Clinical correlates and prognostic impact of impaired iron storage versus impaired iron transport in an international cohort of 1821 patients with chronic heart failure

Intravenous iron for acute and chronic heart failure with reduced ejection fraction (HFrEF) patients with iron deficiency: An updated systematic review and meta-analysis

Patients with heart failure (HF) and iron deficiency are at increased risk of adverse clinical outcomes. We searched databases for randomised controlled trials that compared IV iron to placebo, in patients with HF with reduced ejection fraction (HFrEF). A total of 7,813 participants, all having HFrEF with 3,998 receiving IV iron therapy, and 3,815 control recipients were included. There was a significant improvement in Kansas City Cardiomyopathy Questionnaire favouring IV iron with MD 7.39, 95% CI [3.55, 11.22], p = 0.0002. Subgroup analysis, based on acute and chronic HF, has displayed a sustained statistical significance. Additionally, a significant increase in the left ventricular ejection fraction % was observed, with MD 3.76, 95% CI [2.32, 5.21], p < 0.00001. A significant improvement in 6-min walk test was noted, with MD 34.87, 95% CI [20.02, 49.72], p < 0.00001. Furthermore, IV iron showed significant improvement in NYHA class, peak VO2, serum ferritin, and haemoglobin levels. Finally, despite the lack of difference in terms of all-cause hospitalisation and HF-related death, IV iron was associated with a significant reduction in HF-related, any cardiovascular reason hospitalisations, and all-cause death; which supports the need for implementation of IV iron as a standard of care in patients with HF and iron deficiency.

Iron deficiency and anemia in pediatric dilated cardiomyopathy are associated with clinical, biochemical, and hematological markers of severe disease and adverse outcomes

BACKGROUND

There is limited evidence regarding the prevalence and impact of iron deficiency (ID) in children with dilated cardiomyopathy (DCM).

METHODS

Retrospective single-center review of all children between 2010 and 2020 with a diagnosis of DCM and complete iron studies. ID was defined as ≥2 of ferritin <20 μg/liter, iron <9 μmol/liter, transferrin >3 g/liter, or transferrin saturation (TSat) <15%. Clinical and laboratory indices and freedom from a composite adverse event (CAE) of mechanical circulatory support (MCS), heart transplant, or death were compared between children with and without ID.

RESULTS

Of 138 patients with DCM, 47 had available iron studies. Twenty-nine (62%) were iron deficient. Children with ID were more likely to be receiving inotropes (17, 59%, p = 0.005) or invasive/noninvasive ventilation (13, 45%, p = 0.016) than those who were iron replete. They had a higher incidence of anemia (22, 76%, p = 0.004) and higher NT-proBNP (1,590 pmol/liter, IQR 456-3,447, p = 0.001). Children with ID had significantly less freedom from the CAE at 1-year (54% ± 10%), 2-years (45 ± 10), and 5-years (37% ± 11%) than those without (p = 0.011). ID and anemia were the only significant predictors of the CAE on univariate Cox regression.

CONCLUSIONS

ID is highly prevalent in children with DCM. Iron studies are undermeasured in clinical practice, but ID is associated with severe heart failure (HF) and an increased risk of the CAE. The need for iron replacement therapy should be considered in children who present in HF with DCM.

Impact of anaemia and iron deficiency on outcomes in cardiogenic shock complicating acute myocardial infarction

AIMS

Anaemia and iron deficiency (ID) are common comorbidities in cardiovascular patients and are associated with a poor clinical status, as well as a worse outcome in patients with heart failure and acute myocardial infarction (AMI). Nevertheless, data concerning the impact of anaemia and ID on clinical outcomes in patients with cardiogenic shock (CS) are scarce. This study aimed to assess the impact of anaemia and ID on clinical outcomes in patients with CS complicating AMI.

METHODS AND RESULTS

The presence of anaemia (haemoglobin <13 g/dl in men and <12 g/dl in women) or ID (ferritin <100 ng/ml or transferrin saturation <20%) was determined in patients with CS due to AMI from the CULPRIT-SHOCK trial. Blood samples were collected in the catheterization laboratory during initial percutaneous coronary intervention. Clinical outcomes were compared in four groups of patients having neither anaemia nor ID, against patients with anaemia with or without ID and patients with ID only. A total of 427 CS patients were included in this analysis. Anaemia without ID was diagnosed in 93 (21.7%), anaemia with ID in 54 study participants (12.6%), ID without anaemia in 72 patients (16.8%), whereas in 208 patients neither anaemia nor ID was present (48.9%). CS patients with anaemia without ID were older (73 ± 10 years, p = 0.001), had more frequently a history of arterial hypertension (72.8%, p = 0.01), diabetes mellitus (47.8%, p = 0.001), as well as chronic kidney disease (14.1%, p = 0.004) compared to CS patients in other groups. Anaemic CS patients without ID presence were at higher risk to develop a composite from all-cause death or renal replacement therapy at 30-day follow-up (odds ratio [OR] 3.83, 95% confidence interval [CI] 2.23-6.62, p < 0.001) than CS patients without anaemia/ID. The presence of ID in CS patients, with and without concomitant anaemia, did not increase the risk for the primary outcome (OR 1.17, 95% CI 0.64-2.13, p = 0.64; and OR 1.01, 95% CI 0.59-1.73, p = 0.54; respectively) within 30 days of follow-up. In time-to-event Kaplan-Meier analysis, anaemic CS patients without ID had a significantly higher hazard ratio (HR) for the primary outcome (HR 2.11, 95% CI 1.52-2.89, p < 0.001), as well as for death from any cause (HR 1.90, 95% CI 1.36-2.65, p < 0.001) and renal replacement therapy during 30-day follow-up (HR 2.99, 95% CI 1.69-5.31, p < 0.001).

CONCLUSION

Concomitant anaemia without ID presence in patients with CS at hospital presentation is associated with higher risk for death from any cause or renal replacement therapy and the individual components of this composite endpoint within 30 days after hospitalization. ID has no relevant impact on clinical outcomes in patients with CS.

Physiology of exercise and heart failure treatments: cardiopulmonary exercise testing as a tool for choosing the optimal therapeutic strategy

In the last decades, the pharmacological treatment of heart failure (HF) become more complex due to the availability of new highly effective drugs. Although the cardiovascular effects of HF therapies have been extensively described, less known are their effects on cardiopulmonary function considered as a whole, both at rest and in response to exercise. This is a 'holistic' approach to disease treatment that can be accurately evaluated by a cardiopulmonary exercise test. The aim of this paper is to assess the main differences in the effects of different drugs [angiotensin-converting enzyme (ACE)-inhibitors, Angiotensin II receptor blockers, β-blockers, Angiotensin receptor-neprilysin inhibitors, renal sodium-glucose co-transporter 2 inhibitors, iron supplementation] on cardiopulmonary function in patients with HF, both at rest and during exercise, and to understand how these differences can be taken into account when choosing the most appropriate treatment protocol for each individual patient leading to a precision medicine approach.

