Clinical and prognostic implications of phenomapping in patients with heart failure receiving cardiac resynchronization therapy

Despite having an indication for cardiac resynchronization therapy according to current guidelines, patients with heart failure with reduced ejection fraction who receive cardiac resynchronization therapy do not consistently derive benefit from it.; To determine whether unsupervised clustering analysis (phenomapping) can identify distinct phenogroups of patients with differential outcomes among cardiac resynchronization therapy recipients from routine clinical practice.; We used unsupervised hierarchical cluster analysis of phenotypic data after data reduction (55 clinical, biological and echocardiographic variables) to define new phenogroups among 328 patients with heart failure with reduced ejection fraction from routine clinical practice enrolled before cardiac resynchronization therapy. Clinical outcomes and cardiac resynchronization therapy response rate were studied according to phenogroups.; Although all patients met the recommended criteria for cardiac resynchronization therapy implantation, phenomapping analysis classified study participants into four phenogroups that differed distinctively in clinical, biological, electrocardiographic and echocardiographic characteristics and outcomes. Patients from phenogroups 1 and 2 had the most improved outcome in terms of mortality, associated with cardiac resynchronization therapy response rates of 81% and 78%, respectively. In contrast, patients from phenogroups 3 and 4 had cardiac resynchronization therapy response rates of 39% and 59%, respectively, and the worst outcome, with a considerably increased risk of mortality compared with patients from phenogroup 1 (hazard ratio 3.23, 95% confidence interval 1.9-5.5 and hazard ratio 2.49, 95% confidence interval 1.38-4.50, respectively).; Among patients with heart failure with reduced ejection fraction with an indication for cardiac resynchronization therapy from routine clinical practice, phenomapping identifies subgroups of patients with differential clinical, biological and echocardiographic features strongly linked to divergent outcomes and responses to cardiac resynchronization therapy. This approach may help to identify patients who will derive most benefit from cardiac resynchronization therapy in "individualized" clinical practice

An experimental protocol to analyze the structure of nanoparticles deposit in pleats of industrial HEPA filters.

International audienceFire is one of the most probable hazards of internal aggression in a nuclear facility. For many years, IRSN is conducting research programs dealing with the impact of a fire on the behaviour of containment devices of radioactive materials such as High Efficiency Particulate Air (HEPA) filters. It has been already observed, in addition to the well-known regimes of in depth and surface filtration, that for a high deposited mass of nanometrics aerosols (mainly soot particles emitted in case of fire) and low filtration velocity, an additional pressure drop increase occurs for pleated HEPA filters used in the French nuclear industry (Mocho and Ouf 2011). Up to now, little information is available in the literature about this last regime of filtration. The most probable phenomenon is an unbalance in the aerosol repartition along the pleat which causes a reduction of the filtration surface (Del Fabbro et al., 2002). This paper deals with an experimental method to measure the repartition of deposited nanoparticles in the depth of a pleat using embedded samples and electronic microscopy. In this study, HEPA filters were clogged at various controlled filtration velocities on a test bench generating nanoparticles aggregates of Zinc/Aluminium denoting similarities in terms of size and morphology to soot particles emitted in case of fire (Mocho et al., 2011). A pleat of 20 mm in depth of the pleated filter was stabilized in a polymer resin (Schmidt et al., 1990) and deposited mass along the pleat was measured using electronic microscopy. Results show an influence of the filtration velocity on the deposit

An experimental protocol to analyze the structure of nanoparticles deposit in pleats of industrial HEPA filters.

International audienceFire is one of the most probable hazards of internal aggression in a nuclear facility. For many years, IRSN is conducting research programs dealing with the impact of a fire on the behaviour of containment devices of radioactive materials such as High Efficiency Particulate Air (HEPA) filters. It has been already observed, in addition to the well-known regimes of in depth and surface filtration, that for a high deposited mass of nanometrics aerosols (mainly soot particles emitted in case of fire) and low filtration velocity, an additional pressure drop increase occurs for pleated HEPA filters used in the French nuclear industry (Mocho and Ouf 2011). Up to now, little information is available in the literature about this last regime of filtration. The most probable phenomenon is an unbalance in the aerosol repartition along the pleat which causes a reduction of the filtration surface (Del Fabbro et al., 2002). This paper deals with an experimental method to measure the repartition of deposited nanoparticles in the depth of a pleat using embedded samples and electronic microscopy. In this study, HEPA filters were clogged at various controlled filtration velocities on a test bench generating nanoparticles aggregates of Zinc/Aluminium denoting similarities in terms of size and morphology to soot particles emitted in case of fire (Mocho et al., 2011). A pleat of 20 mm in depth of the pleated filter was stabilized in a polymer resin (Schmidt et al., 1990) and deposited mass along the pleat was measured using electronic microscopy. Results show an influence of the filtration velocity on the deposit

An experimental protocol to analyze the structure of nanoparticles deposit in pleats of industrial HEPA filters.

