Short-term Changes in Hemoglobin and Changes in Functional Status, Quality of Life and Natriuretic Peptides After Initiation of Dapagliflozin in Heart Failure With Reduced Ejection Fraction.

BACKGROUND: We aimed to evaluate the effect of dapagliflozin on short-term changes in hemoglobin in patients with stable heart failure with reduced ejection fraction (HFrEF) and whether these changes mediated the effect of dapagliflozin on functional capacity, quality of life and NT-proBNP levels. METHODS: This is an exploratory analysis of a randomized, double-blinded clinical trial in which 90 stable patients with HFrEF were randomly allocated to dapagliflozin or placebo to evaluate short-term changes in peak oxygen consumption (peak VO2) (NCT04197635). This substudy evaluated 1- and 3-month changes in hemoglobin levels and whether these changes mediated the effects of dapagliflozin on peak VO2, Minnesota Living-With-Heart-Failure test (MLHFQ) and NT-proBNP levels. RESULTS: At baseline, mean hemoglobin levels were 14.3 ± 1.7 g/dL. Hemoglobin levels significantly increased in those taking dapagliflozin (1 month: + 0.45 g/dL (P = 0.037) and 3 months:+ 0.55 g/dL (P = 0.012)]. Changes in hemoglobin levels positively mediated the changes in peak VO2 at 3 months (59.5%; P < 0.001). Changes in hemoglobin levels significantly mediated the effect of dapagliflozin in the MLHFQ at 3 months (-53.2% and -48.7%; P = 0.017) and NT-proBNP levels at 1 and 3 months (-68.0%; P = 0.048 and -62.7%; P = 0.029, respectively). CONCLUSIONS: In patients with stable HFrEF, dapagliflozin caused a short-term increase in hemoglobin levels, identifying patients with greater improvements in maximal functional capacity, quality of life and reduction of NT-proBNP levels.

Monitoring PHB production in Synechocystis sp. with hyperspectral images.

Microalgae wastewater treatment systems have the potential for producing added-value products. More specifically, cyanobacteria are able to accumulate polyhydroxybutyrates (PHBs), which can be extracted and used for bioplastics production. Nonetheless, PHB production requires proper culture conditions and continue monitoring, challenging the state-of-the-art technologies. The aim of this study was to investigate the application of hyperspectral technologies to monitor cyanobacteria population growth and PHB production. We have established a ground-breaking measurement method able to discern spectral reflectance changes from light emitted to cyanobacteria in different phases. All in all, enabling to distinguish between cyanobacteria growth phase and PHB accumulation phase. Furthermore, first tests of classification algorithms used for machine learning and image recognition technologies had been applied to automatically recognize the different cyanobacteria species from a complex microbial community containing cyanobacteria and microalgae cultivated in pilot-scale photobioreactors (PBRs). We have defined three main indicators for monitoring PHB production: (i) cyanobacteria specific-strain density, (ii) differentiate between growth and PHB-accumulation and (iii) chlorosis progression. The results presented in this study represent an interesting alternative for traditional measurements in cyanobacteria PHB production and its application in pilot-scale PBRs. Although not directly determining the amount of PHB production, they would give insights on the undergoing processes.

Right Heart Dysfunction and Readmission Risk Across Left Ventricular Ejection Fraction Status in Patients With Acute Heart Failure.

