Thrombus Composition and Efficacy of Thrombolysis and Thrombectomy in Acute Ischemic Stroke

The advantages of multi-level omics research on stem cell-based therapies for ischemic stroke

Stem cell transplantation is a potential therapeutic strategy for ischemic stroke. However, despite many years of preclinical research, the application of stem cells is still limited to the clinical trial stage. Although stem cell therapy can be highly beneficial in promoting functional recovery, the precise mechanisms of action that are responsible for this effect have yet to be fully elucidated. Omics analysis provides us with a new perspective to investigate the physiological mechanisms and multiple functions of stem cells in ischemic stroke. Transcriptomic, proteomic, and metabolomic analyses have become important tools for discovering biomarkers and analyzing molecular changes under pathological conditions. Omics analysis could help us to identify new pathways mediated by stem cells for the treatment of ischemic stroke via stem cell therapy, thereby facilitating the translation of stem cell therapies into clinical use. In this review, we summarize the pathophysiology of ischemic stroke and discuss recent progress in the development of stem cell therapies for the treatment of ischemic stroke by applying multi-level omics. We also discuss changes in RNAs, proteins, and metabolites in the cerebral tissues and body fluids under stroke conditions and following stem cell treatment, and summarize the regulatory factors that play a key role in stem cell therapy. The exploration of stem cell therapy at the molecular level will facilitate the clinical application of stem cells and provide new treatment possibilities for the complete recovery of neurological function in patients with ischemic stroke.

The cerebroprotection and prospects of FNDC5/irisin in stroke

Stroke, the leading cause of disability and cognitive impairment, is also the second leading cause of death worldwide. The drugs with multi-targeted brain cytoprotective effects are increasingly being advocated for the treatment of stroke. Irisin, a newly discovered myokine produced by cleavage of fibronectin type III domain 5, has been shown to regulate glucose metabolism, mitochondrial energy, and fat browning. A large amount of evidence indicated that irisin could exert anti-inflammatory, anti-apoptotic, and antioxidant properties in a variety of diseases such as myocardial infarction, inflammatory bowel disease, lung injury, and kidney or liver disease. Studies have found that irisin is widely distributed in multiple brain regions and also plays an important regulatory role in the central nervous system. The most common cause of a stroke is a sudden blockage of an artery (ischemic stroke), and in some circumstances, a blood vessel rupture can also result in a stroke (hemorrhagic stroke). After a stroke, complicated pathophysiological processes lead to serious brain injury and neurological dysfunction. According to recent investigations, irisin may protect elements of the neurovascular unit by acting on multiple pathological processes in stroke. This review aims to outline the currently recognized effects of irisin on stroke and propose possible directions for future research.

Ethanolic extract of Arctium lappa leaves alleviates cerebral ischemia reperfusion-induced inflammatory injury via HDAC9-mediated NF-κB pathway

BACKGROUND

Ischemic stroke (IS) is a major cause of mortality and disability worldwide. Inflammatory response is crucial in the pathogenesis of tissue injury in cerebral infarction. Arctium lappa leaves are traditionally used to treat IS.

PURPOSES

To investigate the neuroprotective effects and molecular mechanisms of the ethanolic extract of A. lappa leaves (ALLEE) on cerebral ischemia-reperfusion (CIR).

METHODS

Middle cerebral artery obstruction reperfusion (MCAO/R) rats and an oxygen-glucose deprivation/reoxygenation (OGD/R) cell model were used to evaluate ALLEE pharmacodynamics. Various methods, including neurological function, 2,3,5-triphenyltetrazolium chloride, hematoxylin and eosin, and Nissl, enzyme-linked immunosorbent, and TdT-mediated dUTP nick-end labeling assays, were used to analyze the neuroprotective effects of ALLEE in vitro and in vivo. The major chemical components and potential target genes of ALLEE were screened using network pharmacology. Molecular docking, western blotting, and immunofluorescence analyses were performed to confirm the effectiveness of the targets in related pathways.

RESULTS

ALLEE exerted potent effects on the MCAO/R model by decreasing the neurological scores, infarct volumes, and pathological features (p < 0.01). Furthermore, network pharmacology results revealed that the treatment of IS with ALLEE involved the regulation of various inflammatory pathways, such as the tumor necrosis factor (TNF) and chemokine signaling pathways. ALLEE also played key roles in targeting key molecules, including nuclear factor (NF)-κBIA, NF-κB1, interleukin (IL)-6, TNF-α and IL1β, and regulating the histone deacetylase (HDAC)-9-mediated signaling pathway. In vivo and in vitro analyses revealed that ALLEE significantly regulated the NF-κB pathway, promoted the phosphorylation activation of NF-κB P65, IκB and IKK (p < 0.01 or p < 0.05), and decreased the expression levels of the inflammatory factors, IL-1β, IL-6 and TNF-α (p < 0.01). Moreover, ALLEE significantly decreased the expression of HDAC9 (p < 0.01) that is associated with inflammatory responses. However, HDAC9 overexpression partially reversed the neuroprotective effects of ALLEE and its suppressive effects on inflammation and phosphorylation of NF-κB (p < 0.01).

CONCLUSIONS

In conclusion, our results revealed that ALLEE ameliorates MCAO/R-induced experimental CIR by modulating inflammatory responses via the inhibition of HDAC9-mediated NF-κB pathway.

THSG alleviates cerebral ischemia/reperfusion injury via the GluN2B-CaMKII-ERK1/2 pathway

BACKGROUND

The potential therapeutic targeting of PINK1-PARK2-mediated mitophagy against cerebral ischemia/reperfusion (CI/R) injury involves the pathophysiological processes of neurovascular unit (NVU) and is closely associated with N-methyl-D-aspartate receptors (NMDARs) commonly expressed in NVU. 2,3,5,4'-Tetrahydroxy-stilbene-2-O-β-D-glucoside (THSG), a compound derived from the traditional Chinese medicine Polygonum multiflorum Thunb., has demonstrated notable neuroprotective properties against CI/R injury. However, it remains unclear whether THSG exerts its protective effects through GluN2B related PINK1/ PARK2 pathway.

PURPOSE

This study aims to explore the pharmacological effects of THSG on alleviating CI/R injury via the GluN2B-CaMKII-ERK1/2 pathway.

METHODS

THSG neuroprotection against CI/R injury was studied in transient middle cerebral artery occlusion/reversion (tMCAO/R) model rats and in oxygen and glucose deprivation/ reoxygenation (OGD/R) induced neurons. PINK1-PARK2-mediated mitophagy involvement in the protective effect of THSG was investigated in tMCAO/R rats and OGD/R-induced neurons via THSG and 3-methyladenine (3-MA) treatment. Furthermore, the beneficial role of GluN2B in reperfusion and its contribution to the THSG effect via CaMKII-ERK1/2 and PINK1-PARK2-mediated mitophagy was explored using the GluN2B-selective antagonist Ro 25-6981 both in vivo and in vitro. Finally, the interaction between THSG and GluN2B was evaluated using molecular docking.

RESULTS

THSG significantly reduced infarct volume, neurological deficits, penumbral neuron structure, and functional damage, upregulated the inhibitory apoptotic marker Bcl-2, and suppressed the increase of pro-apoptotic proteins including cleaved caspase-3 and Bax in tMCAO/R rats. THSG (1 μM) markedly improved the neuronal survival under OGD/R conditions. Furthermore, THSG promoted PINK1 and PARK2 expression and increased mitophagosome numbers and LC3-II-LC3-I ratio both in vivo and in vitro. The effects of THSG were considerably abrogated by the mitophagy inhibitor 3-MA in OGD/R-induced neurons. Inhibiting GluN2B profoundly decreased mitophagosome numbers and OGD/R-induced neuronal viability. Specifically, inhibiting GluN2B abolished the protection of THSG against CI/R injury and reversed the upregulation of PINK1-PARK2-mediated mitophagy by THSG. Inhibiting GluN2B eliminated THSG upregulation of ERK1/2 and CaMKII phosphorylation. The molecular docking analysis results demonstrated that THSG bound to GluN2B (binding energy: -5.2 ± 0.11 kcal/mol).

CONCLUSIONS

This study validates the premise that THSG alleviates CI/R injury by promoting GluN2B expression, activating CaMKII and ERK1/2, and subsequently enhancing PINK1-PARK2-mediated mitophagy. This work enlightens the potential of THSG as a promising candidate for novel therapeutic strategies for treating ischemic stroke.

Utilizing network pharmacology, molecular docking, and animal models to explore the therapeutic potential of the WenYang FuYuan recipe for cerebral ischemia-reperfusion injury through AGE-RAGE and NF-κB/p38MAPK signaling pathway modulation

BACKGROUND

Stroke is a debilitating condition with high morbidity, disability, and mortality that significantly affects the quality of life of patients. In China, the WenYang FuYuan recipe is widely used to treat ischemic stroke. However, the underlying mechanism remains unknown, so exploring the potential mechanism of action of this formula is of great practical significance for stroke treatment.

OBJECTIVE

This study employed network pharmacology, molecular docking, and in vivo experiments to clarify the active ingredients, potential targets, and molecular mechanisms of the WenYang FuYuan recipe in cerebral ischemia-reperfusion injury, with a view to providing a solid scientific foundation for the subsequent study of this recipe.

MATERIALS AND METHODS

Active ingredients of the WenYang FuYuan recipe were screened using the traditional Chinese medicine systems pharmacology database and analysis platform. Network pharmacology approaches were used to explore the potential targets and mechanisms of action of the WenYang FuYuan recipe for the treatment of cerebral ischemia-reperfusion injury. The Middle Cerebral Artery Occlusion/Reperfusion 2 h Sprague Dawley rat model was prepared, and TTC staining and modified neurological severity score were applied to examine the neurological deficits in rats. HE staining and Nissl staining were applied to examine the pathological changes in rats. Immunofluorescence labeling and Elisa assay were applied to examine the expression levels of certain proteins and associated factors, while qRT-PCR and Western blotting were applied to examine the expression levels of linked proteins and mRNAs in disease-related signaling pathways.

