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Experimental results of using a semiconductor optical amplifier (SOA) for amplification of a coherent optical-orthogonal frequency-division-multiplexing (CO-OFDM) transmission system are presented. The impact of the SOA nonlinearities on the amplification of a 10.94-Gb/s quadrature phase-shift keying CO-OFDM signal with respect to the input power, the signal wavelength, and the number of subcarriers is investigated. [ABSTRACT FROM PUBLISHER]

In this paper, we present a full spectro-polarimetric characterization of the Amplified Spontaneous Emission (ASE) emitted from a commercial, strained-bulk Semiconductor Optical Amplifier (SOA). A partly polarised, broadband noise source that draws from the same carrier reservoir as the amplified signal, ASE affects the state of polarisation of the overall outgoing signal of a SOA and its polarimetric behaviour is thus of interest. This study was carried out within the frame of the Stokes formalism, which not only allows a determination of the degree of polarisation (DOP) of ASE directly from its Stokes vector, but also gives access to a full, spectrally resolved characterization of its polarised fraction with respect to the applied bias current. Even when that fraction is small, its state of polarisation was shown to be strongly governed by the spectral dependence of the material gain upon polarisation. The same study was performed with a fully polarised signal injected into the SOA.

After first episodes of venous thromboembolism (VTE), patients are at increased risk of recurrent VTE and arterial thrombotic events (ATE) compared with the general population, two disorders that are influenced by anticoagulation. However, risk factors of these conditions occurring during and after anticoagulation are little described. Using cause-specific hazard regression models, we aimed to determine risk factors of the composite outcome recurrent VTE/ATE, and separately recurrent VTE or ATE, during and after anticoagulation in patients with first episodes of VTE from a prospective cohort. Hazard ratios (HRs) are given with 95% confidence intervals (CIs). A total of 2,011 patients treated for at least 3 months were included. A total of 647 patients had recurrent VTE/ATE (incidence: 4.69% per patient-years) during overall follow-up (median: 92 months). Of these events, 173 occurred during anticoagulation (incidence: 3.67% per patient-years). Among patients free of events at the end of anticoagulation, 801 had a post-anticoagulation follow-up ≥3 months; and 95 had recurrent VTE/ATE (incidence: 1.27% per patient-years). After adjustment for confounders, cancer-associated VTE (HR: 2.64, 95% CI: 1.70-4.11) and unprovoked VTE (HR: 1.95, 95% CI: 1.35-2.81) were the identified risk factors of recurrent VTE/ATE during anticoagulation (vs. transient risk factor-related VTE). Risk factors of recurrent VTE/ATE after anticoagulation included 50 to 65 years of age (vs. < 50, HR: 1.99, 95% CI: 1.04-3.81), older than 65 years (vs. < 50, HR: 5.28, 95% CI: 3.03-9.21), and unprovoked VTE (vs. transient risk factor-related VTE, HR: 2.06, 95% CI: 1.27-3.34). Cancer-associated VTE and unprovoked VTE are the main risk factors of recurrent VTE/ATE during anticoagulation, while older age and unprovoked VTE mainly predict the risk of these events after anticoagulation., Competing Interests: F.C. reports having received research grant support from Pfizer and fees for board memberships or symposia from Bayer and Astra Zeneca and having received travel support from Bayer, Daiichi Sankyo, Leo Pharma, InterMune, and Actelion. All other authors declare that they have no competing interests related to this study., (Thieme. All rights reserved.)

