Clinically Ineffective Reperfusion After Endovascular Therapy in Acute Ischemic Stroke

Influence of Asymptomatic Hemorrhagic Transformation After Endovascular Treatment on Stroke Outcome: A Population-Based Study

BACKGROUND AND OBJECTIVES

In patients with acute ischemic stroke (AIS), the impact of hemorrhagic transformation (HT) after endovascular treatment (EVT) on poorer stroke outcome is well established when associated with clinical deterioration. However, the influence of asymptomatic HT remains unclear. We aimed to examine the impact of asymptomatic HT after EVT on functional outcome and mortality.

METHODS

Drawing on Catalan (Spain) population-based prospective stroke registry data, we included patients from 10 comprehensive stroke centers with anterior circulation AIS (2017-2023) who underwent EVT, excluding patients without data on the presence of HT or functional outcome at 3 months of follow-up. HT was categorized as parenchymal hemorrhage (PH), hemorrhagic infarct (HI) types 1 and 2, and remote PH (rPH). Asymptomatic HT was defined as any HT not causing death or the NIH Stroke Scale (NIHSS) score to increase by ≥ 4 points. Functional outcome was centrally assessed using the modified Rankin Scale (mRS). The primary end point was a shift in the 3-month mRS score. After excluding symptomatic intracerebral hemorrhage (sICH), multivariable ordinal regression analyses (adjusted by age, mRS, baseline NIHSS score, baseline Alberta Stroke Program Early CT Score, and modified Thrombolysis In Cerebral Infarction score ≥2b) were performed to test for asymptomatic HT association with the primary end point.

RESULTS

We included 3,067 patients (72.0 ± 13.6 years, 50.7% women), 179 (5.8%) with sICH and 612 (20.0%) with asymptomatic HT. HT category frequencies were 8.9% HI1, 7.2% HI2, 4.4% PH1, 3.8% PH2, and 1.5% rPH. The percentage of asymptomatic patients showed a hierarchical distribution, ranging from 93.4% in HI1 to 25.0% in PH2. In the multivariable analysis, asymptomatic HT was associated with poorer outcomes (common odds ratio [cOR] 2.24, 95% CI 1.89-2.66) and higher mortality (adjusted odds ratio 1.50, 95% CI 1.17-1.91). In the sensitivity analyses, the association with functional outcome remained significant for each HT category, with asymptomatic PH2 showing the highest odds of poorer outcomes (cOR 3.15, 95% CI 1.46-6.83).

DISCUSSION

In patients with AIS undergoing EVT, asymptomatic HT was associated with poorer functional outcomes and higher mortality, suggesting that any HT, regardless of its clinical impact or radiologic category, should be considered as an additional EVT safety measure.

Antioxidative activity of a novel antioxidant resorcimoline

During the synthesis of a known drug, we synthesized a novel compound impromptu, which we have named resorcimoline. This compound exhibited significant antioxidative activity. In this report, we present the concentration-dependent free radical scavenging activity of resorcimoline against various free radical species. The scavenging activity of resorcimoline was evaluated against nine free radicals using electron spin resonance spectroscopy with a spin-trapping method. These free radicals were hydroxyl radical, superoxide anion, tert-butyl peroxyl radical, tert-butoxyl radical, ascorbyl free radical, singlet oxygen, nitric oxide, 2,2-diphenyl-1-picrylhydrazyl, and tyrosyl radical. Sigmoid concentration-response curves were fitted to estimate the reaction rate constants of resorcimoline for the free radicals, and these were compared with those of edaravone, the only current clinically approved free radical scavenger. The antioxidative activity of resorcimoline against lipid peroxidation within tissue was assessed using the thiobarbituric acid reactive substance (TBARS) assay. The cytotoxicity and stability of resorcimoline were also evaluated. Resorcimoline demonstrated significant concentration-dependent scavenging activity against all tested free radicals. Notably, the reaction rate constants for superoxide anion and nitric oxide were significantly higher than those of edaravone, while the rate constant for hydroxyl radical was significantly lower. The TBARS assay revealed that resorcimoline inhibited tissue lipid peroxidation in a concentration-dependent manner. Moreover, resorcimoline exhibited no cytotoxicity at concentrations up to 100 μM and remained stable at room temperature under ambient light for 7 days. These findings indicate that resorcimoline's direct free radical scavenging activity could contribute to its potential clinical antioxidative effects.

Efficacy and safety of intra-arterial thrombolysis following successful endovascular thrombectomy in patients with large vessel occlusion stroke: A meta-analysis

INTRODUCTION

The impact of intra-arterial thrombolysis (IAT) following successful endovascular thrombectomy (EVT) in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) remains uncertain. This study aims to assess the efficacy and safety of IAT as an adjunct to EVT in patients with AIS-LVO.

PATIENTS AND METHODS

We searched PubMed, Embase, and Cochrane databases to identify randomized controlled trials (RCTs) that compared EVT + IAT with EVT-only for AIS-LVO. The primary outcome was an excellent functional outcome, defined as a modified Rankin Scale (mRS) score of 0-1 at 90 days. Secondary outcomes included functional independence (mRS 0-2), symptomatic intracranial hemorrhage (sICH), and mortality. The pooled data were analyzed using random-effects models.

DISCUSSION AND CONCLUSION

A total of four RCTs, involving 1395 patients, were included in the analysis. The results showed that patients who received EVT + IAT had a significantly higher likelihood of achieving an excellent functional outcome at 90 days compared to those who received EVT-only (risk ratio [RR], 1.16; 95% confidence interval [CI], 1.03-1.31). No statistically significant differences were observed between the EVT + IAT and EVT-only groups in terms of 90-day functional independence (RR, 1.03; 95% CI, 0.94-1.13), sICH (RR, 1.30; 95% CI, 0.80-2.13), or 90-day mortality (RR, 0.94; 95% CI, 0.76-1.17).

CONCLUSIONS

Among patients with AIS-LVO who have undergone successful EVT, the use of adjunct IAT, compared to no additional treatment, was associated with a greater likelihood of achieving an excellent functional outcome at 90 days.

SYSTEMATIC REVIEW REGISTRATION

CRD42024602099.

Incomplete reperfusion and the presence of distal emboli in predicting clinical outcome after endovascular thrombectomy

Objectives

To explore the relationship between final expanded treatment in cerebral infarction (eTICI) score and the presence or absence of distal emboli on final angiography on clinical outcome after endovascular thrombectomy (EVT) for acute ischaemic stroke (AIS). Persistent distal emboli on angiography are commonly noted, yet not all patients with intermediate eTICI scores demonstrate clear angiographic emboli, raising the possibility that these angiographic differences may correlate with distinct mechanisms of 'no-reflow'. Therefore, we sought to better understand the potential clinical impact of such angiographic markers in cases of incomplete reperfusion.

Design

We performed an exploratory retrospective analysis of a prospectively collected group of AIS patients who underwent EVT for M1 occlusions using the ASSIST Registry.

Setting

71 sites in 11 countries participated in the registry.

Participants

A total of 650 patients with M1 occlusions were included.

Main outcome measures

We compared 90-day modified Rankin scale (mRS) scores based on eTICI score as well as the presence or absence of distal emboli on final angiography.

Results

Clinical outcome based only on eTICI score revealed a shift in 90-day mRS, with a significant difference across eTICI scores in predicting 90-day mRS 0-2. In the intermediate eTICI grades 2b67 and 2c, there was a trend towards better 90-day mRS when emboli were present on final angiography than when emboli were absent. However, pairwise comparisons between these levels were non-significant.

Conclusion

In patients with final eTICI 2b67 or 2c, those with persistent emboli trended towards better clinical outcomes. With intermediate eTICI reperfusion, identifying the presence or absence of distal emboli on final angiography may be useful in distinguishing patterns of incomplete reperfusion. These findings should be followed by investigations on correlation between angiography and other markers of microcirculatory 'no-reflow'.

Trial registration number

NCT03845491.

Single-Cell Transcriptomes of Immune Cells from Multiple Compartments Redefine the Ontology of Myeloid Subtypes Post-Stroke

The activation and infiltration of immune cells are hallmarks of ischemic stroke. However, the precise origins and the molecular alterations of these infiltrating cells post-stroke remain poorly characterized. Here, a murine model of stroke (permanent middle cerebral artery occlusion [p-MCAO]) is utilized to profile single-cell transcriptomes of immune cells in the brain and their potential origins, including the calvarial bone marrow (CBM), femur bone marrow (FBM), and peripheral blood mononuclear cells (PBMCs). This analysis reveals transcriptomically distinct populations of cerebral myeloid cells and brain-resident immune cells after stroke. These include a novel CD14+ neutrophil subpopulation that transcriptomically resembles CBM neutrophils. Moreover, the sequential activation of transcription factor regulatory networks in neutrophils during stroke progression is delineated, many of which are unique to the CD14+ population and underlie their acquisition of chemotaxis and granule release capacities. Two distinct origins of post-stroke disease-related immune cell subtypes are also identified: disease inflammatory macrophages, likely deriving from circulating monocytes in the skull, and transcriptionally immature disease-associated microglia, possibly arising from pre-existing homeostatic microglia. Together, a comprehensive molecular survey of post-stroke immune responses is performed, encompassing both local and distant bone marrow sites and peripheral blood.

Evaluation of cortical venous drainage in patients with Acute Ischemic Stroke

The emergence of Mechanical thrombectomy (MT) has changed the treatment modalities for Acute Ischemic Stroke (AIS). But still 45 to 55% of patients cannot achieve functional independence after sufficient recanalization through endovascular treatment, defined as "futile reperfusion." Poor collateral circulation and microcirculation are key factors affecting prognosis. In the past, the assessment of these mainly focused on intracranial arteries and their collateral, neglecting the important role of the venous system in acute brain injury. More and more studies have found that "poor venous drainage" is associated with poor prognosis. However, there is currently no unified standard for the assessment of "cortical venous drainage." This paper reviews the pathophysiology of the relationship between "cortical venous drainage" and prognosis, as well as the assessment methods and indicators of "cortical venous drainage," aiming to provide a strong basis for the preoperative assessment of AIS patients and the selection of treatment plans.