RESULTS

We identified 62 key active ingredients in the WenYang FuYuan recipe, with 222 highly significant I/R targets, forming 138 pairs of medication components and component-targets, with the top five being Quercetin, Kaempferol, Luteolin, β-sitosterol, and Stigmasterol. The key targets included TP53, RELA, TNF, STAT1, and MAPK14 (p38MAPK). Targets related to cerebral ischemia-reperfusion injury were enriched in chemical responses, enzyme binding, endomembrane system, while enriched pathways included lipid and atherosclerosis, fluid shear stress and atherosclerosis, AGE-RAGE signaling in diabetic complications. In addition, the main five active ingredients and targets in the WenYang FuYuan recipe showed high binding affinity (e.g. Stigmasterol and MAPK14, total energy <-10.5 Kcal/mol). In animal experiments, the WenYang FuYuan recipe reduced brain tissue damage, increased the number of surviving neurons, and down-regulated S100β and RAGE protein expression. Moreover, the relative expression levels of key targets such as TP53, RELA and p38MAPK mRNA were significantly down-regulated in the WenYang FuYuan recipe group, and serum IL-6 and TNF-a factor levels were reduced. After WenYang FuYuan recipe treatment, the AGE-RAGE signaling pathway and downstream NF-kB/p38MAPK signaling pathway-related proteins were significantly modulated.

CONCLUSION

This study utilized network pharmacology, molecular docking, and animal experiments to identify the potential mechanism of the WenYang FuYuan recipe, which may be associated with the regulation of the AGE-RAGE signaling pathway and the inhibition of target proteins and mRNAs in the downstream NF-kB/p38MAPK pathway.

How Topographic Diffusion-Weighted Imaging Patterns can Predict the Potential Embolic Source

PURPOSE

To develop an imaging prediction model for patients with embolic stroke of undetermined source (ESUS), we investigated the association of topographic diffusion-weighted imaging (DWI) patterns with potential embolic sources (PES) identified by transesophageal echocardiography.

METHODS

From a total of 992 consecutive patients with embolic stroke, 366 patients with the ESUS group were selected. ESUS was defined as no atrial fibrillation (Af) within 24h from admission and no PES after general examination. Clinical variables include age (> 80years, 70-80 years), sex, vascular risk factors and left atrial diameter > 4 cm. Age, sex and vascular risk factors adjusted odds ratio of each DWI for the different PESs were calculated. DWI was determined based on the arterial territories. Middle cerebral arteries were divided into 4 segments, i.e., M1-M4. Moreover, M2 segments were subdivided into superior and inferior branches.

RESULTS

The 366 patients consisted of 168 with paroxysmal Af (pAf), 77 with paradoxical embolism, 71 with aortic embolism and 50 with undetermined embolism after transesophageal echocardiography. The variables adjusted odds ratio (OR) of internal carotid artery (OR: 12.1, p = 0.037), M1 (4.2, p = 0.001), inferior M2 (7.5, p = 0.0041) and multiple cortical branches (12.6, p < 0.0001) were significantly higher in patients with pAf. Striatocapsular infarction (12.5, p < 0.0001) and posterior inferior cerebellar artery infarcts (3.6, p = 0.018) were significantly associated with paradoxical embolism. Clinical variables adjusted OR of multiple small scattered infarcts (8.3, p < 0.0001) were significantly higher in patients with aortic embolism.

CONCLUSION

The associations of DWI with different PES have their distinctive characteristics and DWI along with clinical variables may help predict PES in patients with ESUS.

Systemic biomarker associated with poor outcome after futile reperfusion

BACKGROUND

Successful recanalization does not lead to complete tissue reperfusion in a considerable percentage of ischemic stroke patients. This study aimed to identify biomarkers associated with futile recanalization. Leukoaraiosis predicts poor outcomes of this phenomenon. Soluble tumour necrosis factor-like weak inducer of apoptosis (sTWEAK), which is associated with leukoaraiosis degrees, could be a potential biomarker.

METHODS

This study includes two cohorts of ischemic stroke patients in a multicentre retrospective observational study. Effective reperfusion, defined as a reduction of ≥8 points in the National Institutes of Health Stroke Scale (NIHSS) within the first 24 h, was used as a clinical marker of effective reperfusion.

RESULTS

In the first cohort study, female sex, age, and high NIHSS at admission (44.7% vs. 81.1%, 71.3 ± 13.7 vs. 81.1 ± 6.7; 16 [13, 21] vs. 23 [17, 28] respectively; p < .0001) were confirmed as predictors of futile recanalization. ROC curve analysis showed that leukocyte levels (sensitivity of 99%, specificity of 55%) and sTWEAK level (sensitivity of 92%, specificity of 88%) can discriminate between poor and good outcomes. Both biomarkers simultaneously are higher associated with outcome after effective reperfusion (OR: 2.17; CI 95% 1.63-4.19; p < .0001) than individually (leukocytes OR: 1.38; CI 95% 1.00-1.64, p = .042; sTWEAK OR: 1.00; C I95% 1.00-1.01, p = .019). These results were validated using a second cohort, where leukocytes and sTWEAK showed a sensitivity of 100% and specificity of 66.7% and 75% respectively.

CONCLUSIONS

Leukocyte and sTWEAK could be biomarkers of reperfusion failure and subsequent poor outcomes. Further studies will be necessary to explore its role in reperfusion processes.

Thrombus histology does not predict stroke etiological subtype but influences recanalization

BACKGROUND

There is conflicting data on whether clot retrieved from mechanical thrombectomy can predict stroke etiology or the success of recanalization. We aimed to analyse the relation between thrombus histology and stroke aetiology as well as recanalization.

METHODOLOGY

Histopathological analysis of clots retrieved from patients with acute ischemic stroke and large vessel occlusion was done. Quantification of the amount of fibrin, red blood cells(RBC), platelets and white blood cells (WBC) in the clots were done. The clinical, imaging data and recanalization parameters were collected. The correlation between clot composition and stroke etiology as well as recanalization were analysed.

RESULTS

Of the 77 patients, the mean age was 58. 67 ± 12.96 years. The stroke etiology were cardioembolism 44(57.1 %), large artery atherosclerosis 13(16.8 %), other determined aetiology 4(5.1 %) and undetermined in 16(20.7 %) patients. There was no significant correlation between the proportions of RBC-rich, platelet-rich and fibrin-rich thrombi and the stroke etiology. The susceptibility vessel sign was associated with RBC-rich clot(92.3 % vs 7.7 %, p = .03). All RBC-rich clots(100 %) had good recanalization(p = .05). Platelet-rich clots needed less number of passes(64.7 % vs 35.3 %, p = .006) and reduced groin puncture to recanalization time(87.9 % vs 12.1 %, p = .033). WBC-rich clots required lesser number of passes(57.5 % vs 42.5 %, P = .044). In multivariate analysis, WBC-rich clots (OR 0.230, CI 0.07-0.78, p = .018) showed an independent association with reduced recanalization attempts, while platelet-rich clots showed reduced recanalization time(OR 0.09, CI 0.01-0.63, p = .016).

CONCLUSION

There was no correlation between thrombus histology and the etiological stroke subtype. However, clot composition predicted the degree of recanalization and number of passes.

Relationship between thrombus composition and prognosis in patients with acute ischemic stroke undergoing mechanical thrombectomy

BACKGROUND

Mechanical thrombectomy has emerged as the primary endovascular treatment for acute ischemic stroke. Numerous studies have investigated the relationship between thrombus composition and factors such as pharmacological thrombolysis, stroke etiology, mechanical thrombectomy, and radiological imaging. However, limited research has explored the association between thrombus composition and clinical outcomes.

METHODS

This retrospective analysis examined the histopathological examination of thrombi retrieved from 50 patients with acute ischemic stroke between May 2020 and May 2023. The composition of the retrieved thrombi was assessed using HE staining to quantify the proportions of red blood cells, white blood cells, platelets, and fibrin. Based on the predominant composition of the thrombus, the patients were divided into two groups: erythrocyte-rich and fibrin-rich. Demographics, clinical characteristics, and clinical outcomes assessed by the National Institutes of Health Stroke Scale (NIHSS) score and modified Rankin Scale (mRS) scores were collected retrospectively.

RESULT

Of the 50 patients, 23 were classified in the erythrocyte-rich group, and 27 were classified in the fibrin-rich group. There were no significant differences between the two groups in terms of age, sex, stroke subtype, history of hypertension and diabetes, thrombus location, NIHSS scores, mRS scores on admission, the time interval from symptom onset to hospitalization and reperfusion, or the rate of successful reperfusion. However, erythrocyte-rich thrombi were associated with a shorter time interval from puncture to reperfusion. No significant differences were found in the red blood cell fraction and fibrin/platelet fraction between large artery atherosclerosis and cardioembolism. At the 90-day follow-up, patients with erythrocyte-rich thrombi exhibited lower NIHSS scores and more favorable functional outcomes (mRS scores of 0-2) compared to those with fibrin-rich thrombi.

CONCLUSION

Erythrocyte-rich thrombi were linked to shorter time intervals from puncture to reperfusion and favorable clinical outcomes in patients with acute ischemic stroke. The composition of the thrombus may influence the thrombectomy strategy for endovascular therapy.

Relationship between thrombus vWF and NETs with clinical severity and peripheral blood immunocytes' indicators in patients with acute ischemic stroke

OBJECTIVE

To investigate the association between von Willebrand factor (vWF) and neutrophil extracellular traps (NETs) in thrombus with clinical severity and peripheral blood immunocytes' indicators in patients with early-stage acute ischemic stroke (AIS).

METHODS

A retrospective study was conducted using the clinical data of 66 patients with AIS who underwent endovascular mechanical thrombectomy and had their thrombus samples collected. The concentrations of vWF and NETs in the thrombus samples were quantitatively assessed. Peripheral blood samples taken in the early stages of the disease were analyzed for total white blood cell counts (WBC), ratios of neutrophils (NEU%), lymphocytes (LYM%), eosinophils (EOS%), and monocytes (MONO%). The severity of clinical symptoms in these patients was evaluated using the modified Rankin Scale (mRS), Essen Stroke Risk Score (ESRS), Barthel Index (BI), and National Institute of Health Stroke Scale (NIHSS).

RESULTS

Higher vWF levels in thrombus were associated with lower NIHSS scores, while higher NETs levels were associated with higher initial NIHSS scores. In the early stages of AIS, WBC count and vWF levels were negatively correlated, as well as NEU%. LYM% was positively correlated with vWF level; however, it was negatively correlated with NETs. EOS% was positively correlated with vWF levels.