Influence of serum transferrin concentration on diagnostic criteria for iron deficiency in chronic heart failure

AIMS

Transferrin saturation (TSAT), a marker of iron deficiency, reflects both serum concentrations of iron (SIC) and transferrin (STC). TSAT is susceptible to changes in each of these biomarkers. Little is known about determinants of STC and its influence on TSAT and mortality in patients with heart failure. Accordingly, we studied the relationship of STC to clinical characteristics, to markers of iron deficiency and inflammation and to mortality in chronic heart failure (CHF).

METHODS AND RESULTS

Prospective cohort of patients with CHF attending a clinic serving a large local population. A total of 4422 patients were included (median age 75 (68-82) years; 40% women; 32% with left ventricular ejection fraction ≤40%). STC ≤ 2.3 g/L (lowest quartile) was associated with older age, lower SIC and haemoglobin and higher high-sensitivity C-reactive protein, ferritin and N-terminal pro-brain natriuretic peptide compared with those with STC > 2.3 g/L. In the lowest STC quartile, 624 (52%) patients had SIC ≤13 μmol/L, of whom 38% had TSAT ≥20%. For patients in the highest STC quartile, TSAT was <20% when SIC was >13 μmol/L in 185 (17%) patients. STC correlated inversely with ferritin (r = -0.52) and high-sensitivity C-reactive protein (r = -0.17) and directly with albumin (r = 0.29); all P < 0.001. In models adjusted for age, N-terminal pro-brain natriuretic peptide and haemoglobin, both higher SIC (hazard ratio 0.87 [95% CI: 0.81-0.95]) and STC (hazard ratio 0.82 [95% CI: 0.73-0.91]) were associated with lower mortality. SIC was more strongly associated with both anaemia and mortality than either STC or TSAT.

CONCLUSIONS

Many patients with CHF and a low STC have low SIC even when TSAT is >20% and serum ferritin >100 μg/L; such patients have a high prevalence of anaemia and a poor prognosis and might have iron deficiency but are currently excluded from clinical trials of iron repletion.

Heart Failure with Preserved Ejection Fraction: a Pharmacotherapeutic Update

While guidelines for management of heart failure with reduced ejection fraction (HFrEF) are consensual and have led to improved survival, treatment options for heart failure with preserved ejection fraction (HFpEF) remain limited and aim primarily for symptom relief and improvement of quality of life. Due to the shortage of therapeutic options, several drugs have been investigated in multiple clinical trials. The majority of these trials have reported disappointing results and have suggested that HFpEF might not be as simply described by ejection fraction as previously though. In fact, HFpEF is a complex clinical syndrome with various comorbidities and overlapping distinct phenotypes that could benefit from personalized therapeutic approaches. This review summarizes the results from the most recent phase III clinical trials for HFpEF and the most promising drugs arising from phase II trials as well as the various challenges that are currently holding back the development of new pharmacotherapeutic options for these patients.

How to diagnose iron deficiency in chronic disease: A review of current methods and potential marker for the outcome

Iron deficiency (ID) is the most common nutritional disorder worldwide. It is often observed in patients with chronic diseases, such as heart failure (HF), chronic kidney disease (CKD), inflammatory bowel disease (IBD) and cancer. ID is associated with poor clinical outcome, including poor performance, reduced quality of life, as well as increased hospitalization and mortality. The aim of this review is to provide an overview about the role of ID in chronic diseases (HF, CKD, IBD, cancer) regarding their current definitions and clinical relevance; diagnostic accuracy of iron parameters in chronic inflammatory conditions and its potential as prognostic markers. Due to different definitions and guideline recommendations of ID, various laboratory parameters for ID diagnostic exist and there is no general consensus about the definition of ID and its treatment. Still, a general trend can be observed across all investigated indications of this review (HF, CKD, IBD, cancer) that serum ferritin and transferrin saturation (TSAT) are the two parameters mentioned most often and emphasized in all guidelines to define ID and guide treatment. The most commonly used threshold values for the diagnosis of ID are TSAT of < 20% and serum ferritin of < 100-300 µg/L. Noteworthy, both TSAT and particularly ferritin are frequently applied, but both may vary due to inflammatory conditions. Studies showed that TSAT is less affected by inflammatory processes and may therefore be more accurate and reliable than serum ferritin, particularly in conditions with elevated inflammatory state. A low iron status and particularly a low TSAT value was associated with a poor outcome in all investigated indications, with the strongest evidence in HF patients. Routine surveillance of iron status in these groups of patients with chronic conditions is advisable to detect ID early. Depending on the inflammatory state, TSAT < 20% may be the more accurate diagnostic marker of ID than ferritin. Moreover, TSAT may also be the more reliable estimate for the prognosis, particularly in HF.

Is red distribution width a valid tool to predict impaired iron transport in heart failure?

Background

Impaired iron transport (IIT) is a form of iron deficiency (ID) defined as transferrin saturation (TSAT) < 20% irrespective of serum ferritin levels. It is frequently observed in heart failure (HF) where it negatively affects prognosis irrespective of anaemia.

Objectives

In this retrospective study we searched for a surrogate biomarker of IIT.

Methods

We tested the predictive power of red distribution width (RDW), mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC) to detect IIT in 797 non-anaemic HF patients.

Results

At ROC analysis, RDW provided the best AUC (0.6928). An RDW cut-off value of 14.2% identified patients with IIT, with positive and negative predictive values of 48 and 80%, respectively. Comparison between the true and false negative groups showed that estimated glomerular filtration rate (eGFR) was significantly higher (p = 0.0092) in the true negative vs. false negative group. Therefore, we divided the study population according to eGFR value: 109 patients with eGFR ≥ 90 ml/min/1.73 m², 318 patients with eGFR 60-89 ml/min/1.73 m², 308 patients with eGFR 30-59 ml/min/1.73 m² and 62 patients with eGFR < 30 ml/min/1.73 m². In the first group, positive and negative predictive values were 48 and 81% respectively, 51 and 85% in the second group, 48 and 73% in the third group and 43 and 67% in the fourth group.

Conclusion

RDW may be seen as a reliable marker to exclude IIT in non-anaemic HF patients with eGFR ≥60 ml/min/1.73 m².

Association between iron metabolism and non-alcoholic fatty liver disease: results from the National Health and Nutrition Examination Survey (NHANES 2017-2018) and a controlled animal study

BACKGROUND

Iron metabolism may be involved in the pathogenesis of the non-alcoholic fatty liver disease (NAFLD). The relationship between iron metabolism and NAFLD has not been clearly established. This study aimed to clarify the relationship between biomarkers of iron metabolism and NAFLD.

METHODS

Based on the National Health and Nutrition Examination Survey (NHANES), restricted cubic spline models and multivariable logistic regression were used to examine the association between iron metabolism [serum iron (SI), serum ferritin (SF), transferrin saturation (TSAT), and soluble transferrin receptor (sTfR)] and the risk for NAFLD. In addition, stratified subgroup analysis was performed for the association between TSAT and NAFLD. Moreover, serum TSAT levels were determined in male mice with NAFLD. The expression of hepcidin and ferroportin, vital regulators of iron metabolism, were analyzed in the livers of mice by quantitative real-time PCR (qRT-PCR) and patients with NAFLD by microarray collected from the GEO data repository.