International audienceFire is one of the most probable hazards of internal aggression in a nuclear facility. For many years, IRSN is conducting research programs dealing with the impact of a fire on the behaviour of containment devices of radioactive materials such as High Efficiency Particulate Air (HEPA) filters. It has been already observed, in addition to the well-known regimes of in depth and surface filtration, that for a high deposited mass of nanometrics aerosols (mainly soot particles emitted in case of fire) and low filtration velocity, an additional pressure drop increase occurs for pleated HEPA filters used in the French nuclear industry (Mocho and Ouf 2011). Up to now, little information is available in the literature about this last regime of filtration. The most probable phenomenon is an unbalance in the aerosol repartition along the pleat which causes a reduction of the filtration surface (Del Fabbro et al., 2002). This paper deals with an experimental method to measure the repartition of deposited nanoparticles in the depth of a pleat using embedded samples and electronic microscopy. In this study, HEPA filters were clogged at various controlled filtration velocities on a test bench generating nanoparticles aggregates of Zinc/Aluminium denoting similarities in terms of size and morphology to soot particles emitted in case of fire (Mocho et al., 2011). A pleat of 20 mm in depth of the pleated filter was stabilized in a polymer resin (Schmidt et al., 1990) and deposited mass along the pleat was measured using electronic microscopy. Results show an influence of the filtration velocity on the deposit

Etude de la phase de filtration profonde et de la transition vers la phase de filtration en surface pour des filtres THE colmatés avec des aérosols nanométriques

National audienc

Ситуации запрета в аспекте повседневности

Запрет – одно из первых общекультурных понятий в истории человечества, которое может трактоваться как организующее начало, поскольку момент структурирования содержит в себе и функцию ограничения. Современному обществу приписываются че-тыре базовые ситуации запрета (запреты на секс, власть, агрессию и творчество

Etude de la phase de filtration profonde et de la transition vers la phase de filtration en surface pour des filtres THE colmatés avec des aérosols manométriques

National audienceLa majorité des techniques de traitement de l'air passent par l'utilisation de media fibreux à base de fibres de verre du fait de leur simplicité de mise en oeuvre et de leur bon rapport prix/performance. En outre, leur application dans des secteurs spécifiques, comme l'industrie nucléaire, nécessite une très haute efficacité de filtration et une grande fiabilité. En cas d'incendie, la production de particules de suies de très faibles dimensions engendre un colmatage très rapide des filtres, susceptible de conduire à leur altération. La prédiction de la perte de charge est donc un élément important pour le maintien de la fonction de sûreté des dispositifs de ventilation et de confinement. La présente étude vise à proposer une approche afin de modéliser plus fidèlement le colmatage des filtres THE par des aérosols nanométriques. Pour cela, un générateur de nanoparticules Palas GFG 1000 monté sur une veine aéraulique permet le colmatage de différents media plans (THE et HE). Des techniques d'analyse et d'observation spécifiques (enrobage d'échantillons dans une matrice polymérisée et observation de coupes de media colmatés couplée à une analyse EDX) sont utilisées pour comprendre la phénoménologie en vue de proposer des pistes pour l'établissement d'un modèle prédictif de la perte de charge des filtres THE par des aérosols nanométriques jusqu'à la formation du gâteau

Measurement of the Nanoparticles Distribution in Flat and Pleated Filters During Clogging

International audienceIt is currently admitted that for each filtration process using pleated filters, at least three steps can be distinguished: depth and surface filtration, which are common to flat filters, and surface reduction. This step is caused by inefficient filling of the pleat due to the filter geometry. For combustion aerosol, it has been proved that this third step strongly depends on the filtration velocity resulting in an increase of the resistance when air flow decreases. This observation leads one to think that Brownian diffusion, higher for low velocities, could influence the clogging dynamic of a pleated filter. In this article, a protocol derived from the dust cake preparation method published by Schmidt is developed. The aim of this study is to measure the aerosol penetration inside a filter media as well as in a pleat using a scanning electronic microscope and energy dispersive X-ray spectroscopy elementary detection. This method has also been extended to the study of pleated filters to measure the particle distribution inside the pleat. Filters were loaded with nanoparticles in order to evaluate the specificity of the diffusional regime on the clogging of pleated HEPA filters. For pleated filters, two filtration velocities were investigated: 2.5 and 0.2 cm/s

Clinical significance of energy loss index in patients with low-gradient severe aortic stenosis and preserved ejection fraction

We hypothesized that among patients with low-gradient severe aortic stenosis (AS) and preserved left ventricular ejection fraction (LVEF), reclassification of AS severity as moderate by pressure recovery adjusted indexed aortic valve area (AVAi) = energy loss index (ELI), may identify a subgroup of patients with a better outcome.; Three hundred and seventy-nine patients with low-gradient AS (defined by AVAi ≤ 0.6 cm2/m2 and mean aortic pressure gradient 0.6 cm2/m2. Cardiac events [cardiac mortality and/or need for aortic valve replacement (AVR)] during follow-up were studied. One hundred and forty-eight patients (39%) were reclassified as moderate AS by ELI. Reclassification as moderate AS was independently associated with decreased body surface area, normal flow status, decreased left ventricular mass index, and left atrial volume index (all P < 0.05). After adjustment for variables of prognostic interest, reclassification as moderate AS by ELI was associated with a considerable reduction of risk of cardiac events {adjusted hazard ratio (HR) 0.49 [95% confidence interval (CI) 0.33-0.72]; P < 0.001}, need for AVR [adjusted HR 0.52 (95% CI 0.34-0.81); P = 0.004], and cardiac mortality [adjusted HR 0.46 (95% CI 0.22-0.98); P = 0.044].; In patients with low-gradient severe AS and preserved LVEF, calculation of ELI permits to reclassify almost 40% of patients as having moderate AS. These reclassified patients have a considerable reduction of the risk of cardiac events during follow-up. Calculation of ELI is useful for decision-making in patients with low-gradient severe AS and preserved ejection fraction