CONCLUSION

In the early stages of AIS, a higher peripheral WBC count and NEU%, combined with decreased EOS% and LYM%, were significantly correlated with a lower vWF level in the thrombus, potentially indicating more severe symptoms. Consequently, the timely administration of vWF-targeted medications is recommended for such patients. Reduced LYM% is indicative of elevated NETs levels and correlated with more severe clinical symptoms. Therefore, the prompt initiation of NETs-targeted medication is warranted for these patients.

Activation of Inflammasomes and Relevant Modulators for the Treatment of Microglia-mediated Neuroinflammation in Ischemic Stroke

As the brain's resident immune patrol, microglia mediate endogenous immune responses to central nervous system injury in ischemic stroke, thereby eliciting either neuroprotective or neurotoxic effects. The association of microglia-mediated neuroinflammation with the progression of ischemic stroke is evident through diverse signaling pathways, notably involving inflammasomes. Within microglia, inflammasomes play a pivotal role in promoting the maturation of interleukin-1β (IL-1β) and interleukin-18 (IL-18), facilitating pyroptosis, and triggering immune infiltration, ultimately leading to neuronal cell dysfunction. Addressing the persistent and widespread inflammation holds promise as a breakthrough in enhancing the treatment of ischemic stroke.

Application and advances of biomimetic membrane materials in central nervous system disorders

Central nervous system (CNS) diseases encompass spinal cord injuries, brain tumors, neurodegenerative diseases, and ischemic strokes. Recently, there has been a growing global recognition of CNS disorders as a leading cause of disability and death in humans and the second most common cause of death worldwide. The global burdens and treatment challenges posed by CNS disorders are particularly significant in the context of a rapidly expanding global population and aging demographics. The blood-brain barrier (BBB) presents a challenge for effective drug delivery in CNS disorders, as conventional drugs often have limited penetration into the brain. Advances in biomimetic membrane nanomaterials technology have shown promise in enhancing drug delivery for various CNS disorders, leveraging properties such as natural biological surfaces, high biocompatibility and biosafety. This review discusses recent developments in biomimetic membrane materials, summarizes the types and preparation methods of these materials, analyzes their applications in treating CNS injuries, and provides insights into the future prospects and limitations of biomimetic membrane materials.

Idarucizumab in dabigatran-treated patients with acute stroke: a review and clinical update

Idarucizumab is an antibody fragment specific for the immediate reversal of dabigatran anticoagulation effects. The use of idarucizumab is approved for dabigatran-treated patients suffering from life-threatening or uncontrolled bleeding and those in need of urgent surgery or invasive procedures. Data from randomized controlled clinical trials and real-world experience provide reassuring evidence about the efficacy and safety of idarucizmab use in patients with acute stroke. In this narrative review, we summarize the available real-world evidence and discuss the relevance and importance of idarucizumab treatment in acute stroke patients in everyday clinical practice. In addition, we also discuss special issues like prothrombin complex concentrate application as an alternative to idarucizumab, its application before endovascular therapy, sensitivity of thrombi to lysis, and necessary laboratory examinations.

Minimally invasive vagus nerve stimulation modulates mast cell degranulation via the microbiota-gut-brain axis to ameliorate blood-brain barrier and intestinal barrier damage following ischemic stroke

Mast cells (MCs) play a significant role in various diseases, and their activation and degranulation can trigger inflammatory responses and barrier damage. Several studies have indicated that vagus nerve stimulation (VNS) exerts ameliorates neurological injury, and regulates gut MC degranulation. However, there is limited research on the modulatory effect of VNS on MCs in both the gut and brain in brain ischemia-reperfusion (I/R) injury in this process. We aim to develop a minimally invasive, targeted and convenient VNS approach to assess the impact of VNS and to clarify the relationship between VNS and MCs on the prognosis of acute ischemic stroke. We utilized middle cerebral artery occlusion/reperfusion (MCAO/r) to induce brain I/R injury. After the experiment, the motor function and neurofunctional impairments of the rats were detected, and the gastrointestinal function, blood-brain barrier (BBB) and intestinal barrier damage, and systemic and local inflammation were evaluated by Nissl, TTC staining, Evans blue, immunofluorescence staining, transmission electron microscopy, western blot assays, ELISA, and fecal 16S rRNA sequencing methods. Our research confirmed that our minimally invasive VNS method is a novel approach for stimulating the vagus nerve. VNS alleviated motor deficits and gastrointestinal dysfunction while also suppressing intestinal and neuroinflammation. Additionally, VNS ameliorated gut microbiota dysbiosis in rats. Furthermore, our analysis indicated that VNS reduces chymase secretion by modulating MCs degranulation and improves intestinal and BBB damage. Our results showed that VNS treatment can alleviate the damage of BBB and colonic barrier after cerebral I/R by modulating mast cell degranulation, and alleviates systemic inflammatory responses.

DCPIB Attenuates Ischemia-Reperfusion Injury by Regulating Microglial M1/M2 Polarization and Oxidative Stress

The inflammatory response plays an indispensable role in ischemia-reperfusion injury, the most significant of which is the inflammatory response caused by microglial polarization. Anti-inflammatory therapy is also an important remedial measure after failed vascular reconstruction. Maintaining the internal homeostasis of the brain is a crucial measure for suppressing the inflammatory response. The mechanism underlying the relationship between DCPIB, a selective blocker of volume-regulated anion channels (VRAC), and inflammation induced by cerebral ischemia-reperfusion injury is currently unclear. The purpose of this study was to investigate the relationship between DCPIB and microglial M1/M2 polarization-mediated inflammation after cerebral ischemia-reperfusion injury. C57BL/6 mice were subjected to transient middle cerebral artery occlusion (tMCAO). DCPIB was administered by a lateral ventricular injection within 5 min after reperfusion. Behavioral assessments were conducted at 1, 3, and 7 days after tMCAO/R. Pathological injuries were evaluated using TTC assay, HE and Nissl staining, brain water content measurement, and immunofluorescence staining. The levels of inflammatory cytokines were analyzed using qPCR and ELISA. Additionally, the phenotypic variations of microglia were examined using immunofluorescence staining. In mouse tMCAO/R model, DCPIB administration markably reduced mortality, improved behavioral performance, and alleviated pathological injury. DCPIB treatment significantly inhibited the inflammatory response, promoted the conversion of M1 microglia to M2 microglia via the MAPK signaling pathway, and ultimately protected neurons from the microglia-mediated inflammatory response. In addition, DCPIB inhibited oxidative stress induced by cerebral ischemia-reperfusion injury. In conclusion, DCPIB attenuates cerebral ischemia-reperfusion injury by regulating microglial M1/M2 polarization and oxidative stress.

Effects of a step-by-step inpatient rehabilitation program on self-care ability and quality of life in patients with acute cerebral infarction following intravascular stent implantation: a prospective cohort study

Objective

This study aims to evaluate the influence of a step-by-step inpatient rehabilitation program (SIRP) on the self-care capability and quality of life of patients who have undergone intravascular stent implantation to treat large vessel occlusion during acute cerebral infarction (ACI).

Methods

This study included a cohort of 90 patients with ACI who received intravascular stent implantations at a tertiary hospital in the Third Affiliated Hospital of Anhui Medical University from January 2020 to February 2024. The patients were followed up for at least 3 months. Cohort grouping was based on the type of nursing care each patient received. The observation group participated in SIRP along with receiving routine nursing care, whereas the control group received only routine nursing care. Key outcome measures included the Barthel index, the National Institute of Health Stroke Scale (NIHSS) score, the incidence of complications, length of hospital stay, and 36-item short-form survey (SF-36) scores. These parameters were compared between the two groups.

Results

At the time of admission, there were no significant differences in demographic data, NIHSS score, Barthel index, or SF-36 scores between the observation and control groups (all p > 0.05). However, at 3 months postoperatively, the observation group showed significant improvements, with higher average scores in the Barthel index (62.49 ± 7.32 vs. 53.16 ± 4.37, p < 0.001) and SF-36 scores (502.33 ± 14.28 vs. 417.64 ± 9.65, p < 0.001). Additionally, this group had significantly lower NIHSS scores (3.38 ± 1.19 vs. 10.24 ± 2.10, p < 0.001), fewer complications (3 vs. 15, p = 0.002), and shorter hospital stays (12.40 ± 1.68 vs. 15.56 ± 1.87, p < 0.001).

Conclusion

Implementing SIRP notably enhanced self-care capabilities and overall quality of life, while also reducing complication rates and the length of hospital stays for patients with ACI who underwent intravascular stent implantation. This underscores the potential benefits of incorporating structured rehabilitation programs in the treatment and recovery processes of such patients.

Mechanical Thrombectomy in Anticoagulated Patients With Acute Ischemic Stroke: A Meta-Analysis

BACKGROUND

According to a previous studies, mechanical thrombectomy(MT) is safe for anticoagulated patients. However, the safety and prognosis of direct oral anticoagulants (DOACs) and vitamin K antagonists (VKA) have not been compared with those of MT.This meta-analysis aimed at determining the efficacy of DOACs or VKA for patients after MT.

REVIEW SUMMARY

We searched PubMed, Embase, Web of Science databases, and Cochrane from their inception to Aug 2022. Revman 5.3 served for the meta-analysis. The meta-analysis included 12 studies that covered 3571 patients, finding that after MT treatment, DOACs significantly decreased the symptomatic intracerebral hemorrhage [odd ratio (OR)=0.49, 95% CI 0.30-0.80, P =0.004] and mortality (OR=0.63, 95% CI 0.48-0.83, P =0.001) compared with VKA. Meanwhile, no obvious differences were found between DOACs and VKA after MT treatment in terms of in any hemorrhagic transformation (OR=1.07, 95% CI 0.84-1.37, P =0.59), good functional outcome (OR=1.06, 95% CI 0.88-1.27, P =0.53), and successful arterial recanalization (OR=1.24, 95% CI 1.00-1.53, P =0.05).

CONCLUSIONS

This meta-analysis demonstrates that the application of DOACs in MT treatment for anticoagulated patients with acute ischemic stroke is safer than that in the VKA group. However, further studies are necessary to confirm these results.

