168 research outputs found

    Detection of radio emission at mas scales from HESS J0632+057 with the e-EVN

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    HESS J0632+057 is a variable TeV gamma-ray source. The likely low energy counterparts of the source are XMMU J063259.3+054801, the B0pe-type star MWC 148, and a point-like probable non-thermal radio source

    Orbital X-Ray Variability of the Microquasar LS 5039

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    The properties of the orbit and the donor star in the high mass X-ray binary microquasar LS 5039 indicate that accretion processes should mainly occur via a radiatively driven wind. In such a scenario, significant X-ray variability would be expected due to the eccentricity of the orbit. The source has been observed at X-rays by several missions, although with a poor coverage that prevents to reach any conclusion about orbital variability. Therefore, we conducted RossiXTE observations of the microquasar system LS 5039 covering a full orbital period of 4 days. Individual observations are well fitted with an absorbed power-law plus a Gaussian at 6.7 keV, to account for iron line emission that is probably a diffuse background feature. In addition, we have taken into account that the continuum is also affected by significant diffuse background contamination. Our results show moderate power-law flux variations on timescales of days, as well as the presence of miniflares on shorter timescales. The new orbital ephemeris of the system recently obtained by Casares et al. have allowed us to show, for the first time, that an increase of emission is seen close to the periastron passage, as expected in an accretion scenario. Moreover, the detected orbital variability is a factor of ~4 smaller than the one expected by using a simple wind accretion model, and we suggest that an accretion disk around the compact object could be responsible for this discrepancy. On the other hand, significant changes in the photon index are also observed clearly anti-correlated with the flux variations. We interpret the overall X-ray spectral characteristics of LS 5039 in the context of X-ray radiation produced by inverse Compton and/or synchrotron processes in the jet of this microquasar.Comment: published in Astrophysical Journal, submission format (real number of pages: 7, 4 figures

    Geographical Requirements for the Applicability of the Results of the RACECAT Study to Other Stroke Networks

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    Prehospital stroke triage; Reperfusion therapyTriaje prehospitalario de ictus; Terapia de reperfusiónTriatge prehospitalari d'ictus; Teràpia de reperfusióBackground The RACECAT (Transfer to the Closest Local Stroke Center vs Direct Transfer to Endovascular Stroke Center of Acute Stroke Patients With Suspected Large Vessel Occlusion in the Catalan Territory) trial was the first randomized trial addressing the prehospital triage of acute stroke patients based on the distribution of thrombolysis centers and intervention centers in Catalonia, Spain. The study compared the drip‐and‐ship with the mothership paradigm in regions where a local thrombolysis center can be reached faster than the nearest intervention center (equipoise region). The present study aims to determine the population‐based applicability of the results of the RACECAT study to 4 stroke networks with a different degree of clustering of the intervention centers (clustered, dispersed). Methods and Results Stroke networks were compared with regard to transport time saved for thrombolysis (under the drip‐and‐ship approach) and transport time saved for endovascular therapy (under the mothership approach). Population‐based transport times were modeled with a local instance of an openrouteservice server using open data from OpenStreetMap.The fraction of the population in the equipoise region differed substantially between clustered networks (Catalonia, 63.4%; France North, 87.7%) and dispersed networks (Southwest Bavaria, 40.1%; Switzerland, 40.0%). Transport time savings for thrombolysis under the drip‐and‐ship approach were more marked in clustered networks (Catalonia, 29 minutes; France North, 27 minutes) than in dispersed networks (Southwest Bavaria and Switzerland, both 18 minutes). Conclusions Infrastructure differences between stroke networks may hamper the applicability of the results of the RACECAT study to other stroke networks with a different distribution of intervention centers. Stroke networks should assess the population densities and hospital type/distribution in the temporal domain before applying prehospital triage algorithms to their specific setting.M.G. has received grants from the Swiss Academy of Medical Sciences/Bangerter‐Rhyner‐Foundation, Swiss Stroke Society, and Mittelbauvereinigung der Universität Bern as well as a congress grant from Pfizer, not related to this project. J.G. reports being global co‐principal investigator of the STAR Study, NCT01327989; consultancy Medtronic; global co‐principal investigator of SWIFT DIRECT, NCT03192332; consultancy Medtronic; principal investigator: Stroke treatment goes personalized: Gaining added diagnostic yield by computer‐assisted treatment selection (the STRAY‐CATS project), Swiss National Funds 170 060. J.K. reports grants from the Swiss Academy of Medical Sciences/Bangerter Foundation, Swiss Stroke Society, and Clinical Trials Unit Bern during the conduct of the study. T.R.M. reports grants from the Swiss Academy of Medical Sciences/Bangerter Foundation, Swiss National Science Society, and Swiss Heart Foundation during the conduct of the study. U.F. reports research grants from Medtronic for the SWIFT DIRECT trial and BEYOND SWIFT registry, Swiss National Science Foundation, Swiss Heart Foundation; consulting fees from Medtronic, Stryker, and CSL Behring (fees paid to institution); membership of a Data Safety Monitoring Board for the IN EXTREMIS trial and TITAN trial and Portola (Alexion), advisory board (fees paid to institution); and vice presidency of the Swiss Neurological Society. The remaining authors have no disclosures to report

