Large Core Research Articles

Extended Tetrathiafulvalenes with Fluoreno[3,2-b]fluorene and Diindeno[1,2-b : 1',2'-i]anthracene Cores.

In one-dimensional polycyclic aromatic hydrocarbons (PAHs) containing five- and six-membered rings fused together, one key question is whether the structures possess a quinoidal or aromatic diradical character. Here, we generate such PAHs by reversible oxidation of PAH-extended tetrathiafulvalenes (TTFs). Extended TTFs were thus prepared and studied for their geometrical properties (crystallography), redox properties, and UV/Vis/NIR/EPR characteristics as a function of charge state. The EPR measurements of radical cations showed unique features for each PAH-TTF. The dications, formally composed of fluoreno[3,2-b]fluorene and diindeno[1,2-b:1',2'-i]anthracene cores, were experimentally found to exhibit singlet ground states. For the latter, calculations reveal the closed shell, quinoid singlet state to be isoenergetic with the open shell singlet diradical. Each charge state exhibited unique optical properties with radical cations absorbing strongly in the NIR region with signatures from π-dimers for the large core. The experimental results were paralleled and supported by detailed computations, including spin density distribution calculations, EPR simulations, and nucleus independent chemical shift (NICS) xy scans.

Carotid artery perivascular adipose tissue on magnetic resonance imaging: a potential indicator for carotid vulnerable atherosclerotic plaque.

Magnetic resonance imaging (MRI) has the potential in assessing the inflammation of perivascular adipose tissue (PVAT) due to its excellent soft tissue contrast. However, evidence is lacking for the association between carotid PVAT measured by MRI and carotid vulnerable atherosclerotic plaques. This study aimed to investigate the association between signal intensity of PVAT and vulnerable plaques in carotid arteries using multi-contrast magnetic resonance (MR) vessel wall imaging. In this cross-sectional study, a total of 104 patients (mean age, 64.9±7.0 years; 86 men) with unilateral moderate-to-severe atherosclerotic stenosis referred to carotid endarterectomy (CEA) were recruited from April 2018 to December 2020 at Department of Neurosurgery of Peking University Third Hospital. All patients underwent multi-contrast MR vessel wall imaging including time-of-flight (ToF) MR angiography, black-blood T1-weighted (T1w) and T2-weighted (T2w) and simultaneous non-contrast angiography and intraplaque hemorrhage (IPH) imaging sequences. Patients with contraindications to endarterectomy or MRI examinations were excluded. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of PVAT were measured on ToF images and vulnerable plaque characteristics including IPH, large lipid-rich necrotic core (LRNC), and fibrous cap rupture (FCR) were identified. The SNR and CNR of PVAT were compared between slices with and without vulnerable plaque features using Mann-Whitney U test and their associations were analyzed using the generalized linear mixed model (GLMM). Carotid artery slices with IPH (30.93±14.56 vs. 27.34±10.02; P<0.001), FCR (30.35±13.82 vs. 27.53±10.37; P=0.006), and vulnerable plaque (29.15±12.52 vs. 27.32±10.05; P=0.016) had significantly higher value of SNR of PVAT compared to those without. After adjusting for clinical confounders, the SNR of PVAT was significantly associated with presence of IPH [odds ratio (OR) =0.627, 95% confidence interval (CI): 0.465-0.847, Puncorr=0.002, PFDR=0.016] and vulnerable plaque (OR =0.762, 95% CI: 0.629-0.924, Puncorr=0.006, PFDR=0.020). However, no significant association was found between the CNR of PVAT and presence of vulnerable plaque features (all P>0.05). The SNR of carotid artery PVAT measured by ToF MR angiography is independently associated with vulnerable atherosclerotic plaque features, suggesting that the signal intensity of PVAT might be an effective indicator for vulnerable plaque.

Protein Nanotubes as Advanced Material Platforms and Delivery Systems.