Carotid Artery Perivascular Adipose Tissue Density and Response to Intravenous Tissue Plasminogen Activator in Acute Ischemic Stroke

The importance of Carotid Artery Perivascular Adipose Tissue Density (CAPATd), a parameter that can be readily evaluated on emergency computed tomographic angiography (CTA), in acute stroke has not been adequately clarified. We created exploratory logistic regression models to detect the interaction between the effect of CAPATd and intravenous (IV) tissue plasminogen activator (tPA) in 174 patients (mean age 71 ± 14 years, 94 women) with acute ischemic stroke treated with IV-tPA alone. The CAPATd-average mean (-60.6 ± 18.7 vs -89.8 ± 25.3 Hounsfield units (HU), P = .002) and CAPATd-maximum (14.8 ± 68.9 vs -20.5 ± 39.8 HU, P = .020) values were higher on the ipsilateral side of carotid artery stenosis >60%. CAPATd-maximum ipsilateral emerged as an independent predictor for both modified Rankin's Score 0-2 (52%) [exp(β) = .984] and mRS 0-1 outcome (32%) [exp(β) = .828] in addition to admission National Institutes of Health Stroke Scale, age and carotid plaque burden. CAPATd-maximum ipsilateral was acceptably accurate (Area under the Receiver operating characteristic Curve was .607, P = .0109 for mRS 0-2 and .613, P = .0102 for mRS 0-1). Ipsilateral CAPATd ≥ -25 HU predicted both mRS >3 and mRS >2 with usable sensitivity (59.8% and 66.07%) and specificity (63.6% and 59.68%). In conclusion, higher maximum CAPATd measured on emergency CTA indicates poorer functional prognosis in acute stroke patients treated with IV-tPA.

Innovations in Breaking Barriers: Liposomes as Near-Perfect Drug Carriers in Ischemic Stroke Therapy

Liposomes, noted for their tunable particle size, surface customization, and varied drug delivery capacities, are increasingly acknowledged in therapeutic applications. These vesicles exhibit surface flexibility, enabling the incorporation of targeting moieties or peptides to achieve specific targeting and avoid lysosomal entrapment. Internally, their adaptable architecture permits the inclusion of a broad spectrum of drugs, contingent on their solubility characteristics. This study thoroughly reviews liposome fabrication, surface modifications, and drug release mechanisms post-systemic administration, with a particular emphasis on drugs crossing the blood-brain barrier (BBB) to address lesions. Additionally, the review delves into recent developments in the use of liposomes in ischemic stroke models, offering a comparative evaluation with other nanocarriers like exosomes and nano-micelles, thereby facilitating their clinical advancement.

Observation of efficacy of rt-PA thrombolysis combined with Solitaire AB stent mechanical thrombectomy in patients with acute ischemic stroke: a retrospective analysis

OBJECTIVE

To observe and analyze the efficacy of recombinant tissue-plasminogen activator (rt-PA) thrombolysis combined with Solitaire AB stent mechanical thrombectomy in patients with acute ischemic stroke.

METHODS

Clinical efficacy, neurological function, oxidative stress response, adverse reactions, and quality of life were compared between the two groups.

RESULTS

Lower NIHSS scores were observed among patients who received treatment within 2 h after stroke onset when compared with those in a timeframe of 2-6 h, suggesting better neurological function recovery of the patients with early intervention and thus emphasizing the importance of early treatment for patients with stroke onset. Clinical efficacy in the combination group was significantly higher than in the control group (p < 0.05). After treatment, Paraoxonase-1 (PON-1) levels were higher, while lipoprotein-associated phospholipase A2 (Lp-PLA2) and Serum Amyloid A (SAA) levels were lower in the combination group compared to the control group (p < 0.05). The incidence of adverse reactions was significantly lower in the combination group (p < 0.05). At discharge, we observed significantly more patients with good recovery in the combination group when compared to the control group (p < 0.05), suggesting better quality of life of the patients, while this statistical significance was no longer observable at 90 days after discharge (p > 0.05).

CONCLUSION

For acute ischemic stroke patients, rt-PA thrombolysis combined with Solitaire AB stent mechanical thrombectomy treatment is effective. It promotes neurological function recovery, improves vascular stenosis, reduces inflammation and adverse reactions, and enhances quality of life, showing promising clinical applications.

FDA compound library screening Baicalin upregulates TREM2 for the treatment of cerebral ischemia-reperfusion injury

Acute ischemic stroke (AIS) is a leading cause of global incidence and mortality rates. Oxidative stress and inflammation are key factors in the pathogenesis of AIS neuroinjury. Therefore, it is necessary to develop drugs that target neuroinflammation and oxidative stress in AIS. The Triggering Receptor Expressed on Myeloid Cells 2 (TREM2), primarily expressed on microglial cell membranes, plays a critical role in reducing inflammation and oxidative stress in AIS. In this study, we employed a high-throughput screening (HTS) strategy to evaluate 2625 compounds from the (Food and Drug Administration) FDA library in vitro to identify compounds that upregulate the TREM2 receptor on microglia. Through this screening, we identified Baicalin as a potential drug for AIS treatment. Baicalin, a flavonoid compound extracted and isolated from the root of Scutellaria baicalensis, demonstrated promising results. Next, we established an in vivo mouse model of cerebral ischemia-reperfusion injury (MCAO/R) and an in vitro microglia cell of oxygen-glucose deprivation reperfusion (OGD/R) to investigate the role of Baicalin in inflammation injury, oxidative stress, and neuronal apoptosis. Our results showed that baicalin effectively inhibited microglia activation, reactive oxygen species (ROS) production, and inflammatory responses in vitro. Additionally, baicalin suppressed neuronal cell apoptosis. In the in vivo experiments, baicalin not only improved neurological functional deficits and reduced infarct volume but also inhibited microglia activation and inflammatory responses. Overall, our findings demonstrate the efficacy of Baicalin in treating MCAO/R by upregulating TREM2 to reduce inflammatory responses and inhibit neuronal apoptosis.

Association of Time to Thrombolysis With Early Reperfusion After Alteplase and Tenecteplase in Patients With Large Vessel Occlusion

BACKGROUND AND OBJECTIVES

Early treatment with intravenous alteplase increases the probability of lytic-induced reperfusion in large vessel occlusion (LVO) patients. The relationship of tenecteplase-induced reperfusion and the timing of thrombolytic administration has not been explored. In this study, we performed a comparative analysis of tenecteplase and alteplase reperfusion rates and assessed their relationship to the time of thrombolytic administration.

METHODS

Patients who were initially treated with a thrombolytic within 4.5 hours of symptom onset were pooled from the Royal Melbourne Stroke Registry, EXTEND-IA, EXTEND-IA TNK, and EXTEND-IA TNK part 2 trials. The primary outcome, thrombolytic-induced reperfusion, was defined as the absence of retrievable thrombus or >50% reperfusion at initial angiographic assessment (or repeat CT perfusion/angiography). We compared the treatment effect of tenecteplase and alteplase through fixed-effects Poisson regression modelling.

RESULTS

Among 846 patients included in the primary analysis, early reperfusion was observed in 173 (20%) patients (tenecteplase: 98/470 [21%], onset-to-thrombolytic time: 132 minutes [interquartile range (IQR): 99-170], and thrombolytic-to-assessment time: 61 minutes [IQR: 39-96]; alteplase: 75/376 [19%], onset-to-thrombolytic time: 143 minutes [IQR: 105-180], thrombolytic-to-assessment time: 92 minutes [IQR: 63-144]). Earlier onset-to-thrombolytic administration times were associated with an increased probability of thrombolytic-induced reperfusion in patients treated with either tenecteplase (adjusted risk ratio [aRR] 1.05 per 15 minutes [95% confidence interval (CI) 1.00-1.12] or alteplase (aRR 1.06 per 15 minutes [95% CI 1.00-1.13]). Tenecteplase remained associated with higher rates of reperfusion vs alteplase after adjustment for onset-to-thrombolytic time, occlusion site, thrombolytic-to-assessment time, and study as a fixed effect, (adjusted incidence rate ratio: 1.41 [95% CI 1.02-1.93]). No significant treatment-by-time interaction was observed (p = 0.87).

DISCUSSION

In patients with LVO presenting within 4.5 hours of symptom onset, earlier thrombolytic administration increased successful reperfusion rates. Compared with alteplase, tenecteplase was associated with a higher probability of lytic-induced reperfusion, independent of onset-to-lytic administration times.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifiers: NCT02388061, NCT03340493.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that among patients with LVO receiving a thrombolytic, reperfusion was more likely with tenecteplase than alteplase.

Stepwise targeted strategies for improving neurological function by inhibiting oxidative stress levels and inflammation following ischemic stroke

Ischemia-reperfusion injury is caused by excessive production of reactive oxygen species (ROS) and inflammation accompanied by ischemic injury symptoms and blood-brain barrier (BBB) dysfunction. This causes neuronal damage, for which no effective treatments or drugs exist. Herein, we provided a stepwise targeted drug delivery strategy and successfully prepared multifunctional ORD@SHp@ANG nanoparticles (NPs) that consist of a stroke homing peptide (DSPE-PEG2000-SHp), BBB-targeting peptide (DSPE-PEG2000-ANG), and ROS-responsive Danshensu (salvianic acid A) chain self-assembly. ORD@SHp@ANG NPs effectively crossed the BBB by ANG peptide and selectively targeted the ischemic brain sites using stroke-homing peptide. The results showed that ORD@SHp@ANG NPs can effective at scavenging ROS, and protect SH-SY5Y cells from oxidative damage in vitro. Furthermore, ORD@SHp@ANG NPs showed excellent biocompatibility. These NPs recognized brain endothelial cells and crossed the BBB, regulated the transformation of microglia into the anti-inflammatory phenotype, and inhibited the production of inflammatory factors in a rat ischemia-reperfusion model, thereby reducing cerebral infarction, neuronal apoptosis and preserving BBB integrity. Sequencing revealed that ORD@SHp@ANG NPs promote cell proliferation, activate immune responses, suppress inflammatory responses, and ameliorate ischemic stroke. In conclusion, this study reports a simple and promising drug delivery strategy for managing ischemic stroke.

Initial clinical experience with a novel mechanical thrombectomy device-the ThrombX retriever

BACKGROUND AND PURPOSE

The ThrombX Retriever is a novel mechanical thrombectomy device that adjusts the distance between two mesh segments to axially hold thrombus. A post-market study assessed safety and performance in acute ischemic stroke patients with large artery occlusion.