    Initial Experience with the Solitaire X 3 mm Stent Retriever for the Treatment of Distal Medium Vessel Occlusions

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    Distal medium vessel occlusions; Endovascular thrombectomy; StrokeOclusiones de vasos distales medianos; Trombectomía endovascular; IctusOclusió dels vasos distals mitjans; Trombectomia endovascular; IctusEndovascular therapy (EVT) is the standard treatment for ischemic stroke caused by a large vessel occlusion (LVO). The effectiveness of EVT for distal medium vessel occlusions (MDVOs) is still uncertain, but newer, smaller devices show potential for EVT in MDVOs. The new Solitaire X 3 mm device offers a treatment option for MDVOs. Our study encompassed consecutive cases of primary and secondary MDVOs treated with the Solitaire X 3 mm stent-retriever as first-line EVT device between January and December 2022 at 12 European stroke centers. The primary endpoint was a first-pass near-complete or complete reperfusion, defined as a modified treatment in cerebral infarction (mTICI) score of 2c/3. Additionally, we examined reperfusion results, National Institutes of Health Stroke Scale (NIHSS) scores at 24 h and discharge, device malfunctions, complications and procedural technical parameters. Sixty-eight patients (38 women, mean age 72 ± 14 years) were included in our study. Median NIHSS at admission was 11 (IQR 6–16). In 53 (78%) cases, a primary combined approach was used as the frontline technique. Among all enrolled patients, first-pass mTICI 2c/3 was achieved in 22 (32%) and final mTICI 2c/3 in 46 (67.6%) patients after a median of 1.5 (IQR 1–2) passes. Final reperfusion mTICI 2b/3 was observed in 89.7% of our cases. We observed no device malfunctions. Median NIHSS at discharge was 2 (IQR 0–4), and no symptomatic intracranial hemorrhages were reported. Based on our analysis, the utilization of the Solitaire X 3 mm device appears to be both effective and safe for performing EVT in cases of MDVO stroke

    Cost-effectiveness of Direct Transfer to Angiography Suite of Patients With Suspected Large Vessel Occlusion