Background: It was recently established that patients who developed VTE are at increased risk of major adverse cardiovascular events (MACE) compared with the general population. However, whether the anticoagulation used for VTE influences the risk of MACE remains undescribed., Research Question: Does the anticoagulant treatment for VTE affect the risk of subsequent MACE?, Study Design and Methods: This study included patients from a large prospective cohort who received only one family of anticoagulant treatment after the acute phase of VTE, including vitamin K antagonist (VKAs) and direct oral anticoagulants (DOACs). MACE included nonfatal acute coronary syndrome, nonfatal stroke, and all-cause death. The secondary outcome, MACE-2, included cardiovascular death instead of all-cause death. Cox proportional and Fine-Gray models served to study the relationship between anticoagulation characteristics and the risk of outcomes., Results: A total of 3,790 patients (47.2% male; mean age, 60.48 years) were included. A total of 1,228 patients (32.4%) were treated for 0 to 3 months (median in overall population, 6 months). Compared with these patients, those treated for 3 to 12 months (hazard ratio [HR], 0.64; 95% CI, 0.54-0.76) or > 12 months (HR, 0.47, 95% CI, 0.39-0.56) had a significant reduced risk of MACE following adjustment for confounders. Findings were similar for MACE-2 (sub-HR for 3-12 months, 0.61 [95% CI, 0.47-0.79]; sub-HR > 12 months, 0.52 [95% CI, 0.39-0.68]). After adjustment for confounders, there was a reduced risk of MACE (HR, 0.53; 95% CI, 0.39-0.71) and MACE-2 (sub-HR, 0.48; 95% CI, 0.29-0.77) in patients treated with DOACs (vs VKAs)., Interpretation: Treatment of VTE for > 3 months is associated with a reduced risk of MACE, as is treatment with DOACs vs VKAs. These findings, which may influence the choice of anticoagulation strategies for VTE, need confirmation by randomized clinical trials., (Copyright © 2022 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background:  Cardiovascular deaths (CVDTs) are more frequent in patients with venous thromboembolism (VTE) than in the general population; however, risk factors associated with this increased risk of CVDT in patients with VTE are not described., Methods:  To determine the risk factors of CVDT in patients with VTE from a multicenter prospective cohort study, Fine and Gray subdistribution hazard models were conducted., Results:  Of the 3,988 included patients, 426 (10.7%) died of CVDT during a median follow-up of 5 years. The risk factors of CVDT after multivariate analyses were: age of 50 to 65 years (vs. <50 years, hazard ratio [HR]: 3.22, 95% confidence interval [CI]: 1.67-6.62), age >65 years (vs. <50 years, HR: 7.60, 95% CI: 3.73-15.52), cancer-associated VTE (vs. transient risk factor-related VTE, HR: 1.73, 95% CI: 1.15-2.61), unprovoked VTE (vs. transient risk factor-related VTE, HR: 1.42, 95% CI: 1.02-2.00), past tobacco use (vs. never, HR: 1.43, 95% CI: 1.06-1.94), current tobacco use (vs. never, HR: 1.87, 95% CI: 1.15-3.01), hypertension (HR: 2.11, 95% CI: 1.51-2.96), chronic heart failure (HR: 2.28, 95% CI: 1.37-3.79), chronic respiratory failure (HR: 1.72, 95% CI: 1.02-2.89), and atrial fibrillation (HR: 1.67, 95% CI: 1.06-2.60). The risk of CVDT was significantly reduced with direct oral anticoagulants (vs. vitamin-K antagonists) and with longer duration of treatment (>3 months)., Conclusion:  Risk factors of CVDT after VTE include some traditional cardiovascular risk factors and other risk factors that are related to characteristics of VTE, and patients' comorbidities., Competing Interests: F.C. reports having received research grant support from Pfizer and fees for board memberships or symposia from Bayer and Astra-Zeneca and having received travel support from Bayer, Daiichi Sankyo, Leo Pharma, InterMune, and Actelion. All other authors declare that they have no competing interests related to this study., (Thieme. All rights reserved.)