RESULTS

Patients with NAFLD showed decreased SI, SF, and TSAT levels and increased STfR levels based on the NHANES. After adjusting for confounding factors, TSAT was significantly negatively correlated with NAFLD. Of note, the relationship between TSAT and NAFLD differed in the four subgroups of age, sex, race, and BMI (P for interaction < 0.05). Consistently, mice with NAFLD exhibited decreased serum TSAT levels. Decreased hepcidin and increased ferroportin gene expression were observed in the livers of patients and mice with NAFLD.

CONCLUSION

Serum TSAT levels and hepatic hepcidin expression were decreased in both patients and mice with NAFLD. Among multiple biomarkers of iron metabolism, lower TSAT levels were significantly associated with a higher risk of NAFLD in the U.S. general population. These findings might provide new ideas for the prediction, diagnosis, and mechanistic exploration of NAFLD.

Iron deficiency screening is a key issue in chronic inflammatory diseases: A call to action

Iron deficiency is frequent in patients with chronic inflammatory conditions (e.g., chronic heart failure, chronic kidney disease, cancers, and bowel inflammatory diseases). Indeed, high concentrations of inflammatory cytokines increase hepcidin concentrations that lead to the sequestration of iron in cells of the reticuloendothelial system (functional iron deficiency). Iron parameters are often assessed only in the context of anemia, but iron deficiency, even without anemia, is present in about half of patients with inflammatory conditions. Iron deficiency worsens underlying chronic diseases and is an independent factor of morbidity and mortality. In daily practice, the most effective biomarkers of iron status are serum ferritin, which reflects iron storage, and transferrin saturation, which reflects the transport of iron. Serum ferritin is increased in an inflammatory context, and there is still no consensus on the threshold to be used in chronic inflammatory conditions. Nevertheless, recent recommendations of international guidelines agreed to define iron deficiency by serum ferritin &lt;100 µg/L and/or transferrin saturation &lt;20%. Iron parameters remain, however, insufficiently assessed in patients with chronic inflammatory conditions. Indeed, clinical symptoms of iron deficiency, such as fatigue, are not specific and often confused with those of the primary disease. Iron repletion, preferably by the intravenous route to bypass tissue sequestration, improves clinical signs and quality of life. Because of the negative impact of iron deficiency on chronic inflammatory diseases and the efficacy of intravenous iron repletion, screening of iron parameters should be part of the routine examination of all patients with chronic inflammatory diseases.

Prevalence and clinical associations of iron deficiency in patients with decompensated heart failure, depending on the diagnostic criteria used for iron deficiency

Aim. To compare the frequency of iron deficiency (ID) in patients with decompensated heart failure (HF), defined by international guideline criterion ferritin 100 ng/ml or ferritin from 100 to 299 ng/ml with TSAT20% (criterion A) and by bone marrow biopsy criterion TSAT19.8% and serum iron 13 mol/l (criterion B); to evaluate the effect of ID, diagnosed on the basis of different ID criteria, on NT pro-BNP, sST2, CRP levels and New York Heart Association (NYHA) functional classes (FC) distribution between groups with ID and without ID. Materials and methods. The study included 223 patients (median age 73 [65; 82] years, 58% males) who were hospitalized to V.V. Vinogradov Moscow City Clinical Hospital No. 64 with decompensated HF. All patients underwent a standard physiological examination, laboratory and instrumental studies, including determination of NT-proBNP, sST2, CRP, and ferrokinetic parameters (serum iron, transferrin, ferritin). TSAT was calculated as: serum iron / transferrin 3.98. NYHA FC was determined according to Heart Failure Severity Rating Scale score. All patients underwent echocardiography to assess the ejection fraction of the left ventricle. Results. According to criterion A ID was detected in 89% (n=199) of patients. There were no significant differences between levels of CRP, NT-proBNP and sST2. According to criterion B ID was detected in 70% (n=156) of patients. In the ID group, higher levels of CRP (15.1 mg/l vs 6.2 mg/l, p0.001), NT-proBNP (5422 pg/ml vs 2380 pg/ml, p0.001) and sST2 (59.6 ng/ml vs 42 ng/ml, p=0.02) were detected. Intravenous FCM admission according to current international guidelines (diagnosis of ID according to criterion A) is recommended to 57% of patients included in this study. Both methods formed groups with ID, in which patients had higher NYHA FC compared to groups without ID. According to current clinical guidelines, iron deficiency should be assessed according to method 1. More than half of patients (57, n=127) have indications for intravenous FCM to reduce risk of HF hospitalizations. Conclusion. The frequency of ID in patients with decompensated heart failure varies from 70 to 89% depending on the criterion used to diagnose ID, but in any case, remains high. Intravenous FCM should be prescribed in 57% (n=127) of patients. Criterion B, validated against the gold standard of diagnostics, unlike criterion A, makes it possible to form groups of patients with ID and without ID, significantly differing in CRP, NT-proBNP, and sST2 levels.

Deficiência de Ferro na Insuficiência Cardíaca com Fração de Ejeção Reduzida: Fisiopatologia, Diagnóstico e Tratamento

A deficiência de ferro (DF) ou ferropenia é uma importante comorbidade na insuficiência cardíaca com fração de ejeção reduzida (ICFER) estável, e muito prevalente tanto nos anêmicos como não anêmicos. A ferropenia na ICFER deve ser pesquisada por meio da coleta de saturação de transferrina e ferritina. Há dois tipos de ferropenia na IC: absoluta, em que as reservas de ferro estão depletadas; e funcional, onde o suprimento de ferro é inadequado apesar das reservas normais. A ferropenia está associada com pior classe funcional e maior risco de morte em pacientes com ICFER, e evidências científicas apontam melhora de sintomas e de qualidade de vida desses pacientes com tratamento com ferro parenteral na forma de carboximaltose férrica. O ferro exerce funções imprescindíveis como o transporte (hemoglobina) e armazenamento (mioglobina) de oxigênio, além de ser fundamental para o funcionamento das mitocôndrias, constituídas de proteínas à base de ferro, e local de geração de energia na cadeia respiratória pelo metabolismo oxidativo. A geração insuficiente e utilização anormal de ferro nas células musculares esquelética e cardíaca contribuem para a fisiopatologia da IC. A presente revisão tem o objetivo de aprofundar o conhecimento a respeito da fisiopatologia da ferropenia na ICFER, abordar as ferramentas disponíveis para o diagnóstico e discutir sobre a evidência científica existente de reposição de ferro.

Towards a Common Definition for the Diagnosis of Iron Deficiency in Chronic Inflammatory Diseases

Iron deficiency (ID) in patients with chronic inflammatory diseases is frequent. However, under-diagnosis is also frequent due to the heterogeneity between guidelines from different medical societies. We applied a common definition for the diagnosis of ID to a large panel of patients with cancer, heart failure (HF), inflammatory bowel disease (IBD), and chronic kidney disease (CKD), where ID was defined as serum ferritin concentration <100 μg/L and/or a transferrin saturation (TSAT) index <20%. Prevalence estimates using this common definition were compared with that obtained with officially accepted definitions (ESMO 2018, ESC 2016, ECCO 2015, and ERBP 2013). For that purpose, we used data collected during the French CARENFER studies, which included 1232, 1733, 1090, and 1245 patients with cancer, HF, IBD, and CKD, respectively. When applying the common definition, ID prevalence increased to 58.1% (vs. 57.9%), 62.8% (49.6%), and 61.2% (23.7%) in cancer, HF, and IBD patients, respectively. Both prevalence estimates were similar (47.1%) in CKD patients. Based on our results, we recommend combining both ferritin concentration and TSAT index to define ID in patients with chronic inflammatory diseases. In those patients, adopting this common definition of ID should contribute to a better screening for ID, whatever the condition.