BACKGROUND: Right heart dysfunction (RHD) parameters are increasingly important in heart failure (HF). This study aimed to evaluate the association of advanced RHD with the risk of recurrent admissions across the spectrum of left ventricular ejection fraction (LVEF). METHODS AND RESULTS: We included 3383 consecutive patients discharged for acute HF. Of them, in 1435 patients (42.4%), the pulmonary artery systolic pressure could not be measured accurately, leaving a final sample size of 1948 patients. Advanced RHD was defined as the combination of a ratio of tricuspid annular plane systolic excursion/pulmonary artery systolic pressure of less than 0.36 and significant tricuspid regurgitation (n = 196, 10.2%). Negative binomial regression analyses were used to evaluate the risk of recurrent admissions. At a median follow-up of 2.2 years (interquartile range 0.63-4.71), 3782 readmissions were registered in 1296 patients (66.5%). Patients with advanced RHD showed higher readmission rates, but only if the LVEF was 40% or greater (P < .001). In multivariable analyses, this differential association persisted for cardiovascular and HF recurrent admissions (P value for interaction = .015 and P = .016; respectively). Advanced RHD was independently associated with the risk of recurrent cardiovascular and HF admissions if HF with an LVEF of 40% or greater (incidence rate ratio 1.64, 95% confidence interval 1.18-2.26, P = .003; and incidence rate ratio 1.73; 95% confidence interval 1.25-2.41, P = .001;respectively). In contrast, it was not associated with readmission risks if the LVEF was less than 40%. CONCLUSIONS: After an admission for acute HF, advanced RHD was strongly associated with a higher risk of recurrent cardiovascular and HF admissions, but only in patients with an LVEF of 40% or greater.

Magnetic Resonance Simulation in Education: Quantitative Evaluation of an Actual Classroom Experience.

Magnetic resonance is an imaging modality that implies a high complexity for radiographers. Despite some simulators having been developed for training purposes, we are not aware of any attempt to quantitatively measure their educational performance. The present study gives an answer to the question: Does an MRI simulator built on specific functional and non-functional requirements help radiographers learn MRI theoretical and practical concepts better than traditional educational method based on lectures? Our study was carried out in a single day by a total of 60 students of a main hospital in Madrid, Spain. The experiment followed a randomized pre-test post-test design with a control group that used a traditional educational method, and an experimental group that used our simulator. Knowledge level was assessed by means of an instrument with evidence of validity in its format and content, while its reliability was analyzed after the experiment. Statistical differences between both groups were measured. Significant statistical differences were found in favor of the participants who used the simulator for both the post-test score and the gain (difference between post-test and pre-test scores). The effect size turned out to be significant as well. In this work we evaluated a magnetic resonance simulation paradigm as a tool to help in the training of radiographers. The study shows that a simulator built on specific design requirements is a valuable complement to traditional education procedures, backed up with significant quantitative results.

Integrating intraseasonal grassland dynamics in cross-scale distribution modeling to support waterbird recovery plans.

Despite much discussion about the utility of remote sensing for effective conservation, the inclusion of these technologies in species recovery plans remains largely anecdotal. We developed a modeling approach for the integration of local, spatially measured ecosystem functional dynamics into a species distribution modeling (SDM) framework in which other ecologically relevant factors are modeled separately at broad scales. To illustrate the approach, we incorporated intraseasonal water-vegetation dynamics into a cross-scale SDM for the Common Snipe (Gallinago gallinago), which is highly dependent on water and vegetation dynamics. The Common Snipe is an Iberian grassland waterbird characteristic of European agricultural meadows and a member of one of the most threatened bird guilds. The intraseasonal dynamics of water content of vegetation were measured using the standard deviation of the normalized difference water index time series computed from bimonthly images of the Sentinel-2 satellite. The recovery plan for the Common Snipe in Galicia (northwestern Iberian Peninsula) provided an opportunity to apply our modeling framework. Model accuracy in predicting the species' distribution at a regional scale (resulting from integration of downscaled climate projections with regional habitat-topographic suitability models) was very high (area under the curve [AUC] of 0.981 and Boyce's index of 0.971). Local water-vegetation dynamic models, based exclusively on Sentinel-2 imagery, were good predictors (AUC of 0.849 and Boyce's index of 0.976). The predictive power improved (AUC of 0.92 and Boyce's index of 0.98) when local model predictions were restricted to areas identified by the continental and regional models as priorities for conservation. Our models also performed well (AUC of 0.90 and Boyce's index of 0.93) when projected to updated water-vegetation conditions. Our modeling framework enabled incorporation of key ecosystem processes closely related to water and carbon cycles while accounting for other factors ecologically relevant to endangered grassland waterbirds across different scales, allowed identification of priority areas for conservation, and provided an opportunity for cost-effective recovery planning by monitoring management effectiveness from space.