Background: We aimed to validate and to refine current recurrent venous thromboembolism (VTE) risk classification., Methods: We performed a post hoc analysis of a multicentre cohort including 1881 patients with a first symptomatic VTE prospectively followed after anticoagulation discontinuation. The primary objective was to validate the International Society of Thrombosis and Haemostasis (ISTH) risk classification in predicting recurrence risk. The secondary objective was to evaluate a refined ISTH classification based on the recurrence risk estimate for each individual risk factor., Results: During a 4.8-year median follow-up after anticoagulation discontinuation, symptomatic recurrent VTE occurred in 230 patients (12.2%). Based on the ISTH classification, patients with unprovoked VTE or VTE with minor or major persistent risk factors had a 2-fold increased recurrence risk compared with those with VTE and major transient risk factors. Recurrence risk was not increased in patients with minor transient factors (hazard ratio (HR) 1.31, 95% CI 0.84-2.06). Individual risk factors analysis identified hormone-related VTE (pregnancy: HR 0.26, 95% CI 0.08-0.82; oestrogens: HR 0.25, 95% CI 0.14-0.47) and amyotrophic lateral sclerosis (HR 5.84, 95% CI 1.82-18.70). After reclassification of these factors as major transient for the former and major persistent for the latter, the modified ISTH classification allowed us to accurately discriminate between patients at low risk of recurrence ( i.e. with major transient risk factors) and those at high risk of recurrence ( i.e. without major transient risk factors)., Conclusions: Among patients who stopped anticoagulation after a first VTE, a refined ISTH classification based on recurrence risk intensity of individual factors allowed discrimination between patients at low recurrence risk, including hormonal exposure in women, and patients at high recurrence risk., Competing Interests: Conflict of interest: D. Jimenez has served as an advisor or consultant for Bayer HealthCare Pharmaceuticals, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi Sankyo, Leo Pharma, Pfizer, ROVI and Sanofi; served as a speaker or a member of a speakers’ bureau for Bayer HealthCare Pharmaceuticals, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi Sankyo, Leo Pharma, ROVI and Sanofi; received grants for clinical research from Daiichi Sankyo, Sanofi and ROVI. E. Le Moigne reports having received research grants from Leo Pharma. C. Leroyer reports having received research grant support from Pfizer and fees for board memberships or symposia from Bayer and AstraZeneca and having received travel support from Bayer, Daiichi Sankyo, Leo Pharma, Intermune and Actelion. K. Lacut reports having received personal fees from Bayer Health Care, Bristol-Myers Squibb and Boehringer Ingelheim. F. Couturaud reports having received research grant support from Pfizer and fees for board memberships or symposia from Bayer, Bristol-Myers Squibb/Pfizer and AstraZeneca, and having received travel support from Bayer, Bristol-Myers Squibb/Pfizer, Boehringer Ingelheim, Leo Pharma and Actelion. The remaining authors declare no conflict of interest related to this research., (Copyright ©The authors 2022. For reproduction rights and permissions contact permissions@ersnet.org.)

Background:  There is an increased risk of arterial events including major adverse cardiovascular events (MACE) and major adverse limb events (MALE) after venous thromboembolism (VTE). However, their risk factors remain little explored., Methods:  We aimed to determine the risk factors for MACE (acute coronary syndrome/stroke/cardiovascular death) and MALE (limb ischemia/critical limb ischemia/non-traumatic amputation/any limb revascularization) after VTE. Competing risk models (Fine-Gray) were used in a multicenter prospective cohort of 4,940 patients (mean age: 64.6 years and median follow-up: 64 months)., Results:  MACE occurred in 17.3% of participants (2.35% per patient-years) and MALE in 1.7% (0.27% per patient-years). In multivariable analysis, the identified risk factors for MACE were the age of 50 to 65 years (vs. <50 years, hazard ratio [HR]: 2.00, 95% confidence interval [CI]: 1.38-2.91), age >65 years (vs. <50 years, HR 4.85, 95% CI: 3.35-7.02), pulmonary embolism + deep vein thrombosis (DVT) (vs. isolated-DVT, HR: 1.25, 95% CI: 1.02-1.55), unprovoked-VTE (vs. transient risk factor associated-VTE, HR: 1.29, 95% CI: 1.04-1.59), current tobacco use (vs. never, HR: 1.45, 95% CI: 1.07-1.98), hypertension (HR: 1.61, 95% CI: 1.30-1.98), past history of symptomatic atherosclerosis (HR: 1.52, 95% CI: 1.17-1.98), heart failure (HR: 1.71, 95% CI: 1.21-2.42), atrial fibrillation (HR: 1.55, 95% CI: 1.15-2.08), and vena cava filter insertion (HR: 1.46, 95% CI: 1.03-2.08). The identified risk factors for MALE were the age of 50-65 years (vs. <50 years, HR: 3.49, 95% CI: 1.26-9.65) and atrial fibrillation (HR: 2.37, 95% CI: 1.15-4.89)., Conclusions:  Risk factors for MACE and MALE after VTE included some traditional cardiovascular risk factors, patient's comorbidities, and some characteristics of VTE., Competing Interests: None declared., (Thieme. All rights reserved.)

