114 research outputs found
Impact of an interatrial shunt device on survival and heart failure hospitalization in patients with preserved ejection fraction
Aims:
Impaired left ventricular diastolic function leading to elevated left atrial pressures, particularly during exertion, is a key driver of symptoms and outcomes in heart failure with preserved ejection fraction (HFpEF). Insertion of an interatrial shunt device (IASD) to reduce left atrial pressure in HFpEF has been shown to be associated with shortâterm haemodynamic and symptomatic benefit. We aimed to investigate the potential effects of IASD placement on HFpEF survival and heart failure hospitalization (HFH).
Methods and results:
Heart failure with preserved ejection fraction patients participating in the Reduce Elevated Left Atrial Pressure in Patients with Heart Failure study (Corvia Medical) of an IASD were followed for a median duration of 739 days. The theoretical impact of IASD implantation on HFpEF mortality was investigated by comparing the observed survival of the study cohort with the survival predicted from baseline data using the Metaâanalysis Global Group in Chronic Heart Failure heart failure risk survival score. Baseline and postâIASD implant parameters associated with HFH were also investigated. Based upon the individual baseline demographic and cardiovascular profile of the study cohort, the Metaâanalysis Global Group in Chronic Heart Failure scoreâpredicted mortality was 10.2/100 pt years. The observed mortality rate of the IASDâtreated cohort was 3.4/100 pt years, representing a 33% lower rate (P = 0.02). By KaplanâMeier analysis, the observed survival in IASD patients was greater than predicted (P = 0.014). Baseline parameters were not predictive of future HFH events; however, poorer exercise tolerance and a higher workloadâcorrected exercise pulmonary capillary wedge pressure at the 6 months postâIASD study were associated with HFH.
Conclusions:
The current study suggests IASD implantation may be associated with a reduction in mortality in HFpEF. Largeâscale ongoing randomized studies are required to confirm the potential benefit of this therapy
A two-phase flow model to simulate mold filling and saturation in Resin Transfer Molding
The final publication is available at Springer via http://dx.doi.org/10.1007/s12289-015-1225-zThis paper addresses the numerical simulation of void formation and transport during mold filling in Resin Transfer Molding (RTM). The saturation equation, based on a two-phase flow model resin/air, is coupled with Darcy s law and mass conservation to simulate the unsaturated filling flow
that takes place in a RTM mold when resin is injected through the fiber bed. These equations lead to a system composed of an advection diffusion equation for saturation including capillary effects and an elliptic equation for pressure taking into account the effect of air residual saturation. The model introduces the relative permeability as a function of resin saturation. When capillary effects are omitted, the hyperbolic nature of the saturation equation and its strong coupling with Darcy
equation through relative permeability represent a challenging numerical issue. The combination of the constitutive physical laws relating permeability to saturation with the coupled system
of the pressure and saturation equations allows predicting the saturation profiles. The model was validated by comparison with experimental data obtained for a fiberglass reinforcement
injected in a RTM mold at constant flow rate. The saturation measured as a function of time during the resin impregnation of the fiber bed compared very well with numerical predictions.The authors acknowledge financial support of the Spanish Government (Projects DPI2010-20333 and DPI2013-44903-R-AR), of the National Science and Research Council of Canada (NSERC) and of the Canada Reseach Chair (CRC) program.GascĂłn MartĂnez, ML.; GarcĂa Manrique, JA.; Lebel, F.; Ruiz, E.; Trochu, F. (2016). A two-phase flow model to simulate mold filling and saturation in Resin Transfer Molding. International Journal of Material Forming. 