Blood Oxygenation Level-Dependent Cerebrovascular Reactivity-Derived Steal Phenomenon May Indicate Tissue Reperfusion Failure After Successful Endovascular Thrombectomy

In acute ischemic stroke due to large-vessel occlusion (LVO), the clinical outcome after endovascular thrombectomy (EVT) is influenced by the extent of autoregulatory hemodynamic impairment, which can be derived from blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR). BOLD-CVR imaging identifies brain areas influenced by hemodynamic steal. We sought to investigate the presence of steal phenomenon and its relationship to DWI lesions and clinical deficit in the acute phase of ischemic stroke following successful vessel recanalization.From the prospective longitudinal IMPreST (Interplay of Microcirculation and Plasticity after ischemic Stroke) cohort study, patients with acute ischemic unilateral LVO stroke of the anterior circulation with successful endovascular thrombectomy (EVT; mTICI scale ≥ 2b) and subsequent BOLD-CVR examination were included for this analysis. We analyzed the spatial correlation between brain areas exhibiting BOLD-CVR-associated steal phenomenon and DWI infarct lesion as well as the relationship between steal phenomenon and NIHSS score at hospital discharge.Included patients (n = 21) exhibited steal phenomenon to different extents, whereas there was only a partial spatial overlap with the DWI lesion (median 19%; IQR, 8-59). The volume of steal phenomenon outside the DWI lesion showed a positive correlation with overall DWI lesion volume and was a significant predictor for the NIHSS score at hospital discharge.Patients with acute ischemic unilateral LVO stroke exhibited hemodynamic steal identified by BOLD-CVR after successful EVT. Steal volume was associated with DWI infarct lesion size and with poor clinical outcome at hospital discharge. BOLD-CVR may further aid in better understanding persisting hemodynamic impairment following reperfusion therapy.

Intravenous tenecteplase bridging reperfusion ameliorates cerebral ischemia/reperfusion injury by improving microvascular circulation in rats

BACKGROUND

Endovascular thrombectomy (EVT) alone was not demonstrated to be noninferior to intravenous alteplase bridging EVT in acute large vessel occlusion stroke. Using the cerebral ischemia/reperfusion (I/R) injury model, intravenous tenecteplase (TNK) was administrated after ischemia, followed by reperfusion at various time points.

OBJECTIVES

To investigate whether intravenous TNK bridging EVT vs EVT alone could improve I/R injury, and this effect may be associated with the time from TNK to reperfusion.

METHODS

Rats received intravenous TNK (1.4 mg/kg) or vehicle (sterile water) 1.0 hours after middle cerebral artery occlusion, followed by reperfusion after 0.5 or 1.0 hours following TNK. Neurological deficit scores, infarct volume, and brain edema were measured 24 hours after middle cerebral artery occlusion. Microthrombi were determined by immunofluorescence staining for CD31+/fibrinogen+ and CD31+/thrombocyte+. Inflammatory cell infiltration in the ischemic brain region was determined by flow cytometry.

RESULTS

Compared with vehicle, TNK significantly reduced neurological deficit scores, brain infarction, neuroinflammation, and blood-brain barrier disruption, and significantly reduced intravascular fibrin and platelet deposition and brain inflammatory cell infiltration in the penumbra of I/R rats. Furthermore, a better beneficial trend was found in TNK bridging reperfusion at 0.5 hours after TNK compared with TNK bridging reperfusion at 1.0 hours after TNK.

CONCLUSION

Our results demonstrate that intravenous TNK bridging reperfusion produced neuroprotective action through dissolving microvascular thrombus and alleviating inflammatory cell infiltration to improve microcirculation, with the result of maintaining blood-brain barrier integrity and inhibiting neuroinflammation, and the neuroprotective benefit may be associated with the time from TNK to reperfusion.

Early automated cerebral edema assessment following endovascular therapy: impact on stroke outcome

BACKGROUND

Cerebral edema (CED) is associated with poorer outcome in patients with acute ischemic stroke (AIS). The aim of the study was to investigate the factors contributing to greater early CED formation in patients with AIS who underwent endovascular therapy (EVT) and its association with functional outcome.

METHODS

We conducted a multicenter cohort study of patients with an anterior circulation AIS undergoing EVT. The volume of cerebrospinal fluid (CSF) was extracted from baseline and 24-hour follow-up CT using an automated algorithm. The severity of CED was quantified by the percentage reduction in CSF volume between CT scans (∆CSF). The primary endpoint was a shift towards an unfavorable outcome, assessed by modified Rankin Scale (mRS) score at 3 months. Multivariable ordinal logistic regression analyses were performed. The ∆CSF threshold that predicted unfavorable outcome was selected using receiver operating characteristic curve analysis.

RESULTS

We analyzed 201 patients (mean age 72.7 years, 47.8% women) in whom CED was assessable for 85.6%. Higher systolic blood pressure during EVT and failure to achieve modified Thrombolysis In Cerebral Infarction (mTICI) 3 were found to be independent predictors of greater CED. ∆CSF was independently associated with the probability of a one-point worsening in the mRS score (common odds ratio (cOR) 1.05, 95% CI 1.03 to 1.08) after adjusting for age, baseline mRS, National Institutes of Health Stroke Scale (NIHSS), and number of passes. Displacement of more than 25% of CSF was associated with an unfavorable outcome (OR 6.09, 95% CI 3.01 to 12.33) and mortality (OR 6.72, 95% CI 2.94 to 15.32).

CONCLUSIONS

Early CED formation in patients undergoing EVT was affected by higher blood pressure and incomplete reperfusion. The extent of early CED, measured by automated ∆CSF, was associated with worse outcomes.

Edaravone dexborneol for ischemic stroke with sufficient recanalization after thrombectomy: a randomized phase II trial

This phase II, randomized, double blinded, multi-center study aims to explore whether intravenous edaravone dexborneol (ED) could improve clinical outcomes in patients with anterior circulation stroke with successful endovascular reperfusion (ClinicalTrials.gov: NCT04667637). Eligible patients were randomly (1:1) assigned into ED, which received intravenous ED (37.5 mg, 2/day, for 12 days) or control group, which received placebo. The primary endpoint was favorable functional outcome (a modified Rankin Scale [mRS] of 0-2 at 90 days). Two hundred patients were enrolled, including 97 in ED group and 103 in control group. The proportion of patients with 90-day mRS (0-2) was 58.7% (54/92) in ED group and 52.1% (49/94) in control group (unadjusted odds ratio 1.37, [95% CI 0.76-2.44], P = 0.29). This work suggests that intravenous ED is safe, but do not statistically improve 90-day functional outcomes in patients with anterior circulation stroke with successful endovascular reperfusion.

Amide proton transfer MRI may reflect effective reperfusion and predict functional outcomes in patients with ischemic stroke

Perfusion imaging is useful to assess tissue recovery in patients with acute ischemic stroke (AIS); however, it cannot reflect tissue metabolism. We postulated that amide proton transfer (APT) imaging can characterize the tissue status after reperfusion therapy, thus providing prognostic value for 90-day functional outcomes. We included 63 patients with AIS and large-vessel occlusion (LVO). The APT signals, including APT# and NOE# (nuclear Overhauser enhancement) were quantified. Ischemic lesions observed on APT# and diffusion-weighted imaging (DWI) were classified according to their mismatch patterns (APT# < DWI; APT# ≥ DWI). Predictors of 90-day good outcomes (modified Rankin scale score 0-2) were evaluated. Patients with successful reperfusion exhibited higher APT#, smaller percentage change of APT#, and a greater likelihood of presenting APT# < DWI compared to those with poor reperfusion (all P < 0.05). The APT# (odds ratio [OR] = 11.48, P = 0.046) and a mismatch pattern of APT# < DWI (OR = 7.41, P = 0.020) independently predicted good outcomes besides the clinical parameters. A mismatch pattern of APT# ≥ DWI was a significant marker of poor outcomes despite successful reperfusion (P = 0.002). Our study provides preliminary evidence that APT may reveal tissue recovery after reperfusion and predict good outcomes at 90 days in patients with AIS and LVO.

Is Reperfusion Injury a Largely Intra-Ischemic Injury?

Reperfusion injury (RI) refers to an array of detrimental cellular and biochemical processes that are widely believed to be triggered by reperfusion following focal cerebral ischemia and to contribute to infarct extension and poor outcome despite complete recanalization. Accordingly, it is widely recommended that therapies targeting RI be administered after recanalization. The present topical review demonstrates, however, that the vast majority of, and possibly all, processes considered part of RI are not actually provoked by reperfusion but develop during the ischemic phase. This notion has significant implications for clinical trials. Thus, for optimal efficacy, treatments targeting RI should accordingly be started before recanalization. Conversely, interventions aimed at protecting the ischemic penumbra, either pharmacological or nonpharmacological, during arterial occlusion are likely to also benefit RI-related processes and should probably be continued after recanalization. Overall, that RI is largely an intra-ischemic process has important ramifications for drug development as well as clinical trials, and more broadly for the management of hyperacute ischemic stroke patients prior to, and following, recanalization.