Integración de las Dinámicas Intraestacionales de los Pastizales al Modelado de la Distribución a través de Diversas Escalas para Respaldar los Planes de Recuperación de Aves Acuáticas Resumen A pesar A pesar del potencial de la teledetección para la conservación, la inclusión de estas tecnologías en los planes de recuperación de especies es muy poco habitual. En este trabajo, desarrollamos una estrategia de modelado para la integración de dinámicas ecosistémicas funcionales locales medidas espacialmente dentro de un marco de trabajo del modelado de distribución de especies (MDE), en el cual otros factores ecológicamente relevantes se modelan por separado y a escalas más generales. Para ilustrar la estrategia incorporamos las dinámicas Intraestacionales de la vegetación acuática en un MDE multiescala escalas para la agachadiza común (Gallinago gallinago), la cual es sumamente dependiente de las dinámicas del agua y la vegetación. La agachadiza común es un ave acuática de los pastizales ibéricos, característica de las praderas agrícolas de Europa y miembro de uno de los grupos de aves más amenazados. Medimos las dinámicas intraestacionales del contenido de agua de la vegetación con la desviación estándar de la serie temporal del índice de diferencia normalizada de agua a partir de las imágenes bimensuales del satélite Sentinel-2. El plan de recuperación para la agachadiza común en Galicia (noroeste de la península ibérica) proporcionó una oportunidad para aplicar nuestro marco de trabajo. La capacidad del modelo para predecir la distribución de la especie a una escala regional (resultante de la integración de proyecciones climáticas a escala reducida con modelos regionales de idoneidad hábitat-topografía) fue muy alta (área bajo la curva [AUC] de 0.981 e índice de Boyce de 0.971). El poder de predicción aumentó (AUC de 0.92 e índice de Boyce de 0.98) cuando las predicciones de los modelos locales estuvieron restringidos a áreas identificadas por los modelos continentales y regionales como prioritarias para la conservación. Nuestros modelos también tuvieron un buen desempeño (AUC de 0.90 e índice de Boyce de 0.93) cuando los proyectamos hacia las condiciones actualizadas de vegetación acuática. Nuestro marco de trabajo permitió la incorporación de procesos ecosistémicos clave intimamente relacionados con los ciclos del agua y del carbono a la vez que representaba otros factores ecológicamente relevantes para las aves acuáticas amenazadas de pastizal, a través de diferentes escalas. También permitió la identificación de áreas prioritarias para la conservación y proporcionó oportunidades para la planificación rentable de la recuperación al monitorear la efectividad del manejo desde el espacio.

A Web-Based Educational Magnetic Resonance Simulator: Design, Implementation and Testing.

A new web-based education-oriented magnetic resonance (MR) simulator is presented. We have identified the main requirements that this simulator should comply with, so that trainees can face useful practical tasks such as setting the exact slice position and its properties, selecting the correct protocol or fitting the parameters to acquire an image. The tool follows the client-server model. The client contains the interface that mimics the console of a real machine and several of its features. The server stores anatomical models and executes the bulk of the simulation. This cross-platform simulator has been used in two real educational scenarios. The acceptance of the tool has been measured using two criteria, namely, the System Usability Scale and the Likelihood to Recommend, both with satisfactory results. Therefore, we conclude that given the potential of the tool, it may play a relevant role for the training of MRI operators and other involved personnel.

Noncardiovascular morbidity and mortality across left ventricular ejection fraction categories following hospitalization for heart failure.

