12 research outputs found

    Telecommunications Demand and Pricing Structure: An Econometric Analysis

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    International audienceThe main objective of this paper is to analyse residential demand by traffic destination, using a translogarithmic indirect utility function. We focus on five traffic directions, in order to construct a model adapted to evaluate the characteristics of telecommunications demand in a competitive market. The resulting price elasticities express high reactivity to own price changes for the main traffic directions, as well as little interactions between the different types of traffic. Moreover, the high values of income elasticities confirm the importance of income effects when analysing residential telecommunications demand. This model shows useful for welfare analysis. The computation of customers' income equivalent variation shows, on average, a higher willingness to pay for some traffic directions than the bill actually paid. Finally, we show that the optimal prices for the operator, in a cost minimisation point of view, are higher than the observed prices for local and national traffic directions. This emphasises the existence of important cross-subsidies among the different segments of customers

    Right ventricular outflow tract prestenting with AndraStent XXL before percutaneous pulmonary valve implantation

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    BACKGROUND: The indications for percutaneous pulmonary valve implantation (PPVI) have been extended to include large dysfunctional right ventricular outflow tracts (RVOTs). Prestenting of the RVOT is commonly performed before PPVI in order to ensure a stable landing zone. The AndraStent XXL (AndraMed GmbH, Reutlingen, Germany), a cobalt-chromium stent with semi-open cell design, has unique mechanical properties in this indication but is no longer available in France. AIMS: To assess the efficiency of AndraStent XXL before PPVI. METHODS: In this retrospective multicentre cohort study, 86 AndraStents XXL were implanted in 77 patients in 6 centres. RESULTS: PPVI was indicated mainly for pulmonary regurgitation (75.3%) in native or patched RVOT (88.3%). The stents were manually mounted on balloon catheters and delivered through sheaths using a conventional femoral approach. PPVI was performed successfully in 97.4% of patients after successful prestenting, generally during the same procedure (77.9%). There were no deaths associated with stent implantation, and four patients experienced five complications, mainly stent embolization, including one requiring surgery. Neither stent fracture nor dysfunction were observed in any patient during a mean follow-up of 19.2±8.7months. Stent analysis showed an excellent maximal stent expansion (97.1%) regardless of balloon size. A 22.3%±3.4 stent shortening with a 30mm balloon was observed. CONCLUSIONS: Implantation of large cobalt-chromium AndraStent XXL stents is efficient for prestenting before PPVI.status: publishe

    Efficacy of phosphodiesterase type 5 inhibitors in univentricular congenital heart disease: the SV‐INHIBITION study design

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    International audienceAims: In univentricular hearts, selective lung vasodilators such as phosphodiesterase type 5 (PDE5) inhibitors would decrease pulmonary resistance and improve exercise tolerance. However, the level of evidence for the use of PDE5 inhibitors in patients with a single ventricle (SV) remains limited. We present the SV-INHIBITION study rationale, design, and methods.Methods and results: The SV-INHIBITION trial is a nationwide multicentre, randomized, double blind, placebo-controlled, Phase III study, aiming to evaluate the efficacy of sildenafil on the ventilatory efficiency during exercise, in teenagers and adult patients (>15 years old) with an SV. Patients with a mean pulmonary arterial pressure >15 mmHg and a trans-pulmonary gradient >5 mmHg, measured by cardiac catheterization, will be eligible. The primary outcome is the variation of the VE/VCO2 slope, measured by a cardiopulmonary exercise test, between baseline and 6 months of treatment. A total of 50 patients are required to observe a decrease of 5 ± 5 points in the VE/VCO2 slope, with a power of 90% and an alpha risk of 5%. The secondary outcomes are clinical outcomes, oxygen saturation, 6 min walk test, SV function, NT-proBNP, peak VO2 , stroke volume, mean pulmonary arterial pressure, trans-pulmonary gradient, SF36 quality of life score, safety, and acceptability.Conclusions: The SV-INHIBITION study aims to answer the question whether PDE5 inhibitors should be prescribed in patients with an SV. This trial has been built focusing on the three levels of research defined by the World Health Organization: disability (exercise tolerance), deficit (SV function), and handicap (quality of life).Trial registration: ClinicalTrials.gov NCT03997097
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