Introduction: The increased risk of arterial thrombotic (ATE) after VTE, particularly when they are unprovoked or cancer-associated has been established. However, the risk factors of ATE after these VTE remain unclear., Material and Methods: Using cause-specific hazard regression models, we determined risk factors of ATE (myocardial infarction, ischemic stroke, acute limb ischemia, digestive tract ischemia, or renal ischemia) in 2242 patients with unprovoked VTE and in 914 patients with cancer-associated VTE from a multi-center prospective cohort., Results: Of patients with unprovoked-VTE, 174 developed ATE (7.8%, incidence: 1.26 per 100 patient-years) during follow-up (median: 68 months). Among patients with cancer-associated VTE, 57 developed ATE (6.2%, incidence: 1.98 per 100 patient-years) during follow-up (median: 30 months). After multivariable analysis, the identified risk factors of ATE in patients with unprovoked-VTE were age > 65 years (vs. <50 years, HR 2.59, 95% CI: 1.56-4.29), past history of symptomatic atherosclerosis (HR 2.11, 95% CI: 1.40-3.19), and treatment with low molecule weight heparin (vs. vitamin K antagonists, HR: 2.26, 95% CI: 1.13-4.52). In patients with cancer-associated VTE, the identified risk factors of ATE were: past history of symptomatic atherosclerosis (HR: 3.13, 95% CI: 1.72-5.67), and ongoing anticoagulation at the diagnosis of VTE (HR: 2.77, 95% CI: 1.07-7.22)., Conclusions: The risk of ATE after unprovoked VTE and after cancer-associated VTE, is determined by some classic cardiovascular risk factors and appears to be influenced by anticoagulant treatment introduced for VTE, as well as the presence or absence of ongoing anticoagulation at the diagnosis of VTE., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Women with a previous venous thromboembolism (VTE) are at risk of recurrence during pregnancy., Objectives: We aimed to assess the incidence rate of recurrent VTE during pregnancy, according to the period of pregnancy, and the clinical parameters associated with recurrence, in a prospective cohort of women of childbearing age after a first VTE., Patients/methods: A total of 189 women aged 15-49 years with a first documented VTE were followed until a subsequent pregnancy of at least 20 weeks' gestation between 2000 and 2020. VTE recurrences during pregnancy were recorded, as were potential clinical risk factors for recurrence., Results: Recurrent VTE occurred in six women during antepartum: five during the first trimester (incidence rate 106.4 per 1000 women-years) (95% confidence interval [CI] 46.3-226.0); none during the second trimester; and one during the third trimester (incidence rate 27.0 per 1000 women-years [95% CI 4.8-138.2]). During postpartum, recurrences occurred in 11 women (incidence rate 212.8 per 1000 women-years [95% CI 119.9-349.1]). These 17 recurrent VTEs presented as pulmonary embolism ± deep vein thrombosis (DVT) in five patients and isolated DVT in 12. Failure of thromboprophylaxis occurred in two cases (33.3%) antepartum and in 10 cases (90.9%) postpartum. In multivariable analysis, only obesity (defined on prepregnancy body mass index) was associated with recurrent VTE (odds ratio 3.34 [95% CI 1.11-10.05, p = .03])., Conclusions: This study confirms a high risk of recurrent VTE postpartum, despite thromboprophylaxis, in women with a previous VTE. Only obesity was associated with VTE recurrence during pregnancy, suggesting that low-dose anticoagulation might not be appropriate in obese pregnant women., (© 2022 International Society on Thrombosis and Haemostasis.)

Background: Growing evidence suggests the relationship between obstructive sleep apnea (OSA) and venous thromboembolism (VTE). Few studies focused on VTE recurrence risk associated with OSA after anticoagulation cessation., Methods: In a prospective cohort study, patients with documented VTE, were followed for an indefinite length of time and VTE recurrence were documented and adjudicated. The primary outcome was recurrent VTE after anticoagulation discontinuation. Secondary outcomes included all-cause mortality and the clinical presentation of VTE. Univariable and multivariable analyses were performed to identify risk factors for recurrence and mortality., Results: Among the 2109 patients with documented VTE included, 74 patients had moderate to severe OSA diagnosis confirmed by home sleep test or polysomnography. During a median follow-up of 4.8 (interquartile range 2.5-8.0) years recurrent VTE occurred in 252 patients (9 with OSA and 243 without OSA). The recurrence risk in the univariable and multivariable analysis was not increased in patients with OSA, regardless of the time of diagnosis (before or after index VTE or pooled). VTE phenotype was significantly more often PE with or without associated deep vein thrombosis in the first event and recurrence for OSA patients compared to non-OSA patients. The risk of death was not increased in the OSA population compared to non-OSA patients in multivariable analysis., Conclusions: In patients with OSA and VTE, the risk of all-cause mortality and VTE recurrence after anticoagulation discontinuation was not increased compared to non-OSA patients., (© 2021. The Author(s).)

