacking. This is the first update of the Cochrane review published in 2010.

OBJECTIVES

To assess the efficacy and safety of stem cell transplantation compared with control in people with ischemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched August 2018), CENTRAL (last searched August 2018), MEDLINE (1966 to August 2018), Embase (1980 to August 2018), and BIOSIS (1926 to August 2018). We handsearched potentially relevant conference proceedings, screened reference lists, and searched ongoing trials and research registers (last searched August 2018). We also contacted individuals active in the field and stem cell manufacturers (last contacted August 2018).

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that recruited people with ischemic stroke, in any phase of the disease (acute, subacute or chronic), and an ischemic lesion confirmed by computerized tomography or magnetic resonance imaging scan. We included all types of stem cell transplantation, regardless of cell source (autograft, allograft, or xenograft; embryonic, fetal, or adult; from brain or other tissues), route of cell administration (systemic or local), and dosage. The primary outcome was efficacy (assessed as neurologic impairment or functional outcome) at longer term follow-up (minimum six months). Secondary outcomes included post-procedure safety outcomes (death, worsening of neurological deficit, infections, and neoplastic transformation).

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, assessed trial quality and risk of bias, and extracted data. If needed, we contacted study authors for additional information. We performed random effects meta-analyses when two or more RCTs were available for any outcome. We assessed the certainty of the evidence by using the GRADE approach.

MAIN RESULTS

In this updated review, we included seven completed RCTs with 401 participants. All tested adult human non-neural stem cells; cells were transplanted during the acute, subacute, or chronic phase of ischemic stroke; administered intravenously, intra-arterially, intracerebrally, or into the lumbar subarachnoid space. Follow-up ranged from six months to seven years. Efficacy outcomes were measured with the National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), or Barthel Index (BI). Safety outcomes included case fatality, and were measured at the end of the trial.Overall, stem cell transplantation was associated with a better clinical outcome when measured with the NIHSS (mean difference [MD] -1.49, 95% confidence interval [CI] -2.65 to -0.33; five studies, 319 participants; low-certainty evidence), but not with the mRS (MD -0.42, 95% CI -0.86 to 0.02; six studies, 371 participants; very low-certainty evidence), or the BI (MD 14.09, 95% CI -1.94 to 30.13; three studies, 170 participants; very low-certainty evidence). The studies in favor of stem cell transplantation had, on average, a higher risk of bias, and a sample size of 32 or fewer participants.No significant safety concerns associated with stem cell transplantation were raised with respect to death (risk ratio [RR] 0.66, 95% CI 0.39 to 1.14; six studies, participants; low-certainty evidence).We were not able to perform the sensitivity analysis according to the quality of studies, because all of them were at high risk of bias.

AUTHORS' CONCLUSIONS

Overall, in participants with ischemic stroke, stem cell transplantation was associated with a reduced neurological impairment, but not with a better functional outcome. No obvious safety concerns were raised. However, these conclusions came mostly from small RCTs with high risk of bias, and the certainty of the evidence ranged from low to very low. More well-designed trials are needed.

Long-Term Outcomes of Mechanical Thrombectomy for Stroke: A Meta-Analysis

Mechanical thrombectomy (MT) has become the standard treatment for large vessel occlusion (LVO) in acute ischemic stroke (AIS). Few studies have investigated long-term outcomes for AIS treated with MT. Therefore, a pooled meta-analysis using data from randomized clinical trials (RCT) was performed to assess for long-term clinical outcomes. A systematic literature search was conducted on 27 September 2017, by searching the English literature in the Cochrane Library, MEDLINE, and Embase for RCTs investigating long-term outcomes (greater than standard 3-month timepoint) of endovascular intervention versus medical management for patients with AIS. The study was carried out according to PRISMA guidelines and random effects analysis was carried out to account for heterogeneity. Three trials were included: IMS III, MR CLEAN, and REVASCAT, comprising a total of 1,362 patients. Long-term clinical outcomes were available for 1-year follow-up in IMS III and REVASCAT and at 2 years in MR CLEAN. Functional independence at long-term follow-up favored endovascular stroke intervention (OR 1.51; p = 0.02). When stratified by LVO inclusion criteria, greater endovascular functional independence benefits were observed (OR 1.85; p = 0.0005). There was a significant difference between the 2 arms in favor of endovascular therapy for the quality of life at long-term follow-up (mean difference 0.11; p = 0.0002). No difference in mortality at long-term follow-up was observed (OR 0.82; p = 0.12). We conclude that endovascular therapy results in favorable outcomes at long-term follow-up for patients with acute ischemic stroke compared to standard medical treatment alone and that the 90-day timepoint offers a fair representation of the long-term outcomes.