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

rtPA-loaded fucoidan polymer microbubbles for the targeted treatment of stroke

Systemic injection of thrombolytic drugs is the gold standard treatment for non-invasive blood clot resolution. The most serious risks associated with the intravenous injection of tissue plasminogen activator-like proteins are the bleeding complication and the dose related neurotoxicity. Indeed, the drug has to be injected in high concentrations due to its short half-life, the presence of its natural blood inhibitor (PAI-1) and the fast hepatic clearance (0.9 mg/kg in humans, 10 mg/kg in mouse models). Overall, there is a serious need for a dose-reduced targeted treatment to overcome these issues. We present in this article a new acoustic cavitation-based method for polymer MBs synthesis, three times faster than current hydrodynamic-cavitation method. The generated MBs are ultrasound responsive, stable and biocompatible. Their functionalization enabled the efficient and targeted treatment of stroke, without side effects. The stabilizing shell of the MBs is composed of Poly-Isobutyl Cyanoacrylate (PIBCA), copolymerized with fucoidan. Widely studied for its targeting properties, fucoidan exhibit a nanomolar affinity for activated endothelium and activated platelets (P-selectins). Secondly, the thrombolytic agent (rtPA) was loaded onto microbubbles (MBs) with a simple adsorption protocol. Hence, the present study validated the in vivo efficiency of rtPA-loaded Fuco MBs to be over 50 % more efficient than regular free rtPA injection for stroke resolution. In addition, the relative injected rtPA grafted onto targeting MBs was 1/10th of the standard effective dose (1 mg/kg in mouse). As a result, no hemorrhagic event, BBB leakage nor unexpected tissue distribution were observed.

Prognostic Value of Histopathological Thrombus Age in Large Vessel Occlusion-Related Stroke

INTRODUCTION

Acute mechanical thrombectomy (MT) is the preferred treatment for large vessel occlusion-related stroke. Histopathological research on the obtained occlusive embolic thrombus may provide information regarding the aetiology and pathology of the lesion to predict prognosis and propose possible future acute ischaemic stroke therapy.

METHODS

A total of 75 consecutive patients who presented to the Amphia Hospital with acute large vessel occlusion-related stroke and underwent MT were included in the study. The obtained thrombus materials were subjected to standard histopathological examination. Based on histological criteria, they were considered fresh (<1 day old) or old (>1 day old). Patients were followed for 2 years for documentation of all-cause mortality.

RESULTS

Thrombi were classified as fresh in 40 patients (53%) and as older in 35 patients (47%). Univariate Cox regression analysis showed that thrombus age, National Institutes of Health Stroke Scale at hospital admission, and patient age were associated with long-term mortality (p < 0.1). Multivariable Cox hazards and Kaplan-Meier analysis demonstrated that after extensive adjustment for clinical and procedural variables, thrombus age persisted in being independently associated with higher long-term mortality (hazard ratio: 3.34; p = 0.038, log-rank p = 0.013).

CONCLUSION

In this study, older thromboemboli are responsible for almost half of acute large ischaemic strokes. Moreover, the presence of an old thrombus is an independent predictor of mortality in acute large vessel occlusion-related stroke. More research is warranted regarding future therapies based on thrombus composition.

Radiomics features on computed tomography reflect thrombus histological age prior to endovascular treatment of acute ischemic stroke

PURPOSE

To investigate the role of radiomics features in thrombus age identification and establish a CT-based radiomics model for predicting thrombus age of large vessel occlusion stroke patients.

METHODS

We retrospectively reviewed patients with middle cerebral artery occlusion receiving mechanical thrombectomy from July 2020 to March 2022 at our center. The retrieved clots were stained with Hematoxylin and Eosin (H&E) and determined as fresh or older thrombi based on coagulation age. Clot-derived radiomics features were selected by least absolute shrinkage and selection operator (LASSO) regression analysis, by which selected radiomics features were integrated into the Rad-score via the corresponding coefficients. The prediction performance of Rad-score in thrombus age was evaluated with the area under the curve (AUC) of receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 104 patients were included in our analysis, with 52 in training and 52 in validation cohort. Older thrombi were characterized with delayed procedure time, worse functional outcome and marginally associated with more attempts of device. We extracted 982 features from NCCT images. Following T test and LASSO analysis in training cohort, six radiomics features were selected, based on which the Rad-score was generated by the linear combination of features. The Rad-score showed satisfactory performance in distinguishing fresh with older thrombi, with the AUC of 0.873 (95 %CI: 0.777-0.956) and 0.773 (95 %CI: 0.636-0.910) in training and validation cohort, respectively.

CONCLUSION

This study established and validated a CT-based radiomics model that could accurately differentiate fresh with older thrombi for stroke patients receiving mechanical thrombectomy.

Coronary Angiography Complicated by Acute Ischaemic Stroke and the Use of Thrombolysis: a Cardiology Perspective and Narrative Review of Current Literature

PURPOSE OF REVIEW

Coronary angiography-associated acute ischaemic stroke (CAAIS) is an uncommon event but is associated with significant mortality and morbidity. The incidence of CAAIS has increased with a rise in the volume of coronary angiography (CA) and percutaneous coronary intervention (PCI) performed. Intravenous thrombolysis (IVT) is utilized in the general management of acute ischaemic stroke; however, it is associated with a higher risk of intracranial hemorrhage (ICH). As CA or PCI is performed more often in an aging population or high-risk patients that also carry an increased risk of ICH, it is vital to minimize additional complications from the treatment of CAAIS. This article aims to review the pathophysiological mechanisms for CAAIS, clarify the current evidence regarding IVT use in this setting, and thus assist cardiologists in the management of CAAIS.

RECENT FINDINGS

The pathophysiology for CAAIS may be different from acute ischaemic stroke in the general population. Embolic phenomena from dislodgement of calcium or other debris during manipulation of instrumentation during CA or PCI are likely mechanisms. This may contribute to altered thrombus composition, which affects the efficacy of IVT as suggested in recent studies. Furthermore, IVT in the management of CAAIS has not been evaluated specifically. The utilization of IVT should be carefully considered in CAAIS given a paucity of evidence demonstrating safety and efficacy in this setting. A multidisciplinary pathway that emphasizes the involvement of cardiologists in the treatment decision-making process would aid in thoughtful risk-benefit evaluation for IVT use in CAAIS and reduce adverse patient outcomes. Future studies to assess the impact of this pathway on CAAIS outcomes would be beneficial.

Sexual dimorphism in peripheral blood cell characteristics linked to recanalization success of endovascular thrombectomy in acute ischemic stroke

Endovascular thrombectomy (EVT) success to treat acute ischemic stroke varies with factors like stroke etiology and clot composition, which can differ between sexes. We studied if sex-specific blood cell characteristics (BCCs) are related to recanalization success. We analyzed electronic health records of 333 EVT patients from a single intervention center, and extracted 71 BCCs from the Sapphire flow cytometry analyzer. Through Sparse Partial Least Squares Discriminant Analysis, incorporating cross-validation and stability selection, we identified BCCs associated with successful recanalization (TICI 3) in both sexes. Stroke etiology was considered, while controlling for cardiovascular risk factors. Of the patients, successful recanalization was achieved in 51% of women and 49% of men. 21 of the 71 BCCs showed significant differences between sexes  (pFDR-corrected < 0.05). The female-focused recanalization model had lower error rates than both combined [t(192.4) = 5.9, p < 0.001] and male-only models [t(182.6) = - 15.6, p < 0.001]. In women, successful recanalization and cardioembolism were associated with a higher number of reticulocytes, while unsuccessful recanalization and large artery atherosclerosis (LAA) as cause of stroke were associated with a higher mean corpuscular hemoglobin concentration. In men, unsuccessful recanalization and LAA as cause of stroke were associated with a higher coefficient of variance of lymphocyte complexity of the intracellular structure. Sex-specific BCCs related to recanalization success varied and were linked to stroke etiology. This enhanced understanding may facilitate personalized treatment for acute ischemic stroke.

Hemorrhage rates in patients with acute ischemic stroke treated with intravenous alteplase and thrombectomy versus thrombectomy alone

BACKGROUND

Intravenous alteplase treatment (IVT) for acute ischemic stroke carries a risk of intracranial hemorrhage (ICH). However, reperfusion of an occluded vessel itself may contribute to the risk of ICH. We determined whether IVT and reperfusion are associated with ICH or its volume in the Multicenter Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands (MR CLEAN)-NO IV trial.

METHODS

The MR CLEAN-NO IV trial randomized patients with acute ischemic stroke due to large vessel occlusion to receive either IVT followed by endovascular treatment (EVT) or EVT alone. ICH was classified according to the Heidelberg bleeding classification on follow-up MRI or CT approximately 8 hours-7 days after stroke. Hemorrhage volume was measured with ITK-snap. Successful reperfusion was defined as extended Thrombolysis In Cerebral Infarction (eTICI) score of 2b-3. Multinomial and binary adjusted logistic regression were used to determine the association of IVT and reperfusion with ICH subtypes.

RESULTS

Of 539 included patients, 173 (32%) developed ICH and 30 suffered from symptomatic ICH (sICH) (6%). Of the patients with ICH, 102 had hemorrhagic infarction, 47 had parenchymal hematoma, 44 had SAH, and six had other ICH. Reperfusion was associated with a decreased risk of SAH, and IVT was not associated with SAH (eTICI 2b-3: adjusted OR 0.45, 95% CI 0.21 to 0.97; EVT without IVT: OR 1.6, 95% CI 0.91 to 2.8). Reperfusion status and IVT were not associated with overall ICH, hemorrhage volume, and sICH (sICH: EVT without IVT, OR 0.96, 95% CI 0.41 to 2.25; eTICI 2b-3, OR 0.49, 95% CI 0.23 to 1.05).

CONCLUSION

Neither IVT administration before EVT nor successful reperfusion after EVT were associated with ICH, hemorrhage volume, and sICH. SAH occurred more often in patients for whom successful reperfusion was not achieved.