INTRODUCTION AND OBJECTIVES: Noncardiovascular events represent a significant proportion of the morbidity and mortality burden in patients with heart failure (HF). However, the risk of these events appears to differ by left ventricular ejection fraction (LVEF) status. In this study, we sought to evaluate the risk of noncardiovascular death and recurrent noncardiovascular readmission by LVEF status following an admission for acute HF. METHODS: We retrospectively assessed a cohort of 4595 patients discharged after acute HF in a multicenter registry. We evaluated LVEF as a continuum, stratified in 4 categories (LVEF ≤ 40%, 41%-49%, 50%-59%, and ≥ 60%). Study endpoints were the risks of noncardiovascular mortality and recurrent noncardiovascular admissions during follow-up. RESULTS: At a median follow-up of 2.2 [interquartile range, 0.76-4.8] years, we registered 646 noncardiovascular deaths and 4014 noncardiovascular readmissions. After multivariable adjustment including cardiovascular events as a competing event, LVEF status was associated with the risk of noncardiovascular mortality and recurrent noncardiovascular admissions. When compared with patients with LVEF ≤ 40%, those with LVEF 51%-59%, and especially those with LVEF ≥ 60%, were at higher risk of noncardiovascular mortality (HR, 1.31; 95%CI, 1.02-1,68; P=.032; and HR, 1.47; 95%CI, 1.15-1.86; P=.002; respectively), and at higher risk of recurrent noncardiovascular admissions (IRR, 1.17; 95%CI, 1.02-1.35; P=.024; and IRR, 1.26; 95%CI, 1.11-1.45; P=.001; respectively). CONCLUSIONS: Following an admission for HF, LVEF status was directly associated with the risk of noncardiovascular morbidity and mortality. Patients with HFpEF were at higher risk of noncardiovascular death and total noncardiovascular readmissions, especially those with LVEF ≥ 60%.

Association between N-terminal pro-brain natriuretic peptide and maximal functional capacity in heart failure with preserved ejection fraction: The modifying role of obesity.

This study investigates the association between maximal functional capacity (peakVO2) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in 133 ambulatory patients with heart failure with preserved ejection fraction (HFpEF), focusing on patients with obesity. Across all participants, NT-proBNP inversely correlated with peakVO2. However, this association varied based on obesity status. In patients without obesity, there was an inverse relationship between NT-proBNP and peakVO2, while no significant correlation was observed in patients with obesity. These findings suggest that in stable ambulatory HFpEF, NT-proBNP did not predict peakVO2 in patients with obesity.

Intrarenal Venous Flow Pattern Changes Do Relate With Renal Function Alterations in Acute Heart Failure.

BACKGROUND: There is scarce evidence supporting the clinical utility of congestive intrarenal venous flow (IRVF) patterns in patients with acute heart failure. OBJECTIVES: This study aims to: 1) investigate the association between IRVF patterns and the odds of worsening renal function (WRF); 2) track the longitudinal changes of serum creatinine (sCr) across IRVF at predetermined points and its association with decongestion; and 3) explore the relationship between IRVF/WRF categories and patient outcomes. METHODS: IRVF was assessed at baseline (pre-decongestive therapy), 72 hours, and 30 and 90 days postdischarge. Changes in sCr trajectories across dynamic IRVF variations and parameters of decongestion were assessed using linear mixed effect models. The association between IRVF/WRF categories and outcomes was evaluated using univariable/multivariable models. RESULTS: In this prospective, multicenter study with 188 participants, discontinuous IRVF patterns indicated higher odds of WRF (OR: 3.90 [95% CI: 1.24-12.20]; P = 0.020 at 72 hours; and OR: 5.76 [95% CI: 1.67-19.86]; P = 0.006 at 30 days) and an increase in sCr (Δ-72 hours 0.14 mg/dL [95% CI: 0.06-0.22]; P = 0.001; Δ-discharge 0.13 mg/dL [95% CI: 0.03-0.23]; P = 0.007). However, the diuretic response and decongestion significantly influenced the magnitude of these changes. Patients exhibiting both WRF and discontinuous IRVF at 30 days experienced an increased hazard of adverse events (HR: 5.96 [95% CI: 2.63-13.52]; P < 0.001). CONCLUSIONS: Discontinuous IRVF identifies patients with higher odds of WRF during admission and postdischarge periods. Nonetheless, adequate diuretic response and decongestion could modify this association. Patients showing both WRF and discontinuous IRVF at 30 days had increased rates of adverse events.

Combining loop with thiazide diuretics in patients discharged home after a heart failure decompensation: Association with 30-day outcomes.