Protein nanotubes (PNTs) as state-of-the-art nanocarriers are promising for various potential applications both in the food and pharmaceutical industries. Derived fromedible starting sources like α-lactalbumin, lysozyme, and ovalbumin, PNTs bear properties of biocompatibility and biodegradability. Their large specific surface area and hydrophobic core facilitate chemical modification and loading of bioactive substances, respectively. Moreover, their enhanced permeability and penetration ability across biological barriers such as intestinal mucus, extracellular matrix, and thrombus clot, make it promising platforms for health-related applications. Most importantly, their simple preparation processes enable large-scale production, supporting applications in the biomedical and nanotechnological fields. Understanding the self-assembly principles is crucial for controlling their morphology, size, and shape, and thus providesthe ground to a multitude of applications. Here, the current state-of-the-art of PNTs including their building materials, physicochemical properties, and self-assembly mechanisms are comprehensively reviewed. The advantages and limitations, as well as challenges and prospects for their successful applications in biomaterial and pharmaceutical sectors are then discussed and highlighted. Potential cytotoxicity of PNTs and the need of regulations as critical factors for enabling in vivo applications are also highlighted. In the end, a brief summary and future prospects for PNTs as advanced platforms and delivery systems are included.

Efficacy and safety of endovascular thrombectomy in patients with large core ischemic strokes: A systematic review and meta-analysis of randomized controlled trials

Efficacy and safety of endovascular thrombectomy in patients with large core ischemic strokes: A systematic review and meta-analysis of randomized controlled trials

Numerical investigation of toroidal plasma response for ELM control via magnetic perturbations in the DTT Tokamak

Linear plasma response modeling is exploited in this work to assess the effect of different coil configurations on edge localized mode (ELM) stability in full power operational scenarios for the Divertor Tokamak Test (DTT) facility, presently under construction at the ENEA site of Frascati (Italy). The MARS-F code is used to compute, in toroidal geometry and including flow, the resistive plasma response to different vacuum fields with toroidal mode numbers n=1,2,3 . Peeling-like response in particular, correlated with ELM control, is found to be significant for n=2,3 perturbations while n=1 induces a large core response in the investigated scenarios. Two metrics are used to link plasma response to ELM control. Namely the local normal plasma displacement in the x-point region and the Chirikov parameter in PEST-like straight-field-line coordinates. These criteria are used to predict optimal phasing of the active coil arrays and current thresholds based on empirical evidence. Depending on the number of active coils and on the scenario, coil currents between 20 and 40 kAt are predicted to be effective for ELM mitigation in DTT.

Alberta Stroke Program Early Computed Tomography Score, Infarct Core Volume, and Endovascular Therapy Outcomes in Patients With Large Infarct

Endovascular therapy (EVT) demonstrated better outcomes compared with medical management in recent randomized clinical trials (RCTs) of patients with large infarct. To compare outcomes of EVT vs medical management across different strata of the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and infarct core volume in patients with large infarct. This prespecified secondary analysis of subgroups of the Endovascular Therapy in Acute Anterior Circulation Large Vessel Occlusive Patients With a Large Infarct Core (ANGEL-ASPECT) RCT included patients from 46 stroke centers across China between October 2, 2020, and May 18, 2022. Participants were enrolled within 24 hours of symptom onset and had ASPECTS of 3 to 5 or 0 to 2 and infarct core volume of 70 to 100 mL. Patients were divided into 3 groups: ASPECTS of 3 to 5 with infarct core volume less than 70 mL, ASPECTS of 3 to 5 with infarct core volume of 70 mL or greater, and ASPECTS of 0 to 2. Endovascular therapy or medical management. The primary outcome was the ordinal 90-day modified Rankin Scale (mRS) score. There were 455 patients in the trial; median age was 68 years (IQR, 60-73 years), and 279 (61.3%) were male. The treatment effect did not vary significantly across the 3 baseline imaging subgroups (P = .95 for interaction). The generalized odds ratio for the shift in the 90-day mRS distribution toward better outcomes with EVT vs medical management was 1.40 (95% CI, 1.06-1.85; P = .01) in patients with ASPECTS of 3 to 5 and infarct core volume less than 70 mL, 1.22 (95% CI, 0.81-1.83; P = .23) in patients with ASPECTS of 3 to 5 and infarct core volume of 70 mL or greater, and 1.59 (95% CI, 0.89-2.86; P = .09) in patients with ASPECTS of 0 to 2. In this study, no significant interaction was found between baseline imaging status and the benefit of EVT compared with medical management in patients with large infarct core volume. However, estimates within subgroups were underpowered. A pooled analysis of large core trials stratified by ASPECTS and infarct core volume strata is warranted. ClinicalTrials.gov Identifier: NCT04551664.