Safety and Efficacy of Neuroprotective Agents as Adjunctive Therapies for Reperfusion in the Treatment of Acute Ischemic Stroke: A Systematic Review and Meta-analysis of Randomized Controlled Trials

There is still no clear evidence of the efficacy of the application of neuroprotective agents (NPAs) for acute ischemic stroke (AIS) patients receiving reperfusion therapies. This meta-analysis aimed to determine the effects of NPAs versus placebo on functional and safety outcomes as an adjunctive treatment to intravenous thrombolysis (IVT) or endovascular therapy (EVT) in AIS patients. The primary outcome was neurological functional independence, as evaluated by the proportion of patients whose modified Rankin Scale scores were 0 to 2 at 90 days after treatment. Thirteen randomized controlled trials with a total of 3736 patients were included. The application of NPAs was associated with greater odds of functional independence (odds ratio [OR]: 1.28; 95% CI: 1.12 to 1.46; P < 0.001; I2 = 0.0%) within 90 days. However, subgroup analysis of reperfusion therapy type (IVT, EVT, or both) revealed that only the EVT subgroup showed a significant association between NPAs or placebo and functional independence at 90 days (EVT group, OR: 1.43; 95% CI: 1.05 to 1.94; P = 0.022; I2 = 0.0%; IVT group, OR: 1.51; 95% CI: 0.93 to 2.46; P = 0.099; I2 = 39.8%; IVT plus EVT group, OR: 1.17; 95% CI: 0.94 to 1.45; P = 0.157; I2 = 16.0%). This meta-analysis revealed that NPAs could increase the possibility of AIS patients undergoing reperfusion therapies achieving functional independence within 90 days of onset; however, with the limited number of studies on each drug, further evidence is still needed to demonstrate the efficacy of each individual agent as an adjunctive therapy for different means of reperfusion.

Endothelial Cells and the Blood-Brain Barrier: Critical Determinants of Ineffective Reperfusion in Stroke

Ineffective reperfusion remains a critical challenge in neurointerventional treatment following ischemic stroke, with the integrity of the blood-brain barrier (BBB) being a key determinant of patient outcomes. This review explores the distinctive characteristics and roles of brain endothelial cells (ECs) in the context of stroke and ineffective reperfusion. We examine the unique properties of brain ECs compared to their counterparts in other tissues, focusing on their pathophysiological changes, functional impairments and the inflammatory cascades that follow stroke. Differences in gene expression between brain ECs and those in other organs offer deeper insights into their role in neuroprotective therapies. Additionally, drawing parallels between brain ECs and ECs from organs with similar ischemia-reperfusion injury profiles may inspire novel therapeutic approaches. This review highlights the critical importance of understanding the nuanced roles of ECs in BBB regulation, which ultimately impacts reperfusion outcomes.

Proteomic analysis of whole blood to investigate the therapeutic effects of nervonic acid on cerebral ischemia-reperfusion injury in rats

Introduction

Blood proteomics offers a powerful approach for identifying disease-specific biomarkers. However, no reliable blood markers are currently available for the diagnosis stroke. Nervonic acid (NA), a vital long-chain monounsaturated fatty acid found in mammalian nervous tissue, shows promising therapeutic potential in neurological disorders. This study aimed to develop a reliable methodology for whole blood proteomics to identify early warning biomarkers and evaluate drug treatment efficacy.

Methods

After modeling via the classic thread embolization method, whole blood samples were collected from the rats. Morphological assessments of brain tissue indicated that NA significantly mitigated brain and neuronal damage in rats. The differential protein expression profile was analyzed using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) whole blood proteomics.

Results

ZZZGene Ontology (GO) analysis revealed that, compared to ginkgo biloba extract (EGb), the proteins differentially expressed under NA intervention were predominantly involved in oxidative stress response and calcium-dependent adhesion processes. Key targets of NA in the treatment of middle cerebral artery occlusion (MCAO) models included ENO1, STAT3, NME2, VCL, and CCT3.

Discussion

This whole blood proteomic approach provides a comprehensive understanding of protein profiles associated with disease states, offering valuable insights into potential therapeutic targets and enabling the evaluation of NA and EGb intervention efficacy. Our findings underscore the protective effects of NA against cerebral ischemia-reperfusion injury and highlight its potential as a treatment for stroke.

Advancements in the treatment of cerebral ischemia-reperfusion injury: Acupuncture combined with mesenchymal stem cells transplantation

Cerebral ischemia-reperfusion injury (CIRI) constitutes a significant etiology of exacerbated cerebral tissue damage subsequent to intravenous thrombolysis and endovascular mechanical thrombectomy in patients diagnosed with acute ischemic stroke. The treatment of CIRI has been extensively investigated through a multitude of clinical studies. Acupuncture has been demonstrated to be effective in treating CIRI. Recent 5 years studies have identified potential mechanisms of acupuncture, including regulation of autophagy, promotion of angiogenesis, inhibition of inflammation and apoptosis, modulation of cell activation, neuroplasticity regulation, and promotion of nerve regeneration. The transplantation of mesenchymal stem cells (MSCs) can effectively suppress apoptosis, modulate immune responses, and enhance the proliferation and migration of endogenous neural stem cells (NSCs), thereby compensating for the NSCs deficiency following cerebral ischemia/reperfusion injury. The combination of acupuncture and MSCs transplantation demonstrates superiority over individual treatments, significantly enhancing the survival rate of MSCs. Moreover, it facilitates the secretion of various cytokines to promote their homing and differentiation into functional neurons, thereby providing a novel approach for clinical treatment of CIRI.

Predicting Functional Outcomes of Endovascular Thrombectomy in Acute Ischemic Stroke Using a Clinical-Radiomics Nomogram

BACKGROUND

Endovascular thrombectomy (EVT) is recommended for acute ischemic stroke due to large-vessel occlusion. However, approximately 50% of patients still experience poor outcomes after the procedure. This study aimed to assess whether a nomogram model that integrates computed tomography angiography radiomics features and clinical variables can predict EVT outcomes in patients with acute ischemic stroke.

METHODS

A total of 159 patients undergoing EVT were randomly divided into training and validation groups at a 7:3 ratio. A modified Rankin Scale score ≤ 2 at 90 days indicated a favorable outcome. We used univariate and multivariate logistic regression to identify analytic and radiomics predictors and create predictive models. Model performance was evaluated using the area under the curve, Hosmer-Lemeshow test, and decision curve analysis for discrimination, calibration, and clinical utility.

RESULTS

A 19-feature radiomics signature reached an area under the curve of 0.79. Combining it with age, baseline National Institutes of Health Stroke Scale score, diabetes, and statin use increased the area under the curve of the clinical-radiomics nomogram to 0.85. Both decision curve and calibration curve analyses showed strong performance.

CONCLUSIONS

Combining a radiomics nomogram with clinical predictors could effectively forecast EVT outcomes in patients with acute anterior circulation large vessel occlusion stroke.

Intra-arterial cocktail therapy for patients with anterior circulation large vessel occlusion who achieved endovascular reperfusion

Background

Clinically ineffective reperfusion (CIR) refers to the discrepancy between successful reperfusion and a favorable functional outcome in patients with large vessel occlusion (LVO) stroke after endovascular treatment (EVT). The Improving Neuroprotective Strategy for Ischemic Stroke with Sufficient Recanalization after Thrombectomy by Intra-arterial Cocktail Therapy (INSIST-CT) trial aimed to explore the safety, feasibility, and efficacy of intra-arterial cocktail therapy using argatroban, dexamethasone, and edaravone in patients who achieved sufficient reperfusion after EVT.

Methods

In this prospective, single-arm, pilot study, eligible patients with anterior circulation LVO who achieved sufficient reperfusion after EVT were enrolled in the INSIST-CT trial. Consecutive patients who met the inclusion/exclusion criteria were included in the control group retrospectively. In the INSIST-CT group, argatroban, dexamethasone, and edaravone were continuously administered for 30 min into the culprit artery after sufficient recanalization. The primary endpoint was the proportion of favorable functional outcome, defined as a modified Rankin Scale (mRS) score of 0-2 at 90 days. The primary safety outcome was symptomatic intracranial hemorrhage (sICH). Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) analyses were performed to account for multiple confounders.

Results

A total of 30 patients were included in the INSIST-CT group, and 261 patients were included in the control group. The proportion of the patients with the primary endpoint was 60% in the INSIST-CT group and 55.9% in the control group (unadjusted odds ratio [OR] 1.18, 95% CI 0.55-2.61, p = 0.67; adjusted OR 1.42, 95% CI 0.62-3.26, p = 0.41). No significant difference in sICH at 48 h after treatment was observed between the two groups (unadjusted OR 0.96, 95% CI 0.15-3.56, p = 0.96; adjusted OR 0.82 95% CI 0.17-3.97, p = 0.809). Similar results were observed after the PSM and IPTW analyses.

Conclusion

In anterior circulation, LVO patients who achieved sufficient reperfusion after EVT, bridging intra-arterial cocktail therapy with argatroban, dexamethasone, and edaravone may be safe and feasible. However, it did not improve the 90-day functional outcomes. A numerically higher probability of a favorable outcome in the INSIST-CT group suggests the potential promise of this cocktail therapy in reducing clinically ineffective reperfusion.

Clinical trial registration

ClinicalTrials.gov, NCT04202549.

Reevaluating the role of heparin during mechanical thrombectomy for acute ischemic stroke: Increased risks without functional benefit

BACKGROUND

Heparin may be administered during mechanical thrombectomy (MT) for acute ischemic stroke due to large vessel occlusions (AIS-LVO), with the aim of enhancing reperfusion and improving patient outcomes. The uncertain balance between risks and benefits of administering heparin during MT prompted us to perform this systematic review and meta-analysis.

METHODS

A comprehensive search was conducted in PubMed, Embase, and Scopus to find studies that report the safety or efficacy of administering heparin during MT for AIS-LVO. Meta-analysis was performed using the random effects model. In case of significant heterogeneity a subgroup analysis was performed.