Neuroimaging Modalities Used for Ischemic Stroke Diagnosis and Monitoring

Strokes are one of the global leading causes of physical or mental impairment and fatality, classified into hemorrhagic and ischemic strokes. Ischemic strokes happen when a thrombus blocks or plugs an artery and interrupts or reduces blood supply to the brain tissue. Deciding on the imaging modality which will be used for stroke detection depends on the expertise and availability of staff and the infrastructure of hospitals. Magnetic resonance imaging provides valuable information, and its sensitivity for smaller infarcts is greater, while computed tomography is more extensively used, since it can promptly exclude acute cerebral hemorrhages and is more favorable speed-wise. The aim of this article was to give information about the neuroimaging modalities used for the diagnosis and monitoring of ischemic strokes. We reviewed the available literature and presented the use of computed tomography, CT angiography, CT perfusion, magnetic resonance imaging, MR angiography and MR perfusion for the detection of ischemic strokes and their monitoring in different phases of stroke development.

Evolving Clinical-Translational Investigations of Cerebroprotection in Ischemic Stroke

Ischemic stroke is a highly morbid disease, with over 50% of large vessel stroke (middle cerebral artery or internal carotid artery terminus occlusion) patients suffering disability despite maximal acute reperfusion therapy with thrombolysis and thrombectomy. The discovery of the ischemic penumbra in the 1980s laid the foundation for a salvageable territory in ischemic stroke. Since then, the concept of neuroprotection has been a focus of post-stroke care to (1) minimize the conversion from penumbra to core irreversible infarct, (2) limit secondary damage from ischemia-reperfusion injury, inflammation, and excitotoxicity and (3) to encourage tissue repair. However, despite multiple studies, the preclinical-clinical research enterprise has not yet created an agent that mitigates post-stroke outcomes beyond thrombolysis and mechanical clot retrieval. These translational gaps have not deterred the scientific community as agents are under continuous investigation. The NIH has recently promoted the concept of cerebroprotection to consider the whole brain post-stroke rather than just the neurons. This review will briefly outline the translational science of past, current, and emerging breakthroughs in cerebroprotection and use of these foundational ideas to develop a novel paradigm for optimizing stroke outcomes.

Longitudinal change of six common inflammatory cytokines and their relationship to anxiety, depression, and cognitive impairment in acute ischemic stroke patients

Inflammatory cytokines are known to be involved in acute ischemic stroke (AIS), while the relationship of multiple inflammatory cytokines with mental disorders in AIS is less reported. This research intended to explore the longitudinal variation of common inflammatory cytokines and their correlation with anxiety, depression, and cognitive impairment in AIS patients. Six inflammatory cytokines were detected by enzyme-linked immunosorbent assay among 175 AIS patients at admission (baseline) and on the day (D)1, D3, and D7 after admission. Anxiety, depression, and cognition were evaluated using the Hospital Anxiety and Depression Scale and Mini-Mental State Examination at discharge, respectively. Anxiety, depression, and cognitive impairment rates were 32.6, 39.4, and 19.4%, respectively. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, and IL-17A increased from baseline to D1, then decreased from D1 to D7 (all P<0.001), while IL-10 presented an opposite trend (P<0.001). Interestingly, TNF-α on D1 and D3, IL-6 on D3, IL-8 on D3 and D7, and IL-17A on D1, D3, and D7 correlated with higher anxiety rate (all P<0.05). TNF-α on D1, D3, and D7, IL-8 at baseline, D1, D3, and D7, IL-17A on D1 and D7 correlated with increased depression rate (all P<0.05). In addition, IL-1β on D1 and IL-17 at baseline, D1, D3, and D7 correlated with elevated cognitive-impairment rate (all P<0.05). Inflammatory cytokines were dysregulated after disease onset, and their longitudinal change correlated with psychological issues in AIS patients.

LncRNA SNHG15 regulates autophagy and prevents cerebral ischaemia-reperfusion injury through mediating miR-153-3p/ATG5 axis

Ischaemic stroke is a common cerebrovascular disease. Long non-coding RNA (lncRNA) of small nucleolar RNA host gene (SNHG15) has been supposedly performed a regulatory role in many diseases. Nonetheless, the function of SNHG15 in cerebral ischaemia-reperfusion injury has not been clarified. The OGD/R of Neuro2A cells simulated the ischaemic and reperfused states of the brain. Neuro2a cell line with stable transfection of plasmid with silent expression of SNHG15 was constructed. Neuro2a cell lines transfected with miR-153-3p mimic (miR-153-3p-mimics) and miR-153-3p inhibitor (miR-153-3p-inhibition) were constructed. Expression of SNHG15, mi R-200a, FOXO3 and ATG7 in mouse brain tissue and N2a cells was identified by qRT-PCR. Western blot (WB) analysis of mouse brain tissue and Neuro2a cells revealed the presence of the proteins ATG5, Cle-caspase-3, Bax, Bcl-2, LC3 II/I and P62 (WB). The representation and distribution of LC3B were observed by immunofluorescence. The death of cells was measured using a technique called flow cytometry (FACS). SNHG15 was highly expressed in cerebral ischaemia-reperfusion injury model. Down-regulation of SNHG15 lead to lower apoptosis rate and decreased autophagy. Dual luciferase assay and co-immunoprecipitation (CoIP) found lncRNA SNHG15/miR-153-3p/ATG5. Compared to cells transfected with NC suppression, cells transfected with miR-153-3p-inhibition had substantially greater overexpression of LC 3 II/I, ATG5, cle-Caspase-3, and Bax, as determined by a recovery experiment, the apoptosis rate was elevated, yet both P62 and Bcl-2 were significantly lower and LC3+ puncta per cells were significantly increased. Co-transfection of miR-153-3p-inhibition and sh-SNHG15 could reverse these results. LncRNA SNHG15 regulated autophagy and prevented cerebral ischaemia-reperfusion injury through mediating the miR-153-3p/ATG5 axis.

5F SOFIA intermediate catheter in the treatment of acute ischemic stroke: A retrospective observational study

BACKGROUND

We herein report our experience with the 5F SOFIA (Soft Torqueable catheter Optimized for Intracranial Access) intermediate catheter for endovascular treatment of patients with acute ischemic stroke (AIS) both in distal middle vessel occlusions (DMVOs) and in large vessel occlusions (LVOs) with unfavorable anatomy.

METHODS

Records of forty-seven patients undergoing endovascular thrombectomy with 5F SOFIA between September 2020 and March 2022 were retrospectively reviewed. Patients' demographic data, clinical presentation, treatment details, and complications were recorded from the medical record. The primary outcomes were successful revascularization (modified treatment in cerebral ischemia, mTICI ≥2b) and good clinical outcome at 3 months (modified rankin scale, mRS 0-2). Secondary outcomes were complication rates and switch to alternative techniques. Our institutional review board approved this study.

RESULTS

Forty-seven patients with AIS treated with 5F SOFIA were examined. In eighteen (38%) cases the occlusion was located on a large vessel while in 29 (61.7%) on a distal-medium vessels. Median national institutes of health strokes scale (NIHSS) score was 16 at admission. Successful revascularization to mTICI 2b-3 was achieved in 14 of 18 patients (77.7%) with LVOs and in 24/29 cases with DMVOs (82.7%) respectively. mRS score 0-2 at three months (3 months-mRS 0-2) was 66.6% for LVOs and 68.9% in DMVOs respectively. Symptomatic intracranial hemorrhage (SICH) occurred in 2 (4.2%) patients.

CONCLUSION

5F SOFIA intermediate catheter could be a safe and effective treatment for AIS and a viable alternative to 6 F conventional intermediate catheters in selected cases.

Partial (SAVE) versus Complete (Solumbra) Stent Retriever Retraction Technique for Mechanical Thrombectomy: A Randomized In Vitro Study

BACKGROUND AND PURPOSE

Mechanical thrombectomy has become a first-line treatment for acute ischemic stroke. Several techniques combining stent retrievers and distal aspiration catheters have been described. We aimed to characterize the efficacy of 2 commonly used techniques according to clot characteristics.

MATERIALS AND METHODS

Soft (mean stiffness = 95.77 [SD, 5.80] kPa) or stiff (mean stiffness = 205.63 [SD, 6.70] kPa) clots (3 × 10 mm and 2 × 10 mm, respectively) were embolized to the distal M1 segment of the MCA in an in vitro model. The technique was randomly allocated (1:1): stent retriever assisted vacuum-locked extraction (SAVE) versus complete retraction (Solumbra). The primary end point was the percentage of first-pass recanalization. Secondary end points were periprocedural distal embolization measures.

RESULTS

A total of 130 mechanical thrombectomies were performed (50 for soft clots and 15 for stiff clots per arm). Overall, the rate of first-pass recanalizaton was 35% with Solumbra and 15% with SAVE (P < .01). For stiff clots, the first-pass recanalizaton was equal for both methods (27%; P = 1.00). With soft clots, the first-pass recanalizaton was higher with Solumbra (38%) than with SAVE (12%; P < .01). When we used soft clots, the maximum embolus size (mean, 1.19 [SD, 0.9] mm versus 2.16 [SD, 1.48] mm; P < .01) and total area of emboli (mean, 1.82 [SD, 2.73] versus 3.34 [SD, 3.2]; P = .01) were also lower with Solumbra than with SAVE.

CONCLUSIONS

Clot characteristics may influence the efficacy of the thrombectomy technique. In occlusions caused by soft clots, complete retrieval into the distal aspiration catheters achieved higher rates of first-pass recanalizaton and lower embolization.

Preprocedural D-Dimer Level as a Predictor of First-Pass Recanalization and Functional Outcome in Endovascular Treatment of Acute Ischemic Stroke

We aimed to evaluate the association between preprocedural D-dimer levels and endovascular and clinical outcomes. We retrospectively reviewed patients with acute intracranial large-vessel occlusion who underwent mechanical thrombectomy. Plasma D-dimer levels were measured immediately before the endovascular procedure. Endovascular outcomes included successful recanalization, first-pass recanalization (first-pass effect (FPE) and modified FPE (mFPE)), thrombus fragmentation, and the number of passes of the thrombectomy device. Clinical outcomes were assessed at 3 months using the modified Rankin Scale. A total of 215 patients were included. Preprocedural D-dimer levels were lower in patients with FPE (606.0 ng/mL [interquartile range, 268.0-1062.0]) than in those without (879.0 ng/mL [437.0-2748.0]; p = 0.002). Preprocedural D-dimer level was the only factor affecting FPE (odds ratio, 0.92 [95% confidence interval, 0.85-0.98] per 500 ng/mL; p = 0.022). D-dimer levels did not differ significantly based on successful recanalization and thrombus fragmentation. The number of passes of the thrombectomy device was higher (p = 0.002 for trend) and the puncture-to-recanalization time was longer (p = 0.044 for trend) as the D-dimer levels increased. Patients with favorable outcome had significantly lower D-dimer levels (495.0 ng/mL [290.0-856.0]) than those without (1189.0 ng/mL [526.0-3208.0]; p < 0.001). Preprocedural D-dimer level was an independent factor for favorable outcome (adjusted odds ratio, 0.88 [0.81-0.97] per 500 ng/mL; p = 0.008). In conclusion, higher preprocedural D-dimer levels were significantly associated with poor endovascular and unfavorable functional outcomes.