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    Cost-effectiveness; Angiography; Large vessel occlusionCost-efectivitat; Angiografia; Oclusió de grans vasosCosto-efectividad; Angiografía; Oclusión de grandes vasosBackground and Objectives Patients with acute ischemic stroke due to large vessel occlusion (LVO) deemed eligible for endovascular thrombectomy (EVT) are transferred from the emergency room to the angiography suite to undergo the procedure. Recently, the strategy of direct transfer of patients with suspected LVO to the angiography suite (DTAS) has been shown to improve functional outcomes. This study aims to evaluate the cost-effectiveness of the DTAS strategy vs initial transfer of patients with suspected LVO (Rapid Arterial Occlusion Evaluation score >4 and NIH Stroke Scale >10) to the emergency room (ITER). Methods A decision-analytic Markov model was developed to estimate the cost-effectiveness of the DTAS strategy vs the ITER strategy from a Dutch health care perspective with a 10-year time horizon. The primary outcome was the incremental cost-effectiveness ratio (ICER) using Dutch thresholds of 59,135(50,000)and59,135 (€50,000) and 94,616 (€80,000) per quality-adjusted life year (QALY). Uncertainty of input parameters was assessed using 1-way sensitivity analysis, scenario analysis, and probabilistic sensitivity analysis. Results The DTAS strategy yielded 0.65 additional QALYs at an additional 16,089,resultinginanICERof16,089, resulting in an ICER of 24,925/QALY compared with the ITER strategy. The ICER varied from 27,169to27,169 to 38,325/QALY across different scenarios. The probabilistic sensitivity analysis showed that the DTAS strategy had a 91.8% and 97.0% likelihood of being cost-effective at a decision threshold of 59,135/QALYand59,135/QALY and 94,616/QALY, respectively. Discussion The cost-effectiveness of the DTAS strategy over ITER is robust for patients with suspected LVO. Together with recently published clinical results, this means that implementation of the DTAS strategy may be considered to improve the workflow and outcome of EVT.The CONTRAST consortium is supported by Netherlands Cardiovascular Research Initiative, an initiative of the Dutch Heart Foundation (CVON2015-01: CONTRAST) and by the Brain Foundation Netherlands (HA2015.01.06) and powered by Health∼Holland, Top Sector Life Sciences and receives unrestricted funding from Medtronic and Cerenovus. The collaboration project is additionally financed by the Ministry of Economic Affairs by means of the PPP Allowance made available by the Top Sector Life Sciences & Health to stimulate public-private partnerships (LSHM17016). This work was funded in part through unrestricted funding by Stryker, Medtronic and Cerenovus

    Functional and Safety Outcomes of Carotid Artery Stenting and Mechanical Thrombectomy for Large Vessel Occlusion Ischemic Stroke With Tandem Lesions

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    Arteria carótida; Trombectomía mecánica; Accidente cerebrovascular isquémicoArtèria caròtida; Trombectomia mecànica; Accident cerebrovascular isquèmicCarotid artery; Mechanical thrombectomy; Ischemic strokeImportance Approximately 10% to 20% of large vessel occlusion (LVO) strokes involve tandem lesions (TLs), defined as concomitant intracranial LVO and stenosis or occlusion of the cervical internal carotid artery. Mechanical thrombectomy (MT) may benefit patients with TLs; however, optimal management and procedural strategy of the cervical lesion remain unclear. Objective To evaluate the association of carotid artery stenting (CAS) vs no stenting and medical management with functional and safety outcomes among patients with TL-LVOs. Design, Setting, and Participants This cross-sectional study included consecutive patients with acute anterior circulation TLs admitted across 17 stroke centers in the US and Spain between January 1, 2015, and December 31, 2020. Data analysis was performed from August 2021 to February 2022. Inclusion criteria were age of 18 years or older, endovascular therapy for intracranial occlusion, and presence of extracranial internal carotid artery stenosis (>50%) demonstrated on pre-MT computed tomography angiography, magnetic resonance angiography, or digital subtraction angiography. Exposures Patients with TLs were divided into CAS vs nonstenting groups. Main Outcomes and Measures Primary clinical and safety outcomes were 90-day functional independence measured by a modified Rankin Scale (mRS) score of 0 to 2 and symptomatic intracranial hemorrhage (sICH), respectively. Secondary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction score ≥2b), discharge mRS score, ordinal mRS score, and mortality at 90 days. Results Of 685 patients, 623 (mean [SD] age, 67 [12.2] years; 406 [65.2%] male) were included in the analysis, of whom 363 (58.4%) were in the CAS group and 260 (41.6%) were in the nonstenting group. The CAS group had a lower proportion of patients with atrial fibrillation (38 [10.6%] vs 49 [19.2%], P = .002), a higher proportion of preprocedural degree of cervical stenosis on digital subtraction angiography (90%-99%: 107 [32.2%] vs 42 [20.5%], P < .001) and atherosclerotic disease (296 [82.0%] vs 194 [74.6%], P = .003), a lower median (IQR) National Institutes of Health Stroke Scale score (15 [10-19] vs 17 [13-21], P < .001), and similar rates of intravenous thrombolysis and stroke time metrics when compared with the nonstenting group. After adjustment for confounders, the odds of favorable functional outcome (adjusted odds ratio [aOR], 1.67; 95% CI, 1.20-2.40; P = .007), favorable shift in mRS scores (aOR, 1.46; 95% CI, 1.02-2.10; P = .04), and successful reperfusion (aOR, 1.70; 95% CI, 1.02-3.60; P = .002) were significantly higher for the CAS group compared with the nonstenting group. Both groups had similar odds of sICH (aOR, 0.90; 95% CI, 0.46-2.40; P = .87) and 90-day mortality (aOR, 0.78; 95% CI, 0.50-1.20; P = .27). No heterogeneity was noted for 90-day functional outcome and sICH in prespecified subgroups. Conclusions and Relevance In this multicenter, international cross-sectional study, CAS of the cervical lesion during MT was associated with improvement in functional outcomes and reperfusion rates without an increased risk of sICH and mortality in patients with TLs