RESULTS

From 2398 screened records, we included 15 studies. Rate of favorable functional outcome (90 day modified Rankin Scale 0-2 (mRS 0-2)) was lower among patients who received heparin (OR, 0.88 [95 %CI 0.79-0.98]; p=.023). Risk of distal embolization was higher in patients who received heparin (OR, 1.25 [95 %CI 1.01-1.55]; p=.04). The subgroup analysis showed that patients who received intravenous thrombolysis (IVT) had higher risk of Symptomatic intracranial hemorrhage (sICH) (OR, 2.94 [95 %CI 1.30-6.63]; p=.009) and lower rate of mRS 0-2 (OR, 0.66 [95 %CI 0.50-0.87]; p=.004). Heparin use didn't affect successful reperfusion rate (Thrombolysis in cerebral infarction ≥2B), mortality or any ICH risk.

CONCLUSION

Overall, our analysis indicates that administering heparin during MT for AIS-LVO correlates with worse clinical outcomes and increased distal embolization rates. Moreover, it is linked to a higher risk of sICH in patients who receive IVT. Consequently, the routine utilization of heparin during MT should be reconsidered.

Futile recanalization after endovascular treatment in acute ischemic stroke with large ischemic core

BACKGROUND

Endovascular therapy (EVT) is the treatment of choice for acute ischemic stroke (AIS) with large vessel occlusion. However, in many patients, successful EVT recanalization does not correspond to a clinical improvement, called futile recanalization (FR). We aimed to identify stroke risk factors and patient characteristics associated with FR in AIS with large core infarct (LCI).

METHODS

A total of 137 patients with AIS with LCI treated by EVT at a single stroke center were retrospectively included from January 2016 to June 2023. LCI was defined by Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECT) < 6. Patient age, sex, modified Rankin Scale (mRS), National Institutes of Health Stroke Scale (NIHSS), time to treatment, risk factors, and radiologic findings were collected, and potential associations with FR were analyzed. FR was defined as successful reperfusion with modified Thrombolysis in Cerebral Infarction (mTICI) ≥ 2b but without functional independence at 90 days (mRS ≥ 3). A multivariate logistic regression analysis was conducted on the clinical characteristics of patients, based on the presence or absence of FR, and the factors influencing FR.

RESULTS

Of 137 patients, 120 showed successful recanalization (mTICI ≥ 2b). All patients were divided into FR (n = 80) and no FR (n = 40) groups. Older age (odds ratio [OR] 1.052, 95% confidence interval [CI] 1.002-1.105; p = 0.041), the higher the initial NIHSS score (OR 1.181, 95% CI 1.037-1.344; p = 0.012), and prior intravenous plasminogen activator (OR 0.310, 95% CI 0.118-0.813, p = 0.017) were independent influencing factors of FR.

CONCLUSIONS

The older age, the higher the initial NIHSS, and not receiving intravenous plasminogen activator were independently associated with FR in AIS with LCI. These factors could identify poor responders to EVT recanalization.

Zhachong Shisanwei pill drug-containing serum protects H2O2-Induced PC12 cells injury by suppressing apoptosis, oxidative stress via regulating the MAPK signaling pathway

Introduction

Zhachong Shisanwei Pill (ZSP) is a classical Mongolian formula that combines 13 types of Chinese medicinal materials and has been used for treating ischemic stroke (IS) for centuries. However, the underlying molecular mechanisms have yet to be fully elucidated. The aim of this study is to explore potential mechanism of ZSP on nerve cells in cerebral ischemic injury.

Methods

To simulate the pathological process of oxidative stress following IS, an injury model using PC12 cells was induced with hydrogen peroxide (H2O2). Afterward, PC12 cells were treated with ZSP medicated serum at low, medium, and high doses. Various assays were conducted to assess cell viability and oxidative stress indicators, including lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reactive oxygen species (ROS), and mitochondrial membrane potential (MMP). Cell apoptosis was evaluated through morphological assessment and flow cytometry. Additionally, the expression levels of apoptosis-related proteins (Bcl-2, Bax, Caspase-9, Caspase-3, PARP) and signaling pathway proteins (JNK, phosphorylated JNK, ERK, phosphorylated ERK, p38, and phosphorylated p38) were measured using automated Western blotting.

Results

Our findings indicate that ZSP medicated serum preconditioning improves the condition of PC12 cells injured by H2O2. Specifically, it increased cell survival rates and reduced LDH release. Additionally, ZSP treatment decreased ROS levels and MDA content, while enhancing the activity of SOD and CAT in the injured PC12 cells. ZSP also reversed the depolarization of mitochondrial membrane potential and protected cells from apoptosis by modulating the expression of apoptosis-related proteins, including Bcl-2, Bax, Caspase-9, Caspase-3, and PARP. Furthermore, the overactivation of the MAPK signaling pathway due to H2O2-induced injury was inhibited, as evidenced by the downregulation of phosphorylated JNK, ERK, and p38 levels.

Discussion

Mongolian medicine ZSP demonstrates protective effects against H2O2-induced oxidative stress and apoptosis in PC12 cells. The underlying mechanism may involve the inhibition of the MAPK signaling pathway, enhancement of antioxidant enzyme activity, reduction of intracellular peroxidation levels, and suppression of intrinsic apoptosis pathways.

High Systemic Inflammatory Protein Index Is Associated with Clinically Ineffective Reperfusion in Acute Anterior Circulation Ischemic Stroke Patients Undergoing Endovascular Treatment

Nearly half of the patients undergoing endovascular treatment (EVT) do not have favorable outcomes despite successful recanalization of the occluded artery, which is also known as clinically ineffective reperfusion. We proposed a novel index-the systemic inflammatory protein index (SIPI), based on albumin, globulin, and C-reaction protein (CRP). We aimed to evaluate the relationship between inflammatory biomarkers at varying time points and the 90-day functional outcomes and investigate inflammatory biomarkers' dynamic changes during hospitalization in acute ischemic stroke (AIS) patients of anterior circulation undergoing EVT. We retrospectively recruited consecutive patients diagnosed with AIS of anterior circulation and treated with EVT from January 2018 to June 2022 in Nanfang Hospital. Albumin, globulin, and CRP were recorded on admission, 1 day, 3 days, and 7 days after EVT. An unfavorable functional outcome was defined as 90-day modified Rankin Scale (mRS) of 3-6. Albumin-to-globulin ratio (AGR), C-reactive protein-to-albumin ratio (CAR), and SIPI were calculated as follows: AGR = albumin/globulin; CAR = CRP/albumin; SIPI = CRP × globulin/albumin. A total of 238 consecutive anterior circulation AIS patients with EVT were included, among which 145 (60.9%) patients had unfavorable outcomes. After adjusting for confounding factors, admission globulin, admission AGR, 1-day AGR, 3-day albumin, 3-day CRP, 3-day CAR, 3-day SIPI, 7-day albumin, 7-day CRP, 7-day CAR, and 7-day SIPI showed an independent association with 90-day functional outcome. Of them, 3-day SIPI had the most robust discriminative ability with an area under the curve of 0.719 (CI 0.630-0.808, p < 0.001). There were differences in the dynamic change of inflammatory biomarkers between the subjects with favorable and unfavorable functional outcomes. Inflammatory biomarkers, including albumin, globulin, CRP, AGR, CAR, and SIPI, are independent predictors of 90-day unfavorable outcomes in anterior circulation AIS patients with EVT. SIPI of day 3 has the highest predictive value.

Multi-Target and Multi-Phase Adjunctive Cerebral Protection for Acute Ischemic Stroke in the Reperfusion Era

Stroke remains the leading cause of death and disability in some countries, predominantly attributed to acute ischemic stroke (AIS). While intravenous thrombolysis and endovascular thrombectomy are widely acknowledged as effective treatments for AIS, boasting a high recanalization rate, there is a significant discrepancy between the success of revascularization and the mediocre clinical outcomes observed among patients with AIS. It is now increasingly understood that the implementation of effective cerebral protection strategies, serving as adjunctive treatments to reperfusion, can potentially improve the outcomes of AIS patients following recanalization therapy. Herein, we reviewed several promising cerebral protective methods that have the potential to slow down infarct growth and protect ischemic penumbra. We dissect the underlying reasons for the mismatch between high recanalization rates and moderate prognosis and introduce a novel concept of "multi-target and multi-phase adjunctive cerebral protection" to guide our search for neuroprotective agents that can be administered alongside recanalization therapy.

Ischemic Microenvironment-Targeted Bioinspired Lipoprotein Sequentially Penetrates Cerebral Ischemic Lesions to Rescue Ischemic Stroke

Reperfusion injury represents a significant impediment to recovery after recanalization in an ischemic stroke and can be alleviated by neuroprotectants. However, inadequate drug delivery to ischemic lesions impairs the therapeutic effects of neuroprotectants. To address this issue, an ischemic microenvironment-targeted bioinspired lipoprotein system encapsulating lipoic acid (LA@PHDL) is herein designed to sequentially penetrate ischemic lesions and be readily taken up by neurons and microglia. In transient middle cerebral artery occlusion (tMCAO) mouse models, LA@PHDL accumulates rapidly and preferentially in the ischemic brain, with a 2.29-fold higher than the nontargeted nanoplatform in the early stage. Furthermore, LA@PHDL effectively restores neurological function, reduces infarct volume to 17.70%, prevents brain cell necrosis and apoptosis, and attenuates inflammation in tMCAO mouse models. This design presents new opportunities for delivering neuroprotectants to cerebral ischemic lesions to improve the outcome of an ischemic stroke.

Stress hyperglycemia is associated with futile recanalization in patients with anterior large vessel occlusion undergoing mechanical thrombectomy

INTRODUCTION

Mechanical thrombectomy (MT) is the standard treatment for acute ischemic stroke (AIS) due to anterior large vessel occlusion (LVO). Despite successful recanalization, some patients remain disabled after 3 months. Mechanisms that can cause futile recanalization (FR) are still largely unknown. We investigated if stress hyperglycemia might be associated with FR.