Endotheliitis and cytokine storm as a mechanism of clot formation in COVID-19 ischemic stroke patients: A histopathologic study of retrieved clots

BACKGROUND

Studies during the COVID-19 pandemic have demonstrated an association between COVID-19 virus infection and the development of acute ischemic stroke, particularly large vessel occlusion (LVO). Studying the characteristics and immunohistochemistry of retrieved stroke emboli during mechanical thrombectomy for LVO may offer insights into the pathogenesis of LVO in COVID-19 patients. We examined retrieved COVID-19 emboli from the STRIP, EXCELLENT, and RESTORE registries and compared their characteristics to a control group.

METHODS

We identified COVID-positive LVO patients from the STRIP, RESTORE, and EXCELLENT studies who underwent mechanical thrombectomy. These patients were matched to a control group controlling for stroke etiology based on Trial of Org 10172 in Acute Stroke Treatment criteria. All clots were stained with Martius Scarlet Blue (MSB) along with immunohistochemistry for interleukin-6 (IL-6), C-reactive protein (CRP), von Willebrand factor (vWF), CD66b, fibrinogen, and citrullinated Histone H3. Clot composition was compared between groups.

RESULTS

Nineteen COVID-19-positive patients and 38 controls were included. COVID-19-positive patients had a significantly higher percentage of CRP and vWF. There was no difference in IL-6, fibrin, CD66b, or citrullinated Histone H3 between groups. Based on MSB staining, there was no statistically significant difference regarding the percentage of red blood cells, white blood cells, fibrin, and platelets.

CONCLUSIONS

Our study found higher concentrations of CRP and vWF in retrieved clots of COVID-19-positive stroke patients compared to COVID-19-negative controls. These findings support the potential role of systemic inflammation as indicated by elevated CRP and endothelial injury as indicated by elevated vWF as precipitating factors in thrombus development in these patients.

Aspiration thrombectomy with the Penumbra System for patients with stroke and late onset to treatment: a subset analysis of the COMPLETE registry

Background

The purpose of this study was to report the safety and performance of aspiration thrombectomy with the Penumbra System for patients with acute ischemic stroke (AIS) due to anterior circulation large vessel occlusion (LVO) and late onset to treatment.

Methods

This is a retrospective subset analysis of a global prospective multicenter registry (COMPLETE) that enrolled adults with AIS due to LVO and a pre-stroke modified Rankin Scale score (mRS) of 0 or 1 who were treated first-line with aspiration thrombectomy either alone (A Direct Aspiration First Pass Technique [ADAPT]) or in combination with the 3D Revascularization Device (ADAPT + 3D). This subset analysis included all patients in the registry who had anterior circulation LVO, an Alberta Stroke Program Early CT Score of at least 6, and late onset to treatment (>6 h from stroke onset to puncture).

Results

Of the 650 patients in the COMPLETE registry, 167 were included in this subset analysis. The rate of successful revascularization (modified thrombolysis in cerebral infarction score 2b-3 achieved) at the end of the procedure was 83.2%, the rate of good functional outcome (mRS 0-2) at 90 days was 55.4%, and the all-cause mortality rate at 90 days was 14.4%. No device-related serious adverse events (SAEs) occurred. Procedure-related SAEs occurred in 9 patients (5.4%) within 24 h and in 12 patients (7.2%) overall. The rate of successful revascularization was higher for patients treated first-line with ADAPT (88.0%) than for patients treated first-line with ADAPT + 3D (75.0%; p = 0.035); no significant difference was observed between the ADAPT and ADAPT + 3D groups for any other primary or secondary outcome.

Conclusion

For patients with AIS due to anterior circulation LVO and with late onset to treatment, aspiration thrombectomy with the Penumbra System appears to be safe and effective. The rates of good functional outcome and all-cause mortality from this study compared favorably with those rates from the medical management arms of the DAWN and DEFUSE-3 studies.

Clinical trial registration

https://www.clinicaltrials.gov, NCT03464565.

Gene expression profiles of ischemic stroke clots retrieved by mechanical thrombectomy are associated with disease etiology

BACKGROUND

Determining stroke etiology is crucial for secondary prevention, but intensive workups fail to classify ~30% of strokes that are cryptogenic.

OBJECTIVE

To examine the hypothesis that the transcriptomic profiles of clots retrieved during mechanical thrombectomy are unique to strokes of different subtypes.

METHODS

We isolated RNA from the clots of 73 patients undergoing mechanical thrombectomy. Samples of sufficient quality were subjected to 100-cycle, paired-end RNAseq, and transcriptomes with less than 10 million unique reads were excluded from analysis. Significant differentially expressed genes (DEGs) between subtypes (defined by the Trial of Org 10 172 in Acute Stroke Treatment) were identified by expression analysis in edgeR. Gene ontology enrichment analysis was used to study the biologic differences between stroke etiologies.

RESULTS

In all, 38 clot transcriptomes were analyzed; 6 from large artery atherosclerosis (LAA), 21 from cardioembolism (CE), 5 from strokes of other determined origin, and 6 from cryptogenic strokes. Among all comparisons, there were 816 unique DEGs, 174 of which were shared by at least two comparisons, and 20 of which were shared by all three. Gene ontology analysis showed that CE clots reflected high levels of inflammation, LAA clots had greater oxidoreduction and T-cell processes, and clots of other determined origin were enriched for aberrant platelet and hemoglobin-related processes. Principal component analysis indicated separation between these subtypes and showed cryptogenic samples clustered among several different groups.

CONCLUSIONS

Expression profiles of stroke clots were identified between stroke etiologies and reflected different biologic responses. Cryptogenic thrombi may be related to multiple etiologies.

Thrombus radiomics in patients with anterior circulation acute ischemic stroke undergoing endovascular treatment

BACKGROUND

Thrombus radiomics (TR) describe complex shape and textural thrombus imaging features. We aimed to study the relationship of TR extracted from non-contrast CT with procedural and functional outcome in endovascular-treated patients with acute ischemic stroke.

METHODS

Thrombi were segmented on thin-slice non-contrast CT (≤1 mm) from 699 patients included in the MR CLEAN Registry. In a pilot study, we selected 51 TR with consistent values across two raters' segmentations (ICC >0.75). Random forest models using TR in addition or as a substitute to baseline clinical variables (CV) and manual thrombus measurements (MTM) were trained with 499 patients and evaluated on 200 patients for predicting successful reperfusion (extended Thrombolysis in Cerebral Ischemia (eTICI) ≥2B), first attempt reperfusion, reperfusion within three attempts, and functional independence (modified Rankin Scale (mRS) ≤2). Three texture and shape features were selected based on feature importance and related to eTICI ≥2B, number of attempts to eTICI ≥2B, and 90-day mRS with ordinal logistic regression.

RESULTS

Random forest models using TR, CV or MTM had comparable predictive performance. Thrombus texture (inverse difference moment normalized) was independently associated with reperfusion (adjusted common OR (acOR) 0.85, 95% CI 0.72 to 0.99). Thrombus volume and texture were also independently associated with the number of attempts to successful reperfusion (acOR 1.36, 95% CI 1.03 to 1.88 and acOR 1.24, 95% CI 1.04 to 1.49).

CONCLUSIONS

TR describing thrombus volume and texture were associated with more attempts to successful reperfusion. Compared with models using CV and MTM, TR had no added value for predicting procedural and functional outcome.

A pharmacokinetics interaction study of antiplatelet agents aspirin and clopidogrel combined with dl-3-n-butylphthalide in rats by liquid chromatography-tandem mass spectrometry

A sensitive and specific high-performance liquid chromatography-tandem mass spectrometry method has been developed to determine the pharmacokinetic interactions of the antiplatelet agents aspirin and clopidogrel combined with dl-3-n-butylphthalide. For the determination of aspirin metabolite salicylic acid, clopidogrel inactive metabolite SR26334 and NBP prototype drug in rat plasma, plasma samples were prepared by precipitation of proteins using methanol containing 0.1% formic acid, followed by centrifugation. Chromatography was performed on a C18 column, eluting with a gradient of acetonitrile (with 0.1% formic acid)-water (with 0.1% formic acid). The detection adopted electrospray ion source and positive ion multiple reaction monitoring modes. The linear detection response range of salicylic acid is 80-80,000 ng/ml, and the linear detection response range of SR26334 and dl-3-n-butylphthalide is 10-10,000 ng/ml. Our study revealed that dl-3-n-butylphthalide affected the pharmacokinetics of aspirin and clopidogrel when administered to rats.

Clinical significance and prevalence of subarachnoid hyperdensities on flat detector CT after mechanical thrombectomy: does it really matter?

BACKGROUND

Subarachnoid hyperdensities after mechanical thrombectomy (MT) are a common finding. However, it is often regarded as clinically insignificant.

OBJECTIVE

With this single-center investigation, to identify the prevalence of subarachnoid hyperdensities following MT, associated predictors, and the impact on the clinical outcome of the patients.

METHODS

383 patients from the stroke registry were analyzed for the presence of subarachnoid hyperdensities on flat detector CT (FDCT) directly after the completion of MT, and on follow-up dual-energy CT, then classified according to a visual grading scale. 178 patients were included with anterior circulation occlusions. Regression analysis was performed to identify significant predictors, and Kruskal-Wallis analysis and Χ2 test were performed to test the variables among the different groups. The primary outcome was the modified Rankin Scale (mRS) score at 90 days and was analyzed with the Wilcoxon-Mann-Whitney rank-sum test.