Interstitial lung disease (ILD) encompasses various parenchymal lung disorders, which has the potential to increase the risk of venous thromboembolism (VTE). To evaluate, in patients with ILD and VTE, the risk of recurrent VTE during follow-up after stopping anticoagulation. This was a cohort of patients with a first VTE recruited between 1997 and 2015. The primary outcome was adjudicated fatal or nonfatal recurrent VTE after stopping anticoagulation. Main secondary outcomes were major or clinically relevant non-major bleeding under anticoagulation. Among 4314 patients with VTE, 50 had ILD diagnosed before VTE. Of these, anticoagulation was stopped in 30 patients after a median duration of 180 days and continued indefinitely in 20 patients. During a median follow-up of 27.8 months after anticoagulation discontinuation, recurrent VTE occurred in 15 on 30 patients (annual incidence of 19.2 events per 100-person-years [95%CI 12.0-29.3], case-fatality rate of 6.7% [95%CI 1.21-29.8]). The risk of recurrence was threefold higher when VTE was unprovoked and case-fatality rate of recurrence was increased by 3 when VTE index was PE. During the anticoagulant period, (median duration of 8.6 months), 6 patients had a major or clinically relevant bleeding (annual incidence of 7.3 events per 100-person-years [95%CI 3.4-15.1], case-fatality rate of 16.7% [95%CI 3.0-56.4]). In patients with ILD, the risk of recurrent VTE after stopping anticoagulation and the risk of bleeding under anticoagulation were very high. Our results suggest that anticoagulation should not be prolonged beyond 3-6 months of anticoagulation in most of cases., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background:  We aimed to assess whether high pulmonary vascular obstruction index (PVOI) measured at the time of pulmonary embolism (PE) diagnosis is associated with an increased risk of recurrent venous thromboembolism (VTE)., Study Design and Methods:  French prospective cohort of patients with a symptomatic episode of PE diagnosed with spiral computerized tomography pulmonary angiography (CTPA) or ventilation-perfusion (V/Q) lung scan and a follow-up of at least 6 months after anticoagulation discontinuation. PVOI was assessed based on the available diagnostic exam (V/Q lung scan or CTPA). All patients had standardized follow-up and independent clinicians adjudicated all deaths and recurrent VTE events. Main outcome was recurrent VTE after stopping anticoagulation., Results:  A total of 418 patients with PE were included. During a median follow-up period of 3.6 (1.2-6.0) years, 109 recurrences occurred. In multivariate analysis, PVOI ≥ 40% was an independent risk factor for recurrence (hazard ratio 1.77, 95% confidence interval 1.20-2.62, p  < 0.01), whether PE was provoked by a major transient risk factor or not. A threshold at 41% was identified as the best value associated with the risk of recurrence 6 months after stopping anticoagulation (area under curve = 0.64)., Conclusion:  PVOI ≥ 40% at PE diagnosis was an independent risk factor for recurrence VTE. Further prospective validation studies are needed., Competing Interests: F.C. reports having received research grant support from Pfizer and fees for board memberships or symposia from Bayer and Astra Zeneca and having received travel support from Bayer, Daiichi Sankyo, Leo Pharma, Intermune, and Actelion. C.O. declares he has no conflict of interest related to this research. C.T. declares she has no conflict of interest related to this research. P.R. declares he has no conflict of interest related to this research. R.L.M. declares he has no conflict of interest related to this research. P.-Y.L.R. declares he has no conflict of interest related to this research. P.-Y.S. declares he has no conflict of interest related to this research. C.H. declares he has no conflict of interest related to this research. L.B. declares he has no conflict of interest related to this research. P.-Y.L.F. declares he has no conflict of interest related to this research. M.N. declares he has no conflict of interest related to this research. M.G. declares she has no conflict of interest related to this research. E.P. declares she has no conflict of interest related to this research. C.A.L. declares she has no conflict of interest related to this research. K.L. reports having received personal fees from Bayer-Health Care, Bristol-Myers Squibb, and Boehringer Ingelheim. C.L. reports having received research grant support from Pfizer and fees for board memberships or symposia from Bayer and Astra Zeneca and having received travel support from Bayer, Daiichi Sankyo, Leo Pharma, Intermune, and Actelion. No other potential conflict of interest relevant to this article was reported., (Thieme. All rights reserved.)