9(2):229-239. doi:10.1007/s12289-015-1225-zS22923992Patel N, Lee LJ (1996) Modeling of void formation and removal in liquid composite molding. Part I: wettability analysis. Polym Compos 17(1):96â103Ruiz E, Achim V, Soukane S, Trochu F, BrĂŠard J (2006) Optimization of injection flow rate to minimize micro/macro-voids formation in resin transfer molded composites. Compos Sci Technol 66(3â4):475â486Trochu F, Ruiz E, Achim V, Soukane S (2006) Advanced numerical simulation of liquid composite molding for process analysis and optimization. Compos A: Appl Sci Manuf 37(6):890â902Park CH, Lee W (2011) Modeling void formation and unsaturated flow in liquid composite molding processes: a survey and review. J Reinf Plast Compos 30(11):957â977Pillai KM (2004) Modeling the unsaturated flow in liquid composite molding processes: a review and some thoughts. J Compos Mater 38(23):2097â2118Breard J, Saouab A, Bouquet G (2003) Numerical simulation of void formation in LCM. Compos A: Appl Sci Manuf 34:517â523Breard J, Henzel Y, Trochu F, Gauvin R (2003) Analysis of dynamic flows through porous media. Part I: comparison between saturated and unsaturated flows in fibrous reinforcements. Polym Compos 24(3):391â408Parnas RS, Phelan FR Jr (1991) The effect of heterogeneous porous media on mold filling in Resin Transfer Molding. SAMPE Q 22(2):53â60Parseval DY, Pillai KM, Advani SG (1997) A simple model for the variation of permeability due to partial saturation in dual scale porous media. Transp Porous Media 27(3):243â264Pillai KM (2002) Governing equations for unsaturated flow through woven fiber mats. Part 1. Isothermal flows. Compos A: Appl Sci Manuf 33(7):1007â1019Simacek P, Advani SG (2003) A numerical model to predict fiber tow saturation during Liquid Composite Molding. Compos Sci Technol 63:1725â1736GarcĂa JA, GascĂłn L, Chinesta F (2010) A flux limiter strategy for solving the saturation equation in RTM process simulation. Compos A: Appl Sci Manuf 41:78â82Chui WK, Glimm J, Tangerman FM, Jardine AP, Madsen JS, Donnellan TM, Leek R (1997) Process modeling in Resin Transfer Molding as a method to enhance product quality. SIAM Rev 39(4):714â727Nordlund M, Michaud V (2012) Dynamic saturation curve measurement for resin flow in glass fibre reinforcement. Compos A: Appl Sci Manuf 43:333â343GarcĂa JA, Ll G, Chinesta F (2003) A fixed mesh numerical method for modelling the flow in liquid composites moulding processes using a volume of fluid technique. Comput Methods Appl Mech Eng 192(7â8):877â893GarcĂa JA, Ll G, Chinesta F, Trochu F, Ruiz E (2010) An efficient solver of the saturation equation in liquid composite molding processes. Int J Mater Form 3(2):1295â1302Lebel F (2012) ContrĂ´le de la fabrication des composites par injection sur renforts. Ăcole Polytechnique de MontrĂŠal, CanadaVan Genuchten MT (1980) Closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am J 44(5):892â898Buckley SE, Leverett MC (1942) Mechanism of fluid displacement in sands. Pet Trans AWME 146:107â116Lundstrom TS, Gebart BR (1994) Influence from process parameters on void formation in Resin Transfer Molding. Polym Compos 15(1):25â33Lundstrom TS (1997) Measurement of void collapse during Resin Transfer Molding. Compos A: Appl Sci Manuf 28(3):201â214Lundstrom TS, Frishfelds V, Jakovics A (2010) Bubble formation and motion in non-crimp fabrics with perturbed bundle geometry. Compos A: Appl Sci Manuf 41:83â92Lebel F, Fanaei A, Ruiz E, Trochu F (2012) Experimental characterization by fluorescence of capillary flows in the fiber tows of engineering fabrics. Open J Inorg Non-Metallic Mater 2(3):25â45Brooks RH, Corey AT (1964) Hydraulic properties of porous media. Colorado State University. Hydrology Papers 1â37Corey AT (1954) The interrelation between gas and oil relative permeabilities. Prod Monthly 19(1):38â4
Mavacamten for treatment of symptomatic obstructive hypertrophic cardiomyopathy (EXPLORER-HCM): a randomised, double-blind, placebo-controlled, phase 3 trial
Experimental determination of the permeability of engineering textiles: Benchmark II