RESULTS

The prevalence of subarachnoid hyperdensities on FDCT was (66/178, 37.1%) with patients experiencing a significant unfavorable outcome (P=0.035). Significantly fewer patients with subarachnoid hyperdensities achieved a mRS score of ≤3 at 90 days 25/66 (37.9%) vs 60/112 (53.6%), P=0.043). In addition, mortality was significantly higher in the subarachnoid hyperdensities group (34.8% vs 19.6%, P=0.024). Distal occlusions and a higher number of device passes were significantly associated with subarachnoid hyperdensities (P=0.026) and (P=0.001), respectively. Patients who received intravenous tissue plasminogen activator had significantly fewer subarachnoid hyperdensities (P=0.029).

CONCLUSIONS

Postinterventional subarachnoid hyperdensities are a frequent finding after MT and are associated with neurological decline and worse functional outcome. They are more common with distal occlusions and multiple device passes.

Identification of Genes and miRNAs Associated with TAFI-Related Thrombosis: An in Silico Study

Thrombin-Activatable Fibrinolysis Inhibitor (TAFI) is a carboxypeptidase B-like proenzyme encoded by the CPB2 gene. After thrombin activation, TAFI downregulates fibrinolysis, thus linking the latter with coagulation. TAFI has been shown to play a role in venous and arterial thrombotic diseases, yet, data regarding the molecular mechanisms underlying its function have been conflicting. In this study, we focused on the prediction and functional enrichment analysis (FEA) of the TAFI interaction network and the microRNAs (miRNAs) targeting the members of this network in an attempt to identify novel components and pathways of TAFI-related thrombosis. To this end, we used nine bioinformatics software tools. We found that the TAFI interactome consists of 28 unique genes mainly involved in hemostasis. Twenty-four miRNAs were predicted to target these genes. Co-annotation analysis of the predicted interactors with respect to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and transcription factors (TFs) pointed to the complement and coagulation cascades as well as neutrophil extracellular trap formation. Cancer, stroke, and intracranial aneurysm were among the top 20 significant diseases related to the identified miRNAs. We reason that the predicted biomolecules should be further studied in the context of TAFI-related thrombosis.

Triglyceride-glucose index predicts death in patients with stroke younger than 65

Background

The triglyceride-glucose index (TGI), a reliable surrogate indicator of insulin resistance (IR), has been proven to be a predictor of the incidence of ischemic stroke. The role of TGI in predicting the outcomes of stroke patients remains controversial. Susceptibility to IR-related diseases varies among patients of different ages. The study aims to evaluate the predictive value of TGI levels on clinical outcomes of patients with ischemic stroke of different ages.

Method

This was a retrospective cohort study including patients with ischemic stroke in the Department of Neurology at West China Hospital. TGI was calculated as ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. The patients were subdivided into 3 tertiles according to TGI levels. Multivariate logistic regression analyses were conducted to estimate the association between TGI levels and post-stroke outcomes among the whole patients, younger patients (<65), and older patients (>=65). The outcomes included death and unfavorable functional outcome (modified Rankin scale score 3-6) at 3 and 12 months after stroke.

Results

A total of 3,704 patients (men, 65.08%, mean age, 61.44 ± 14.15; women 34.92%, mean age, 65.70 ± 13.69) were enrolled in this study. TGI levels were not associated with 3 month or 12 month death in the whole patients. Patients with higher TGI levels (T2 and T3) had a higher risk of 3 month death than those had lower TGI levels (T1) in the younger group (T2 vs. T1: OR 2.64, 95% CI 1.03-6.79, p = 0.043; T3 vs. T1: OR 2.69, 95% CI 1.00-7.10, p = 0.049) but not in the older group. Additionally, Kaplan-Meier estimate analysis illustrated that the 12 month death risk was significantly higher in the group with the highest TGI among younger patients (p for log-rank test = 0.028) but not among older patients. There was an interactive effect between TGI and age on 3 month death (p for interaction = 0.013) and 12 month death (p for interaction = 0.027). However, TGI was not associated with unfavorable functional outcome at 3 month or 12 month after stroke.

Conclusion

Elevated TGI independently predicts death at 3 months and 12 months in patients under 65 with ischemic stroke. Regulating TGI is expected to be an approach to enhance prognosis in young individuals affected by ischemic stroke.

Mechanical thrombectomy with combined stent retriever and contact aspiration versus stent retriever alone for acute large vessel occlusion: data from ANGEL-ACT registry

BACKGROUND AND PURPOSE

An analysis of the ASTER 2 trial revealed similar final recanalisation levels and clinical outcomes in acute large vessel occlusion (LVO) stroke between stent retrieval (SR) alone as a first-line mechanical thrombectomy (MT) technique (SR alone first-line) and concomitant use of contact aspiration (CA) plus SR as a first-line MT technique (SR+CA first-line). The purpose of the present study was to compare the safety and efficacy of SR+CA first-line with those of SR alone first-line for patients with LVO in China.

METHODS

We conducted the present study by using the data from the ANGEL-ACT registry. We divided the selected patients into SR+CA first-line and SR alone first-line groups. We performed logistic regression and generalised linear models with adjustments to compare the angiographic and clinical outcomes, including successful/complete recanalisation after the first technique alone and all procedures, first-pass successful/complete recanalisation, number of passes, 90-day modified Rankin Scale, procedure duration, rescue treatment and intracranial haemorrhage within 24 hours.

RESULTS

Of the 1233 enrolled patients, 1069 (86.7%) received SR alone first-line, and 164 (13.3%) received SR+CA first-line. SR+CA first-line was associated with more thrombectomy passes (3 (2-4) vs 2 (1-2); β=1.77, 95% CI=1.55 to 1.99, p<0.001), and longer procedure duration (86 (60-129) min vs 80 (50-122) min; β=10.76, 95% CI=1.08 to 20.43, p=0.029) than SR alone first-line group. Other outcomes were comparable (all p>0.05) between the two groups.

CONCLUSIONS

Patients undergoing SR+CA first-line had more thrombectomy passes and longer procedure duration than patients undergoing SR alone first-line. Additionally, we suggested that SR+CA first-line was not superior to SR alone first-line in final recanalisation level, first-pass recanalisation level and 90-day clinical outcomes in the Chinese population.

MR microscopy to assess clot composition following mechanical thrombectomy predicts recanalization and clinical outcome

BACKGROUND

Mechanical thrombectomy (MT) is the standard of care for patients with a stroke and large vessel occlusion. Clot composition is not routinely assessed in clinical practice as no specific diagnostic value is attributed to it, and MT is performed in a standardized 'non-personalized' approach. Whether different clot compositions are associated with intrinsic likelihoods of recanalization success or treatment outcome is unknown.

METHODS

We performed a prospective, non-randomized, single-center study and analyzed the clot composition in 60 consecutive patients with ischemic stroke undergoing MT. Clots were assessed by ex vivo multiparametric MRI at 9.4 T (MR microscopy), cone beam CT, and histopathology. Clot imaging was correlated with preinterventional CT and clinical data.

RESULTS

MR microscopy showed red blood cell (RBC)-rich (21.7%), platelet-rich (white,38.3%) or mixed clots (40.0%) as distinct morphological entities, and MR microscopy had high accuracy of 95.4% to differentiate clots. Clot composition could be further stratified on preinterventional non-contrast head CT by quantification of the hyperdense artery sign. During MT, white clots required more passes to achieve final recanalization and were not amenable to contact aspiration compared with mixed and RBC-rich clots (maneuvers: 4.7 vs 3.1 and 1.2 passes, P<0.05 and P<0.001, respectively), whereas RBC-rich clots showed higher probability of first pass recanalization (76.9%) compared with white clots (17.4%). White clots were associated with poorer clinical outcome at discharge and 90 days after MT.

CONCLUSION

Our study introduces MR microscopy to show that the hyperdense artery sign or MR relaxometry could guide interventional strategy. This could enable a personalized treatment approach to improve outcome of patients undergoing MT.

Overexpression of FSP1 Ameliorates ferroptosis via PI3K/ AKT /GSK3β pathway in PC12 cells with Oxygen-Glucose Deprivation/Reoxygenation

After ischemia and reperfusion (I/R), nerve cell damage is a pathogenic process that involves numerous molecular processes. In the last ten years, one new classification of programmed cell death is ferroptosis. More recent research has demonstrated that ferroptosis has a role in a variety of neurological disorders, including stroke, cancer, and neurodegenerative illnesses. Ferroptosis suppressor protein 1 (FSP1) plays a significant role in inhibiting ferroptosis. The purpose of this work is to determine how overexpression of FSP1 affects the ferroptosis of PC12 cells under the condition of oxygen-glucose deprivation/reoxygenation (OGD/R). The expression of FSP1 was regulated by lentivirus transfection technology. Western blot and immunofluorescence were used to measure protein levels related to ferroptosis and the PI3K/AKT/GSK3β signal pathway. Determine cell viability using the appropriate kit. Mitochondrial structural morphology was checked by transmission electron microscopy in PC12 cells. Reactive oxygen species (ROS) and Malondialdehyde (MDA) were quantified using the relevant kits. OGD/R induced ferroptosis in PC12 cells, however, FSP1 overexpression reverses ferroptosis and promotes cell viability, lowering ROS and MDA content. The expression of FSP1 decreased in OGD/R0h and OGD/R6h and rebounded in OGD/R24h and OGD/R48h. During the processes of OGD/R-induced ferroptosis, FSP1 overexpression significantly stimulated PI3K/AKT/GSK3β pathway, but LY294002 weakens the protective effect of FSP1 overexpression. Our outcomes demonstrate that overexpression of FSP1 markedly enhances the ability to resist ferroptosis via the PI3K/AKT/GSK3β pathway. The above results may provide a new preliminary lead for the treatment of the cerebral ischemia-reperfusion injury.

Elucidation of the mechanism of Yiqi Tongluo Granule against cerebral ischemia/reperfusion injury based on a combined strategy of network pharmacology, multi-omics and molecular biology

BACKGROUND

Ischemic stroke is caused by local lesions of the central nervous system and is a severe cerebrovascular disease. A traditional Chinese medicine, Yiqi Tongluo Granule (YQTL), shows valuable therapeutic effects. However, the substances and mechanisms remain unclear.