Iron deficiency in heart failure patients: the French CARENFER prospective study

Aims

Iron deficiency (ID) is reported as one of the main co‐morbidities in patients with chronic heart failure (CHF), which then influences quality of life and prognosis. The CARENFER study aimed to assess the prevalence of ID in a large panel of heart failure (HF) patients at different stages of the disease.

Methods and results

This prospective cross‐sectional nationwide study was conducted in 48 medical units in France in 2019. Serum ferritin concentration and transferrin saturation (TSAT) index were determined in all eligible patients with a diagnosis of HF. ID diagnosis was based on the European Society of Cardiology (ESC) 2016 guidelines. Patients were classified as having either a decompensated HF or a CHF. Left ventricular ejection fraction (LVEF) was categorized as preserved (≥50%), mildly reduced (40–49%), or reduced (<40%). ID diagnosis was determined in 1661 patients, of whom 1475 could be classified as having a decompensated HF or a CHF. Patients' median age was 78 years. Decompensated HF represented 60.1% of cases. The overall prevalence of ID was 49.6% (47.1–52.1). In CHF and decompensated HF patients, respectively, ID prevalence was 39.0% (35.1–43.1) and 58.1% (54.7–61.4), P < 0.001; TSAT < 20% was respectively reported in 34.7% and 70.0% of patients (P < 0.001). Patients with preserved LVEF were more likely to have an ID (57.5%) compared with patients with mildly reduced (47.4%) or reduced LVEF (44.3%) (P < 0.001).

Conclusions

Iron deficiency was highly prevalent in patients with decompensated HF or CHF with preserved LVEF. ID prevalence defined by TSAT was higher than by the ESC criteria in decompensated HF patients, questioning the importance of ID definition to assess its prevalence.

Role of impaired iron transport on exercise performance in heart failure patients

AIMS

Impaired iron transport (IIT) occurs frequently in heart failure (HF) patients, even in the absence of anaemia and it is associated with a poor quality of life and prognosis. The impact of IIT on exercise capacity, as assessed by the cardiopulmonary exercise test (CPET), in HF is at present unknown. The aim of this article is to evaluate in HF patients the impact on exercise performance of IIT, defined as transferrin saturation (TSAT) <20%.

METHODS AND RESULTS

We collected data of 676 patients hospitalized for HF. All underwent laboratory analysis, cardiac ultrasound, and CPET. Patients were grouped by the presence/absence of IIT and anaemia (haemoglobin <13 and <12 g/dL in male and female, respectively): Group 1 (G1) no anaemia, no IIT; Group 2 (G2) anaemia, no IIT; Group 3 (G3) no anaemia, IIT; Group 4 (G4) anaemia and IIT. Peak oxygen uptake (peakVO2) reduced from G1 to G3 and from G2 to G4 (G1: 1266 ± 497 mL/min, G2: 1011 ± 385 mL/min, G3: 1041 ± 395 mL/min, G4: 833 ± 241 mL/min), whereas the ventilation to carbon dioxide relationship slope (VE/VCO2 slope) increased (G1: 31.8 ± 7.5, G2: 34.5 ± 7.4, G3: 36.1 ± 10.2, G4: 37.5 ± 8.4). At multivariate regression analysis, peakVO2 independent predictors were anaemia, brain natriuretic peptide (BNP), and left ventricular ejection fraction, whereas VE/VCO2 slope independent predictors were IIT and BNP.

CONCLUSION

In HF IIT is associated with exercise performance impairment independently from anaemia, and it is a predictor of elevated VE/VCO2 slope, a pivotal index of HF prognosis.

Iron Deficiency and Reduced Muscle Strength in Patients with Acute and Chronic Ischemic Stroke

(1) Introduction: Iron deficiency (ID) contributes to impaired functional performance and reduced quality of life in patients with chronic illnesses. The role of ID in stroke is unclear. The aim of this prospective study was to evaluate the prevalence of ID and to evaluate its association with long-term functional outcome in patients with ischemic stroke. (2) Patients and Methods: 140 patients (age 69 ± 13 years, BMI 27.7 ± 4.6 kg/m², mean ± SD) admitted to a university hospital stroke Unit, with acute ischemic stroke of the middle cerebral artery were consecutively recruited to this observational study. Study examinations were completed after admission (3 ± 2 days after acute stroke) and at one-year follow up (N = 64, 382 ± 27 days after stroke). Neurological status was evaluated according to the National Institute of Health Stroke Scale (NIHSS) and the modified Rankin scale (mRS). Muscle isometric strength of the non-affected limb was assessed by the maximum handgrip test and knee extension leg test. ID was diagnosed with serum ferritin levels ≤ 100 µg/L (ID Type I) or 100-300 µg/L if transferrin saturation (TSAT) < 20% (ID Type II). (3) Results: The prevalence of ID in acute stroke patients was 48% (N = 67), with about two-thirds of patients (N = 45) displaying ID Type I and one-third (N = 22) Type II. Handgrip strength (HGS) and quadriceps muscle strength were reduced in patients with ID compared to patients without ID at baseline (HGS: 26.5 ± 10.4 vs. 33.8 ± 13.2 kg, p < 0.001 and quadriceps: 332 ± 130 vs. 391 ± 143 N, p = 0.06). One year after stroke, prevalence of ID increased to 77% (p = 0.001). While an improvement of HGS was observed in patients with normal iron status, patients with ID had no improvement in HGS difference (4.6 ± 8.3 vs. -0.7 ± 6.5 kg, p < 0.05). Patients with ID remained with lower HGS compared to patients with normal iron status (28.2 ± 12.5 vs. 44.0 ± 8.6 kg, p < 0.0001). (4) Conclusions: Prevalence of ID was high in patients after acute stroke and further increased one year after stroke. ID was associated with lower muscle strength in acute stroke patients. In patients with ID, skeletal muscle strength did not improve one year after stroke.

Iron Deficiency in Heart Failure: Mechanisms and Pathophysiology

Iron is an essential micronutrient for a myriad of physiological processes in the body beyond erythropoiesis. Iron deficiency (ID) is a common comorbidity in patients with heart failure (HF), with a prevalence reaching up to 59% even in non-anaemic patients. ID impairs exercise capacity, reduces the quality of life, increases hospitalisation rate and mortality risk regardless of anaemia. Intravenously correcting ID has emerged as a promising treatment in HF as it has been shown to alleviate symptoms, improve quality of life and exercise capacity and reduce hospitalisations. However, the pathophysiology of ID in HF remains poorly characterised. Recognition of ID in HF triggered more research with the aim to explain how correcting ID improves HF status as well as the underlying causes of ID in the first place. In the past few years, significant progress has been made in understanding iron homeostasis by characterising the role of the iron-regulating hormone hepcidin, the effects of ID on skeletal and cardiac myocytes, kidneys and the immune system. In this review, we summarise the current knowledge and recent advances in the pathophysiology of ID in heart failure, the deleterious systemic and cellular consequences of ID.