METHODS

A single-arm prospective multi-center study enrolled patients at 5 European Centers. Patients had a symptomatic large-artery occlusion of the intracranial Internal Carotid or the Middle Cerebral Artery, M1 segment. The primary outcome measure was the modified treatment in cerebral infarction (mTICI) score, on the immediate post-procedure angiogram after up to three device passes. Key secondary outcome measures were the mTICI score after a single pass and functional independence, defined as an mRS score ≤ 2 at 90 days.

RESULTS

Thirty patients (16 Females, mean age 72 years), with NIHSS 4-25 (mean 15.5) were treated. Twenty-eight (93%) achieved mTICI 2b-3 within 3 passes, and 24 (80%) were with the first pass (FP). FP mTICI 2c-3 reperfusion was achieved in 19 (63%) cases. Seventeen of 24 (71%) patients treated with a balloon guide and the ThrombX Retriever had a FP mTICI 2c-3 reperfusion. After all interventions, mTICI 2b-3 was seen in 30 (100%) patients. Twenty-one of the 29 (73%) patients with 90-day follow-up were functionally independent (mRS≤2). No device-related serious adverse events were observed.

CONCLUSION

This preliminary study suggests the ThrombX Retriever is safe and has a high rate of substantial reperfusion. A larger prospective trial to assess the device effectiveness is planned.

Ischemic Stroke in Cancer: Mechanisms, Biomarkers, and Implications for Treatment

Ischemic stroke is an important cause of morbidity and mortality in cancer patients. The underlying mechanisms linking cancer and stroke are not completely understood. Long-standing and more recent evidence suggests that cancer-associated prothrombotic states, along with treatment-related vascular toxicity, such as with chemotherapy and immunotherapy, contribute to an increased risk of ischemic stroke in cancer patients. Novel biomarkers, including coagulation, platelet and endothelial markers, cell-free DNA, and extracellular vesicles are being investigated for their potential to improve risk stratification and patient selection for clinical trials and to help guide personalized antithrombotic strategies. Treatment of cancer-related stroke poses unique challenges, including the need to balance the risk of recurrent stroke and other thromboembolic events with that of bleeding associated with antithrombotic therapy. In addition, how and when to restart cancer treatment after stroke remains unclear. In this review, we summarize current knowledge on the mechanisms underlying ischemic stroke in cancer, propose an etiological classification system unique to cancer-related stroke to help guide patient characterization, provide an overview of promising biomarkers and their clinical utility, and discuss the current state of evidence-based management strategies for cancer-related stroke. Ultimately, a personalized approach to stroke prevention and treatment is required in cancer patients, considering both the underlying cancer biology and the individual patient's risk profile.

Clot-based time attenuation curve as a novel imaging predictor of mechanical thrombectomy functional outcome in acute ischemia stroke

OBJECTIVES

To investigate whether a novel assessment of thrombus permeability obtained from perfusion computed tomography (CTP) can act as a more accurate predictor of clinical response to mechanical thrombectomy (MT) in acute ischemic stroke (AIS).

MATERIALS AND METHODS

We performed a study including two cohorts of AIS patients who underwent MT admitted to a single-center between April 2018 and February 2022: a retrospective development cohort (n = 71) and a prospective independent validation cohort (n = 96). Thrombus permeability was determined in terms of entire thrombus time-attenuation curve (TAC) on CTP. Association between thrombus TAC distributions and histopathological results was analyzed in the development cohort. Logistic regression was used to assess the performance of the TAC for predicting 90-day modified Rankin Scale (mRS) score, and good outcome was defined as a mRS score of  ≤ 2. Basic clinical characteristics was used to build a routine clinical model. A combined model gathered TAC and basic clinical characteristics was also developed. The performance of the three models is compared on the independent validation set.

RESULTS

Two TAC distributions were observed-unimodal (uTAC) and linear (lTAC). TAC distributions achieved strong correlations (|r|= 0.627, p < 0.001) with histopathological results, in which uTAC associated with fibrin- and platelet-rich clot while lTAC associated with red blood cell-rich clot. The uTAC was independently associated with poor outcome (odds ratio, 0.08 [95% confidence interval (CI), 0.02-0.31]; p < 0.001). TAC distributions yielded an AUC of 0.78 (95% CI, 0.70-0.87) for predicting clinical outcome. When combined clinical characteristics, the performance was significantly improved (AUC, 0.85 [95% CI, 0.76-0.93]; p < 0.001) and higher than routine clinical model (AUC, 0.69 [95% CI, 0.59-0.83]; p < 0.001).

CONCLUSIONS

Thrombus TAC on CTP were found to be a promising new imaging biomarker to predict the outcomes of MT in AIS.

CLINICAL RELEVANCE STATEMENT

This study revealed that clot-based time attenuation curve based on admission perfusion CT could reflect the permeability and composition of thrombus and, also, provide valuable information to predict the clinical outcomes of mechanical thrombectomy in patients with acute ischemia stroke.

KEY POINTS

• Two time-attenuation curves distributions achieved strong correlations (|r|= 0.627, p < 0.001) with histopathological results. • The unimodal time-attenuation curve was independently associated with poor outcome (odds ratio, 0.08 [0.02-0.31]; p < 0.001). • The time-attenuation curve distributions yielded a higher performance for detecting clinical outcome than routine clinical model (AUC, 0.78 [0.70-0.87] vs 0.69 [0.59-0.83]; p < 0.001).

Thrombus Imaging Characteristics to Predict Early Recanalization in Anterior Circulation Large Vessel Occlusion Stroke

The early management of transferred patients with a large vessel occlusion (LVO) stroke could be improved by identifying patients who are likely to recanalize early. We aim to predict early recanalization based on patient clinical and thrombus imaging characteristics. We included 81 transferred anterior-circulation LVO patients with an early recanalization, defined as the resolution of the LVO or the migration to a distal location not reachable with endovascular treatment upon repeated radiological imaging. We compared their clinical and imaging characteristics with all (322) transferred patients with a persistent LVO in the MR CLEAN Registry. We measured distance from carotid terminus to thrombus (DT), thrombus length, density, and perviousness on baseline CT images. We built logistic regression models to predict early recanalization. We validated the predictive ability by computing the median area-under-the-curve (AUC) of the receiver operating characteristics curve for 100 5-fold cross-validations. The administration of intravenous thrombolysis (IVT), longer transfer times, more distal occlusions, and shorter, pervious, less dense thrombi were characteristic of early recanalization. After backward elimination, IVT administration, DT and thrombus density remained in the multivariable model, with an AUC of 0.77 (IQR 0.72-0.83). Baseline thrombus imaging characteristics are valuable in predicting early recanalization and can potentially be used to optimize repeated imaging workflow.

Synergistic effects and molecular mechanisms of DL-3-n-butylphthalide combined with dual antiplatelet therapy in acute ischemic stroke

DL-3-n-butylphthalide (NBP) is isolated from the seeds of Apium graveolens L., and has been recently used as a neuroprotective agent for acute ischemic stroke. The present study aimed to determine the efficacy and safety of the combined use of dual antiplatelet therapy (DAPT) and NBP for treating of acute ischemic stroke in rats and to explore the synergistic mechanism of this treatment strategy in rat middle cerebral artery occlusion models. The efficacy of DAPT combined with NBP was evaluated by determining neurological deficits, infarction status, and histological changes. Changes in body weight, blood glucose level, blood count, and serum biochemical parameters were detected to evaluate the safety. To explore the synergistic pharmacological mechanism, the mRNA expression and protein levels of key proteins in the pyroptosis-inflammatory pathway, and the pyroptosis ratio of microglias were examined. Compared with the administration of NBP or DAPT alone, combination of them significantly improved neurological deficits, reduced infarct area, and repaired tissue injury and inflammation after cerebral ischemia. No hepatorenal toxicity was observed. The mRNA expression and protein levels of key proteins in the pyroptosis-inflammation pathway, and the pyroptosis ratio of microglias were significantly downregulated in the combined administration group than in the monotherapy group. We demonstrated that the combined use of NBP and DAPT exhibits better efficacy and high safety and plays a synergistic role by inhibiting the pyroptosis-inflammation pathway in the brain tissues, particularly in microglial cells.

Inducing cavitation within hollow cylindrical radially polarized transducers for intravascular applications

Thrombotic occlusions of large blood vessels are increasingly treated with catheter based mechanical approaches, one of the most prominent being to employ aspiration to extract clots through a hollow catheter lumen. A central technical challenge for aspiration catheters is to achieve sufficient suction force to overcome the resistance of clot material entering into the distal tip. In this study, we examine the feasibility of inducing cavitation within hollow cylindrical transducers with a view to ultimately using them to degrade the mechanical integrity of thrombus within the tip of an aspiration catheter. Hollow cylindrical radially polarized PZT transducers with 3.3/2.5 mm outer/inner diameters were assessed. Finite element simulations and hydrophone experiments were used to investigate the pressure field distribution as a function of element length and resonant mode (thickness, length). Operating in thickness mode (∼5 MHz) was found to be associated with the highest internal pressures, estimated to exceed 23 MPa. Cavitation was demonstrated to be achievable within the transducer under degassed water (10 %) conditions using hydrophone detection and high-frequency ultrasound imaging (40 MHz). Cavitation clouds occupied a substantial portion of the transducer lumen, in a manner that was dependent on the pulsing scheme employed (10 and 100 μs pulse lengths; 1.1, 11, and 110 ms pulse intervals). Collectively the results support the feasibility of achieving cavitation within a transducer compatible with mounting in the tip of an aspiration format catheter.

Electrical impedance measurements can identify red blood cell-rich content in acute ischemic stroke clots ex vivo associated with first-pass successful recanalization

Background

Electrochemical impedance spectroscopy can determine characteristics such as cell density, size, and shape. The development of an electrical impedance-based medical device to estimate acute ischemic stroke (AIS) clot characteristics could improve stroke patient outcomes by informing clinical decision making.

Objectives

To assess how well electrical impedance combined with machine learning identified red blood cell (RBC)-rich composition of AIS clots ex vivo, which is associated with a successfully modified first-pass effect.