    Cost-effectiveness of Direct Transfer to Angiography Suite of Patients With Suspected Large Vessel Occlusion

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    BACKGROUND AND OBJECTIVES: Patients with acute ischemic stroke due to large vessel occlusion (LVO) deemed eligible for endovascular thrombectomy (EVT) are transferred from the emergency room to the angiography suite to undergo the procedure. Recently, the strategy of direct transfer of patients with suspected LVO to the angiography suite (DTAS) has been shown to improve functional outcomes. This study aims to evaluate the cost-effectiveness of the DTAS strategy vs initial transfer of patients with suspected LVO (Rapid Arterial Occlusion Evaluation score &gt;4 and NIH Stroke Scale &gt;10) to the emergency room (ITER).METHODS: A decision-analytic Markov model was developed to estimate the cost-effectiveness of the DTAS strategy vs the ITER strategy from a Dutch health care perspective with a 10-year time horizon. The primary outcome was the incremental cost-effectiveness ratio (ICER) using Dutch thresholds of 59,135(50,000)and59,135 (€50,000) and 94,616 (€80,000) per quality-adjusted life year (QALY). Uncertainty of input parameters was assessed using 1-way sensitivity analysis, scenario analysis, and probabilistic sensitivity analysis.RESULTS: The DTAS strategy yielded 0.65 additional QALYs at an additional 16,089,resultinginanICERof16,089, resulting in an ICER of 24,925/QALY compared with the ITER strategy. The ICER varied from 27,169to27,169 to 38,325/QALY across different scenarios. The probabilistic sensitivity analysis showed that the DTAS strategy had a 91.8% and 97.0% likelihood of being cost-effective at a decision threshold of 59,135/QALYand59,135/QALY and 94,616/QALY, respectively.DISCUSSION: The cost-effectiveness of the DTAS strategy over ITER is robust for patients with suspected LVO. Together with recently published clinical results, this means that implementation of the DTAS strategy may be considered to improve the workflow and outcome of EVT.</p

    Stroke etiologies in patients with COVID-19: the SVIN COVID-19 multinational registry

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    Background and purpose: Coronavirus disease 2019 (COVID-19) is associated with a small but clinically significant risk of stroke, the cause of which is frequently cryptogenic. In a large multinational cohort of consecutive COVID-19 patients with stroke, we evaluated clinical predictors of cryptogenic stroke, short-term functional outcomes and inhospital mortality among patients according to stroke etiology. Methods: We explored clinical characteristics and short-term outcomes of consecutively evaluated patients 18 years of age or older with acute ischemic stroke (AIS) and laboratory-confirmed COVID-19 from 31 hospitals in 4 countries (3/1/20–6/16/20). Results:Of the 14.483 laboratory-confirmed patients with COVID-19, 156 (1.1%) were diagnosed with AIS. Sixty-one (39.4%) were female, 84 (67.2%) white, and 88 (61.5%) were between 60 and 79 years of age. The most frequently reported etiology of AIS was cryptogenic (55/129, 42.6%), which was associated with significantly higher white blood cell count, c-reactive protein, and D-dimer levels than non-cryptogenic AIS patients (p Conclusions: Our findings suggest that cryptogenic stroke among COVID-19 patients carries a significant risk of early mortality
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