Morbimortalidad no cardiovascular en función de la fracción de eyección del ventrículo izquierdo tras una hospitalización por insuficiencia cardiaca / Noncardiovascular morbidity and mortality across left ventricular ejection fraction categories following hospitalization for heart failure

Introducción y objetivos Los eventos no cardiovasculares son una importante causa de morbimortalidad en pacientes con insuficiencia cardiaca (IC), pero parece que su riesgo difiere en función de la fracción de eyección del ventrículo izquierdo (FEVI). Nuestro objetivo es evaluar el riesgo de mortalidad y hospitalizaciones no cardiovasculares totales en función de la FEVI tras una hospitalización por IC. Métodos Se evaluó en retrospectiva a una cohorte multicéntrica de 4.595 pacientes tras una hospitalización por IC. Se evaluó la FEVI como variable continua y estratificada en 4 categorías (FEVI ≤ 40%, 41%-49%, 50-59% y ≥ 60%). Los objetivos fueron los riesgos de muerte no cardiovascular y de hospitalizaciones recurrentes por causas no cardiovasculares según la FEVI. Resultados Tras una mediana de seguimiento de 2,2 [intervalo intercuartílico, 0,76-4,8] años, se registraron 646 muertes y 4.014 episodios de rehospitalización por causas no cardiovasculares. En el análisis multivariante, que incluía el riesgo de evento cardiovascular como evento adverso competitivo, se halló relación directa entre la FEVI y el riesgo de muerte o rehospitalización no cardiovascular (p<0,001). En comparación con la FEVI ≤ 40%, la FEVI del 51-59% y especialmente la ≥ 60% se asociaron de manera significativa con un mayor riesgo de muerte no cardiovascular (respectivamente, HR=1,31; IC95%, 1,02-1,68; p=0,032; y HR=1,47; IC95%, 1,15-1,86; p=0,002) y de rehospitalizaciones no cardiovasculares (IRR=1,17; IC95%, 1,02-1,35; p=0,024; IRR=1,26; IC95%, 1,11-1,45; p=0,001). Conclusiones Tras una hospitalización por IC, la FEVI tiene relación directa con el riesgo de morbimortalidad no cardiovascular. Los pacientes con FEVI conservada tienen un riesgo significativamente mayor de muerte y hospitalizaciones por causas no cardiovasculares, fundamentalmente si la FEVI es ≥ 60%. (AU)

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%. (AU)

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%.

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.

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.

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.

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.

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.

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.

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.

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.

Bending oxygen saturation index and risk of worsening heart failure events in chronic heart failure.

AIMS: Bendopnea is a clinical symptom of advanced heart failure with uncertain prognostic value. We aimed to evaluate whether bendopnea and the change in oxygen saturation when bending forward (bending oxygen saturation index [BOSI]) are associated with adverse outcomes in ambulatory chronic heart failure (CHF) patients. METHODS AND RESULTS: We prospectively evaluated 440 subjects with symptomatic CHF. BOSI was defined as the difference between sitting and bending oxygen saturation (SpO2 ). The endpoint was the total number of worsening heart failure (WHF) events (heart failure hospitalization or urgent heart failure visit requiring parenteral diuretic therapy). The mean age was 74 ± 10 years, 257 (58.6%) were male, and 226 (51.4%) had a left ventricular ejection fraction <50%. Bendopnea was present in 94 (21.4%) patients, and 120 (27.3%) patients had a BOSI ≥-3%. The agreement between BOSI ≥-3% and bendopnea was moderate (Gwet's AC 0.482, p < 0.001). At a median (p25%-p75%) follow-up of 2.17 years (0.88-3.16), we registered 441 WHF events in 148 patients. After multivariable adjustment, BOSI was independently associated with the risk for total WHF episodes (overall, p < 0.001). Compared to improvement/no change in SpO2 when bending (BOSI 0%), those with BOSI ≥-3% showed an increased risk of WHF events (incidence rate ratio [IRR] 2.16, 95% confidence interval [CI] 1.67-2.79; p < 0.001). In contrast, bendopnea was not associated with the risk of total WHF episodes (IRR 1.04, 95% CI 0.83-1.31; p = 0.705). CONCLUSIONS: In ambulatory and stable CHF patients, BOSI ≥-3% and not bendopnea was independently associated with an increased risk of total (first and recurrent) WHF episodes. Awareness of SpO2 while assessing bendopnea may be a useful tool for predicting heart failure decompensations.

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. (AU)

Introducción y objetivos:Muchos de los pacientes que acuden a los servicios de urgencias (SU) por empeoramiento de la insuficiencia cardiaca (EIC) son hospitalizados, en cambio, otros son dados de alta desde el SU sin ingreso hospitalario (EIC-SUSIH). Los factores que definen esta condición son heterogéneos y no están bien establecidos. El objetivo de este estudio fue analizar si la fracción de eyección del ventrículo izquierdo (FEVI) influye en la decisión de ingresar a un paciente en el SU por EIC.Métodos:Análisis retrospectivo de 3.168 pacientes hospitalizados por insuficiencia cardiaca (IC) aguda en un solo centro en España. Durante el seguimiento, se registraron todas las visitas al SU por EIC y se catalogaron en dos grupos según fueron resueltas: hospitalizaciones y EIC-SUSIH. La asociación entre las categorías de FEVI (< 50%-≥ 50%) y las visitas recurrentes por EIC se analizaron mediante regresión binomial negativa.Resultados:La media de edad (desviación estándar) fue de 73,5 (1,2) años. Del total, 1.658 (52,3%) tenían FEVI > 50%. Tras una mediana de seguimiento (percentil 25%-percentil 75%) de 2,7 (1,0-5,8) años, se registraron 3.341 episodios de EIC en 1.439 pacientes y 743 casos de EIC-SUSIH en 468 pacientes (22,2%). Los pacientes con FEVI ≥ 50% mostraron un incremento del riesgo ajustado de presentar episodios recurrentes de EIC-SUSIH (Ratio de tasa incidencia (IRR): 1,36; IC 95%: 1,13-1,62; p = 0,001).Conclusiones:Tras un ingreso por IC aguda, los pacientes con FEVI ≥ 50% que acuden al SU por EIC, presentan un mayor riesgo de ser dados de alta sin ser ingresados. (AU)

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.

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.