Blood Differential Gene Expression in Patients with Chronic Heart Failure and Systemic Iron Deficiency: Pathways Involved in Pathophysiology and Impact on Clinical Outcomes

Background: Iron deficiency is a common disorder in patients with heart failure and is related with adverse outcomes and poor quality of life. Previous experimental studies have shown biological connections between iron homeostasis, mitochondrial metabolism, and myocardial function. However, the mechanisms involved in this crosstalk are yet to be unfolded. Methods: The present research attempts to investigate the intrinsic biological mechanisms between heart failure and iron deficiency and to identify potential prognostic biomarkers by determining the gene expression pattern in the blood of heart failure patients, using whole transcriptome and targeted TaqMan^® low-density array analyses. Results: We performed a stepwise cross-sectional longitudinal study in a cohort of chronic heart failure patients with and without systemic iron deficiency. First, the full transcriptome was performed in a nested case-control exploratory cohort of 7 paired patients and underscored 1128 differentially expressed transcripts according to iron status (cohort1#). Later, we analyzed the messenger RNA levels of 22 genes selected by their statistical significance and pathophysiological relevance, in a validation cohort of 71 patients (cohort 2#). Patients with systemic iron deficiency presented lower mRNA levels of mitochondrial ferritin, sirtuin-7, small integral membrane protein 20, adrenomedullin and endothelin converting enzyme-1. An intermediate mitochondrial ferritin gene expression and an intermediate or low sirtuin7 and small integral membrane protein 20 mRNA levels were associated with an increased risk of all-cause mortality and heart failure admission ((HR 2.40, 95% CI 1.04–5.50, p-value = 0.039), (HR 5.49, 95% CI 1.78–16.92, p-value = 0.003), (HR 9.51, 95% CI 2.69–33.53, p-value < 0.001), respectively). Conclusions: Patients with chronic heart failure present different patterns of blood gene expression depending on systemic iron status that affect pivotal genes involved in iron regulation, mitochondrial metabolism, endothelial function and cardiovascular physiology, and correlate with adverse clinical outcomes.

Impact of change in iron status over time on clinical outcomes in heart failure according to ejection fraction phenotype

Aims

The importance of iron deficiency (ID) in heart failure with preserved ejection fraction (HFpEF) is unknown. In HF with reduced ejection fraction (HFrEF), ID is reported as an independent predictor of mortality in HF although not all published studies agree. Different definitions of ID have been assessed, and the natural history of untreated ID not established, which may explain the conflicting results. This study aimed to assess the relationship between ID and mortality in HFpEF, clarify which definition of ID correlates best with outcomes in HFrEF, and determine the prognostic importance of change in ID status over time.

Methods and results

Analyses were conducted on data from 1563 patients participating in a prospective international cohort study comparing HFpEF with HFrEF. Plasma samples from baseline and 6 month visits were analysed for the presence of ID. Two ID definitions were evaluated: ID_Ferritin = ‘ferritin < 100 mcg/L or ferritin 100–300 mcg/L + transferrin saturation < 20%’ and ID_Tsat = ‘transferrin saturation < 20%’. The risk of all‐cause mortality and death/HF hospitalization associated with baseline ID (ID_Ferritin or ID_Tsat) and change in ID status at 6 months (persistent, resolving, developing, or never present) was estimated in multivariable Cox proportional hazards models. Of 1563 patients, 1115 (71%) had HFrEF and 448 (29%) HFpEF. Prevalence of ID was similar in HFpEF and HFrEF (58%). Patients with ID were more likely to be female, diabetic, and have a higher co‐morbid burden than patients without ID. ID by either definition did not confer independent risk for either all‐cause mortality or death/HF hospitalization for patients with HFpEF [ID_Ferritin hazard ratio (HR) 0.65 (95% confidence interval 0.40–1.05), P = 0.08; ID_Tsat HR 1.16 (0.72–1.87), P = 0.55]. In the overall study cohort (HFrEF + HFpEF) and HFrEF subgroup, ID_Ferritin was inferior to ID_Tsat in prediction of all‐cause mortality [overall cohort: HR 1.21 (0.95–1.53), P = 0.12 vs. HR 1.95 (1.52–2.51), P < 0.01; HFrEF: HR 1.12 (0.85–1.48), P = 0.43 vs. HR 1.57 (1.15–2.14), P < 0.01]. Persistence of ID_Tsat at 6 months was strongly associated with poor outcomes compared with never having ID_Tsat [HR 2.22 (1.42–3.46), P < 0.01] or having ID_Tsat at baseline self‐resolve by 6 months [HR 1.40 (1.06–1.86), P = 0.02].

Conclusions

Iron deficiency is equally prevalent in HFpEF and HFrEF but is negatively prognostic only in HFrEF. The natural history of ID is important; persistent ID is strongly associated with mortality whereas resolution is not. ID_Tsat is the superior definition of ID and should inform future trials investigating the efficacy of intravenous iron replacement in patients with HFrEF.

Iron replacement therapy in heart failure: a literature review

Background

Heart failure (HF) is a major global challenge, emphasised by its designation as the leading cause of hospitalisation in those aged 65 and above. Approximately half of all patients with HF have concurrent iron deficiency (ID) regardless of anaemia status. In HF, iron deficiency is independently associated with higher rates of hospitalisation and death, lower exercise capacity, and poorer quality-of-life than in patients without iron deficiency. With such consequences, several studies have investigated whether correcting ID can improve HF outcomes.

Main body.

As of 1st June 2021, seven randomised controlled trials have explored the use of intravenous (IV) iron in patients with HF and ID, along with various meta-analyses including an individual patient data meta-analysis, all of which are discussed in this review. IV iron was well tolerated, with a comparable frequency of adverse events to placebo. In the context of heart failure with reduced ejection fraction (HFrEF), IV iron reduces the risk of hospitalisation for HF, and improves New York Heart Association (NYHA) functional class, quality-of-life, and exercise capacity (as measured by 6-min walk test (6MWT)) distance and peak oxygen consumption. However, the effect of IV iron on mortality is uncertain. Finally, the evidence for IV iron in patients with acute decompensated heart failure, or heart failure with preserved ejection fraction (HFpEF) is limited.

Conclusions

IV iron improves some outcomes in patients with HFrEF and ID. Patients with HFrEF should be screened for ID, defined as ferritin < 100 µg/L, or ferritin 100–299 µg/L if transferrin saturation < 20%. If ID is found, IV iron should be considered, although causes of ID other than HF must not be overlooked.

