| 1. |
- Zdziarski, Andrzej A., et al.
(författare)
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Hybrid Comptonization and Electron-Positron Pair Production in the Black-hole X-Ray Binary MAXI J1820+070
- 2021
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 914:1
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Tidskriftsartikel (refereegranskat)abstract
- We study X-ray and soft gamma-ray spectra from the hard state of the accreting black-hole binary MAXI J1820+070. We perform an analysis of two joint spectra from NuSTAR and INTEGRAL, covering the range of 3-650 keV, and of an average joint spectrum over the rise of the hard state, covering the 3-2200 keV range. The spectra are well modeled by Comptonization of soft seed photons. However, the distributions of the scattering electrons are not purely thermal; we find they have substantial high-energy tails, well modeled as power laws. The photon tail in the average spectrum is detected well beyond the threshold for electron-positron pair production, 511 keV. This allows us to calculate the rate of the electron-positron pair production and put a lower limit on the size of the source from pair equilibrium. At the fitted Thomson optical depth of the Comptonizing plasma, the limit is about 4 gravitational radii. If we adopt the sizes estimated by us from the reflection spectroscopy of >20 gravitational radii, the fractional pair abundance becomes much less than unity. The low pair abundance is confirmed by the lack of both an annihilation feature and of a pair absorption cutoff above 511 keV in the average spectrum.
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| 2. |
- Becher, Nina, et al.
(författare)
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Anticoagulation with edoxaban in patients with long atrial high-rate episodes ≥24 h
- 2024
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Ingår i: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 45:10, s. 837-849
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: Patients with long atrial high-rate episodes (AHRE) ≥ 24 hours and stroke risk factors are often treated with anticoagulation for stroke prevention. Anticoagulation has never been compared to no anticoagulation in these patients.METHODS: This secondary prespecified analysis of NOAH-AFNET 6 examined interactions between AHRE duration at baseline and anticoagulation with edoxaban compared to placebo in patients with AHRE and stroke risk factors. The primary efficacy outcome was a composite of stroke, systemic embolism, or cardiovascular death. The safety outcome was a composite of major bleeding and death. Key secondary outcomes were components of these outcomes and ECG-diagnosed atrial fibrillation.RESULTS: AHRE ≥24 hours were present at baseline in 259/2389 patients enrolled in NOAH-AFNET 6 (11%, 78 ± 7 years old, 28% women, CHA2DS2-VASc score 4). Clinical characteristics were not different from patients with shorter AHRE. During a median follow-up of 1.8 years, the primary outcome occurred in 9/132 patients with AHRE ≥24 hours (4.3%/patient-year, 2 strokes) treated with anticoagulation and in 14/127 patients treated with placebo (6.9%/patient-year, 2 strokes). AHRE duration did not interact with the efficacy (p-interaction = 0.65) or safety (p-interaction = 0.98) of anticoagulation. Analyses including AHRE as a continuous parameter confirmed this. Patients with AHRE ≥24 hours developed more ECG-diagnosed atrial fibrillation (17.0%/patient-year) than patients with shorter AHRE (8.2%/patient-year; p < 0.001).CONCLUSIONS: This hypothesis-generating analysis does not find an interaction between AHRE duration and anticoagulation therapy in patients with device-detected AHRE and stroke risk factors. Further research is needed to identify patients with long AHRE at high stroke risk.
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| 3. |
- Bertaglia, Emanuele, et al.
(författare)
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Atrial high-rate episodes : prevalence, stroke risk, implications for management, and clinical gaps in evidence
- 2019
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Ingår i: Europace. - : Oxford University Press (OUP). - 1099-5129 .- 1532-2092. ; 21:10, s. 1459-1467
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Forskningsöversikt (refereegranskat)abstract
- Self-terminating atrial arrhythmias are commonly detected on continuous rhythm monitoring, e.g. by pacemakers or defibrillators. It is unclear whether the presence of these arrhythmias has therapeutic consequences. We sought to summarize evidence on the prevalence of atrial high-rate episodes (AHREs) and their impact on risk of stroke. We performed a comprehensive, tabulated review of published literature on the prevalence of AHRE. In patients with AHRE, but without atrial fibrillation (AF), we reviewed the stroke risk and the potential risk/benefit of oral anticoagulation. Atrial high-rate episodes are found in 10-30% of AF-free patients. Presence of AHRE slightly increases stroke risk (0.8% to 1%/year) compared with patients without AHRE. Atrial high-rate episode of longer duration (e.g. those >24 h) could be associated with a higher stroke risk. Oral anticoagulation has the potential to reduce stroke risk in patients with AHRE but is associated with a rate of major bleeding of 2%/year. Oral anticoagulation is not effective in patients with heart failure or survivors of a stroke without AF. It remains unclear whether anticoagulation is effective and safe in patients with AHRE. Atrial high-rate episodes are common and confer a slight increase in stroke risk. There is true equipoise on the best way to reduce stroke risk in patients with AHRE. Two ongoing trials (NOAH-AFNET 6 and ARTESiA) will provide much-needed information on the effectiveness and safety of oral anticoagulation using non-vitamin K antagonist oral anticoagulants in patients with AHRE.