Fluorescence-enhanced dual signal lateral flow immunoassay for flexible and ultrasensitive detection of monkeypox virus

The outbreak of the monkeypox virus (MPXV) worldwide in 2022 highlights the need for a rapid and low-cost MPXV detection tool for effectively monitoring and controlling monkeypox disease. In this study, we developed a flexible lateral flow immunoassay (LFIA) with strong colorimetric and enhanced fluorescence dual-signal output for the rapid, on-site, and highly sensitive detection of the MPXV antigen in different scenarios. A multilayered SiO2-Au core dual-quantum dot (QD) shell nanocomposite (named SiO2-Au/DQD), which consists of a large SiO2 core (~ 200 nm), one layer of density-controlled gold nanoparticles (AuNPs, 20 nm), and thousands of small QDs, was fabricated instead of a traditional colorimetric nanotag (i.e., AuNPs) and a fluorescent nanotag (QD nanobead) to simultaneously provide good stability, strong colorimetric ability and superior fluorescence intensity. With the dual-signal output LFIA, we achieved the specific screening of the MPXV antigen (A29L) in 15 min, with detection limits of 0.5 and 0.0021 ng/mL for the colorimetric and fluorometric modes, respectively. Moreover, the colorimetric mode of SiO2-Au/DQD-LFIA exhibits the same sensitivity as the traditional AuNP- LFIA, whereas the overall sensitivity of this method on the basis of the fluorescent signal can achieve 238- and 3.3-fold improvements in sensitivity for MPXV compared with the AuNP-based LFIA and ELISA methods, respectively, indicating the powerful performance and good versatility of the dual-signal method in the point-of-care testing of the MPXV.

Outcomes of mechanical thrombectomy in stroke patients with extreme large infarction core

BackgroundRecent clinical trials have demonstrated that patients with large vessel occlusion (LVO) and large infarction core may still benefit from mechanical thrombectomy (MT). In this study, we evaluate outcomes of...

MiR-223-3p Prevents Necroptotic Macrophage Death by Targeting Ripk3 in a Negative Feedback Loop and Consequently Ameliorates Advanced Atherosclerosis.

The formation of large necrotic cores results in vulnerable atherosclerotic plaques, which can lead to severe cardiovascular diseases. However, the specific regulatory mechanisms underlying the development of necrotic cores remain unclear. To evaluate how the modes of lesional cell death are reprogrammed during the development of atherosclerosis, the expression levels of key proteins that are involved in the necroptotic, apoptotic, and pyroptotic pathways were compared between different stages of plaques in humans and mice. Luciferase assays and loss-of-function studies were performed to identify the microRNA-mediated regulatory mechanism that protects foamy macrophages from necroptotic cell death. The role of this mechanism in atherosclerosis was determined by using a knockout mouse model with perivascular drug administration and tail vein injection of microRNA inhibitors in Apoe-/- mice. Here, we demonstrate that the necroptotic, rather than the apoptotic or pyroptotic, pathway is more activated in advanced unstable plaques compared with stable plaques in both humans and mice, which closely correlates with necrotic core formation. The upregulated expression of Ripk3 (receptor-interacting protein kinase 3) promotes the C/EBPβ (CCAAT/enhancer binding protein beta)-dependent transcription of the microRNA miR-223-3p, which conversely inhibits Ripk3 expression and forms a negative feedback loop to regulate the necroptosis of foamy macrophages. The knockout of the Mir223 gene in bone marrow cells accelerates atherosclerosis in Apoe-/- mice, but this effect can be rescued by Ripk3 deficiency or treatment with the necroptosis inhibitors necrostatin-1 and GSK-872. Like the Mir223 knockout, treating Apoe-/- mice with miR-223-3p inhibitors increases atherosclerosis. Our study suggests that miR-223-3p expression in macrophages protects against atherosclerotic plaque rupture by limiting the formation of necrotic cores, thus providing a potential microRNA therapeutic candidate for atherosclerosis.