Methods

A total of 253 clots from 231 patients who underwent thrombectomy in 5 hospitals in France, Japan, Serbia, and Spain between February 2021 and October 2023 were analyzed in the Clotbase International Registry. Electrical impedance measurements were taken following clot retrieval by thrombectomy, followed by Martius Scarlet Blue staining. The clot components were quantified via Orbit Image Analysis, and RBC percentages were correlated with the RBC estimations made by the electrical impedance machine learning model.

Results

Quantification by Martius Scarlet Blue staining identified RBCs as the major component in clots (RBCs, 37.6%; white blood cells, 5.7%; fibrin, 25.5%; platelets/other, 30.3%; and collagen, 1%). The impedance-based RBC estimation correlated well with the RBC content determined by histology, with a slope of 0.9 and Spearman's correlation of r = 0.7. Clots removed in 1 pass were significantly richer in RBCs and clots with successful recanalization in 1 pass (modified first-pass effect) were richer in RBCs as assessed using histology and impedance signature.

Conclusion

Electrical impedance estimations of RBC content in AIS clots are consistent with histologic findings and may have potential for clinically relevant parameters.

Role of m6A RNA Methylation in Ischemic Stroke

Ischemic stroke is a prominent contributor to global morbidity and mortality rates. The intricate and diverse mechanisms underlying ischemia-reperfusion injury remain poorly comprehended. RNA methylation, an emerging epigenetic modification, plays a crucial role in regulating numerous biological processes, including immunity, DNA damage response, tumorigenesis, metastasis, stem cell renewal, adipocyte differentiation, circadian rhythms, cellular development and differentiation, and cell division. Among the various RNA modifications, N6-methyladenosine (m6A) modification stands as the most prevalent in mammalian mRNA. Recent studies have demonstrated the crucial involvement of m6A modification in the pathophysiological progression of ischemic stroke. This review aims to elucidate the advancements in ischemic stroke-specific investigations pertaining to m6A modification, consolidate the underlying mechanisms implicated in the participation of m6A modification during the onset of ischemic stroke, and deliberate on the potential of m6A modification as a viable therapeutic target for ischemic stroke.

Alterations of Hemostatic Molecular Markers During Acute Large Vessel Occlusion Stroke

BACKGROUND

This study aimed to investigate regional levels of TAT (thrombin-antithrombin complex), PIC (plasmin-α2 plasmin inhibitor complex), t-PAIC (tissue plasminogen activator-plasminogen activator inhibitor complex), sTM (soluble thrombomodulin), and D-dimer, along with their associations with clinical and procedural characteristics in patients with acute ischemic stroke undergoing endovascular thrombectomy.

METHODS AND RESULTS

We retrospectively analyzed 166 consecutive patients with acute ischemic stroke (62±11.54 years of age, 34.3% women) using prospectively maintained clinical databases and blood samples from local ischemic (proximal to thrombus) and systemic (femoral artery, self-control) arterial compartments. Levels of TAT, PIC, t-PAIC, and D-dimer were significantly elevated, whereas sTM was significantly reduced, in local ischemic regions compared with their systemic levels. Each 1-unit increase in ischemic TAT (adjusted odds ratio [aOR], 1.086 [95% CI, 1.03-1.145]; P=0.002; area under the curve [AUC], 0.833) and PIC (aOR, 1.337 [95% CI, 1.087-1.644]; P=0.006; AUC, 0.771) correlated significantly with higher symptomatic intracranial hemorrhage risk. Additionally, each 1-unit increase in ischemic TAT (aOR, 1.076 [95% CI, 1.016-1.139]; P=0.013; AUC, 0.797), PIC (aOR, 1.554 [95% CI, 1.194-2.022]; P=0.001; AUC, 0.798), and sTM (aOR, 0.769 [95% CI, 0.615-0.961]; P=0.021; AUC, 0.756) was significantly associated with an increased risk of an unfavorable 90-day outcome (modified Rankin scale of 3-6). These hemostatic molecules, individually or combined, significantly improved the predictive power of conventional risk factors, as evidenced by significant increases in net reclassification improvement and integrated discrimination improvement (all P<0.01).

CONCLUSIONS

We observed a hyperactive state of the coagulation-fibrinolysis system within the local ischemic region during hyperacute stroke. Rapid automated measurement of hemostatic molecular markers, particularly TAT, PIC, and sTM, during intra-arterial procedures may provide additional information for stroke risk stratification and therapeutic decision-making, and warrants further investigation.

Annexin A6 mitigates neurological deficit in ischemia/reperfusion injury by promoting synaptic plasticity

AIMS

Alleviating neurological dysfunction caused by acute ischemic stroke (AIS) remains intractable. Given Annexin A6 (ANXA6)'s potential in promoting axon branching and repairing cell membranes, the study aimed to explore ANXA6's potential in alleviating AIS-induced neurological dysfunction.

METHODS

A mouse middle cerebral artery occlusion model was established. Brain and plasma ANXA6 levels were detected at different timepoints post ischemia/reperfusion (I/R). We overexpressed and down-regulated brain ANXA6 and evaluated infarction volume, neurological function, and synaptic plasticity-related proteins post I/R. Plasma ANXA6 levels were measured in patients with AIS and healthy controls, investigating ANXA6 expression's clinical significance.

RESULTS

Brain ANXA6 levels initially decreased, gradually returning to normal post I/R; plasma ANXA6 levels showed an opposite trend. ANXA6 overexpression significantly decreased the modified neurological severity score (p = 0.0109) 1 day post I/R and the infarction area at 1 day (p = 0.0008) and 7 day (p = 0.0013) post I/R, and vice versa. ANXA6 positively influenced synaptic plasticity, upregulating synaptophysin (p = 0.006), myelin basic protein (p = 0.010), neuroligin (p = 0.078), and tropomyosin-related kinase B (p = 0.150). Plasma ANXA6 levels were higher in patients with AIS (1.969 [1.228-3.086]) compared to healthy controls (1.249 [0.757-2.226]) (p < 0.001), that served as an independent risk factor for poor AIS outcomes (2.120 [1.563-3.023], p < 0.001).

CONCLUSIONS

This study is the first to suggest that ANXA6 enhances synaptic plasticity and protects against transient cerebral ischemia.

Stroke emboli from patients with atrial fibrillation enriched with neutrophil extracellular traps

Background

Recent literature has demonstrated remarkable heterogeneity in the composition of acute ischemic stroke (AIS) emboli, which may impact susceptibility to therapy.

Objectives

In this study, we explored differences in proteomic composition of retrieved embolic material from patients with stroke with and without atrial fibrillation (AF) (AF+ and AF-, respectively).

Methods

The full proteome of retrieved thromboembolic material from 24 patients with AIS was obtained by mass spectrometry. Known marker proteins were assigned groups representing broad classes of embolus components: red blood cells, platelets, neutrophils, eosinophils, histones, complement, and other clotting-associated proteins (eg, fibrinogen). Relative protein abundances were compared between AF+ and AF- samples. Functional implications of differences were explored with gene set enrichment analysis and Gene Ontology enrichment analysis and visualization tool.

Results

One hundred sixty-six proteins were differentially expressed between AF+ and AF- specimens. Eight out of the 15 neutrophil proteins (P < .05; fold change, >2) and 4 of the 14 histone proteins were significantly enriched in AF+ emboli (P < .05; fold change, >2). Gene set enrichment analysis revealed a significant representation of proteins from published neutrophil extracellular trap (NET) proteomic gene sets. The most significantly represented functional Gene Ontology pathways in patients with AF involved neutrophil activation and degranulation (P < 1 × 10-7).

Conclusion

The present analysis suggests enrichment of NETs in emboli of patients with stroke and AF. NETs are a significant though understudied structural component of thrombi. This work suggests not only unique stroke biology in AF but also potential therapeutic targets for AIS in this population.

Microfabricated Nitinol Stent Retrievers with a Micro-Patterned Surface

Stent retrievers are medical devices that are designed to physically remove blood clots from within the blood vessels of the brain. This paper focuses on microfabricated nitinol (nickel-titanium alloy) stent retrievers, which feature micro-patterns on their surface to enhance the effectiveness of mechanical thrombectomy. A thick film of nitinol, which was 20 µm in thickness, was sputtered onto a substrate with a micro-patterned surface, using electroplated copper as the sacrificial layer. The nitinol film was released from the substrate and then thermally treated while folded into a cylindrical shape. In vitro experiments with pig blood clots demonstrated that the micro-patterns on the surface improved the efficacy of blood clot retrieval.

Bioactive Ceria Nanoenzymes Target Mitochondria in Reperfusion Injury to Treat Ischemic Stroke

Overproduction of reactive oxygen species by damaged mitochondria after ischemia is a key factor in the subsequent cascade of damage. Delivery of therapeutic agents to the mitochondria of damaged neurons in the brain is a potentially promising targeted therapeutic strategy for the treatment of ischemic stroke. In this study, we developed a ceria nanoenzymes synergistic drug-carrying nanosystem targeting mitochondria to address multiple factors of ischemic stroke. Each component of this nanosystem works individually as well as synergistically, resulting in a comprehensive therapy. Alleviation of oxidative stress and modulation of the mitochondrial microenvironment into a favorable state for ischemic tolerance are combined to restore the ischemic microenvironment by bridging mitochondrial and multiple injuries. This work also revealed the detailed mechanisms by which the proposed nanodelivery system protects the brain, which represents a paradigm shift in ischemic stroke treatment.

Seasonal Variations in Stroke and a Comparison of the Predictors of Unfavorable Outcomes among Patients with Acute Ischemic Stroke and Cardioembolic Stroke

We investigated the seasonal variations in stroke in 4040 retrospectively enrolled patients with acute ischemic stroke (AIS) admitted between January 2011 and December 2022, particularly those with cardioembolic (CE) stroke, and compared predictors of unfavorable outcomes between AIS patients and CE stroke patients. The classification of stroke subtypes was based on the Trial of ORG 10172 in Acute Stroke Treatment. Stroke occurrence was stratified by seasons and weekdays or holidays. Of all AIS cases, 18% were of CE stroke. Of all five ischemic stroke subtypes, CE stroke patients were the oldest; received the most thrombolysis and thrombectomy; had the highest initial National Institutes of Stroke Scale (NIHSS) and discharge modified Rankin Scale (mRS) scores; and had the highest rate of in-hospital complications, unfavorable outcomes (mRS > 2), and mortality. The highest CE stroke prevalence was noted in patients aged ≥ 85 years (30.9%); moreover, CE stroke prevalence increased from 14.9% in summer to 23.0% in winter. The main predictors of death in patients with CE stroke were age > 86 years, heart rate > 79 beats/min, initial NIHSS score > 16, neutrophil-to-lymphocyte ratio (NLR) > 6.4, glucose > 159 mg/dL, cancer history, in-hospital complications, and neurological deterioration (ND). The three most dominant factors influencing death, noted in not only patients with AIS but also those with CE stroke, are high initial NIHSS score, ND, and high NLR. We selected the most significant factors to establish nomograms for predicting fatal outcomes. Effective heart rhythm monitoring, particularly in older patients and during winter, may help develop stroke prevention strategies and facilitate early AF detection.