PATIENTS AND METHODS

This is a retrospective analysis of consecutive patients with successful recanalization treated in four participating centers between January 2021 and December 2022. According to the modified Rankin scale (mRS) status at 3 months, patients were divided into two groups: FR, if mRS score >2, and useful recanalization (UR), if mRS score ⩽2. Stress hyperglycemia was estimated by the glucose-to-glycated hemoglobin ratio (GAR) index.

RESULTS

A total of 691 subjects were included. At 3 months, 403 patients (58.3%) were included in the FR group, while the remaining 288 patients (41.7%) were included in the UR group. At the multivariate analysis, variables independently associated with FR were the following: age (OR 1.04, 95% CI 1.02-1.06, p < 0.001), GAR index (OR 1.08, 95% CI 1.03-1.14, p = 0.003), NIHSS at admission (OR 1.16, 95% CI 1.11-1.22; p < 0.001), and procedure length (OR 1.01, 95% CI 1.00-1.02; p = 0.009). We observed that the model combining age, GAR index, NIHSS at admission, and procedure length had good predictive accuracy (AUC 0.78, 95% CI 0.74-0.81).

CONCLUSIONS

Stress hyperglycemia predicts FR in patients with successful recanalization after MT. Further studies should explore if managing stress hyperglycemia may reduce futile recanalization. Additionally, we recommend paying close attention to AIS patients with a GAR index greater than 24.8 who exhibit a high risk of FR.

Brain border-derived CXCL2+ neutrophils drive NET formation and impair vascular reperfusion following ischemic stroke

BACKGROUND

The brain border compartments harbor a diverse population of immune cells and serve as invasion sites for leukocyte influx into the brain following CNS injury. However, how brain-border myeloid cells affect stroke pathology remains poorly characterized.

METHODS AND RESULTS

Here, we showed that ischemic stroke-induced expansion of CXCL2+ neutrophils, which exhibit highly proinflammatory features. We tracked CXCL2+ neutrophils in vivo by utilizing a photoconvertible Kik-GR mouse (fluorescent proteins Kikume Green Red, Kik-GR) and found that brain-infiltrating CXCL2+ neutrophils following ischemic stroke were mainly derived from the brain border rather than the periphery. We demonstrated that CXCL2 neutralization inhibited the formation and releasing of neutrophil extracellular traps (NETs) from in vitro cultured primary neutrophils. Furthermore, CXCL2-neutralizing antibody treatment reduced brain infarcts and improved vascular reperfusion at day 3 postischemic stroke.

CONCLUSIONS

Collectively, brain border-derived CXCL2+ neutrophil expansion may impair vascular reperfusion by releasing NETs following ischemic stroke.

U-shaped association between low-density lipoprotein cholesterol levels and risk of futile reperfusion mediated by stroke-associated pneumonia in acute ischemic stroke after endovascular thrombectomy

OBJECTIVE

Futile reperfusion (FR) is becoming a major challenge in the treatment of patients with acute ischaemic stroke (AIS) undergoing endovascular thrombectomy. This study aims to determine the dose-response relationship between low-density lipoprotein cholesterol (LDL-C) levels and the risk of FR in patients with AIS undergoing endovascular thrombectomy and to investigate potential mediators.

METHODS

A total of 614 patients with AIS undergoing endovascular thrombectomy were enrolled and divided into five groups according to quintiles of LDL-C levels: Q1(≤2.27 mmol/l), Q2 (2.27-2.5 mmol/l), Q3 (2.5-2.59 mmol/l), Q4 (2.59-2.97 mmol/l) and Q5 (≥2.97 mmol/l). Associations between LDL-C levels and the risk of FR and stroke-associated pneumonia (SAP) were estimated using multivariate logistic regression models. Restricted cubic spline curves were used to describe the dose-response relationship between LDL-C levels and the risk of FR and SAP. Mediation effect analysis was performed in R software with 100 bootstrap samples.

RESULTS

After adjustment for confounders, both low and high LDL-C levels were significantly associated with a higher risk of FR compared with the reference group (Q3). We observed a U-shaped association between LDL-C levels and the risk of FR (P for nonlinear =0.012). Mediation analysis showed that the association between LDL-C levels and the risk of FR was 29.7 % (95 % CI: 2.96 %-75.0 %, P=0.02) mediated by SAP.

CONCLUSIONS

We found a U-shaped association between LDL-C levels and the risk of FR that was mediated by SAP. Clinicians should note that in AIS patients undergoing endovascular thrombectomy, lower LDL-C levels are not always better.

Predicting brain edema and outcomes after thrombectomy in stroke: Frontal delta/alpha ratio as an optimal quantitative EEG index

OBJECTIVE

We aimed to determine whether quantitative electroencephalography (QEEG) measures have predictive value for cerebral edema (CED) and clinical outcomes in acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion who underwent mechanical thrombectomy (MT).

METHODS

A total of 105 patients with AIS in the anterior circulation were enrolled in this prospective study. The occurrence and severity of CED were assessed through computed tomography conducted 24 h after MT. Clinical outcomes were evaluated based on early neurological deterioration (END) and 3-month functional status, as measured by the modified Rankin scale (mRS). Electroencephalography (EEG) recordings were performed 24 h after MT, and QEEG indices were calculated from the standard 16 electrodes and 2 frontal channels (F3-C3, F4-C4). The delta/alpha ratio (DAR), the (delta + theta) / (alpha + beta) ratio (DTABR), and relative delta power were averaged over all electrodes (global) and the F3-C3 and F4-C4 channels (frontal). The predictive effect and value of QEEG indices for CED and clinical outcomes were assessed using ordinal and logistic regression models, as well as receiver operating characteristic (ROC) curves.

RESULTS

Significantly, both global and frontal DAR were found to be associated with the severity of CED, END, and poor functional outcomes at 90 days, while global and frontal DTABR and relative delta power were not associated with outcomes. In ROC analysis, the best predictive effect was observed in frontal DAR, with an area under the curve of approximately 0.80. It exhibited approximately 75% sensitivity and 71% specificity for radiological and clinical outcomes when a threshold of 3.3 was used.

CONCLUSIONS

QEEG techniques may be considered an efficient bedside monitoring method for assessing treatment efficacy, identifying patients at higher risk of severe CED and END, and predicting long-term functional outcomes.

SIGNIFICANCE

QEEG can help identify patients at risk of severe neurological complications that can impact long-term functional recovery in AIS patients who underwent MT.

Prospective randomized controlled trial on the safety and neuroprotective efficacy of remote administration of hypothermia over spleen during acute ischemic stroke with mechanical thrombectomy: rationale, design, and protocol

Background

Brain inflammation plays a key role in ischemia/reperfusion (I/R) injury and is the main cause of "ineffective or futile recanalization" after successful mechanical thrombectomy (MT) in acute ischemic stroke (AIS). One of the primary sources of inflammatory cells after AIS are derived from the spleen. As an innovative and potential neuroprotective strategy after stroke, Remote Administration of Hypothermia (RAH) temporarily suppresses immune activities in the spleen, reduces the release of inflammatory cells and cytokines into blood, and thus reversibly diminishes inflammatory injury in the brain.

Methods

This single-center, prospective, randomized controlled study (RCT) is proposed for AIS patients with anterior circulation large vessel occlusion (LVO). Subjects will be randomly assigned to either the control or intervention groups in a 1:1 ratio (n = 40). Participants allocated to the intervention group will receive RAH on the abdomen above the spleen prior to recanalization until 6 h after thrombectomy. All enrolled patients will receive standard stroke Guideline care. The main adverse events associated with RAH are focal cold intolerance and abdominal pain. The primary outcome will assess safety as it pertains to RAH application. The secondary outcomes include the efficacy of RAH on spleen, determined by spleen volumes, blood inflammatory factor (cells and cytokines), and on brain injury, determined by infarction volumes and poststroke functional outcomes.

Discussion

This study aims to examine the safety and preliminary effectiveness of RAH over the spleen during endovascular therapy in AIS patients. The results of this study are expected to facilitate larger randomized clinical trials and hopefully prove RAH administration confers adjuvant neuroprotective properties in AIS treated with MT.

Clinical trial registration

https://www.chictr.org.cn/. Identifier ChiCTR 2300077052.

Development and validation of outcome prediction model for reperfusion therapy in acute ischemic stroke using nomogram and machine learning

OBJECTIVE

To develop logistic regression nomogram and machine learning (ML)-based models to predict 3-month unfavorable functional outcome for acute ischemic stroke (AIS) patients undergoing reperfusion therapy.

METHODS

Patients undergoing reperfusion therapy (intravenous thrombolysis and/or endovascular treatment) were prospectively recruited. Unfavorable outcome was defined as 3-month modified Rankin Scale (mRS) score 3-6. The independent risk factors associated with unfavorable outcome were obtained by regression analysis and included in the prediction model. The performance of nomogram was assessed by the area under the curve (AUC), calibration curve, and decision curve analysis (DCA). ML models were compared with nomogram using AUC; the generalizability of all models was ascertained in an external cohort.

RESULTS

A total of 505 patients were enrolled, with 256 in the model construction, and 249 in the external validation. Five variables were identified as prognostic factors: baseline NIHSS, D-dimer level, random blood glucose (RBG), blood urea nitrogen (BUN), and systolic blood pressure (SBP) before reperfusion. The AUC values of nomogram were 0.865, 0.818, and 0.779 in the training set, test set, and external validation, respectively. The calibration curve and DCA indicated appreciable reliability and good net benefits. The best three ML models were extra trees (ET), CatBoost, and random forest (RF) models; all of them showed favorable discrimination in the training cohort, and confirmed in the test and external sets.

CONCLUSION

Baseline NIHSS, D-dimer, RBG, BUN, and SBP before reperfusion were independent predictors for 3-month unfavorable outcome after reperfusion therapy in AIS patients. Both nomogram and ML models showed good discrimination and generalizability.