Circulating heart failure biomarkers beyond natriuretic peptides: review from the Biomarker Study Group of the Heart Failure Association (HFA), European Society of Cardiology (ESC)

New biomarkers are being evaluated for their ability to advance the management of patients with heart failure. Despite a large pool of interesting candidate biomarkers, besides natriuretic peptides virtually none have succeeded in being applied into the clinical setting. In this review, we examine the most promising emerging candidates for clinical assessment and management of patients with heart failure. We discuss high-sensitivity cardiac troponins (Tn), procalcitonin, novel kidney markers, soluble suppression of tumorigenicity 2 (sST2), galectin-3, growth differentiation factor-15 (GDF-15), cluster of differentiation 146 (CD146), neprilysin, adrenomedullin (ADM), and also discuss proteomics and genetic-based risk scores. We focused on guidance and assistance with daily clinical care decision-making. For each biomarker, analytical considerations are discussed, as well as performance regarding diagnosis and prognosis. Furthermore, we discuss potential implementation in clinical algorithms and in ongoing clinical trials.

Certain Associations Between Iron Biomarkers and Total and γ' Fibrinogen and Plasma Clot Properties Are Mediated by Fibrinogen Genotypes

Introduction: Evidence for the relationship between body iron and cardiovascular disease (CVD) is inconsistent and mechanisms involved remain poorly understood. Therefore, we first investigated whether there are linear or non-linear relationships between iron status and total and γ' fibrinogen as well as plasma fibrin clot properties and, second, determined whether there are interactions with iron biomarkers and fibrinogen and FXIII single nucleotide polymorphisms (SNPs) in relation to fibrinogen concentration and functionality. Methods: In this cross-sectional analysis of 2,010 apparently healthy Black South Africans we quantified total and γ' fibrinogen, serum iron, ferritin and transferrin using standardized methods and calculated transferrin saturation (TS). Clot architecture and lysis were explored with a global analytical turbidity assay. The SNPs were determined through an Illumina BeadXpress^® platform. Results: Total, but not %γ', fibrinogen negatively correlated with serum iron concentrations, although both decreased over iron tertiles. %γ' fibrinogen correlated negatively with transferrin and decreased over the transferrin tertiles. A weak negative association between total fibrinogen and TS was detected with fibrinogen decreasing over the TS tertiles and categories based on TS. Lag time correlated positively with transferrin and increased over transferrin tertiles, when adjusting for fibrinogen. Before adjusting for fibrinogen, lag time was shorter in those with adequate iron status based on TS than other iron subcategories. Clot lysis time (CLT) negatively correlated with ferritin and was longer in the first than in the third ferritin tertile. Among iron status categories based on ferritin, only CLT differed and was longer in those with adequate iron than with iron-overload. CLT negatively correlated with TS, albeit weakly, shortened over the TS tertiles and was shorter in those with adequate iron based on TS categories. Interactions were observed between FGB SNPs and some of the markers of iron status investigated, in relation to the clot properties with the most prominent associations detected in homozygous carriers of the variant alleles for whom increased iron status was more beneficial than for those harboring the wild-type alleles. Iron modulated the influence of the SNPs so that for the majority iron was beneficial in respect of clot properties, but even more so for a minority group harboring specific variant alleles. Conclusion: This is the first large-scale epidemiological study to relate fibrinogen concentration and functionality to markers of iron status and to take genetic factors into consideration. We have detected a relationship between iron biomarkers and fibrinogen as well as clot characteristics that are influenced by the genetic make-up of an individual.

Intravenous iron for heart failure with evidence of iron deficiency: a meta-analysis of randomised trials

BACKGROUND

The recent AFFIRM-AHF trial assessing the effect of intravenous (IV) iron on outcomes in patients hospitalised with worsening heart failure who had iron deficiency (ID) narrowly missed its primary efficacy endpoint of recurrent hospitalisations for heart failure (HHF) or cardiovascular (CV) death. We conducted a meta-analysis to determine whether these results were consistent with previous trials.

METHODS

We searched for randomised trials of patients with heart failure investigating the effect of IV iron vs placebo/control groups that reported HHF and CV mortality from 1st January 2000 to 5th December 2020. Seven trials were identified and included in this analysis. A fixed effect model was applied to assess the effects of IV iron on the composite of first HHF or CV mortality and individual components of these.

RESULTS

Altogether, 2,166 patients were included (n = 1168 assigned to IV iron; n = 998 assigned to control). IV iron reduced the composite of HHF or CV mortality substantially [OR 0.73; (95% confidence interval 0.59-0.90); p = 0.003]. Outcomes were consistent for the pooled trials prior to AFFIRM-AHF. Whereas first HHF were reduced substantially [OR 0.67; (0.54-0.85); p = 0.0007], the effect on CV mortality was uncertain but appeared smaller [OR 0.89; (0.66-1.21); p = 0.47].

CONCLUSION

Administration of IV iron to patients with heart failure and ID reduces the risk of the composite outcome of first heart failure hospitalisation or cardiovascular mortality, but this outcome may be driven predominantly by an effect on HHF. At least three more substantial trials of intravenous iron are underway.

Natural history and prognostic significance of iron deficiency and anaemia in ambulatory patients with chronic heart failure

AIMS

Iron deficiency (ID) and anaemia are common in heart failure; less is known about changes over time.

METHODS AND RESULTS

We investigated prevalence, incidence and resolution of ID and anaemia in 906 patients with chronic heart failure (median age 73 (65-79) years, 70% men, 51% with heart failure with reduced ejection fraction) 1 year apart. ID was defined as serum iron ≤13 µmol/L and anaemia as haemoglobin <13.0 g/dL for men or <12.0 g/dL for women. FAIR-HF criteria for ID were also considered. At baseline, 10% had anaemia without ID, 23% had ID without anaemia, 20% had both, and 47% had neither. Percentages changed little over 1 year, but 157 (30%) patients had new-onset ID, 104 (16%) new-onset anaemia, whilst ID resolved in 173 (44%) and anaemia in 63 (23%). Compared to those who remained iron replete (iron >13 µmol/L), mortality was higher in those with persistent or incident ID at 1 year [hazard ratio (HR) 1.81 (1.23-2.67), and HR 1.40 (0.91-2.14), respectively] in multivariable models (P = 0.02). Compared to persistent ID, resolution of ID was associated with a lower mortality [HR 0.61 (0.44-0.86); P = 0.004]. Changes in ID defined by FAIR-HF criteria were not similarly associated with mortality. Anaemia was associated with a poor outcome even if it resolved.

CONCLUSIONS

The prevalence and incidence of ID and anaemia are high in chronic heart failure but so is the rate of resolution. Persistent or incident ID, defined by a serum iron ≤13 µmol/L, is associated with higher mortality and resolution of ID with lower mortality.

Intravenous iron for heart failure with evidence of iron deficiency: a meta-analysis of randomised trials

Background

The recent AFFIRM-AHF trial assessing the effect of intravenous (IV) iron on outcomes in patients hospitalised with worsening heart failure who had iron deficiency (ID) narrowly missed its primary efficacy endpoint of recurrent hospitalisations for heart failure (HHF) or cardiovascular (CV) death. We conducted a meta-analysis to determine whether these results were consistent with previous trials.

Methods

We searched for randomised trials of patients with heart failure investigating the effect of IV iron vs placebo/control groups that reported HHF and CV mortality from 1st January 2000 to 5th December 2020. Seven trials were identified and included in this analysis. A fixed effect model was applied to assess the effects of IV iron on the composite of first HHF or CV mortality and individual components of these.