OBJECTIVE: To investigate the association of the addition of thiazide diuretic on top of loop diuretic and standard of care with short-term outcomes of patients discharged after surviving an acute heart failure (AHF) episode. METHODS: This is a secondary analysis of 14,403 patients from three independent cohorts representing the main departments involved in AHF treatment for whom treatment at discharge was recorded and included loop diuretics. Patients were divided according to whether treatment included or not thiazide diuretics. Short-term outcomes consisted of 30-day all-cause mortality, hospitalization (with a separate analysis for hospitalization due to AHF or to other causes) and the combination of death and hospitalization. The association between thiazide diuretics on short-term outcomes was explored by Cox regression and expressed as hazard ratios (HR) with 95 % confidence intervals, which were adjusted for 18 patient-related variables and 9 additional drugs (aside from loop and thiazide diuretics) prescribed at discharge. RESULTS: The median age was 81 (interquartile range=73-86) years, 53 % were women, and patients were mainly discharged from the cardiology (42 %), internal medicine or geriatric department (29 %) and emergency department (19 %). There were 1,367 patients (9.5 %) discharged with thiazide and loop diuretics, while the rest (13,036; 90.5 %) were discharged with only loop diuretics on top of the remaining standard of care treatments. The combination of thiazide and loop diuretics showed a neutral effect on all outcomes: death (adjusted HR 1.149, 0.850-1.552), hospitalization (0.898, 0.770-1.048; hospitalization due to AHF 0.799, 0.599-1.065; hospitalization due to other causes 1.136, 0.756-1.708) and combined event (0.934, 0.811-1.076). CONCLUSION: The combination of thiazide and loop diuretics was not associated with changes in risk of death, hospitalization or a combination of both.

Short-Term Changes in Peak VO2 After Initiation of Dapagliflozin in Heart Failure Across Iron Status.

BACKGROUND: Some studies have indicated that sodium-glucose cotransporter-2 (SGLT2) inhibitors promote an increase in cell iron use. OBJECTIVES: The aim of this study was to examine, in patients with stable heart failure with reduced left ventricular ejection fraction (HFrEF), the effect of dapagliflozin on ferrokinetic parameters and whether short-term changes in peak oxygen consumption (Vo2) after dapagliflozin treatment are influenced by baseline and serial ferrokinetic status. METHODS: This was an exploratory analysis of a randomized, double-blind clinical trial that evaluated the effect of dapagliflozin vs placebo on peak Vo2 in patients with HFrEF (NCT04197635) and included 76 of the 90 patients initially enrolled in the trial. Changes in peak Vo2 at 1 and 3 months were explored according to baseline and longitudinal ferrokinetic parameters (natural logarithm [ln] ferritin, transferrin saturation index [TSAT], soluble transferrin receptor, and hepcidin). Linear mixed-effect regression was used for the analyses. RESULTS: Compared with placebo, dapagliflozin led to a significant decrease in 3-month ln ferritin (P = 0.040) and an increase in 1-month ln soluble transferrin receptor (P = 0.023). Between-treatment comparisons revealed a stepwise increase in peak Vo2 in the dapagliflozin group at 1 and 3 months, which was especially apparent at lower baseline values of TSAT and ferritin (P < 0.05). Lower time-varying values of TSAT (1 and 3 months) also identified patients with greater improvements in peak Vo2. CONCLUSIONS: In patients with stable HFrEF, treatment with dapagliflozin resulted in short-term increases in peak Vo2, which were most marked in patients with surrogates of greater iron deficiency at baseline and during treatment. (Short-Term Effects of Dapagliflozin on Peak Vo2 in HFrEF [DAPA-VO2]; NCT04197635).

Early glomerular filtration rates changes and risk of mortality in acute heart failure. The modifying role of admission renal function and decongestion.