Effects of edaravone dexborneol on functional outcome and inflammatory response in patients with acute ischemic stroke

BACKGROUND

Edaravone dexborneol has been reported as an effective neuroprotective agent in the treatment of acute ischemic stroke (AIS). This study aimed at investigating the impact of edaravone dexborneol on functional outcomes and systematic inflammatory response in AIS patient.

METHODS

All participants were recruited from the AISRNA study (registered 21/11/2019, NCT04175691 [ClinicalTrials.gov]) between January 2022 and December 2022. The AIS patients were divided into two groups based on whether they received the treatment of edaravone dexborneol (37.5 mg/12 hours, IV) within 48 h after stroke onset. Inflammatory response was determined by detecting levels of cytokines (interleukin-2 [IL-2], IL-4, IL-5, IL-8, IL-6, IL-10, IL-12p70, IL-17, tumor necrosis factor-α [TNF-α], interferon-γ [IFN-γ], IFN-α, and IL-1β) within 14 days after stroke onset.

RESULTS

Eighty-five AIS patients were included from the AISRNA study. Patients treated with edaravone dexborneol showed a significantly higher proportion of modified Rankin Scale score < 2 compared to those who did not receive this treatment (70.7% versus 47.8%; P = 0.031). Furthermore, individuals receiving edaravone dexborneol injection exhibited lower expression levels of interleukin (IL)-1β, IL-6, and IL-17, along with higher levels of IL-4 and IL-10 expression during the acute phase of ischemic stroke (P < 0.05). These trends were not observed for IL-2, IL-5, IL-8, IL-12p70, tumor necrosis factor-α, interferon-γ [IFN-γ], and IFN-α (P > 0.05).

CONCLUSIONS

Treatment with edaravone dexborneol resulted in a favorable functional outcome at 90 days post-stroke onset when compared to patients without this intervention; it also suppressed proinflammatory factors expression while increasing anti-inflammatory factors levels.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04175691. Registered November 21, 2019, https://www.

CLINICALTRIALS

gov/ct2/show/NCT04175691 .

Normobaric Hyperoxia Combined With Endovascular Treatment Based on Temporal Gradient: A Dose-Escalation Study

BACKGROUND

Normobaric hyperoxia (NBO) has neuroprotective effects in acute ischemic stroke. Thus, we aimed to identify the optimal NBO treatment duration combined with endovascular treatment.

METHODS

This is a single-center, randomized controlled, open-label, blinded-end point dose-escalation clinical trial. Patients with acute ischemic stroke who had an indication for endovascular treatment at Tianjin Huanhu Hospital were randomly assigned to 4 groups (1:1 ratio) based on NBO therapy duration: (1) control group (1 L/min oxygen for 4 hours); (2) NBO-2h group (10 L/min for 2 hours); (3) NBO-4h group (10 L/min for 4 hours); and (4) NBO-6h group (10 L/min for 6 hours). The primary outcome was cerebral infarction volume at 72 hours after randomization using an intention-to-treat analysis model. The primary safety outcome was the 90-day mortality rate.

RESULTS

Between June 2022 and September 2023, 100 patients were randomly assigned to the following groups: control group (n=25), NBO-2h group (n=25), NBO-4h group (n=25), and NBO-6h group (n=25). The 72-hour cerebral infarct volumes were 39.4±34.3 mL, 30.6±30.1 mL, 19.7±15.4 mL, and 22.6±22.4 mL, respectively (P=0.013). The NBO-4h and NBO-6h groups both showed statistically significant differences (adjusted P values: 0.011 and 0.027, respectively) compared with the control group. Compared with the control group, both the NBO-4h and NBO-6h groups showed significant differences (P<0.05) in the National Institutes of Health Stroke Scale scores at 24 hours, 72 hours, and 7 days, as well as in the change of the National Institutes of Health Stroke Scale scores from baseline to 24 hours. Additionally, there were no significant differences among the 4 groups in terms of 90-day mortality rate, symptomatic intracranial hemorrhage, early neurological deterioration, or severe adverse events.

CONCLUSIONS

The effectiveness of NBO therapy was associated with oxygen administration duration. Among patients with acute ischemic stroke who underwent endovascular treatment, NBO therapy for 4 and 6 hours was found to be more effective. Larger-scale multicenter studies are needed to validate these findings.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05404373.

Influencing factors of futile recanalization after endovascular intervention in patients with acute basilar artery occlusion

OBJECTIVES

To explore the influence factors for futile recanalization following endovascular treatment (EVT) in patients with acute basilar artery occlusion (BAO).

METHODS

Clinical data of patients with acute BAO, who underwent endovascular treatment within 24 h of onset from January 2017 to November 2022, were retrospectively analyzed. The futile recanalization was defined as modified thrombolysis in cerebral infarction (mTICI) grade ≥2b or 3 after successful reperfusion, but the modified Rankin Scale score >2 at 3 months after EVT. Binary logistic regression model was used to analyze the influencing factors of futile recanalization.

RESULTS

A total of 471 patients with a median age of 68 (57, 74) years were included and 68.9% were males, among whom 298 (63.27%) experienced futile recanalization. Multivariate analysis revealed that concomitant atrial fibrillation (OR=0.456, 95%CI: 0.282-0.737, P<0.01), bridging thrombolysis (OR=0.640, 95%CI: 0.416-0.985, P<0.05), achieving mTICI grade 3 (OR=0.554, 95%CI: 0.334-0.918, P<0.05), arterial occlusive lesion (AOL) grade 3 (OR=0.521, 95%CI: 0.326-0.834, P<0.01), and early postoperative statin therapy (OR=0.509, 95%CI: 0.273-0.948, P<0.05) were protective factors for futile recanalization after EVT in acute BAO patients. High baseline National Institutes of Health Stroke Scale (NIHSS) score (OR=1.068, 95%CI: 1.049-1.087, P<0.01), coexisting hypertension (OR=1.571, 95%CI: 1.017-2.427, P<0.05), multiple retrieval attempts (OR=1.237, 95%CI: 1.029-1.488, P<0.05) and postoperative hemorrhagic transformation (OR=8.497, 95%CI: 2.879-25.076, P<0.01) were risk factors. For trial of ORG 10172 in acute stroke treatment (TOAST) classification, cardiogenic embolism (OR=0.321, 95%CI: 0.193-0.534, P<0.01) and other types (OR=0.499, 95%CI: 0.260-0.961, P<0.05) were related to lower incidence of futile recanalization.

CONCLUSIONS

The incidence of futile recanalization after EVT in patients with acute BAO is high. Bridging venous thrombolysis before operation and an early postoperative statin therapy may reduce the incidence of futile recanalization.

A promising frontier: targeting NETs for stroke treatment breakthroughs

Stroke is a prevalent global acute cerebrovascular condition, with ischaemic stroke being the most frequently occurring type. After a stroke, neutrophils accumulate in the brain and subsequently generate and release neutrophil extracellular traps (NETs). The accumulation of NETs exacerbates the impairment of the blood‒brain barrier (BBB), hampers neovascularization, induces notable neurological deficits, worsens the prognosis of stroke patients, and can facilitate the occurrence of t-PA-induced cerebral haemorrhage subsequent to ischaemic stroke. Alternative approaches to pharmacological thrombolysis or endovascular thrombectomy are being explored, and targeting NETs is a promising treatment that warrants further investigation.

A CT texture-based nomogram for predicting futile reperfusion in patients with intraparenchymal hyperdensity after endovascular thrombectomy for acute anterior circulation large vessel occlusion

BACKGROUND

Post-thrombectomy intraparenchymal hyperdensity (PTIH) in patients with acute anterior circulation large vessel occlusion is a common CT sign associated with a higher incidence of futile reperfusion (FR). We aimed to develop a nomogram to predict FR specifically in patients with PTIH.

METHODS

We retrospectively collected information on patients with acute ischemic stroke who underwent endovascular thrombectomy (EVT) at two stroke centers. A total of 398 patients with PTIH were included to develop and validate the nomogram, including 214 patients in the development cohort, 92 patients in the internal validation cohort and 92 patients in the external validation cohort. The nomogram was developed according to the independent predictors obtained from multivariate logistic regression analysis, including clinical factors and CT texture features extracted from hyperdense areas on CT images within half an hour after EVT. The performance of the nomogram was evaluated with integrated discrimination improvement (IDI), category-free net reclassification improvement (NRI), the area under the receiver operating characteristic curve (AUC-ROC), calibration plots, and decision curve analyses for discrimination, calibration ability, and clinical net benefits, respectively.

RESULTS

Our nomogram was constructed based on three clinical factors (age, NIHSS score and ASPECT score) and two CT texture features (entropy and kurtosis), with AUC-ROC of 0.900, 0.897, and 0.870 in the development, internal validation, and external validation cohorts, respectively. NRI and IDI further validated the superior predictive ability of the nomogram compared to the clinical model. The calibration plot revealed good consistency between the predicted and the actual outcome. The decision curve indicated good positive net benefit and clinical validity of the nomogram.

CONCLUSION

The nomogram enables clinicians to accurately predict FR specifically in patients with PTIH within half an hour after EVT and helps to formulate more appropriate treatment plans in the early post-EVT period.

Evolution pattern estimated by computed tomography perfusion post-thrombectomy predicts outcome in acute ischemic stroke

OBJECTIVES

Computed tomography perfusion (CTP) and computed tomography angiography (CTA) have been recommended to select acute ischemic stroke (AIS) patients for endovascular thrombectomy (EVT) but are not widely used for post-treatment evaluation. We aimed to observe abnormalities in CTP and CTA before and after EVT and evaluate post-EVT CTP and CTA as potential tools for improving clinical outcome prediction.

METHODS

Patients with AIS who underwent EVT and received CTP and CTA before and after EVT were retrospectively evaluated. The ischemic core was defined as the volume of relative cerebral blood flow <30% and hypoperfusion as the volume of Tmax >6 s. A reduction in hypoperfusion volume >90% between baseline and post-EVT CTP was defined as tissue optimal reperfusion (TOR). The 90-day modified Rankin scale was used to evaluate the clinical outcome.