PURPOSE

We combined network pharmacology, multi-omics, and molecular biology to elucidate the mechanisms by which YQTL protects against CIRI.

STUDY DESIGN

We innovatively created a combined strategy of network pharmacology, transcriptomics, proteomics and molecular biology to study the active ingredients and mechanisms of YQTL. We performed a network pharmacology study of active ingredients absorbed by the brain to explore the targets, biological processes and pathways of YQTL against CIRI. We also conducted further mechanistic analyses at the gene and protein levels using transcriptomics, proteomics, and molecular biology techniques.

RESULTS

YQTL significantly decreased the infarction volume percentage and improved the neurological function of mice with CIRI, inhibited hippocampal neuronal death, and suppressed apoptosis. Fifteen active ingredients of YQTL were detected in the brains of rats. Network pharmacology combined with multi-omics revealed that the 15 ingredients regulated 19 pathways via 82 targets. Further analysis suggested that YQTL protected against CIRI via the PI3K-Akt signaling pathway, MAPK signaling pathway, and cAMP signaling pathway.

CONCLUSION

We confirmed that YQTL protected against CIRI by inhibiting nerve cell apoptosis enhanced by the PI3K-Akt signaling pathway.

Associations of Chinese visceral adiposity index and new-onset stroke in middle-aged and older Chinese adults: an observational study

BACKGROUND

Stroke represents the second most prevalent contributor to global mortality. The Chinese Visceral Adiposity Index (CVAI) serves as an established metric for assessing visceral adiposity in the Chinese population, exhibiting prognostic capabilities. This investigation aimed to explore the association of CVAI and new-onset stroke among middle-aged and older Chinese populations.

METHODS

The study employed data from the 2011 and 2018 China Health and Retirement Longitudinal Study (CHARLS) to assess the association of CVAI and the incidence of new-onset stroke. Utilizing a directed acyclic graph (DAG), 10 potential confounders were identified. Moreover, to explore the association between CVAI and new-onset stroke, three multifactor logistic regression models were constructed, accounting for the identified confounders and mitigating their influence on the findings.

RESULTS

The study comprised 7070 participants, among whom 417 (5.9%) experienced new-onset strokes. After controlling for confounding variables, regression analysis suggested that the new-onset stroke's highest risk was linked to the fourth quartile (Q4) of the CVAI, with an odds ratio (OR) of 2.33 and a 95% confidence interval (CI) of 1.67-3.28. The decision tree analysis demonstrated a heightened probability of new-onset stroke among hypertensive individuals with a CVAI equal to or greater than 83, coupled with a C-reactive protein level no less than 1.1 mg/l. Age seemed to have a moderating influence on the CVAI and new-onset stroke association, exhibiting a more prominent interaction effect in participants under 60 years.

CONCLUSIONS

In middle-aged and older Chinese populations, a linear relationship was discerned between CVAI and the probability of new-onset stroke. CVAI provides a predictive framework for stroke incidence in this demographic, laying the groundwork for more sophisticated risk prediction models that improve the precision and specificity of stroke risk evaluations.

BRG1 alleviates microglial activation by promoting the KEAP1-NRF2/HO-1 signaling pathway and minimizing oxidative damage in cerebral ischemia-reperfusion

BRG1 is a key factor in the process of apoptosis and oxidative damage; however, its role in the pathophysiology of ischemic stroke is unclear. Here, we discovered that during middle cerebral artery occlusion (MCAO) reperfusion in mice, microglia were significantly activated in the cerebral cortex of the infarct area, and BRG1 expression was increased in the mouse MCAO/R model, peaking at 4 days. In microglia subjected to OGD/R, BRG1 expression increased and peaked at 12 h after reoxygenation. After ischemic stroke, in vitro changing the expression of BRG1 expression levels greatly altered the activation of microglia and the production of antioxidant and pro-oxidant proteins. Knocking down BRG1 expression levels in vitro increased the inflammatory response, promoted microglial activation, and decreased the expression of the NRF2/HO-1 signaling pathway after ischemic stroke. In contrast, overexpression of BRG1 dramatically reduced the expression of NRF2/HO-1 signaling pathway and microglial activation. Our research reveals that BRG1 reduces postischemic oxidative damage via the KEAP1-NRF2/HO-1 signaling pathway, protecting against brain ischemia/reperfusion injury. Using BRG1 as a pharmaceutical target to inhibit inflammatory responses to reduce oxidative damage may be a unique way to explore techniques for the treatment of ischemic stroke and other cerebrovascular illnesses.

15, 16-Dihydrotanshinone I protects against ischemic stroke by inhibiting ferroptosis via the activation of nuclear factor erythroid 2-related factor 2

BACKGROUND

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key regulator of antioxidative stress responses, which are associated with ferroptosis inhibition. Ferroptosis is closely related to the pathophysiological process of ischemic stroke. 15, 16-Dihydrotanshinone I (DHT), a lipophilic tanshinone extracted from the root of Salvia miltiorrhiza Bunge (Danshen), has various pharmacological effects. However, its effect against ischemic stroke remains to be examined.

PURPOSE

This study aimed to investigate the protective effect of DHT against ischemic stroke and its underlying mechanism.

METHODS

Rats with permanent middle cerebral artery occlusion (pMCAO)-induced cerebral ischemia rats and tert-butyl hydroperoxide (t-BHP)-injured PC12 cells were used to investigate the protective effect of DHT against ischemic stroke effect and the potential mechanism.

RESULTS

The results showed that DHT decreased ferroptosis in-vitro experiment, as indicated by decreased lipid ROS generation, increased Gpx4 expression and the ratio of GSH/GSSG, and improved mitochondrial function. The inhibitory effect of DHT on ferroptosis was decreased after Nrf2 silencing. Furthermore, DHT decreased the neurological score, infarct volume, and cerebral edema, increased regional cerebral blood flow, and improved the microstructure of white-grey matter in pMCAO rats. In addition, DHT activated Nrf2 signaling and inhibited ferroptosis marker events. Nrf2 activator and ferroptosis inhibitor also exerted protective effects on pMCAO rats.

CONCLUSIONS

These data demonstrated that DHT might have therapeutic potential for ischemic stroke and protects against ferroptosis via the activation of Nrf2. This study provides new insight into DHT-mediated prevention of ferroptosis in ischemic stroke.

Clinicopathologic Analysis of COVID‐19 Associated Thrombi in the Setting of Large Vessel Occlusion: A Prospective Case–Control Study

BACKGROUND

Acute ischemic stroke secondary to large vessel occlusion is among the most serious complications associated with COVID‐19 infection resulting in worse morbidity and mortality. We sought to study the association between COVID‐19 infection and large vessel occlusion thrombus pathology to better define the etiopathogenesis of this atypical cause of stroke.

METHODS

Thrombi were collected during mechanical thrombectomy and stained using hematoxylin and eosin. Blinded analysis of pathology was prospectively performed by a board‐certified neuropathologist. Red blood cell, fibrin, and white blood cell predominance was ascertained. Concomitant peripheral blood counts and clinical and imaging data were collected and analyzed. All samples underwent performance of reverse transcription polymerase chain reaction for SARS‐CoV2.

RESULTS

Between January 2020 and February 2022, a total of 952 acute ischemic stroke admissions were seen at the University Medical Center of El Paso, TX. Of these, 195 patients (20.5%) had large vessel occlusions and underwent mechanical thrombectomy and 53 patients had thrombus collected and analyzed. Seven patients (3.6%) tested positive for SARS‐CoV2. COVID‐19 positive patients were more likely to be younger (mean 57.4 years; P =0.07), male (85.7%; P =0.03), and have red blood cell predominant thrombi (85.7%; P =0.03). There was a statistically significant association between peripheral neutrophil count and white blood cell lysis in the overall cohort ( P =0.015), who did not differ according to COVID‐19 status.

CONCLUSION

Thrombi retrieved from patients who were COVID‐19 positive and had stroke demonstrated red blood cell predominance. This finding requires further investigation using appropriate immunohistochemical techniques in a larger cohort of patients.

Functional and technical outcomes in acute ischemic stroke patients with hyperdense middle cerebral artery sign treated with endovascular thrombectomy

Background and objective

The hyperdense middle cerebral artery sign (HMCAS) is observed in a proportion of patients with acute ischemic stroke (AIS). This sign reflects the presence of an intravascular thrombus rich in red blood cells. Several studies have demonstrated that HMCAS increases the risk of poor outcomes in AIS patients treated with IV thrombolysis or no reperfusion therapy; however, whether HMCAS predicts a poor outcome in patients treated with endovascular thrombectomy (EVT) is less clear. We aimed to evaluate the functional outcome by the modified Rankin scale (mRS) at 90 days and technical challenges in patients with HMCAS undergoing EVT.

Methods

We studied 143 consecutive AIS patients with middle cerebral artery M1 segment or internal carotid artery + M1 occlusions who underwent EVT.

Results

There were 73 patients (51%) with HMCAS. Patients with HMCAS had a higher frequency of cardioembolic stroke (p = 0.038); otherwise, no other baseline difference was observed. No differences in functional outcomes (mRS) at 90  days (p = 0.698), unfavorable outcomes (mRS > 2) (p = 0.929), frequency of symptomatic intracranial hemorrhage (p = 0.924), and mortality (mRS-6) (p = 0.736) were observed between patients with and without HMCAS. In patients with HMCAS, EVT procedures were 9  min longer, requiring a higher number of passes (p = 0.073); however, optimal recanalization scores (modified thrombolysis in cerebral infarction: 2b-3) were equally achieved by both groups.

Conclusion

Patients with HMCAS treated with EVT do not have a worse outcome at 3  months compared with no-HMCAS patients. Patients with HMCAS required a greater number of thrombus passes and longer procedure times.