BACKGROUND: The pathophysiology of changes in estimated glomerular filtration rate (eGFR) in acute heart failure (AHF) is complex and multifactorial. We evaluated the associated mortality risk of early changes in eGFR across baseline renal function on admission and early changes in natriuretic peptides in patients admitted with AHF. METHODS: We retrospectively evaluated 2,070 patients admitted with AHF. Renal dysfunction on admission was defined as eGFR<60 ml/min/1.73m2 and successful decongestion as NT-proBNP decreased >30% from baseline. We assessed the mortality risk associated with eGFR changes from baseline at 48-72 h after admission (ΔeGFR%) according to baseline renal function, and NT-proBNP changes at 48-72 h through Cox regression analyses. RESULTS: The mean age was 74.4 ± 11.2 years, and 930 (44.9%) were women. The proportion of admission eGFR<60 ml/min/1.73m2 and 48-72 h changes in NT-proBNP>30% were 50.5% and 32.8%, respectively. At a median follow-up of 1.75 years, 928 deaths were registered. In the whole sample, changes in renal function were not associated with mortality (p = 0.208). The adjusted analysis revealed that the risk of mortality related to ΔeGFR% was heterogeneous across baseline renal function and changes in NT-proBNP (p-value for interaction=0.003). ΔeGFR% was not associated with mortality in patients with baseline eGFR≥60 ml/min/1.73m2. In those with eGFR<60 ml/min/1.73m2, a decrease in eGFR was associated with higher mortality, particularly in those with a reduction in NT-proBNP<30%. CONCLUSION: In patients with AHF, early ΔeGFR% was associated with the risk of long-term mortality only in patients with renal dysfunction on admission and no early decline in NT-proBNP.

Kidney function changes in acute heart failure: a practical approach to interpretation and management.

Worsening kidney function (WKF) is common in patients with acute heart failure (AHF) syndromes. Although WKF has traditionally been associated with worse outcomes on a population level, serum creatinine concentrations vary greatly during episodes of worsening heart failure, with substantial individual heterogeneity in terms of their clinical meaning. Consequently, interpreting such changes within the appropriate clinical context is essential to unravel the pathophysiology of kidney function changes and appropriately interpret their clinical meaning. This article aims to provide a critical overview of WKF in AHF, aiming to provide physicians with some tips and tricks to appropriately interpret kidney function changes in the context of AHF.

An update on utilising brain natriuretic peptide for risk stratification, monitoring and guiding therapy in heart failure.

INTRODUCTION: Heart failure (HF) is a dominant health problem with an overall poor prognosis. Natriuretic peptides (NPs) are upregulated in HF as a compensatory mechanism. They have been extensively used for diagnosis and risk stratification. AREAS COVERED: This review addresses the history and physiology of NPs in order to understand their current role in clinical practice. It further provides a detailed and updated narrative review on the utility of those biomarkers for risk stratification, monitoring, and guiding therapy in HF. EXPERT OPINION: NPs show excellent predictive ability in heart failure patients, both in acute and chronic settings. Understanding their pathophysiology and their modifications in specific situations is key for an adequate interpretation in specific clinical scenarios in which their prognostic value may be weaker or less well evaluated. To better promote risk stratification in HF, NPs should be integrated with other predictive tools to develop multiparametric risk models. Both inequalities of access to NPs and evidence caveats and limitations will need to be addressed by future research in the coming years.

Risk of death associated with incident heart failure in patients with known or suspected chronic coronary syndrome.

AIMS: Traditional adverse events in chronic coronary syndrome (CCS) include atherothrombotic events but usually exclude heart failure (HF). Data are scarce about how new-onset HF modifies mortality risk. We aimed to determine the incidence of HF and compare its long-term mortality risk with myocardial infarction (MI) and stroke in patients with known or suspected CCS. METHODS: We prospectively evaluated 5811 consecutive HF-free patients submitted to vasodilator stress cardiac magnetic resonance (CMR) for known or suspected CCS. Ischaemic burden and left ventricular ejection fraction were assessed by CMR. HF included outpatient diagnosis or acute HF hospitalization. The mortality risk for the incident events and their cross-comparisons were evaluated using a Markov illness-death model with transition-specific survival models. RESULTS: The mean age was 55 ± 11 years, and 38.9% were female. At a median follow-up of 5.44 (IQR = 2.53-8.55) years, 591 deaths were registered (1.79 per 100 P-Y). The rates of new-onset HF were higher compared with MI and stroke [1.02, 0.62, and 0.51, respectively (P < 0.05)]. The adjusted association between new-onset HF, MI, and stroke, and subsequent mortality was time dependent. The risk increased almost linearly for HF and became significant by the third year. By Year 10, the mortality risk attributable to new-onset HF was more than 2.5-fold (HR: 2.68, 95% CI = 1.74-4.12). For MI, there was a significant increase in mortality risk up to the second year, followed by a monotonic decrease. For stroke, the mortality risk increased for the entire follow-up but became significant by the third year. A cross-comparison among incident endpoints HF outnumbers risk for those with MI by the sixth year (HRyear6.3 : 1.88, 95% CI = 1.03-3.43). There was no difference in mortality risk between incident HF and stroke. CONCLUSIONS: In patients with CCS, long-term rates of incident HF were higher than MI and stroke. Patients with new-onset HF showed a higher risk of long-term mortality.