In this second international permeability benchmark, the in-plane permeability values of a carbon fabric were studied by twelve research groups worldwide. One participant also investigated the deformation of the tested carbon fabric. The aim of this work was to obtain comparable results in order to make a step toward standardization of permeability measurements. Unidirectional injections were thus conducted to determine the unsaturated in-plane permeability tensor of the fabric. Procedures used by participants were specified in the guidelines defined for this benchmark. Participants were asked to use the same values for parameters such as fiber volume fraction, injection pressure and fluid viscosity to minimize sources of scatter. The comparison of the results from each participant was encouraging. The scatter between data obtained while respecting the guidelines was below 25%. However, a higher dispersion was observed when some parameters differed from the recommendations of this exercise.The authors are grateful to J.M. Beraud from Hexcel Fabrics for his support that made possible this exercise. The contributions of J.B. Alms, N.C. Correia, S. Advani, E. Ruiz and P.C.T. Goncalves to the preparation of the guidelines document and templates are acknowledged by the participants of this benchmark.Vernet, N.; Ruiz, E.; Advani, S.; Alms, JB.; Aubert, M.; Barburski, M.; Barari, B.... (2014). Experimental determination of the permeability of engineering textiles: Benchmark II. Composites Part A: Applied Science and Manufacturing. 61:172-184. doi:10.1016/j.compositesa.2014.02.010S1721846
Atorvastatin Therapy during the Peri-Infarct Period Attenuates Left Ventricular Dysfunction and Remodeling after Myocardial Infarction
Although statins impart a number of cardiovascular benefits, whether statin therapy during the peri-infarct period improves subsequent myocardial structure and function remains unclear. Thus, we evaluated the effects of atorvastatin on cardiac function, remodeling, fibrosis, and apoptosis after myocardial infarction (MI). Two groups of rats were subjected to permanent coronary occlusion. Group II (nâ=â14) received oral atorvastatin (10 mg/kg/d) daily for 3 wk before and 4 wk after MI, while group I (nâ=â12) received equivalent doses of vehicle. Infarct size (Masson's trichrome-stained sections) was similar in both groups. Compared with group I, echocardiographic left ventricular ejection fraction (LVEF) and fractional area change (FAC) were higher while LV end-diastolic volume (LVEDV) and LV end-systolic and end-diastolic diameters (LVESD and LVEDD) were lower in treated rats. Hemodynamically, atorvastatin-treated rats exhibited significantly higher dP/dtmax, end-systolic elastance (Ees), and preload recruitable stroke work (PRSW) and lower LV end-diastolic pressure (LVEDP). Morphometrically, infarct wall thickness was greater in treated rats. The improvement of LV function by atorvastatin was associated with a decrease in hydroxyproline content and in the number of apoptotic cardiomyocyte nuclei. We conclude that atorvastatin therapy during the peri-infarct period significantly improves LV function and limits adverse LV remodeling following MI independent of a reduction in infarct size. These salubrious effects may be due in part to a decrease in myocardial fibrosis and apoptosis
Obesity, Ethnicity, and Risk of Critical Care, Mechanical Ventilation, and Mortality in Patients Admitted to Hospital with COVID-19: Analysis of the ISARIC CCP-UK Cohort
Risk of adverse outcomes in patients with underlying respiratory conditions admitted to hospital with COVID-19:a national, multicentre prospective cohort study using the ISARIC WHO Clinical Characterisation Protocol UK