3D hydrodynamics simulations of a 3 M⊙ core helium burning star

ABSTRACT The inner structure of core helium burning (CHeB) stars remains uncertain due to the yet unknown nature of mixing at the boundary of their cores. Large convective cores beyond a bare Schwarzschild model are favoured both from theoretical arguments and from asteroseismological constraints. However, the exact nature of this extra mixing, and in particular the possible presence of semiconvective layers, is still debated. In this work, we approach this problem through a new avenue by performing the first full-sphere 3D hydrodynamics simulations of the interiors of CHeB stars. We use the ppmstar explicit gas dynamics code to simulate the inner 0.45$\, {\rm M}_{\odot }$ of a 3 M⊙ CHeB star. Simulations are performed using different Cartesian grid resolutions (7683, 11523, and 17283) and heating rates. We use two different initial states, one based on mesas's predictive mixing scheme (which significantly extends the core beyond the Schwarzschild boundary) and one based on the convective premixing approach (which exhibits a semiconvective interface). The general behaviour of the flow in the convective core and in the stable envelope (where internal gravity waves are observed) is consistent with our recent simulations of core convection in massive main-sequence stars, and so are the various luminosity scaling relations. The semiconvective layers are dominated by strong internal gravity waves that do not produce measurable species mixing, but overshooting motions from the convective core gradually homogenize the semiconvective interface. This process can possibly completely erase the semiconvective layers, which would imply that CHeB stars do not harbour a semiconvection zone.

Mycorrhizal fungi-mediated uptake of tree-derived nutrients by crops – the role of tree-maintained versus crop-associated fungal mycelia

Arbuscular mycorrhizal (AM) fungi translocate nutrients within agroforestry systems but the role of common mycorrhizal fungal networks (CMNs) is unclear. We compared AM fungi-mediated nutrient transfer from mango versus faidherbia trees to maize plants to understand how to foster the AM symbiosis for enhanced agroecosystem sustainability. In mesocosms we applied 15N and 33P tracers via tree stem injection or root-free soil labeling compartments to test tree-to-maize versus soil-to-maize nutrient transfer via AM fungi. Maize plants grew in large in-growth cores with intact versus broken mycelia. Soil-to-maize transfer was assessed with and without trees to compare nutrient transfer via tree-maintained AM fungi i.e. CMNs versus maize-associated AM fungi. Tracer application via stem injection neither corroborated nor falsified our hypothesis of tree-to-maize nitrogen and phosphorus transfer. Soil-to-maize nutrient transfer occurred but was not enhanced by the presence of mango or faidherbia trees. Competition with maize plants for nitrogen but not phosphorus was greater with mango than faidherbia trees. Results from our experimental set-up provide neither evidence nor disproval for CMNs between two-year-old trees and ten-week-old maize plants. In the absence of trees and tree-maintained AM fungal mycelia maize plants developed their own AM fungal mycelia that mediated uptake of nutrients from beyond the maize plants’ rooting zones.

Abstract 14130: Efficacy and Safety of Endovascular Therapy in Stroke Patients With Large Ischemic Core in Comparison to Medical Management: Meta-Analysis of Randomized Control Studies

Introduction: Endovascular therapy (EVT) is a treatment recommended for stroke patients with large vessel occlusion and an Alberta Stroke Program Early Computed Tomography Score (ASPECTS) ≥6. However, the utility of EVT in patients with large core ischemic stroke has not been well established. Methods: This meta-analysis assesses EVT's efficacy and safety using available trials comparing EVT to medical management (MM) in stroke patients with large ischemic core. Eligibility criteria: 1) were randomized controlled trials, 2) compared EVT with MM alone, 3) studied patients presenting with LIC cerebrovascular events, and 4) reported outcomes of interest. We extracted data for the major imaging inclusion criteria, the National Institutes of Health Stroke Scale (NIHSS) score, pre-stroke mRs score, and occlusion site. We also extracted outcome data for the EVT groups vs MM groups, including measurement of early neurological recovery, and definition of sICH. Results: Our primary end point was the mean modified Rankin scale score (RSS) at 90-day follow up. EVT was associated with higher odds of significant improvement in functional status with reduction in mean mRS by -0.31 [-0.47; -0.14]) compared to MM. The odds of achieving mRS 0 to 2 was higher in the EVT arm compared to the MM arm (2.53 [1.59; 4.02]). There was no difference in achieving mRS 0 to 3, early neurologic improvement defined according to NIHSS score, overall 90-day mortality and risk of symptomatic ICH between patients treated with EVT or MM in our analysis. Conclusions: Our study suggests that EVT may lead to improved outcomes in stroke patients with large core ischemia.