On the Use of Multi-Step Dies for Improving the Performance against Hydrogen Embrittlement of Cold Drawn Prestressing Steel Wires.

The main cause of in-service failure of cold drawn wires in aggressive environments is hydrogen embrittlement (HE). The non-uniform plastic strains and residual stresses generated after cold drawing play a significant role in the matter of HE susceptibility of prestressing steels. In this paper, a new and innovative design of the drawing scheme is developed, geared towards the reduction in both manufacturing-induced residual stresses and plastic strains. To achieve this goal, three innovative cold drawing chains (consisting in diverse multi-step dies where multiple diameter reductions are progressively carried out in a single die) are numerically simulated by the finite element (FE) method. From the residual stress and plastic strain fields revealed from FE numerical simulations, hydrogen accumulation for diverse times of exposure is obtained by means of FE simulations of the hydrogen diffusion assisted by stress and strains. Thus, an estimation of the HE susceptibility of the cold drawn wires after each process was obtained. Results reveal that cold drawn wire using multi-step dies exhibits lower stress and strain states nearby the wire surface. This reduction causes a decrease in the hydrogen concentration at the prospective damage zones, thereby improving the performance of the prestressing steel wires in hydrogenating environments promoting HE. Thus, the optimal wire drawing process design is carried out using special dies with several reductions per die.

Innovative Design of Residual Stress and Strain Distributions for Analyzing the Hydrogen Embrittlement Phenomenon in Metallic Materials.

Round-notched samples are commonly used for testing the susceptibility to hydrogen embrittlement (HE) of metallic materials. Hydrogen diffusion is influenced by the stress and strain states generated during testing. This state causes hydrogen-assisted micro-damage leading to failure that is due to HE. In this study, it is assumed that hydrogen diffusion can be controlled by modifying such residual stress and strain fields. Thus, the selection of the notch geometry to be used in the experiments becomes a key task. In this paper, different HE behaviors are analyzed in terms of the stress and strain fields obtained under diverse loading conditions (un-preloaded and preloaded causing residual stress and strains) in different notch geometries (shallow notches and deep notches). To achieve this goal, two uncoupled finite element (FE) simulations were carried out: (i) a simulation by FE of the loading sequences applied in the notched geometries for revealing the stress and strain states and (ii) a simulation of hydrogen diffusion assisted by stress and strain, for estimating the hydrogen distributions. According to results, hydrogen accumulation in shallow notches is heavily localized close to the wire surface, whereas for deep notches, hydrogen is more uniformly distributed. The residual stress and plastic strains generated by the applied preload localize maximum hydrogen concentration at deeper points than un-preloaded cases. As results, four different scenarios are established for estimating "a la carte" the HE susceptibility of pearlitic steels just combining two notch depths and the residual stress and strain caused by a preload.

Incidence, Treatment and Clinical Impact of Iron Deficiency in Chronic Heart Failure: A Longitudinal Analysis.

In patients with heart failure (HF), iron deficiency (ID) is a well-recognized therapeutic target; information about its incidence, patterns of iron repletion, and clinical impact is scarce. This single-centre longitudinal cohort study assessed the rates of ID testing and diagnosis in patients with stable HF, patterns of treatment with intravenous iron, and clinical impact of intravenous iron on HF rehospitalization risk. We included 711 consecutive outpatients (4400 visits) with stable chronic HF from 2014 to 2019 (median [interquartile range] visits per patient: 2 [2−7]. ID was defined as serum ferritin <100 µg/L, or 100−299 µg/L with transferrin saturation (TSAT) < 20%. During a median follow-up of 2.20 (1.11−3.78) years, ferritin and TSAT were measured at 2230 (50.7%) and 2183 visits (49.6%), respectively. ID was found at 846 (37.9%) visits, with ferritin and TSAT available (2230/4400), and intravenous iron was administered at 321/4400 (7.3%) visits; 233 (32.8%) patients received intravenous iron during follow-up. After multivariate analyses, iron repletion at any time during follow-up was associated with a lower risk of recurrent HF hospitalization (hazard ratio [HR] = 0.50, 95% confidence interval [CI] = 0.28−0.88; p = 0.016). Thus, ID was a frequent finding in patients with HF, and its repletion reduced the risk of recurrent HF hospitalizations.