Investigating clot-flow interactions by integrating intravital imaging with in silico modeling for analysis of flow, transport, and hemodynamic forces

As a blood clot forms, grows, deforms, and embolizes following a vascular injury, local clot-flow interactions lead to a highly dynamic flow environment. The local flow influences transport of biochemical species relevant for clotting, and determines the forces on the clot that in turn lead to clot deformation and embolization. Despite this central role, quantitative characterization of this dynamic clot-flow interaction and flow environment in the clot neighborhood remains a major challenge. Here, we propose an approach that integrates dynamic intravital imaging with computer geometric modeling and computational flow and transport modeling to develop a unified in silico framework to quantify the dynamic clot-flow interactions. We outline the development of the methodology referred to as Intravital Integrated In Silico Modeling or IVISim, and then demonstrate the method on a sample set of simulations comprising clot formation following laser injury in two mouse cremaster arteriole injury model data: one wild-type mouse case, and one diYF knockout mouse case. Simulation predictions are verified against experimental observations of transport of caged fluorescent Albumin (cAlb) in both models. Through these simulations, we illustrate how the IVISim methodology can provide insights into hemostatic processes, the role of flow and clot-flow interactions, and enable further investigations comparing and contrasting different biological model scenarios and parameter variations.

Nomogram to predict 6-month mortality in acute ischemic stroke patients treated with endovascular treatment

Background

Acute Ischemic Stroke (AIS) presents significant challenges in evaluating the effectiveness of Endovascular Treatment (EVT). This study develops a novel prognostic model to predict 6-month mortality post-EVT, aiding in identifying patients likely to benefit less from this intervention, thus enhancing therapeutic decision-making.

Methods

We employed a cohort of AIS patients from Shenyang First People's Hospital, serving as the Validation set, to develop our model. LASSO regression was used for feature selection, followed by logistic regression to create a prognostic nomogram for predicting 6-month mortality post-EVT. The model's performance was validated using a dataset from PLA Northern Theater Command General Hospital, assessing discriminative ability (C-index), calibration (calibration plot), and clinical utility (decision curve analysis). Statistical significance was set at p < 0.05.

Results

The development cohort consisted of 219 patients. Six key predictors of 6-month mortality were identified: "Lack of Exercise" (OR, 4.792; 95% CI, 1.731-13.269), "Initial TICI Score 1" (OR, 1.334; 95% CI, 0.628-2.836), "MRS Score 5" (OR, 1.688; 95% CI, 0.754-3.78), "Neutrophil Percentage" (OR, 1.08; 95% CI, 1.042-1.121), "Onset Blood Sugar" (OR, 1.119; 95% CI, 1.007-1.245), and "Onset NIHSS Score" (OR, 1.074; 95% CI, 1.029-1.121). The nomogram demonstrated a high predictive capability with a C-index of 0.872 (95% CI, 0.830-0.911) in the development set and 0.830 (95% CI, 0.726-0.920) in the validation set.

Conclusion

Our nomogram, incorporating factors such as Lack of Exercise, Initial TICI Score 1, MRS Score 5, Neutrophil Percentage, Onset Blood Sugar, and Onset NIHSS Score, provides a valuable tool for predicting 6-month mortality in AIS patients post-EVT. It offers potential to refine early clinical decision-making and optimize patient outcomes, reflecting a shift toward more individualized patient care.

Analysis and Regulatory Mechanisms of Platelet-Related Genes in Patients with Ischemic Stroke

It was found that ischemic stroke (IS) was associated with abnormal platelet activity and thrombosis. However, the potential significance of platelet-related genes (PRGs) in IS still needs to be more thorough. This study extracted IS-related transcriptome datasets from the Gene Expression Omnibus (GEO) database. The target genes were obtained by intersecting the differentially expressed genes (DEGs), the module genes related to IS, and PRGs, where the key genes of IS were screened by two machine learning algorithms. The key genes-based diagnostic model was constructed. Gene set enrichment analysis (GSEA) and the immune microenvironment analyses were analyzed targeting key genes in IS. The co-expression, TF-mRNA, and competitive endogenous RNAs (ceRNA) regulatory networks were constructed to reveal the potential regulation of key genes. Potential drugs targeting key genes were predicted as well. Totals of eight target genes were obtained and were associated with immune-related functions. Four platelet-related key genes were acquired, which were related to immunity and energy metabolism. The abnormal expressions of DOCK8, GIMAP5, ICOS were determined by the quantitative real-time polymerase chain reaction (qRT-PCR), and the significant correlations among these key genes were identified. Notably, hsa-miR-17-3p, hsa-miR-3158-3p, hsa-miR-423-3p, and hsa-miR-193a-8p could regulate all key genes at the same time. In addition, Caffeine, Carboplatin, and Vopratelimab were the targeted drugs of these key genes. This study identified four platelet-related key genes of IS, which might help to deepen the understanding of the role of platelet-related genes in the molecular mechanism of IS.

A new multi-parameter imaging platform for in vivo drug efficacy evaluation of ischemic stroke

Ischemic stroke with high incidence and disability rate severely endangers human health. Current clinical treatment strategies are quite limited, new drugs for ischemic stroke are urgently needed. However, most existing methods for the efficacy evaluation of new drugs possess deficiencies of divorcing from the true biological context, single detection indicator and complex operations, leading to evaluation biases and delaying drug development process. In this work, leveraging the advantages of fluorescence imaging with non-invasive, real-time, in-situ, high selectivity and high sensitivity, a new multi-parameter simultaneous fluorescence imaging platform (MPSFL-Platform) based on two fluorescence materials was constructed to evaluate the efficacy of new drug for ischemic stroke. Through simultaneous fluorescence observing three key indicators of ischemic stroke, malondialdehyde (MDA), formaldehyde (FA), and monoamine oxidase A (MAO-A), the efficacy evaluations of three drugs for ischemic stroke were real-time and in-situ performed. Compared with edaravone and butylphthalide, edaravone dexborneol exhibited better therapeutic effect by using MPSFL-Platform. The successful establishment of MPSFL-Platform is serviceable to accelerate the conduction of preclinical trial and the exploration of pathophysiology mechanism for drugs related to ischemic stroke and other brain diseases, which is perspective to promote the efficiency of new drug development.

Periodontitis in ischemic stroke: impact of Porphyromonas gingivalis on thrombus composition and ischemic stroke outcomes

Background

Periodontitis is associated with an increased risk of ischemic stroke, but the mechanisms underlying this association remain unclear.

Objectives

Our objective was to determine whether Porphyromonas gingivalis (Pg), a periodontal bacterium, could be detected within thrombus aspirates, modify thrombus composition, and endovascular therapy responses.

Methods

The presence of Pg gingipain in 175 consecutive thrombi from patients with large vessel occlusion stroke enrolled in the multicenter research cohort compoCLOT was investigated by immunostaining. Thrombus blood cell composition according to gingipain status was analyzed in a subset of 63 patients.

Results

Pg gingipain immunostaining was positive in 33.7% of thrombi (95% CI, 26.7%-40.8%). The percentage of near to complete reperfusion (modified Thrombolysis in Cerebral Infarction Score 2c/3) at the end of the procedure was lower in the Pgpos group than the Pgneg group (39.0% vs 57.8% respectively; adjusted odds ratio, 0.38; 95% CI, 0.19-0.77). At 3 months, 35.7% of patients in the Pgpos group had a favorable neurological outcome vs 49.5% in the Pgneg group (odds ratio, 0.65; 95% CI, 0.30-1.40). Quantitative analysis of a subset of 63 thrombi showed that neutrophil elastase content was significantly (P < .05) higher in Pgpos thrombi than in Pgneg thrombi.

Conclusion

Our results indicate that intrathrombus Pg gingipain is associated with increased neutrophil content and resistance to endovascular therapy.

Predictive Factors of First-Pass Effect in Patients Who Underwent Successful Endovascular Thrombectomy for Emergent Large Vessel Occlusion

OBJECTIVE

The primary treatment goal of current endovascular thrombectomy (EVT) for emergent large-vessel occlusion (ELVO) is complete recanalization after a single maneuver, referred to as the 'first-pass effect' (FPE). Hence, we aimed to identify the predictive factors of FPE and assess its effect on clinical outcomes in patients with ELVO of the anterior circulation.

METHODS

Among the 129 patients who participated, 110 eligible patients with proximal ELVO (intracranial internal carotid artery and proximal middle cerebral artery) who achieved successful recanalization after EVT were retrospectively reviewed. A comparative analysis between patients who achieved FPE and all others (defined as a non-FPE group) was performed regarding baseline characteristics, clinical variables, and clinical outcomes. Multivariate logistic regression analyses were subsequently conducted for potential predictive factors with p<0.10 in the univariate analysis to determine the independent predictive factors of FPE.

RESULTS

FPE was achieved in 31 of the 110 patients (28.2%). The FPE group had a significantly higher level of functional independence at 90 days than did the non-FPE group (80.6% vs. 50.6%, p=0.002). Pretreatment intravenous thrombolysis (IVT) (odds ratio [OR], 3.179; 95% confidence interval [CI], 1.025-9.861; p=0.045), door-to-puncture (DTP) interval (OR, 0.959; 95% CI, 0.932-0.987; p=0.004), and the use of balloon guiding catheter (BGC) (OR, 3.591; 95% CI, 1.231-10.469; p=0.019) were independent predictive factors of FPE.

CONCLUSION

In conclusion, pretreatment IVT, use of BGC, and a shorter DTP interval were positively associated with FPE, increasing the chance of acquiring better clinical outcomes.