RESULTS

Eighty-three patients were included. Patients with an absent ischemic core or with TOR after EVT had a higher rate of modified Thrombolysis in Cerebral Ischemia score 2c-3 and recanalization of post-treatment vessel condition based on follow-up CTA. Multivariable logistic regression revealed that the baseline ischemic core volume (OR:0.934, p=0.009), TOR (OR:8.322, p=0.029) and immediate NIHSS score after EVT (OR:0.761, p=0.012) were factors significantly associated with good clinical outcome. Combining baseline ischemic core volume and TOR with immediate NIHSS score after EVT showed greatest performance for good outcome prediction after EVT(AUC=0.921).

CONCLUSIONS

The addition of pretreatment and post-treatment CTP information to purely clinical NIHSS scores might help to improve the efficacy for good outcome prediction after EVT.

Association between uric acid levels and the risk of futile reperfusion in stroke after thrombectomy: A propensity score matching study

INTRODUCTION

Currently, futile reperfusion (FR) is becoming a major challenge in the endovascular treatment of patients with acute ischemic stroke (AIS). The relationship between serum uric acid (SUA) and FR has not been investigated. This study aims to determine the relationship between SUA and FR using propensity score matching (PSM) analysis.

METHODS

A total of 441 patients with AIS undergoing mechanical thrombectomy (MT) between August 2017 and January 2023 were included and divided into two groups based on the median SUA (297.4 μmol/L). Two groups were balanced using PSM analysis at a 1:1 ratio. The standardized mean difference (SMD) were used to assess the efficacy of the matching. Finally, 158 patients with low SUA (≤ 297.4 μmol/L) were matched with 158 patients with high SUA (>297.4 μmol/L). Predictors of FR were analyzed by multivariate logistic regression analysis in the PSM cohort.

RESULTS

After PSM, patients with low SUA (≤ 297.4 μmol/L) had a significant higher incidence of FR (72.8 %, 115/158) than patients with high SUA (>297.4 μmol/L) (48.1 %, 76/158) (P<0.001). Multivariate logistic regression analysis in the PSM cohort showed that low SUA (≤ 297.4 μmol/L) was an independent risk factor for the efficacy of reperfusion (OR: 6.403, 95 % CI: 3.123-13.129, P<0.001), suggesting that patients with SUA ≤ 297.4 μmol/L have a 6.403 times higher risk of FR than patients with SUA>297.4 μmol/L.

CONCLUSION

The results of this study suggest that low SUA (≤ 297.4 μmol/L) at admission increases the risk of FR in AIS patients undergoing MT by PSM analysis.

Blood Pressure Variability in Acute Stroke: A Narrative Review

The management of blood pressure variability (BPV) in acute stroke presents a complex challenge with profound implications for patient outcomes. This narrative review examines the role of BPV across various stages of acute stroke care, highlighting its impact on treatment strategies and prognostic considerations. In the prehospital setting, while guidelines lack specific recommendations for BP management, emerging evidence suggests a potential link between BPV and outcomes. Among ischaemic stroke patients who are ineligible for reperfusion therapies, BPV independently influences functional outcomes, emphasising the need for individualised approaches to BP control. During intravenous thrombolysis and endovascular therapy, the intricate interplay between BP levels, recanalisation status, and BPV is evident. Striking a balance between aggressive BP lowering and avoiding hypoperfusion-related complications is essential. Intracerebral haemorrhage management is further complicated by BPV, which emerges as a predictor of mortality and disability, necessitating nuanced BP management strategies. Finally, among patients with acute subarachnoid haemorrhage, increased BPV may be correlated with a rebleeding risk and worse outcomes, emphasizing the need for BPV monitoring in this population. Integration of BPV assessment into clinical practice and research protocols is crucial for refining treatment strategies that are tailored to individual patient needs. Future studies should explore novel interventions targeting BPV modulation to optimise stroke care outcomes.

Association between blood pressure variability and outcomes after endovascular thrombectomy for acute ischemic stroke: An individual patient data meta-analysis

INTRODUCTION

Data on the association between blood pressure variability (BPV) after endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) and outcomes are limited. We sought to identify whether BPV within the first 24 hours post EVT was associated with key stroke outcomes.

METHODS

We combined individual patient-data from five studies among AIS-patients who underwent EVT, that provided individual BP measurements after the end of the procedure. BPV was estimated as either systolic-BP (SBP) standard deviation (SD) or coefficient of variation (CV) over 24 h post-EVT. We used a logistic mixed-effects model to estimate the association [expressed as adjusted odds ratios (aOR)] between tertiles of BPV and outcomes of 90-day mortality, 90-day death or disability [modified Rankin Scale-score (mRS) > 2], 90-day functional impairment (⩾1-point increase across all mRS-scores), and symptomatic intracranial hemorrhage (sICH), adjusting for age, sex, stroke severity, co-morbidities, pretreatment with intravenous thrombolysis, successful recanalization, and mean SBP and diastolic-BP levels within the first 24 hours post EVT.

RESULTS

There were 2640 AIS-patients included in the analysis. The highest tertile of SBP-SD was associated with higher 90-day mortality (aOR:1.44;95% CI:1.08-1.92), 90-day death or disability (aOR:1.49;95% CI:1.18-1.89), and 90-day functional impairment (adjusted common OR:1.42;95% CI:1.18-1.72), but not with sICH (aOR:1.22;95% CI:0.76-1.98). Similarly, the highest tertile of SBP-CV was associated with higher 90-day mortality (aOR:1.33;95% CI:1.01-1.74), 90-day death or disability (aOR:1.50;95% CI:1.19-1.89), and 90-day functional impairment (adjusted common OR:1.38;95% CI:1.15-1.65), but not with sICH (aOR:1.33;95% CI:0.83-2.14).

CONCLUSIONS

BPV after EVT appears to be associated with higher mortality and disability, independently of mean BP levels within the first 24 h post EVT. BPV in the first 24 h may be a novel target to improve outcomes after EVT for AIS.

Dynamic cerebral blood flow assessment based on electromagnetic coupling sensing and image feature analysis

Dynamic assessment of cerebral blood flow (CBF) is crucial for guiding personalized management and treatment strategies, and improving the prognosis of stroke. However, a safe, reliable, and effective method for dynamic CBF evaluation is currently lacking in clinical practice. In this study, we developed a CBF monitoring system utilizing electromagnetic coupling sensing (ECS). This system detects variations in brain conductivity and dielectric constant by identifying the resonant frequency (RF) in an equivalent circuit containing both magnetic induction and electrical coupling. We evaluated the performance of the system using a self-made physical model of blood vessel pulsation to test pulsatile CBF. Additionally, we recruited 29 healthy volunteers to monitor cerebral oxygen (CO), cerebral blood flow velocity (CBFV) data and RF data before and after caffeine consumption. We analyzed RF and CBFV trends during immediate responses to abnormal intracranial blood supply, induced by changes in vascular stiffness, and compared them with CO data. Furthermore, we explored a method of dynamically assessing the overall level of CBF by leveraging image feature analysis. Experimental testing substantiates that this system provides a detection range and depth enhanced by three to four times compared to conventional electromagnetic detection techniques, thereby comprehensively covering the principal intracranial blood supply areas. And the system effectively captures CBF responses under different intravascular pressure stimulations. In healthy volunteers, as cerebral vascular stiffness increases and CO decreases due to caffeine intake, the RF pulsation amplitude diminishes progressively. Upon extraction and selection of image features, widely used machine learning algorithms exhibit commendable performance in classifying overall CBF levels. These results highlight that our proposed methodology, predicated on ECS and image feature analysis, enables the capture of immediate responses of abnormal intracranial blood supply triggered by alterations in vascular stiffness. Moreover, it provides an accurate diagnosis of the overall CBF level under varying physiological conditions.

Asymptomatic parenchymal haemorrhage following endovascular treatment: Impact on functional outcome in patients with acute ischaemic stroke

BACKGROUND AND PURPOSE

In patients with acute ischaemic stroke (AIS), haemorrhagic transformation (HT) following endovascular treatment (EVT) is associated with poor functional outcome. However, the impact of asymptomatic HT, not linked to neurological deterioration in the acute phase, is unknown. We aimed to investigate the impact of asymptomatic PH1 (aPH1) and PH2 (aPH2) subtypes of HT on the functional outcome of patients treated with EVT.

METHODS

We conducted a retrospective study of patients with AIS who were consecutively admitted to our comprehensive stroke centre between January 2019 and December 2022, and who underwent EVT. We collected clinical, radiological, and procedural data. HTs were categorized according to the Heidelberg classification. The primary outcome was the shift on the modified Rankin Scale (mRS) at 3 months of follow-up. We performed bivariate and multivariable ordinal regression analyses to test the association between aPH1/aPH2 and the primary outcome.

RESULTS

We included 314 patients (mean age = 72.5 years [SD = 13.6], 171 [54.5%] women). We detected 54 (17.2%) patients with HT; 23 (7.3%) were classified as PH2 (11 asymptomatic) and 17 (5.4%) as PH1 (16 asymptomatic). The adjusted common odds ratio for aPH2 of worsening 1 point on the 3-month mRS was 3.32 (95% confidence interval = 1.16-9.57, p = 0.026). No association was observed for aPH1. aPH2 was also independently associated with lower odds of achieving a favourable outcome (mRS = 0-2). Neither aPH1 nor aPH2 was associated with mortality.

CONCLUSIONS

In patients with AIS treated with EVT, aPH2 is independently associated with unfavourable functional outcome.