Grassland intactness outcompetes species as a more efficient surrogate in conservation design

AbstractMapped representations of species−habitat relationships often underlie approaches to prioritize area‐based conservation strategies to meet conservation goals for biodiversity. Generally a single surrogate species is used to inform conservation design, with the assumption that conservation actions for an appropriately selected species will confer benefits to a broader community of organisms. Emerging conservation frameworks across western North America are now relying on derived measures of intactness from remotely sensed vegetation data, wholly independent from species data. Understanding the efficacy of species‐agnostic planning approaches is a critical step to ensuring the robustness of emerging conservation designs. We developed an approach to quantify ‘strength of surrogacy’, by applying prioritization algorithms to previously developed species models, and measuring their coverage provided to a broader wildlife community. We used this inference to test the relative surrogacy among a suite of species models used for conservation targeting in the endangered grasslands of the Northern Sagebrush Steppe, where careful planning can help stem the loss of private grazing lands to cultivation. In this test, we also derived a simpler surrogate of intact rangelands without species data for conservation targeting, along with a measure of combined migration representative of key areas for connectivity. Our measure of intactness vastly outperformed any species model as a surrogate for conservation, followed by that of combined migration, highlighting the efficacy of strategies that target large and intact rangeland cores for wildlife conservation and restoration efforts.

Endovascular therapy for acute stroke with a large infarct core: A systematic review and meta-analysis

ObjectiveIn this meta-analysis, we aimed to investigate the efficacy and safety of endovascular treatment (EVT) for acute ischemic stroke (AIS) patients with large core infarct. MethodsThree online databases of Web of Science, PubMed and Scopus were systematically searched. Original studies which evaluated AIS participants with large core infarction who underwent EVT were included. R statistical software was used for statistical analyses. Effect sizes were presented with odds ratios (ORs) with their 95% confidence intervals (CIs). The effect sizes were pooled using random effects modeling. ResultsIncluding 47 studies and 15,173 patients, this meta-analysis showed that compared with medical management (MM), EVT was significantly associated with decreased odds of mortality (0.67, 95% CI: 0.51–0.87) and increased odds of favorable outcomes, including a modified Rankin Scale of 0–3 (2.36, 95% CI: 1.69–3.291) and of 0–2 (3.54, 95% CI: 1.96–6.4) in 90 days and remarkable improvement in National Institutes of Health Stroke Scale within 48 h after the procedure (3.6, 95% CI:1.32–9.79). Besides, there was a higher chance of intracranial hemorrhage (ICH) development (1.88, 95% CI: 1.32–2.68) but not symptomatic ICH (1.34, 95% CI: 0.78–2.31) in those who underwent EVT. ConclusionOur study suggests that EVT might be an effective and relatively safe treatment option for the treatment of AIS patients with large vessel occlusion who have large core infarcts, although more large-scale trials are needed to consolidate the results and to make inclusion criteria and the patient selection process clearer.

Abstract 230: Endovascular therapy for large core ischemic strokes: Meta‐analysis of randomized clinical trials