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| 4. |
- Szulkin, Robert, et al.
(författare)
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Prediction of individual genetic risk to prostate cancer using a polygenic score.
- 2015
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 75:13, s. 1467-74
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Polygenic risk scores comprising established susceptibility variants have shown to be informative classifiers for several complex diseases including prostate cancer. For prostate cancer it is unknown if inclusion of genetic markers that have so far not been associated with prostate cancer risk at a genome-wide significant level will improve disease prediction.METHODS: We built polygenic risk scores in a large training set comprising over 25,000 individuals. Initially 65 established prostate cancer susceptibility variants were selected. After LD pruning additional variants were prioritized based on their association with prostate cancer. Six-fold cross validation was performed to assess genetic risk scores and optimize the number of additional variants to be included. The final model was evaluated in an independent study population including 1,370 cases and 1,239 controls.RESULTS: The polygenic risk score with 65 established susceptibility variants provided an area under the curve (AUC) of 0.67. Adding an additional 68 novel variants significantly increased the AUC to 0.68 (P = 0.0012) and the net reclassification index with 0.21 (P = 8.5E-08). All novel variants were located in genomic regions established as associated with prostate cancer risk.CONCLUSIONS: Inclusion of additional genetic variants from established prostate cancer susceptibility regions improves disease prediction.
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| 5. |
- Toennis, Tobias, et al.
(författare)
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The influence of atrial high-rate episodes on stroke and cardiovascular death : an update
- 2023
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Ingår i: Europace. - : Oxford University Press. - 1099-5129 .- 1532-2092. ; 25:7
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Tidskriftsartikel (refereegranskat)abstract
- Atrial high-rate episodes (AHRE) are atrial tachyarrhythmias detected by continuous rhythm monitoring by pacemakers, defibrillators, or implantable cardiac monitors. Atrial high-rate episodes occur in 10-30% of elderly patients without atrial fibrillation. However, it remains unclear whether the presence of these arrhythmias has therapeutic consequences. The presence of AHRE increases the risk of stroke compared with patients without AHRE. Oral anticoagulation would have the potential to reduce the risk of stroke in patients with AHRE but is also associated with a rate of major bleeding of & SIM;2%/year. The stroke rate in patients with AHRE appears to be lower than the stroke rate in patients with atrial fibrillation. Wearables like smart-watches will increase the absolute number of patients in whom atrial arrhythmias are detected. It remains unclear whether anticoagulation is effective and, equally important, safe in patients with AHRE. Two randomized clinical trials, NOAH-AFNET6 and ARTESiA, are expected to report soon. They will provide much-needed information on the efficacy and safety of oral anticoagulation in patients with AHRE.
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| 6. |
- Vijgen, Johan, et al.
(författare)
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Consensus statement of the European Heart Rhythm Association: updated recommendations for driving by patients with implantable cardioverter defibrillators
- 2009
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 11:8, s. 1097-1107
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Forskningsöversikt (refereegranskat)abstract
- Patients with an implantable cardioverter defibrillator (ICD) have an ongoing risk of sudden incapacitation that might cause harm to others while driving a car. Driving restrictions vary across different countries in Europe. The most recent recommendations for driving of ICD patients in Europe were published in 1997 and focused mainly on patients implanted for secondary prevention. In recent years there has been a vast increase in the number of patients with an ICD and in the percentage of patients implanted for primary prevention. The EHRA task force on ICD and driving was formed to reassess the risk of driving for ICD patients based on the literature available. The recommendations are summarized in the following table and are further explained in the document.
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| 7. |
- Vijgen, Johan, et al.
(författare)
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Consensus statement of the European Heart Rhythm Association: Updated recommendations for driving by patients with implantable cardioverter defibrillators
- 2010
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Ingår i: European Journal of Cardiovascular Nursing. - : Oxford University Press (OUP). - 1474-5151 .- 1873-1953. ; 9:1, s. 3-14
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Tidskriftsartikel (refereegranskat)abstract
- Patients with an implantable cardioverter defibrillator (ICD) have in ongoing risk of sudden incapacitation that might cause harm to others while driving a car. Driving restrictions vary across different countries in Europe. The most recent recommendations for driving of ICD patients in Europe were published in 1997 and focused mainly oil patients implanted for secondary prevention. In recent years there has been a vast increase in the number of patients with all ICD and in the percentage of patients implanted for primary prevention. The EHRA task force oil ICD and driving was formed to reassess the risk of driving for ICD patients based oil the literature available. The recommendations are summarized in the following table and are further explained in the document. [GRAPHICS] Driving restrictions are perceived as difficult for patients and their families, and have an immediate consequence for their lifestyle. To increase the adherence to the driving restrictions, adequate discharge of education and follow-up of patients and family are pivotal. The task force members hope this document may serve as an instrument for European and national regulatory authorities to formulate uniform driving regulations. (C) 2010 European Society of Cardiology. Published by Elsevier B.V. All fights reserved.
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