A comprehensive analysis of the hub genes for oxidative stress in ischemic stroke

Ischemic stroke (IS), resulting from the occlusion of the cerebral artery and subsequent interruption of blood flow, represents a major and critical threat to public health. Oxidative stress (OS) has been confirmed to play a role in the IS pathological process and neural death. Understanding the essential role of OS-related genes in ischemic stroke is critical to understanding the current perception of the pathophysiological process in IS. Herein, by integrating three IS datasets (GSE16561, GSE22255, and GSE58294), we divided IS samples into the low- and high-OS groups by calculating the OS score identified by the oxidative stress gene set. The functional enrichment analysis of differentially expressed genes (DEGs) between the low- and high-OS groups indicated that DEGs were associated with hypoxia, the inflammatory response, and oxidative phosphorylation pathways. Furthermore, nine hub genes (namely TLR1, CXCL1, MMP9, TLR4, IL1R2, EGR1, FOS, CXCL10, and DUSP1) were identified through the Girvan-Newman algorithm and cytoHubba algorithms. Nine hub genes were highly expressed in IS samples and positively related to neutrophils and macrophages. Drug-sensitive analysis targeting hub genes defined allopurinol and nickel sulfate as potential candidates for impairing the neural death caused by oxidative stress in IS. Finally, we employed five machine learning methods to check the efficacy of the predictive model identified by nine hub genes. The results showed that our model had superior power for predicting the OS activity of IS patients. TLR4 was found to have excellent diagnostic value and a wide-spectrum interaction with other hub genes. Our research emphasized the impact of oxidative stress on ischemic stroke, which supports the idea that antioxidants hold great promise in ischemic stroke therapy.

Coagulation biomarkers for ischemic stroke

A State of the Art lecture titled "coagulation biomarkers for ischemic stroke" was presented at the International Society on Thrombosis and Haemostasis (ISTH) Congress in 2022. Ischemic stroke (IS) is a common disease with major morbidity and mortality. It is a challenge to determine which patients are at risk for IS or have poor clinical outcome after IS. An imbalance of coagulation markers may contribute to the progression and prognosis of IS. Therefore, we now discuss studies on the association of selected coagulation biomarkers from the hemostasis, inflammation, and immunothrombosis systems with the risk of IS, stroke severity at the acute phase, and clinical outcome after treatment. We report on coagulation biomarker-induced risk of IS, stroke severity, and outcomes following IS derived from prospective population studies, case-control studies, and acute-phase IS studies. We found indications that many coagulation and inflammation biomarkers are associated with IS, but it is early to conclude that any of these biomarkers can be applied in a therapeutic setting to predict patients at risk of IS, stroke severity at the acute phase, and clinical outcome after treatment. The strongest evidence for a role in IS was found for beta-thromboglobulin, von Willebrand factor, factor VIII, fibrinogen, thrombin-activatable fibrinolysis inhibitor, D-dimer, and neutrophil extracellular traps, and therefore, they are promising candidates. Further research and validation in large-size populations using well-defined study designs are warranted. Finally, we provide a selection of recent data relevant to this subject that was presented at the 2022 ISTH Congress.

Thrombus composition and thrombolysis resistance in stroke

A State of the Art lecture titled "Thrombus Composition and Thrombolysis Resistance in Stroke" was presented at the ISTH Congress in 2022. Intravenous thrombolysis (IVT) remains the only pharmacologic option to re-establish cerebral perfusion at the acute phase of ischemic stroke. IVT is based on the administration of recombinant tissue plasminogen activator with the objective of dissolving fibrin, the major fibrillar protein component of thrombi. Almost 30 years on from its introduction, although the clinical benefits of IVT have been clearly demonstrated, IVT still suffers from a relatively low efficacy, with a rate of successful early recanalization below 50% overall. Analyses of thrombectomy-recovered acute ischemic stroke (AIS) thrombi have shown that apart from occlusion site, thrombus length, and collateral status, AIS thrombus structure and composition are also important modulators of IVT efficacy. In this article, after a brief presentation of IVT principle and current knowledge on IVT resistance, we review recent findings on how compaction and structural alterations of fibrin together with nonfibrin thrombus components such as neutrophil extracellular traps and von Willebrand factor interfere with IVT in AIS. We further discuss how these new insights could soon result in the development of original adjuvant therapies for improved IVT in AIS. Finally, we summarize relevant new data presented during the 2022 ISTH Congress.

The Effects of Shock Wave Therapy on Spasticity and Walking Ability in People with Stroke: A Comparative Study of Different Application Sites

BACKGROUND

This study was conducted to investigate the effects of extracorporeal shock wave therapy on the improvement of walking ability through a reduction in spasticity in stroke patients.

METHODS

Thirty-three patients diagnosed with ischemic stroke by a rehabilitation medicine specialist were randomly assigned to three groups. The patients were divided into experimental group 1 in which shock waves were applied to the muscle-tendon junction, experimental group 2 in which shock waves were applied to the middle of the muscle, and experimental group 3 in which shock waves were applied to both the muscle-tendon junction and the middle of the muscle. The MAS was used to evaluate spasticity in the subjects, and the Dartfish software was used to measure knee and ankle angles during heel-off when walking.

RESULTS

Based on the results of the study, a significant decrease in spasticity and increased joint angles were found in experimental groups 1 and 3 compared to experimental group 2, and the change in joint angle was significantly greater in experimental group 3 than in experimental groups 1 and 2.

CONCLUSIONS

These results indicate that treatment effect may vary depending on the application site of the shock wave, and to obtain the best treatment effect, the shock wave should be applied to both the muscle-tendon junction and the middle part of the muscle.

Endovascular Thrombectomy With or Without Intravenous Thrombolysis: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

We performed this meta-analysis of randomized clinical trials to compare the outcomes in patients treated with endovascular thrombectomy who receive prior intravenous thrombolysis with those who do not receive such treatment. Recently, one randomized trial reported outcomes to address this issue, so timely update of meta-analysis is needed to determine the value of administering intravenous thrombolysis before endovascular thrombectomy.

MATERIALS AND METHODS

Four randomized clinical trials are included in our meta-analysis. We calculated pooled odds ratios and 95% CIs using random-effects models. The primary efficacy endpoint was a favorable outcome defined by a modified Rankin Scale score of 0 (no symptoms), 1 (no significant disability), or 2 (slight disability) at 90 days post-randomization. Secondary endpoints analyzed were any intracerebral hemorrhage, symptomatic intracerebral hemorrhage, and mortality.

RESULTS

Of the 1633 patients randomized, the proportion of patients who achieved a favorable outcome was similar between endovascular thrombectomy alone and combined approach with intravenous thrombolysis and endovascular thrombectomy (1631 patients analyzed; odds ratio 1.02; CI 0.84-1.25; p = 0.83). Risk of any intracerebral hemorrhage was significantly lower among those randomized to endovascular thrombectomy alone (1633 patients analyzed; odds ratio 0.75; CI 0.57-0.99; p = 0.04). Rates of symptomatic intracerebral hemorrhage (p = 0.36) and mortality (p = 0.62) were not significantly different between the two groups.

CONCLUSIONS

Compared with endovascular thrombectomy preceded by intravenous thrombolysis, endovascular thrombectomy resulted in similar rates of favorable outcome with a lower rate of intracerebral hemorrhage. A large phase 3 trial is required to conclusively demonstrate equivalency of both approaches to guide future practice.

QiShen YiQi and its components attenuate acute thromboembolic stroke and carotid thrombosis by inhibition of CD62P/PSGL-1-mediated platelet-leukocyte aggregate formation

BACKGROUND

QiShen YiQi (QSYQ) dropping pill, a component-based Chinese medicine consisting of benefiting Qi (YQ) and activating blood (HX) components, has been reported to exert a beneficial effect on cerebral ischemia-induced stroke. However, its efficacy and pharmacological mechanism on acute thromboembolic stroke is not clear.

PURPOSE

This study is to explore the preventative effect and pharmacological mechanism of QSYQ and its YQ/HX components on the formation of platelet-leukocyte aggregation (PLA) in acute thromboembolic stroke.

STUDY DESIGN AND METHODS

In vivo thromboembolic stroke model and FeCl₃-induced carotid arterial occlusion models were used. Immunohistochemistry, Western blot, RT-qPCR, and flow cytometry experiments were performed to reveal the pharmacological mechanisms of QSYQ and its YQ/HX components.

RESULTS

In thromboembolic stroke rats, QSYQ significantly attenuated infarct area, improved neurological recovery, reduced PLA formation, and inhibited P-selection (CD62P)/ P-selectin glycoprotein ligand-1 (PSGL-1) expressions. The YQ component preferentially down-regulated PSGL-1 expression in leukocyte, while the HX component preferentially down-regulated CD62P expression in platelet. In carotid arterial thrombosis mice, QSYQ and its YQ/HX components inhibited thrombus formation, prolonged vessel occlusion time, reduced circulating leukocytes and P-selectin expression. PLA formation and platelet/leukocyte adhesion to endothelial cell were also inhibited by QSYQ and its YQ/HX components in vitro.

CONCLUSION

QSYQ and YQ/HX components attenuated thromboembolic stroke and carotid thrombosis by decreasing PLA formation via inhibiting CD62P/PSGL-1 expressions. This study shed a new light on the prevention of thromboembolic stroke.

Intravenous Thrombolysis for Acute Ischemic Stroke

OBJECTIVE

This article reviews the history of IV thrombolysis, its current indications and implementation, the duality of the "time is brain" versus "tissue clock" approaches, the impact of endovascular thrombectomy on IV thrombolysis, the emergence of tenecteplase, and future research directions.

LATEST DEVELOPMENTS

The growing use of factor Xa inhibitors has increasingly caused patients with stroke to be excluded from treatment with IV thrombolysis. Important geographic, socioeconomic, sex, race, and ethnic disparities have been identified in the implementation of IV thrombolysis and need to be overcome. IV thrombolysis substantially improves outcomes when provided within the first golden hour after stroke onset in patients treated in mobile stroke units, supporting the "time is brain" concept and encouraging the possible value of more widespread implementation of the mobile stroke unit approach. At the same time, other studies have shown that IV thrombolysis can be successful in patients whose "tissue clock" is still ticking up to 9 hours after stroke onset or in patients who awaken with their stroke, as demonstrated by favorable imaging profiles. These considerations, along with the emergence of endovascular thrombectomy, have fostered examination of our care systems, including the "drip and ship" versus direct to comprehensive or endovascular thrombectomy stroke center approaches, as well as the possibility of skipping IV thrombolysis in certain patients treated with endovascular thrombectomy. Data suggesting that tenecteplase is at least noninferior to alteplase, as well as its more convenient dosing, has led to its increased use. Ongoing studies are evaluating newer thrombolytics and adding antithrombotic therapy to IV thrombolysis.