Hospitalization following an emergency-department visit for worsening heart failure: The role of left ventricular ejection fraction.

INTRODUCTION AND OBJECTIVES: Patients with worsening heart failure (WHF) are frequently hospitalized. However, some of the patients with WHF are discharged from the emergency department without hospitalization. The factors influencing the decision of admission are heterogeneous and, in most cases, remain not well-defined. This study aimed to analyze whether left ventricular ejection fraction (LVEF) influences admission decisions following a visit to the emergency department for WHF. PATIENTS AND METHODS: This is a retrospective analysis of 3168 patients discharged from a hospitalization for acute heart failure in a single-center in Spain. During follow-up, visits to the emergency department for WHF, including those hospitalized (WHF-readmissions) and episodes of WHF directly discharged without hospitalization in 24h (WHF-DDWH), were recorded. The association between the LVEF categories (<50% and ≥50%) and recurrent WHF-DDWH was evaluated by negative binomial regression. Estimates of risk were expressed as incidence rate ratios (IRR). RESULTS: The mean age (SD) of the study sample was 73.5 (11.2) years, and 1658 (52.3%) showed LVEF>50%. At a median (percentile 25% to percentile 75%) follow-up of 2.7 (1.0-5.8) years, 3341 episodes of WHF in 1439 patients were recorded. Of them, we registered 743 episodes of WHF-DDWH in 468 patients (22.2%). Compared to patients with LVEF<50%, those with LVEF≥50% exhibited an adjusted increased risk of recurrent WHF-DDWH (IRR: 1.36, CI 95%: 1.13-1.62, p=0.001). CONCLUSIONS: Following an acute heart failure admission, patients with LVEF≥50% showed an increased risk of same-day discharge for WHF.

Sex-Related Differences in Mortality Following Admission for Acute Heart Failure Across the Left Ventricular Ejection Fraction Spectrum.

Background Following a heart failure (HF)-decompensation, there is scarce data about sex-related prognostic differences across left ventricular ejection fraction (LVEF) status. We sought to evaluate sex-related differences in 6-month mortality risk across LVEF following admission for acute HF. Methods and Results We retrospectively evaluated 4812 patients consecutively admitted for acute HF in a multicenter registry from 3 hospitals. Study end points were all-cause, cardiovascular, and HF-related mortality at 6-month follow-up. Multivariable Cox regression models were fitted to investigate sex-related differences across LVEF. A total of 2243 (46.6%) patients were women, 2569 (53.4%) were men, and 2608 (54.2%) showed LVEF≥50%. At 6-month follow-up, 645 patients died (13.4%), being 544 (11.3%) and 416 (8.6%) cardiovascular and HF-related deaths, respectively. LVEF was not independently associated with mortality (HR, 1.02; 95% CI 0.99-1.05; P=0.135). After multivariable adjustment, we found no sex-related differences in all-cause mortality (P value for interaction=0.168). However, a significant interaction between sex and cardiovascular and HF mortality risks was found across LVEF (P value for interaction=0.030 and 0.007, respectively). Compared with men, women had a significantly lower risk of cardiovascular and HF-mortality at LVEF<25% and <43%, respectively. On the contrary, women showed a higher risk of HF-mortality at the upper extreme of LVEF (>80%). Conclusions Following an admission for acute HF, no sex-related differences were found in all-cause mortality risk. However, when compared with men, women showed a lower risk of cardiovascular and HF-mortality at the lower extreme of LVEF. On the contrary, they showed a higher risk of HF death at the upper extreme.