Background Studies of patients admitted to hospital with COVID-19 have found varying mortality outcomes associated with underlying respiratory conditions and inhaled corticosteroid use. Using data from a national, multicentre, prospective cohort, we aimed to characterise people with COVID-19 admitted to hospital with underlying respiratory disease, assess the level of care received, measure in-hospital mortality, and examine the effect of inhaled corticosteroid use. Methods We analysed data from the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) WHO Clinical Characterisation Protocol UK (CCP-UK) study. All patients admitted to hospital with COVID-19 across England, Scotland, and Wales between Jan 17 and Aug 3, 2020, were eligible for inclusion in this analysis. Patients with asthma, chronic pulmonary disease, or both, were identified and stratified by age (<16 years, 16â49 years, and âĽ50 years). In-hospital mortality was measured by use of multilevel Cox proportional hazards, adjusting for demographics, comorbidities, and medications (inhaled corticosteroids, short-acting β-agonists [SABAs], and long-acting β-agonists [LABAs]). Patients with asthma who were taking an inhaled corticosteroid plus LABA plus another maintenance asthma medication were considered to have severe asthma. Findings 75â463 patients from 258 participating health-care facilities were included in this analysis: 860 patients younger than 16 years (74 [8¡6%] with asthma), 8950 patients aged 16â49 years (1867 [20¡9%] with asthma), and 65â653 patients aged 50 years and older (5918 [9¡0%] with asthma, 10â266 [15¡6%] with chronic pulmonary disease, and 2071 [3¡2%] with both asthma and chronic pulmonary disease). Patients with asthma were significantly more likely than those without asthma to receive critical care (patients aged 16â49 years: adjusted odds ratio [OR] 1¡20 [95% CI 1¡05â1¡37]; p=0¡0080; patients aged âĽ50 years: adjusted OR 1¡17 [1¡08â1¡27]; p<0¡0001), and patients aged 50 years and older with chronic pulmonary disease (with or without asthma) were significantly less likely than those without a respiratory condition to receive critical care (adjusted OR 0¡66 [0¡60â0¡72] for those without asthma and 0¡74 [0¡62â0¡87] for those with asthma; p<0¡0001 for both). In patients aged 16â49 years, only those with severe asthma had a significant increase in mortality compared to those with no asthma (adjusted hazard ratio [HR] 1¡17 [95% CI 0¡73â1¡86] for those on no asthma therapy, 0¡99 [0¡61â1¡58] for those on SABAs only, 0¡94 [0¡62â1¡43] for those on inhaled corticosteroids only, 1¡02 [0¡67â1¡54] for those on inhaled corticosteroids plus LABAs, and 1¡96 [1¡25â3¡08] for those with severe asthma). Among patients aged 50 years and older, those with chronic pulmonary disease had a significantly increased mortality risk, regardless of inhaled corticosteroid use, compared to patients without an underlying respiratory condition (adjusted HR 1¡16 [95% CI 1¡12â1¡22] for those not on inhaled corticosteroids, and 1¡10 [1¡04â1¡16] for those on inhaled corticosteroids; p<0¡0001). Patients aged 50 years and older with severe asthma also had an increased mortality risk compared to those not on asthma therapy (adjusted HR 1¡24 [95% CI 1¡04â1¡49]). In patients aged 50 years and older, inhaled corticosteroid use within 2 weeks of hospital admission was associated with decreased mortality in those with asthma, compared to those without an underlying respiratory condition (adjusted HR 0¡86 [95% CI 0¡80â0¡92]). Interpretation Underlying respiratory conditions are common in patients admitted to hospital with COVID-19. Regardless of the severity of symptoms at admission and comorbidities, patients with asthma were more likely, and those with chronic pulmonary disease less likely, to receive critical care than patients without an underlying respiratory condition. In patients aged 16 years and older, severe asthma was associated with increased mortality compared to non-severe asthma. In patients aged 50 years and older, inhaled corticosteroid use in those with asthma was associated with lower mortality than in patients without an underlying respiratory condition; patients with chronic pulmonary disease had significantly increased mortality compared to those with no underlying respiratory condition, regardless of inhaled corticosteroid use. Our results suggest that the use of inhaled corticosteroids, within 2 weeks of admission, improves survival for patients aged 50 years and older with asthma, but not for those with chronic pulmonary disease
Development and validation of the ISARIC 4C Deterioration model for adults hospitalised with COVID-19: a prospective cohort study.