Results

Altogether, 2,166 patients were included (n = 1168 assigned to IV iron; n = 998 assigned to control). IV iron reduced the composite of HHF or CV mortality substantially [OR 0.73; (95% confidence interval 0.59–0.90); p = 0.003]. Outcomes were consistent for the pooled trials prior to AFFIRM-AHF. Whereas first HHF were reduced substantially [OR 0.67; (0.54–0.85); p = 0.0007], the effect on CV mortality was uncertain but appeared smaller [OR 0.89; (0.66–1.21); p = 0.47].

Conclusion

Administration of IV iron to patients with heart failure and ID reduces the risk of the composite outcome of first heart failure hospitalisation or cardiovascular mortality, but this outcome may be driven predominantly by an effect on HHF. At least three more substantial trials of intravenous iron are underway.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01837-8.

Iron deficiency and short-term adverse events in patients with decompensated heart failure

BACKGROUND

For patients with heart failure (HF), iron deficiency (ID) is a common therapeutic target. However, little is known about the utility of transferrin saturation (TSAT) or serum ferritin for risk stratification in decompensated HF (DHF) or the European Society of Cardiology's (ESC) current definition of ID (ferritin < 100 μg/L or TSAT < 20% if ferritin is 100-299 μg/L). We evaluated the association between these potential markers of ID and the risk of 30-day readmission for HF or death in patients with DHF.

METHODS

We retrospectively included 1701 patients from a multicenter registry of DHF. Serum ferritin and TSAT were evaluated 24-72 h after hospital admission, and multivariable Cox regression was used to assess their association with the composite endpoint.

RESULTS

Participants' median (quartiles) age was 76 (68-82) years, 43.8% were women, and 51.7% had a left ventricular ejection fraction > 50%. Medians for NT-proBNP, TSAT, and ferritin were 4067 pg/mL (1900-8764), 14.1% (9.0-20.3), and 103 ug/L (54-202), respectively. According to the current ESC definition, 1,246 (73.3%) patients had ID. By day 30, there were 177 (10.4%) events (95 deaths and 85 HF readmission). After multivariable adjustment, lower TSAT was associated with outcome (p = 0.009) but serum ferritin was not (HR 1.00; 95% confidence interval 0.99-1.00, p = 0.347).

CONCLUSIONS

Lower TSAT, but not ferritin, was associated with a higher risk of short-term events in patients with DHF. Further research is needed to confirm these findings and the utility of serum ferritin as a marker of ID in DHF.

Prognostic role of transferrin saturation in heart failure patients

AIMS

In heart failure (HF) iron deficiency (ID) is frequently observed and represents a major mortality risk factor. Purpose of this study was to evaluate the correlation between mortality and ID in a cohort of 661 consecutive patients hospitalized for HF worsening.

METHODS AND RESULTS

Patients were grouped: (i)according to presence(+)/absence(-) of anaemia (A) and ID defined following World Health Organization (WHO) and European Society of Cardiology (ESC)-American College of Cardiology/American Heart Association/HF society of America (ACC/AHA/HFSA) definitions, respectively: Group A-ID- (n = 123), Group A+ID- (n = 80), Group A+ID+ (n = 247), and Group A-ID+ (n = 211); (ii) according to presence of absolute (serum ferritin < 100μg/L) and functional ID [ferritin between 100 and 300μg/L and transferrin saturation (TSAT) < 20%]; and (iii) according to TSAT <20% and ≥20%. Groups were not different for several clinical features but age, gender, kidney function, and chronic obstructive pulmonary disease. Average follow-up was 1.94 year (±420 days). Overall 5 years mortality rate was 29.5%. Only anaemia and functional ID but not ID as defined by guidelines showed an impact on prognosis. Transferrin saturation <20% (n = 360) patients showed worst prognosis compared to TSAT ≥20% (n = 301) patients. In addition, functional ID patients showed worse prognosis compared patients with ferritin <100μg/L and TSAT <20% or ≥20% likely due to more severe chronic inflammatory status [C-reactive protein, 7.4 (interquartile range 2.7-22.6) and 3.2 (1.4-8.7) mg/L, P < 0.0001 respectively].

CONCLUSION

We confirmed that in HF anaemia is associated to a poor prognosis. Moreover, we showed that patients with TSAT <20% had worse prognosis compared to those with TSAT ≥20% but the composite of ferritin between 100 and 300 μg/L and TSAT <20% identifies HF patients with the poorest survival rate.

The prevalence of iron deficiency and anemia and their impact on survival in patients at a cardio-oncology clinic

Background

Iron deficiency (ID) and anemia are common in both heart failure (HF) and cancer patients and are associated with poor quality of life and survival. The aims of this study were (1) to evaluate the prevalence, types, and confounding factors of ID and anemia in patients referred to cardio-oncology clinic, and (2) identify the association between iron metabolism parameters and survival of cardio-oncology patients.

Methods

We assessed iron, ferritin, hemoglobin concentrations, transferrin saturation (TSAT), cancer type, brain natriuretic peptide (BNP), left ventricular ejection fraction (LVEF), kidney function, cardiovascular risk factors and survival in 599 patients who were referred to cardio-oncology clinic from 2011 to 2017.

ID was defined by a TSAT < 20%, absolute iron deficiency (AID) with a serum ferritin level < 100 μg/L while serum ferritin level of ≥ 100 μg/L was considered as functional iron deficiency (FID) and TSAT ≥ 20% was considered as no ID.

Results

The prevalence of ID, AID, and FID was 46, 31, and 15% of study patients, respectively. Anemia was present in approximately half (54%) of the patients with any ID.

Multivariate Cox analyses showed that male gender (HR 1.704 [1.207–2.404] p = 0.002); previous cancer history (HR 1.879 [1.079–3.272] p = 0.026); elevated BNP (HR 2.126 [1.258–3.590] p = 0.005); TSAT< 20% (HR 1.721 [1.214–2.439] p = 0.002); ferritin ≥ 100 μg/L (HR 2.008 [1.088–3.706] p = 0.026); serum iron concentration < 12 μmol/L (HR 2.292 [1.614–3.255] p < 0.001); FID (HR 2.538 [1.1618–3.981] p < 0.001) and anemia (HR 2.462 [1.734–3.495] p < 0.001) were significantly associated with increased risk of all-cause death.

Conclusions

About half of cardio-oncology patients had anemia and iron deficiency, with the absolute type being twice as prevalent as the functional one. Patients with breast, gastrointestinal, and genitourinary cancer were affected more often. Both anemia and iron deficiency independently predicted all-cause mortality. Future studies are required to confirm ID as a risk factor and evaluate the clinical benefits of iron replacement therapy.

Accurate Noninvasive Assessment of Myocardial Iron Load in Advanced Heart Failure Patients

Background

Heart failure patients presenting with iron deficiency can benefit from systemic iron supplementation; however, there is the potential for iron overload to occur, which can seriously damage the heart. Therefore, myocardial iron (M-Iron) content should be precisely balanced, especially in already failing hearts. Unfortunately, the assessment of M-Iron via repeated heart biopsies or magnetic resonance imaging is unrealistic, and alternative serum markers must be found. This study is aimed at assessing M-Iron in patients with advanced heart failure (HF) and its association with a range of serum markers of iron metabolism.