ESSENTIAL POINTS

IV thrombolysis remains the most common acute stroke treatment. Advances in acting faster to treat stroke have increased its efficacy, and advances in imaging have expanded its use. However, implementing these advances and overcoming disparities in IV thrombolysis use remain major challenges.

Direct Aspiration versus Combined Technique for Distal Medium-Vessel Occlusions: Comparison on a Human Placenta Model

BACKGROUND AND PURPOSE

Mechanical thrombectomy appears to be a promising option for distal medium-vessel occlusions, for which intravenous thrombolysis is effective but may be insufficient when used alone. This study aimed to determine the optimal technique for these distal mechanical thrombectomies using the human placenta model.

MATERIALS AND METHODS

Twenty-four procedures were performed, allowing comparison of direct aspiration (n = 12) versus the combined technique (n = 12). Two positions of the aspiration catheter were tested for each of these techniques: in direct contact with the clot and at a distance from it (5-10 mm). Two types of clots were tested: red blood cell-rich clots and fibrin-rich clots. First-pass recanalization and induced arterial collapse and traction were assessed.

RESULTS

The first-pass recanalization was less frequent for direct aspiration than for the combined technique, without reaching statistical significance (41.7% versus 75.0%, P = .098). Full collapse (P < .001) and extended arterial traction (P = .001) were significantly less frequent for direct aspiration. For direct aspiration with the aspiration catheter not in direct contact with the clot, there was not a single first-pass recanalization and there was systematic arterial collapse, resulting in a no-flow in the aspiration syringe.

CONCLUSIONS

The combined technique appears to be more harmful, and although direct aspiration has a lower rate of first-pass recanalization, it seems appropriate to try direct aspiration as a first-line procedure. However, if the aspiration catheter cannot reach the clot, it is not useful or even risky to try aspiration alone. These results need to be confirmed by clinical studies.

Impact of the COVID-19 pandemic on emergent stroke care in Beijing, China

The coronavirus disease 2019 (COVID-19) pandemic has caused an unprecedented disruption to health care systems around the globe. Stroke is still an ongoing issue during the pandemic. We investigated the impact of the COVID-19 outbreak on emergent stroke care in Beijing, China. This is a retrospective analysis of two groups of patients with acute ischaemic stroke (AIS) registered in the Beijing Emergency Care Database between January 1, 2019, and December 31, 2020. Based on a database including 77 stroke centres, the quantity and quality of emergency care for stroke were compared. Subgroup analyses based on hospitals in different areas (high-risk and low/medium-risk areas) were carried out. A total of 6440 and 8699 admissions with suspected stroke were recorded in 2020 and 2019, respectively. There were no significant differences in the mean age and sex distribution for the patients between the two observational periods. The number of AIS admissions decreased by approximately 23.9% during the COVID-19 pandemic compared to that during the prepandemic period. The proportions of intravenous thrombolysis and endovascular treatment were 76.4% and 13.1%, respectively, in 2020, which were higher than those in 2019 (71.7% and 9.3%, respectively). There was no statistically significant difference in the time from stroke onset to arrival at the hospital (97.97 ± 23.09 min vs. 99.40 ± 20.76 min, p = 0.832) between the two periods. The door-to-needle time for thrombolysis (44.92 ± 9.20 min vs. 42.37 ± 9.06 min, p < 0.001) and door-to-thrombectomy time (138.56 ± 32.45 min vs. 120.55 ± 32.68 min, p < 0.001) were increased significantly in the pandemic period compared to those in the prepandemic period, especially in hospitals in high-risk areas. The decline in the number of patients with AIS and delay in treatment started after the launch of the level-1 public health emergency response and returned to stability after the release of professional protocols and consensus statements. Disruptions to medical services during the COVID-19 pandemic have substantially impacted AIS patients, with a clear drop in admission and a decline in the quality of emergent AIS care, especially in hospitals in high-risk areas and at the time of the initial outbreak of COVID-19. Health care systems need to maintain rapid adaptation to possible outbreaks of COVID-19 or similar crises in the future.

Fibrin clot properties in cardiovascular disease: from basic mechanisms to clinical practice

Fibrinogen conversion into insoluble fibrin and the formation of a stable clot is the final step of the coagulation cascade. Fibrin clot porosity and its susceptibility to plasmin-mediated lysis are the key fibrin measures, describing the properties of clots prepared ex vivo from citrated plasma. Cardiovascular disease (CVD), referring to coronary heart disease, heart failure, stroke, and hypertension, has been shown to be associated with the formation of dense fibrin networks that are relatively resistant to lysis. Denser fibrin mesh characterized acute patients at the onset of myocardial infarction or ischaemic stroke, while hypofibrinolysis has been identified as a persistent fibrin feature in patients following thrombotic events or in those with stable coronary artery disease. Traditional cardiovascular risk factors, such as smoking, diabetes mellitus, hyperlipidaemia, obesity, and hypertension, have also been linked with unfavourably altered fibrin clot properties, while some lifestyle modifications and pharmacological treatment, in particular statins and anticoagulants, may improve fibrin structure and function. Prospective studies have suggested that prothrombotic fibrin clot phenotype can predict cardiovascular events in short- and long-term follow-ups. Mutations and splice variants of the fibrinogen molecule that have been proved to be associated with thrombophilia or increased cardiovascular risk, along with fibrinogen post-translational modifications, prothrombotic state, inflammation, platelet activation, and neutrophil extracellular traps formation, contribute also to prothrombotic fibrin clot phenotype. Moreover, about 500 clot-bound proteins have been identified within plasma fibrin clots, including fibronectin, α2-antiplasmin, factor XIII, complement component C3, and histidine-rich glycoprotein. This review summarizes the current knowledge on the mechanisms underlying unfavourable fibrin clot properties and their implications in CVD and its thrombo-embolic manifestations.

Chrysin protects against cerebral ischemia-reperfusion injury in hippocampus via restraining oxidative stress and transition elements

Chrysin is a natural flavonoid compound that has antioxidant and neuroprotective effects. Cerebral ischemia reperfusion (CIR) is closely connected with increased oxidative stress in the hippocampal CA1 region and homeostasis disorder of transition elements such as iron (Fe), copper (Cu) and zinc (Zn). This exploration was conducted to elucidate the antioxidant and neuroprotective effects of chrysin based on transient middle cerebral artery occlusion (tMCAO) in rats. Experimentally, sham group, model group, chrysin (50.0 mg/kg) group, Ginaton (21.6 mg/kg) group, Dimethyloxallyl Glycine (DMOG, 20.0 mg/kg) + chrysin group and DMOG group were devised. The rats in each group were performed to behavioral evaluation, histological staining, biochemical kit detection, and molecular biological detection. The results indicated that chrysin restrained oxidative stress and the rise of transition element levels, and regulated transition element transporter levels in tMCAO rats. DMOG activated hypoxia-inducible factor-1 subunit alpha (HIF-1α), reversed the antioxidant and neuroprotective effects of chrysin, and increased transition element levels. In a word, our findings emphasize that chrysin plays a critical role in protecting CIR injury via inhibiting HIF-1α against enhancive oxidative stress and raised transition metal levels.

Effects of predictive nursing intervention on cognitive impairment and neurological function in ischemic stroke patients

BACKGROUND

Ischemic stroke is a clinical emergency caused by insufficient intracranial blood supply, which eventually leads to brain tissue necrosis and neurological impairment. Predictive nursing intervention has achieved impressive success in the nursing of multiple surgeries. However, the role of predictive nursing intervention in the care of patients with ischemic stroke remains unclear.

METHODS

This study was a randomized controlled trial. Based on the inclusion and exclusion criteria, 126 patients were randomly assigned into two groups, namely the control group and the predictive nursing intervention group. Both groups were treated with thrombolytic therapy with alteplase. The patients in the control group were given routine nursing intervention and the predictive nursing intervention group received additional predictive care. Neurologic functions and cognitive impairment were evaluated by National Institutes of Health Stroke Scale (NIHSS), Fugl-Meyer assessment (FMA), Montreal cognitive assessment (MoCA), and mini-mental state examination (MMSE) scales, respectively. Door-to-Needle Times, venous thromboembolism (VTE)-related parameters, and complications were recorded.

RESULTS

Predictive nursing intervention significantly shortened the Door-to-Needle Times and enhanced the peak/average femoral venous blood flow and femoral venous diameter. In addition, predictive nursing intervention improved the NIHSS, FMA, MMSE, and MoCA scores and remarkably reduced the recurrence of ischemic stroke, deep vein thrombosis and gingival bleeding.

CONCLUSION

Predictive nursing intervention is beneficial to improve the effects of thrombolytic therapy in patients with ischemic stroke, which improves the neurological, cognitive and motor functions of patients, and reduces the occurrence of complications, suggesting an important clinical application value.

Reverse Translation to Develop Post-stroke Therapeutic Interventions during Mechanical Thrombectomy: Lessons from the BACTRAC Trial

The majority of strokes, approximately 87%, are ischemic in etiology with the remaining hemorrhagic in origin. Emergent large vessel occlusions (ELVOs) are a subtype of ischemic stroke accounting for approximately 30-40% of acute large vessel blockages. Treatment for ELVOs focuses on recanalization of the occluded vessel by time-sensitive administration of tissue plasminogen activator (tPA) or thrombus removal using mechanical thrombectomy. Although a great deal of time and resources have focused on translational stroke research, little progress has been made in the area of identifying additional new treatments for stroke. Translational limitations include difficulty simulating human comorbid conditions in animal models, as well as the temporal nature of stroke pathology. The Blood And Clot Thrombectomy Registry And Collaboration represents an ongoing tissue registry for thrombectomy patients and includes collection of intracranial arterial blood, systemic arterial blood, thrombi, as well as a series of clinical and radiographic data points for analysis. This chapter will explore the methodologies employed and results obtained from studying BACTRAC-derived human biological specimens and how they can inform translational experimental design in animal studies.