BACKGROUND: Prognostic models to predict the risk of clinical deterioration in acute COVID-19 cases are urgently required to inform clinical management decisions. METHODS: We developed and validated a multivariable logistic regression model for in-hospital clinical deterioration (defined as any requirement of ventilatory support or critical care, or death) among consecutively hospitalised adults with highly suspected or confirmed COVID-19 who were prospectively recruited to the International Severe Acute Respiratory and Emerging Infections Consortium Coronavirus Clinical Characterisation Consortium (ISARIC4C) study across 260 hospitals in England, Scotland, and Wales. Candidate predictors that were specified a priori were considered for inclusion in the model on the basis of previous prognostic scores and emerging literature describing routinely measured biomarkers associated with COVID-19 prognosis. We used internal-external cross-validation to evaluate discrimination, calibration, and clinical utility across eight National Health Service (NHS) regions in the development cohort. We further validated the final model in held-out data from an additional NHS region (London). FINDINGS: 74â944 participants (recruited between Feb 6 and Aug 26, 2020) were included, of whom 31â924 (43¡2%) of 73â948 with available outcomes met the composite clinical deterioration outcome. In internal-external cross-validation in the development cohort of 66â705 participants, the selected model (comprising 11 predictors routinely measured at the point of hospital admission) showed consistent discrimination, calibration, and clinical utility across all eight NHS regions. In held-out data from London (n=8239), the model showed a similarly consistent performance (C-statistic 0¡77 [95% CI 0¡76 to 0¡78]; calibration-in-the-large 0¡00 [-0¡05 to 0¡05]); calibration slope 0¡96 [0¡91 to 1¡01]), and greater net benefit than any other reproducible prognostic model. INTERPRETATION: The 4C Deterioration model has strong potential for clinical utility and generalisability to predict clinical deterioration and inform decision making among adults hospitalised with COVID-19. FUNDING: National Institute for Health Research (NIHR), UK Medical Research Council, Wellcome Trust, Department for International Development, Bill & Melinda Gates Foundation, EU Platform for European Preparedness Against (Re-)emerging Epidemics, NIHR Health Protection Research Unit (HPRU) in Emerging and Zoonotic Infections at University of Liverpool, NIHR HPRU in Respiratory Infections at Imperial College London
Baseline characteristics of patients in the reduction of events with darbepoetin alfa in heart failure trial (RED-HF)
<p>Aims: This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes.</p>
<p>Methods and results: Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate <60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106â117) g/L.</p>
<p>Conclusion: The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity.</p>
Genetic Association Study Identifies HSPB7 as a Risk Gene for Idiopathic Dilated Cardiomyopathy
Dilated cardiomyopathy (DCM) is a structural heart disease with strong genetic background. Monogenic forms of DCM are observed in families with mutations located mostly in genes encoding structural and sarcomeric proteins. However, strong evidence suggests that genetic factors also affect the susceptibility to idiopathic DCM. To identify risk alleles for non-familial forms of DCM, we carried out a case-control association study, genotyping 664 DCM cases and 1,874 population-based healthy controls from Germany using a 50K human cardiovascular disease bead chip covering more than 2,000 genes pre-selected for cardiovascular relevance. After quality control, 30,920 single nucleotide polymorphisms (SNP) were tested for association with the disease by logistic regression adjusted for gender, and results were genomic-control corrected. The analysis revealed a significant association between a SNP in HSPB7 gene (rs1739843, minor allele frequency 39%) and idiopathic DCM (pâ=â1.06Ă10â6, ORâ=â0.67 [95% CI 0.57â0.79] for the minor allele T). Three more SNPs showed p < 2.21Ă10â5. De novo genotyping of these four SNPs was done in three independent case-control studies of idiopathic DCM. Association between SNP rs1739843 and DCM was significant in all replication samples: Germany (nâ=â564, nâ=â981 controls, pâ=â2.07Ă10â3, ORâ=â0.79 [95% CI 0.67â0.92]), France 1 (nâ=â433 cases, nâ=â395 controls, pâ=â3.73Ă10â3, ORâ=â0.74 [95% CI 0.60â0.91]), and France 2 (nâ=â249 cases, nâ=â380 controls, pâ=â2.26Ă10â4, ORâ=â0.63 [95% CI 0.50â0.81]). The combined analysis of all four studies including a total of nâ=â1,910 cases and nâ=â3,630 controls showed highly significant evidence for association between rs1739843 and idiopathic DCM (pâ=â5.28Ă10â13, ORâ=â0.72 [95% CI 0.65â0.78]). None of the other three SNPs showed significant results in the replication stage
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