Impact of smoking on one year functional outcomes after thrombectomy for young stroke patients

BACKGROUND

The incidence of stroke in young patients (20-50 years old) has increased in recent decades. Unlike the use of good functional outcomes to evaluate prognosis, excellent functional outcomes are a better indicator of return to work among younger patients. The rate of return to work increases with time after stroke. This study investigated the short term (3 months) and long term (1 year) predictors of excellent functional outcomes in young patients after endovascular thrombectomy (EVT).

METHODS

We included young patients who underwent EVT for acute ischemic stroke (AIS) due to large vessel occlusion within 6 hours after stroke onset between 2015 and 2021. Patients with intracerebral hemorrhage on pretreatment CT were excluded. The associations between clinical, imaging, and procedure variables, and excellent functional outcomes were analyzed using univariate and multivariable logistic regression analyses. An excellent functional outcome was defined as a modified Rankin Scale score of ≤1.

RESULTS

Of the 361 patients with AIS eligible for EVT, 55 young patients (aged 24-50 years) were included. Of these, 36.4% and 41.8% achieved excellent functional outcomes at 3 and 12 months, respectively. Multivariate analysis revealed that smoking was the independent negative predictor of both 3 month (adjusted OR (aOR) 0.232, 95% CI 0.058 to 0.928; p=0.039) and 12 month (aOR 0.180, 95% CI 0.044 to 0.741; p=0.018) excellent functional outcomes.

CONCLUSIONS

Current or former smoking habit was an independent negative predictor of both short term and long term excellent functional outcomes in young adults with AIS.

The impact of platelet indices on ischemic stroke: a Mendelian randomization study and mediation analysis

Introduction

Platelet indices (PIs) are hematological parameters that indicate the number, morphology, and activation of platelets. Although some clinical trials suggest an association between PIs and the risk of stroke, the lack of robust evidence is attributed to confounding effects and reverse causation.

Objective

This study aimed to evaluate the association between PIs and stroke risk through Mendelian randomization (MR) while exploring the mediating effect of blood pressure in this association.

Methods

We identified genetic variants associated with PIs, including platelet count (PLT), platelet distribution width (PDW), mean platelet volume (MPV), and platelet crit (PCT), in the UK Biobank (n = 350,474). Relevant genome-wide association studies were utilized to gather summary statistics pertaining to the traits of interest. We primarily used the inverse-variance weighted analysis to obtain estimates for individual causal power.

Result

We observed a positive correlation between genetically predicted increases in PCT levels with the stroke onset [PCT: OR (95%CI) = 1.113(1.047, 1.183), p < 0.001]. However, no significant causal relationship was found between PLT, PDW, and MPV and the risk of stroke [PLT: OR (95%CI) = 1.037(0.979, 1.098), p = 0.221; PDW: OR (95%CI) = 0.973(0.923, 1.024), p = 0.294; MPV: OR (95%CI) = 0.990(0.945, 1.038), p = 0.675]. Multivariable MR analyses and mediation analysis found that the proportion mediated by systolic blood pressure (SBP) is 23.71% [95%CI (10.85-33.31%)] and the proportion mediated by diastolic blood pressure (DBP) is 28.09% [95%CI (12.92-39.63%)].

Conclusion

This large MR study presents evidence for the potential causal relationship between the PCT level and the risk of ischemic stroke, which might be mediated by blood pressure.

REVIEW: "ISCHEMIC STROKE: From Fibrinolysis to Functional Recovery" Nanomedicine: Emerging Approaches to Treat Ischemic Stroke

Stroke is responsible for 11% of all deaths worldwide, the majority of which are caused by ischemic strokes, thus making the need to urgently find safe and effective therapies. Today, these can be cured either by mechanical thrombectomy when the thrombus is accessible, or by intravenous injection of fibrinolytics. However, the latter present several limitations, such as potential severe side effects, few eligible patients and low rate of partial and full recovery. To design safer and more effective treatments, nanomedicine appeared in this medical field a few decades ago. This review will explain why nanoparticle-based therapies and imaging techniques are relevant for ischemic stroke management. Then, it will present the different nanoparticle types that have been recently developed to treat this pathology. It will also study the various targeting strategies used to bring nanoparticles to the stroke site, thereby limiting side effects and improving the therapeutic efficacy. Finally, this review will present the few clinical studies testing nanomedicine on stroke and discuss potential causes for their scarcity.

Impact of atrial fibrillation on the treatment effect of bridging thrombolysis in ischemic stroke patients undergoing endovascular thrombectomy: a multicenter international cohort study

BACKGROUND

The role of bridging intravenous thrombolysis (IVT) before endovascular thrombectomy (EVT) in the treatment of acute ischemic stroke (AIS) remains debatable. Atrial fibrillation (AF) associated strokes may be associated with reduced treatment effect from IVT. This study compares the effect of bridging IVT in AF and non-AF patients.

METHODS

This retrospective cohort study comprised anterior circulation large vessel occlusion (LVO) AIS patients receiving EVT alone or bridging IVT plus EVT within 6 hours of symptom onset. Primary outcome was good functional outcome defined as modified Rankin Scale (mRS) 0-2 at 90 days. Secondary outcomes were successful reperfusion defined as expanded Thrombolysis In Cerebral Infarction (eTICI) grading ≥2b flow, symptomatic intracerebral hemorrhage (sICH), and in-hospital mortality.

RESULTS

We included 705 patients (314 AF and 391 non-AF patients). The mean age was 68.6 years and 53.9% were male. The odds of good functional outcomes with bridging IVT was higher in the non-AF (adjusted odds ratio (aOR) 2.28, 95% CI 1.06 to 4.91, P=0.035) compared with the AF subgroups (aOR 1.89, 95% CI 0.89 to 4.01, P=0.097). However, this did not constitute a significant effect modification by the presence of AF on bridging IVT (interaction aOR 0.12, 95% CI -1.94 to 2.18, P=0.455). The rate of successful reperfusion, sICH, and mortality were similar between bridging IVT and EVT for both AF and non-AF patients.

CONCLUSION

The presence of AF did not modify the treatment effect of bridging IVT. Further individual patient data meta-analysis of randomized trials may shed light on the comparative efficacy of bridging IVT in AF versus non-AF LVO strokes.

Double stent-retriever as the first-line approach in mechanical thrombectomy: a randomized in vitro evaluation

BACKGROUND

A repeated number of passes during mechanical thrombectomy leads to worse clinical outcomes in acute ischemic stroke. Initial experiences with the simultaneous double stent-retriever (double-SR) technique as the first-line treatment showed promising safety and efficacy results.

OBJECTIVE

To characterize the potential benefits of using the double-SR as first-line technique as compared with the traditional single-SR approach.

METHODS

Three types of clot analogs (soft, moderately stiff, and stiff) were used to create terminal internal carotid artery (T-ICA=44) and middle cerebral artery (MCA=88) occlusions in an in vitro neurovascular model. Sixty-six cases were randomized into each treatment arm: single-SR or double-SR, in combination with a 0.071" distal aspiration catheter. A total of 132 in vitro thrombectomies were performed. Primary endpoints were the rate of first-pass recanalization (%FPR) and procedural-related distal emboli.

RESULTS

FPR was achieved in 42% of the cases. Overall, double-SR achieved a significantly higher %FPR than single-SR (52% vs 33%, P=0.035). Both techniques showed similar %FPR in T-ICA occlusions (single vs double: 23% vs 27%, P=0.728). Double-SR significantly outperformed single-SR in MCA occlusions (63% vs 38%, P=0.019), most notably in saddle occlusions (64% vs 14%, P=0.011), although no significant differences were found in single-branch occlusions (64% vs 50%, P=0.275). Double-SR reduced the maximal size of the clot fragments migrating distally (Feret diameter=1.08±0.65 mm vs 2.05±1.14 mm, P=0.038).

CONCLUSIONS

This randomized in vitro evaluation demonstrates that the front-line double-SR technique is more effective than single-SR in achieving FPR when treating MCA bifurcation occlusions that present saddle thrombus.

Most Promising Approaches to Improve Stroke Outcomes: The Stroke Treatment Academic Industry Roundtable XII Workshop

The Stroke Treatment Academic Industry Roundtable XII included a workshop to discuss the most promising approaches to improve outcome from acute stroke. The workshop brought together representatives from academia, industry, and government representatives. The discussion examined approaches in 4 epochs: pre-reperfusion, reperfusion, post-reperfusion, and access to acute stroke interventions. The participants identified areas of priority for developing new and existing treatments and approaches to improve stroke outcomes. Although many advances in acute stroke therapy have been achieved, more work is necessary for reperfusion therapies to benefit the most possible patients. Prioritization of promising approaches should help guide the use of resources and investigator efforts.

What is a Challenging Clot? : A DELPHI Consensus Statement from the CLOTS 7.0 Summit

BACKGROUND

Predicting a challenging clot when performing mechanical thrombectomy in acute stroke can be difficult. One reason for this difficulty is a lack of agreement on how to precisely define these clots. We explored the opinions of stroke thrombectomy and clot research experts regarding challenging clots, defined as difficult to recanalize clots by endovascular approaches, and clot/patient features that may be indicative of such clots.

METHODS

A modified DELPHI technique was used before and during the CLOTS 7.0 Summit, which included experts in thrombectomy and clot research from different specialties. The first round included open-ended questions and the second and final rounds each consisted of 30 closed-ended questions, 29 on various clinical and clot features, and 1 on number of passes before switching techniques. Consensus was defined as agreement ≥ 50%. Features with consensus and rated ≥ 3 out of 4 on the certainty scale were included in the definition of a challenging clot.

RESULTS

Three DELPHI rounds were performed. Panelists achieved consensus on 16/30 questions, of which 8 were rated 3 or 4 on the certainty scale, namely white-colored clots (mean certainty score 3.1), calcified clots under histology (3.7) and imaging (3.7), stiff clots (3.0), sticky/adherent clots (3.1), hard clots (3.1), difficult to pass clots (3.1) and clots that are resistant to pulling (3.0). Most panelists considered switching endovascular treatment (EVT) techniques after 2-3 unsuccessful attempts.

CONCLUSION

This DELPHI consensus identified 8 distinct features of a challenging clot. The varying degree of certainty amongst the panelists emphasizes the need for more pragmatic studies to enable accurate a priori identification of such occlusions prior to EVT.