Non-porous thrombi are less pervious and easier to be retrieved: implication from scanning electron microscopy study

BACKGROUND

Scanning electron microscopy (SEM) studies found that the porosity of thrombi might vary among individuals. However, its relationship with the clinical presentation and efficacy of mechanical thrombectomy (MT) remains unknown. We aimed to characterize the ultrastructure of thrombi and explore its association with the complexity of MT and clot perviousness.

METHODS

SEM was used to observe the morphological features of different components of thrombi obtained from patients with anterior circulation large vessel occlusion undergoing MT and to determine the porosity of thrombi by semi-quantitative analysis. Non-porous thrombi were defined as thrombi with porosity <2%. Clot perviousness was also evaluated using thrombus attenuation increase on CT perfusion (TAI_ctp). We assessed the complexity of MT by attempts of retrieval >3 and procedural duration >60 min, defined as the time interval between groin puncture and recanalization.

RESULTS

A total of 49 thrombi were analyzed and 31 (63.3%) were classified as non-porous thrombi. The presence of non-porous thrombi was negatively associated with procedure >60 min (OR 0.152, 95% CI 0.031 to 0.734, p=0.019) and attempts >3 (OR 0.194, 95% CI 0.046 to 0.822, p=0.026) after adjustment. Additionally, receiver operating characteristic curve analysis indicated that TAI_ctp <17.9 Hounsfield units could predict the presence of non-porous thrombi with an area under the curve of 0.915.

CONCLUSIONS

Non-porous thrombi on SEM are easier to be retrieved during MT and could be identified as less pervious clots on CT images.

Thrombus enhancement sign on CT angiography is associated with the first pass effect of stent retrievers

BACKGROUND

The thrombus enhancement sign (TES) is thought to be associated with the source of the stroke and thrombus composition. We investigated whether this imaging sign along with other thrombus characteristics could be used to predict the successful first pass effect (FPE) of mechanical thrombectomy.

METHODS

246 consecutive patients with acute ischemic stroke in the anterior circulation with large vessel occlusion who underwent thrombectomy with a stent retriever and clot collection were included. Patients were divided into FPE (modified Thrombolysis in Cerebral Infarction (mTICI) grade 2c or 3)/non-FPE (mTICI 0-2b) and modified FPE (mFPE) (mTICI 2b-3)/non-mFPE (mTICI 0-2a) groups based on flow restoration after the first pass. TES presence, thrombus density, thrombus length, clot burden score, and thrombus composition were compared. The association between FPE and imaging biomarkers, along with clinical and interventional parameters, was investigated by univariate and multivariate analysis.

RESULTS

FPE was achieved in 85 (34.6%) patients. TES presence was significantly lower in the FPE group (64.7% vs 80.7% in the non-FPE group, p=0.008) and mFPE group (69.1% vs 81.0% in the non-mFPE group, p=0.039). Histopathological examination revealed that TES (+) thrombi contained a higher fibrin/platelet proportion (50.9% vs 46.9% in TES (-) thrombi, p=0.029) and fewer erythrocytes (43.3% vs 47.3% in TES (-) thrombi, p=0.030). Thrombus characteristics, namely shorter thrombus length (p=0.032), higher erythrocyte proportions (p=0.026), and less fibrin/platelets (p=0.014), were confirmed in patients with FPE. In multivariable analysis, TES was the only independent predictor of FPE failure (OR 0.51, 95% CI 0.28 to 0.94; p=0.031).

CONCLUSIONS

TES was independently associated with first pass angiographic failure in patients treated with a stent retriever.

Clot-based radiomics model for cardioembolic stroke prediction with CT imaging before recanalization: a multicenter study

OBJECTIVES

To develop a clot-based radiomics model using CT imaging radiomic features and machine learning to identify cardioembolic (CE) stroke before mechanical thrombectomy (MTB) in patients with acute ischemic stroke (AIS).

MATERIALS AND METHODS

This retrospective four-center study consecutively included 403 patients with AIS who sequentially underwent CT and MTB between April 2016 and July 2021. These were grouped into training, testing, and external validation cohorts. Thrombus-extracted radiomic features and basic information were gathered to construct a machine learning model to predict CE stroke. The radiological characteristics and basic information were used to build a routine radiological model. A combined radiomics and radiological features model was also developed. The performances of all models were evaluated and compared in the validation cohort. A histological analysis helped further assess the proposed model in all patients.

RESULTS

The radiomics model yielded an area under the curve (AUC) of 0.838 (95% confidence interval [CI], 0.771-0.891) for predicting CE stroke in the validation cohort, significantly higher than the radiological model (AUC, 0.713; 95% CI, 0.636-0.781; p = 0.007) but similar to the combined model (AUC, 0.855; 95% CI, 0.791-0.906; p = 0.14). The thrombus radiomic features achieved stronger correlations with red blood cells (|r_max|, 0.74 vs. 0.32) and fibrin and platelet (|r_max|, 0.68 vs. 0.18) than radiological characteristics.

CONCLUSION

The proposed CT-based radiomics model could reliably predict CE stroke in AIS, performing better than the routine radiological method.

KEY POINTS

• Admission CT imaging could offer valuable information to identify the acute ischemic stroke source by radiomics analysis. • The proposed CT imaging-based radiomics model yielded a higher area under the curve (0.838) than the routine radiological method (0.713; p = 0.007). • Several radiomic features showed significantly stronger correlations with two main thrombus constituents (red blood cells, |r_max|, 0.74; fibrin and platelet, |r_max|, 0.68) than routine radiological characteristics.

A nomogram for predicting thrombus composition in stroke patients with large vessel occlusion: combination of thrombus density and perviousness with clinical features

PURPOSE

To establish a nomogram incorporating pretreatment imaging parameters and clinical characteristics for predicting the thrombus composition of acute ischemic stroke (AIS) with large vessel occlusion (LVO).

METHODS

We retrospectively enrolled patients with occlusion of the Middle Cerebral Artery (MCA) who underwent Mechanical Thrombectomy (MT). Retrieved thrombi were stained with Hematoxylin and Eosin (H&E) and Martius Scarlet Blue (MSB). Thrombi are assigned to the Fibrin-rich or RBC-rich group based on the relative fractions of Red Blood Cells (RBC), fibrin, and platelet. The independent risk factors for Fibrin-rich clots were determined via univariate and multivariate logistic regression analysis and were then integrated to establish a nomogram.

RESULTS

In total, 98 patients were included in this study. Patients with fibrin-rich clots had worse functional outcome [modified Rankin scale (mRS) 0-2, 34.7% vs 63.2%, p = 0.005], longer procedure time (76.8 min vs 50.8 min, p = 0.001), and increased maneuvers of MT (1.84 vs 1.46, p = 0.703) than those with RBC-rich clots. The independent risk factors for Fibrin-rich clots were lower perviousness measured by Non-Contrast Computer Tomography (NCCT) and CT Angiography (CTA), lower thrombus relative attenuation on NCCT, elevated Platelet-WBC ratio (PWR) of admission peripheral blood, and previous antithrombotic medication. The nomogram showed good discrimination with an area under the Receiver Operating Characteristic (ROC) curve (AUC) of 0.852 (95% CI: 0.778-0.926). The calibration curve and decision curve analysis also displayed satisfactory accuracy and clinical utility.

CONCLUSION

This study has developed and internally validated an easy-to-use nomogram which can help predict clot composition and optimize therapeutic strategies for thrombectomy.

Cerebral tumor embolism from thyroid cancer treated by mechanical thrombectomy: illustrative case

BACKGROUND

Development in mechanical thrombectomy is progressing dramatically. Tumor embolism has been rarely reported on the basis of pathological study of the retrieved thrombus. Herein, the authors report a case of cerebral tumor embolism from advanced thyroid cancer, which was successfully treated with mechanical thrombectomy.

OBSERVATIONS

A 57-year-old man was diagnosed with thyroid cancer with multiple lung metastases and chemotherapy was planned. He experienced left hemiparesis and was bought to the emergency section of the authors' hospital. Magnetic resonance angiography revealed right internal carotid artery occlusion and endovascular treatment was performed. Using a combination of aspiration catheter and stent retriever, white jelly-like embolus was retrieved. The pathological study demonstrated thyroid cancer embolism. Pulmonary vein invasion following lung metastasis of thyroid cancer was most presumably the cause of the tumor embolism.

LESSONS

Lung metastasis invading the pulmonary vein may be a cause of tumor embolism. Mechanical thrombectomy using a combination of stent retriever and aspiration catheter is effective in removing the tumor embolus and the pathological examination of the embolus is essential.

Correlation between Thrombus Perviousness and Distal Embolization during Mechanical Thrombectomy in Acute Stroke

PURPOSE

Thrombus permeability has been related to clot composition and treatment outcomes in stroke patients undergoing reperfusion therapies. The aim of this study was to evaluate whether thrombus perviousness, evaluated by multiphase computed tomography angiography (mCTA), is associated with distal embolization risk.

METHODS

We interrogated our dataset of acute ischemic stroke (AIS) patients involving the M1 segment of the middle cerebral artery (MCA) who had undergone mechanical thrombectomy, and we calculated thrombus average attenuation measurement (dHU) on non-contrast CT (NCCT) and clot perviousness on mCTA. dHU was calculated as the difference between the thrombus HU average value (tHU) and the HU average value on the contralateral side (cHU), while perviousness was calculated as the difference in mean clot density on mCTA and NCCT both in arterial (Perviousness pre-post-1) and delayed (Perviousness pre-post 2) phases.

RESULTS

A total of 100 patients (53 females (53%), mean age 72.74 [± 2.31]) with M1 occlusion were available for analysis. Perviousness, calculated between baseline and arterial phase of mCTA (Perviousness pre-post1), was lower in patients with distal embolization (p = 0.05), revealing an association between reduced perviousness and distal embolization risk. Logistic regression showed that thrombus perviousness calculated on the arterial phase of mCTA (OR, 0.66; 95% CI, 0.44-0.99] (p = 0.04)) and the contact aspiration technique (OR, 0.39; 95% CI, 0.15-1.02] (p = 0.05)) were protecting factors against distal embolization.

CONCLUSION

Our study showed an association between reduced perviousness and distal embolization, suggesting that perviousness evaluation may be a useful neuroimaging biomarker in predicting distal embolization risk during mechanical thrombectomy.