Predictive role of neutrophil-to-platelet ratio in futile recanalization of patients after endovascular therapy

Aim: To explore the association between the neutrophil-to-platelet ratio (NPR) and futile recanalization (FR) in patients with acute ischemic stroke due to large vascular occlusions after endovascular therapy (EVT). Methods: FR after EVT was defined as a poor 90-day prognosis (modified Rankin scale [mRS] score ≥3) despite successful reperfusion (modified thrombolysis in cerebral infarction grade 2b-3). Patients were divided into high NPR (>35; n = 115) and low NPR (≤35; n = 81) groups. Results: The FR rate was significantly higher in the high NPR group than low NPR group (81.74 vs 55.56%; p = 0.000). NPR was independently associated with FR (odds ratio: 2.107; 95% CI: 1.017-4.364; p = 0.045). Conclusion: High NPR was associated with the risk of FR in patients with acute ischemic stroke due to large vascular occlusions.

No-reflow after stroke reperfusion therapy: An emerging phenomenon to be explored

In the field of stroke thrombectomy, ineffective clinical and angiographic reperfusion after successful recanalization has drawn attention. Partial or complete microcirculatory reperfusion failure after the achievement of full patency of a former obstructed large vessel, known as the "no-reflow phenomenon" or "microvascular obstruction," was first reported in the 1960s and was later detected in both experimental models and patients with stroke. The no-reflow phenomenon (NRP) was reported to result from intraluminal occlusions formed by blood components and extraluminal constriction exerted by the surrounding structures of the vessel wall. More recently, an emerging number of clinical studies have estimated the prevalence of the NRP in stroke patients following reperfusion therapy, ranging from 3.3% to 63% depending on its evaluation methods or study population. Studies also demonstrated its detrimental effects on infarction progress and neurological outcomes. In this review, we discuss the research advances, underlying pathogenesis, diagnostic techniques, and management approaches concerning the no-reflow phenomenon in the stroke population to provide a comprehensive understanding of this phenomenon and offer references for future investigations.

Incidence, severity and impact on functional outcome of persistent hypoperfusion despite large-vessel recanalization, a potential marker of impaired microvascular reperfusion: Systematic review of the clinical literature

The reported incidence of persistent hypoperfusion despite complete recanalization as surrogate for impaired microvascular reperfusion (IMR) has varied widely among clinical studies, possibly due to differences in i) definition of complete recanalization, with only recent Thrombolysis in Cerebral Infarction (TICI) grading schemes allowing distinction between complete (TICI3) and partial recanalization with distal occlusions (TICI2c); ii) operational definition of IMR; and iii) consideration of potential alternative causes for hypoperfusion, notably carotid stenosis, re-occlusion and post-thrombectomy hemorrhage. We performed a systematic review to identify clinical studies that carried out brain perfusion imaging within 72 hrs post-thrombectomy for anterior circulation stroke and reported hypoperfusion rates separately for TICI3 and TICI2c grades. Authors were contacted if this data was missing. We identified eight eligible articles, altogether reporting 636 patients. The incidence of IMR after complete recanalization (i.e., TICI3) tended to decrease with the number of considered alternative causes of hypoperfusion: range 12.5-42.9%, 0-31.6% and 0-9.1% in articles that considered none, two or all three causes, respectively. No study reported the impact of IMR on functional outcome separately for TICI-3 patients. Based on this systematic review, IMR in true complete recanalization appears relatively rare, and reported incidence highly depends on definition used and consideration of confounding factors.

Adipokine vaspin maintains angiogenesis and neurological function during cerebral ischemia-reperfusion via suppressing endoplasmic reticulum stress

INTRODUCTION

Visceral adipose tissue-derived serine protease inhibitor (vaspin) is an adipokine. It has been reported that decreased serum vaspin levels are significantly associated with stroke severity and prognosis.

OBJECTIVE

This article aims to explore the theoretical feasibility of vaspin supplementation for cerebral ischemia-reperfusion (I/R) injury.

METHODS

The I/R mouse models were constructed by the middle cerebral artery occlusion (MCAO) method, and the effects of vaspin on cerebral infarction, neurological function, angiogenesis and endoplasmic reticulum (ER) stress were explored. To verify the mediation of ER stress in the regulation of vaspin, human brain microvascular endothelial cells (HBMECs) were subjected to ER stress agonist tunicamycin in vitro. The impacts of vaspin and tunicamycin on oxygen glucose deprivation/ recovery (OGD/R)-induced cell viability, apoptosis, and angiogenesis were examined.

RESULTS

Vaspin inhibited blood-brain barrier breakdown and infarction occurred in the brain tissue of the I/R mice. Vaspin also enhanced cerebral neovascularization and reduced the apoptosis. Additional tunicamycin increased the apoptosis of HBMECs and inhibited angiogenesis, reversing the protective effect of vaspin on cells.

CONCLUSION

Together, this study reveals that vaspin supplementation reduces cerebral infarction and works against neurological dysfunction. It maintains the survival and angiogenesis capacity of HBMECs by inhibiting ER stress.

Impacts of futile reperfusion and reperfusion injury in acute ischemic stroke

Acute ischemic stroke (AIS) remains to be a challenging cerebrovascular disease. The mainstay of AIS management is endovascular reperfusion therapy, including thrombectomy and thrombolysis. However, ineffective (futile) reperfusion (FR) or reperfusion injury (RI) can be seen in a significant number of patients undergoing reperfusion strategy. In this article, we discuss two clinically relevant concepts known as "time window" and "tissue window" that can impact the clinical outcome of reperfusion therapy. We also explore patient risk factors, leading to FR and RI as well as an emerging concept of "no-reflow phenomenon" seen in ineffective reperfusion. These fundamental concepts provide insight into the clinical management of AIS patients and provide references for future research.

Postoperative blood glucose increase is associated with futile recanalization in patients with successful thrombectomy: a retrospective study

BACKGROUND

Timely recognition of futile recanalization might enable a prompt response and an improved outcome in post-thrombectomy patients. This study aims to evaluate whether postoperative blood glucose increase (BGI) could act as an indicator of futile recanalization in patients receiving a successful thrombectomy.

METHODS

This is a single-center, retrospective analysis of patients with anterior circulation large-vessel occlusion and successful thrombectomy between February 2019 and June 2022. BGI was defined as a higher level of blood glucose at the first postoperative morning than at admission. Futile recanalization was defined as patients with a modified Rankin Scale score of 3-6 at 90 days after onset. Multivariable binary logistic regression was used to assess the association of BGI with futile recanalization.

RESULTS

A total of 276 patients were enrolled, amongst which 120 patients (43.5%) had BGI. Futile recanalization was more prevalent among patients with BGI compared to those without (70.0 vs. 49.4%, P = 0.001). After adjusting for potential confounders, BGI was associated with a higher likelihood of futile recanalization (adjusted OR: 2.97, 95%CI: 1.50-5.86, P = 0.002). This association was consistently observed regardless of diabetes history, occlusion site, time from symptom onset to groin puncture, or reperfusion status.

CONCLUSION

Our findings support BGI serving as an indicator of futile recanalization in patients with anterior circulation large-vessel occlusion and successful thrombectomy.

Postoperative fibrinogen-to-albumin ratio acting as an indicator of futile recanalization in patients with successful thrombectomy

BACKGROUND

Timely recognition of futile recanalization might enable a prompter response and thus improve outcomes in patients receiving successful thrombectomy. This study aims to evaluate whether postoperative fibrinogen-to-albumin ratio (FAR) could act as an indicator of futile recanalization.

METHODS

This is a single-center, retrospective analysis of patients with acute anterior circulation large-vessel occlusion and successful thrombectomy between May 2019 and June 2022. FAR was defined as postoperative blood levels of fibrinogen divided by those of albumin, and dichotomized into high and low levels based on the Youden index. Futile recanalization was defined as patients achieving a successful recanalization with a modified Rankin Scale score of 3-6 at 90 days. Multivariable logistic regression was used to assess the association of FAR with futile recanalization.

RESULTS

A total of 255 patients were enrolled, amongst which 87 patients (34.1%) had high postoperative FAR. Futile recanalization was more prevalent among patients with high FAR compared to those with low FAR (74.7% vs. 53.0%, p = .001). After adjusting for potential confounders, high postoperative FAR was found to independently correspond with the occurrence of futile recanalization (adjusted OR 2.40, 95%CI 1.18-4.87, p = .015). This association was consistently observed regardless of prior antithrombotic therapy, treatment of intravenous thrombolysis, occlusion site, time from symptom onset to groin puncture, and reperfusion status.

CONCLUSION

Our findings support high postoperative FAR serving as an indicator of futile recanalization in patients with anterior circulation large-vessel occlusion and successful thrombectomy.

Risk Factors, Pathophysiologic Mechanisms, and Potential Treatment Strategies of Futile Recanalization after Endovascular Therapy in Acute Ischemic Stroke

Endovascular therapy is the first-line treatment for acute ischemic stroke. However, studies have shown that, even with the timely opening of occluded blood vessels, nearly half of all patients treated with endovascular therapy for acute ischemic stroke still have poor functional recovery, a phenomenon called "futile recanalization.". The pathophysiology of futile recanalization is complex and may include tissue no-reflow (microcirculation reperfusion failure despite recanalization of the occluded large artery), early arterial reocclusion (reocclusion of the recanalized artery 24-48 hours post endovascular therapy), poor collateral circulation, hemorrhagic transformation (cerebral bleeding following primary ischemic stroke), impaired cerebrovascular autoregulation, and large hypoperfusion volume. Therapeutic strategies targeting these mechanisms have been attempted in preclinical research; however, translation to the bedside remains to be explored. This review summarizes the risk factors, pathophysiological mechanisms, and targeted therapy strategies of futile recanalization, focusing on the mechanisms and targeted therapy strategies of no-reflow to deepen the understanding of this phenomenon and provide new translational research ideas and potential intervention targets for improving the efficacy of endovascular therapy for acute ischemic stroke.