Introduction Background: Patients with acute strokes with large infarct size are traditionally excluded from endovascular therapies, as like as clinical care. However, questions remain with respect to the safety and efficacy of EVT in these patients. Methods We conducted a meta‐analysis based on pooled data from SELECT 2 trial [1], ANGEL‐ASPECT trial [2], RESCUE Japan [3], and HERMES study [4]. We explored the efficacy of EVT for large infarcts to achieve a favorable 90‐day modified Rankin Scale. Also, we compared favorable outcomes following EVT in those with a core infarct at baseline of more than 70 ml, delayed thrombectomy of more than 6 hours, older than 75 years, and those who received concomitant IV thrombolysis. We also examined the pooled rate of hemorrhagic transformation following EVT in large core strokes. Results This meta‐analysis showed a statistically significant higher rate of favorable outcome in subjects with extremely large infarct size who undergone EVT compared to those who were managed by medical therapy alone (RR: 1.41, 95% CI: [1.05‐1.98], p: 0.03). In the subgroups of patients with core size &gt; 70ml (RR: 1.51, 95% CI: [1.23‐1.87]), late window presentation (LKN to randomization ≥ 6 hours), (RR: 1.53, 95% CI: [1.27‐1.84]), or those 75 or older than 75 years old (RR: 1.43, 95% CI: [1.12‐1.84]), EVT was associated with higher rates of favorable 90‐day mRS score of 0‐3 compared to medical therapy alone. However, EVT was not associated with better outcomes in those who received IV thrombolysis (RR: 1.37, 95% CI: [0.93‐2.01]. Based on pooled data from SELECT‐2, ANGEL‐ASPECT, and RESCUE Japan trials, the overall rate of early symptomatic hemorrhagic transformation among cases with ASPECT 0‐5 in the thrombectomy group was not significantly higher compared to patients who were managed non‐surgically (OR 1.75, 95% CI: [0.89‐3.47]). Conclusion Endovascular therapy is a reasonable option for the management of large infarcts. EVT results in favorable outcome by a delayed thrombectomy for a large core infarct and in older patients.

Multimodal photoacoustic imaging in analytic vulnerability of atherosclerosis

AbstractAtherosclerosis is a major cause of mortality and morbidity, and rupture can lead to myocardial infarction and stroke. The vulnerability assessment of atherosclerosis plaques is important for providing medical treatment. Identifying vulnerable plaques requires noninvasive, high‐resolution imaging techniques for capturing and locating high‐risk markers. Photoacoustic imaging (PAI) is a hybrid and novel imaging modality that uses nonionizing excitation and has substantial promise for vulnerability assessment of atherosclerosis. The current review examined current applications of multimodal PAI for identification of atherosclerosis plaques. Furthermore, we discuss the challenges and limitations in the implementation this method and future research directions to overcome these difficulties. First, we discuss two aspects of vulnerable plaque characterization: large necrotic cores and thin degraded cap component identification. Then, we then discuss applications of high‐risk plaque characterization, including intraplaque hemorrhage and heme degradation markers detection. We hope that this review will shed light on the potential application of optical imaging techniques in atherosclerosis identification and facilitate further studies that will ultimately lead to the broader application of multimodal PAI in clinical practice.

Correction to: "Large Core Thrombectomies: Are We Still Conflicted or Confident".

Correction to: "Large Core Thrombectomies: Are We Still Conflicted or Confident".

Characterization and Mitigation of Dimensional Effects on Core Loss in High-Power High-Frequency Converters

To date, LLC Resonant converters are deployed in many applications for improved efficiency, density, and reliability. With the introduction of WBG devices coupled with the soft switching feature, the switching frequency can be extended beyond MHz. With the significant increase in operating frequency, complicated magnetic components can be broken down into a cellular structure, each with a few number of turns. They can be easily implemented using 4-6 layers of PCB windings. Moreover, integrating the cellular cores using flux cancellation can further improve the power density. The proposed integrated magnetics can be automated in the manufacturing process. With the recently developed high-frequency core material, phenomena referred to as the dimensional effects on core loss are observed. The dimensional effects were discussed in the literature when using an unusually large core structure; however, at high excitation frequencies, it can be observed more frequently, particularly with integrated magnetic components. In this paper, we give an overview of the dimensional effects on core loss, namely flux crowding, dimensional resonance, and eddy loss, with the latest being a dominant factor in the 1 MHz transformer loss. We also introduce a practical method for the characterization of the dimensional effects to help engineers better their design of the high frequency converter. This includes measuring the ferrite material characteristics and evaluating the dimensional effects using Finite-Element Analysis. Finally, a case study of 1MHz 400-to-48 V converter design is presented, showing superiority in both power density and efficiency metrics compared to other reported literature from the same category. This shows the importance of including the dimensional effects and, specifically, the core eddy loss in the design procedure.

Abstract 218: Evaluating Thrombectomy Candidacy in Large Core Strokes: Lessons from the SELECT2 Trial at Our Institution

Introduction Reperfusion therapy for patients with large vessel occlusion stroke includes thrombolytics and mechanical thrombectomy. Candidacy for thrombectomy depends on patient factors under active investigation. Historically, patients with large strokes have been excluded from major trials evaluating thrombectomy due to concern that thrombectomy would pose considerable risk with limited benefit. However, new evidence from the Select‐2 Trial found improved modified Rankin scale scores and higher rates of functional independence at 90 days following large stroke in patients who underwent thrombectomy versus medical therapy alone. We explored if patients presenting with large stroke at our institution resemble those in the Select‐2 Trial and, how many previously excluded patients could have possibly benefitted from thrombectomy. Methods Patients presenting as a code stroke at our institution from 1/2022 to 7/2022 were retrospectively analyzed. Large strokes, defined as CTP volume greater than 50mL, were identified. Background information included age, sex, race, and prior stroke. Regarding patient stroke presentation, the following data were gathered: NIHSS, LVO status, CTA results, CTP, tPA, thrombectomy status, TICI score, and discharge status. Our patients included in this study were compared to the patients included the Select‐2 Trial. Mortality rates and NIHSS at discharge were compared between thrombectomized and non‐thrombectomized patients at our institution. Results Of the 365 code strokes activated at our institution during the study period, 26 met criteria for a large stroke. Of those 26, 13 met all criteria for inclusion in SELECT‐2. Only 9 of the 26 patients received thrombectomy, including 7 of 13 patients otherwise meeting SELECT‐2 criteria. 6 patients were excluded from thrombectomy who would have met criteria for SELECT‐2. Of the 9 who underwent thrombectomy, one expired, and the average NIHSS calculated from physical exam at discharge of surviving patients was 13. Of the 17 who did not undergo thrombectomy, seven expired and the average NIHSS at discharge was 19.4. Of large stroke patients, average age was 69.5 years (SD 11.0), similar to Select‐2 (median age 66). Average NIHSS at presentation was 19 (SD 6.55), similar to Select 2. Compared to SELECT2 enrollment, our patients were more likely to be female (50% vs 41%), Black (50% vs 25%), have a history of prior stroke (38% vs. 9%). LVO was identified on 23 of 26 patients. Of these 23, 17 MCA, 3 ACA, 6 ICA, and 2 carotid terminus occlusions were identified (6 had tandem occlusions). The average rCBF volume was 102.3 mL (SD 64.3) compared to median estimated ischemic core volume of 80mL in Select 2. Conclusion The patients presenting to our institution with large stroke resemble those included in the Select 2 trial, which demonstrates positive outcomes following mechanical thrombectomy for this special population. Patients with large strokes are frequently excluded from receiving treatment with mechanical thrombectomy. Analysis of a larger data set, including large stroke patients from 2018 to 2022, is currently pending. In light of the Select 2 trial, patients in our community and in our referral basis stand to benefit from an institutional practice of offering thrombectomy to those presenting with large stroke.

Current and future trends in acute ischemic stroke treatment: direct-to-angiography suite, middle vessel occlusion, large core, and minor strokes

Since the publication of the landmark thrombectomy trials in 2015, the field of endovascular therapy for ischemic stroke has been rapidly growing. The very low number needed to treat to provide functional benefits shown by the initial randomized trials has led clinicians and investigators to seek to translate the benefits of endovascular therapy to other patient subgroups. Even if the treatment effect is diminished, currently available data has provided sufficient information to extend endovascular therapy to large infarct core patients. Recently, published data have also shown that sophisticated imaging is not necessary for late time- window patients. As a result, further research into patient selection and the stroke pathway now focuses on dramatically reducing door-to-groin times and improving outcomes by circumventing classical imaging paradigms altogether and employing a direct-to-angio suite approach for selected large vessel occlusion patients in the early time window. While the results of this approach mainly concern patients with severe deficits, there are further struggles to provide evidence of the efficacy and safety of endovascular treatment in minor stroke and large vessel occlusion, as well as in patients with middle vessel occlusions. The current lack of good quality data regarding these patients provides significant challenges for accurately selecting potential candidates for endovascular treatment. However, current and future randomized trials will probably elucidate the efficacy of endovascular treatment in these patient populations.