Methods

Left ventricle (LV) myocardial biopsies and serum samples were collected from 33 consecutive HF patients (25 males) with LV dysfunction (LV ejection fraction 22 (11) %; NT-proBNP 5464 (3308) pg/ml) during heart transplantation. Myocardial ferritin (M-FR) and soluble transferrin receptor (M-sTfR1) were assessed by ELISA, and M-Iron was determined by Instrumental Neutron Activation Analysis in LV biopsies. Nonfailing hearts (n = 11) were used as control/reference tissue. Concentrations of serum iron-related proteins (FR and sTfR1) were assessed.

Results

LV M-Iron load was reduced in all HF patients and negatively associated with M-FR (r = -0.37, p = 0.05). Of the serum markers, sTfR1/logFR correlated with (r = -0.42; p = 0.04) and predicted (in a step-wise analysis, R ² = 0.18; p = 0.04) LV M-Iron. LV M-Iron load (μg/g) can be calculated using the following formula: 210.24-22.869 × sTfR1/logFR.

Conclusions

The sTfR1/logFR ratio can be used to predict LV M-Iron levels. Therefore, serum FR and sTfR1 levels could be used to indirectly assess LV M-Iron, thereby increasing the safety of iron repletion therapy in HF patients.

Impact of non-cardiovascular comorbidities on the quality of life of patients with chronic heart failure: a scoping review

PURPOSE

To determine the impact of non-cardiovascular comorbidities on the health-related quality of life (HRQoL) of patients with chronic heart failure (CHF).

METHODS

A scoping review of the scientific literature published between 2009 and 2019 was carried out. Observational studies which assessed the HRQoL of patients with CHF using validated questionnaires and its association with non-cardiovascular comorbidities were included.

RESULTS

The search identified 1904 studies, of which 21 fulfilled the inclusion criteria to be included for analysis. HRQoL was measured through specific, generic, or both types of questionnaires in 72.2%, 16.7%, and 11.1% of the studies, respectively. The most common comorbidities studied were diabetes mellitus (12 studies), mental and behavioral disorders (8 studies), anemia and/or iron deficiency (7 studies), and respiratory diseases (6 studies). Across studies, 93 possible associations between non-cardiovascular comorbidities and HRQoL were tested, of which 21.5% regarded anemia or iron deficiency, 20.4% mental and behavioral disorders, 20.4% diabetes mellitus, and 14.0% respiratory diseases. Despite the large heterogeneity across studies, all 21 showed that the presence of a non-cardiovascular comorbidity had a negative impact on the HRQoL of patients with CHF. A statistically significant impact on worse HRQoL was found in 84.2% of associations between mental and behavioral disorders and HRQoL (patients with depression had up to 200% worse HRQoL than patients without depression); 73.7% of associations between diabetes mellitus and HRQoL (patients with diabetes mellitus had up to 21.8% worse HRQoL than patients without diabetes mellitus); 75% of associations between anemia and/or iron deficiency and HRQoL (patients with anemia and/or iron deficiency had up to 25.6% worse HRQoL than between patients without anemia and/or iron deficiency); and 61.5% of associations between respiratory diseases and HRQoL (patients with a respiratory disease had up to 21.3% worse HRQoL than patients without a respiratory disease).

CONCLUSION

The comprehensive management of patients with CHF should include the management of comorbidities which have been associated with a worse HRQoL, with special emphasis on anemia and iron deficiency, mental and behavioral disorders, diabetes mellitus, and respiratory diseases. An adequate control of these comorbidities may have a positive impact on the HRQoL of patients.

Iron deficiency markers in patients undergoing iron replacement therapy: a 9-year retrospective real-world evidence study using healthcare databases

The diagnosis and treatment of iron deficiency is a primary public health goal. This study aimed to make an inventory of the use of biomarkers to assess the iron supply in patients given iron replacement therapy. A retrospective longitudinal real-world study of a cohort of patients receiving iron replacement therapy was conducted using data from healthcare coverage databases between January 2006 and December 2015 in France. The frequency of oral or intravenous iron treatment episodes preceded and/or followed by a biological assessment of iron deficiency was described. We then differentiate patients with or without chronic inflammatory diseases, which could impact the prescription. The evolution between 2006 and 2015 was also studied. The 96,724 patients received an average of 4.9 administrations of iron per patient, corresponding to 1.7 treatment episodes. In one-third of treatment episodes (34.6%), patients had a pre-treatment biological assessment, 15.5% a post-treatment assessment, and 7.3% both. The post-treatment measure of iron supply markers (i.e., Ferritin and transferrin saturation) was more frequent in patients suffering from chronic inflammatory diseases than in those without underlying chronic condition (22.6% to 41.0% vs. 3.1%; p < 0.0001). Serum ferritin was measured 30 times more than transferrin saturation measurements. The use of both tests increased steadily during the study period, although remaining low. Despite the recommendations, biological assessments of iron status are seldom prescribed and/or performed in the context of a pre- or post-treatment assessment, although more frequently realized in patients with chronic inflammatory diseases.

Should we use ferritin in the diagnostic criteria of iron deficiency in heart failure patients?

BACKGROUND AND AIMS

Iron deficiency (ID) is a common comorbidity in patients with chronic heart failure (HF) and is associated with worse prognosis. We aimed at comparing the currently European Society of Cardiology (ESC) criterion for diagnosis of ID (ferritin < 100 μg/L or ferritin 100-299 μg/L with transferrin saturation [TSAT] < 20%) with either isolated low TSAT or isolated low ferritin on survival, in a cohort of HF patients.

METHODS

This was an observational prospective study, investigating ambulatory patients with HF and reduced ejection fraction (n = 108). All patients were assessed for clinical aspects and iron indexes. The primary endpoint was all-cause death.

RESULTS

Abnormal iron status was observed in 50 (46%) of patients. During the median follow-up time of 857.5 [647-899] days, 31 patients died (29%). In univariate analyses ESC-criterion (p = 0.022) and isolated TSAT <20% (p = 0.002), but not isolated ferritin <100 μg/L (p = 0.439), were significantly related to an increased risk of all-cause death. However, in multivariate analyses only TSAT <20% (HR = 2.3; [95% CI: 1.11-4.85]; p = 0.026) was independently related to all-cause mortality.

CONCLUSIONS

Our results indicated that diagnosis of ID based on isolated TSAT <20% identifies HF patients with worse prognosis, while ferritin was not associated with mortality risk, suggesting that ferritin should not be taken into account for evaluation of clinical impact of ID in HF patients.

Anaemia, iron status, and gender predict the outcome in patients with chronic heart failure

Aims

Anaemia and iron deficiency (ID) are frequently found in patients with chronic heart failure (CHF) and associated with adverse outcome. However, it is unclear whether absolute [transferrin saturation (TSAT) <20%, ferritin <100 μg/L] or inflammation‐driven functional ID (TSAT <20%, ferritin >100 μg/L) with and without anaemia had similar or different consequences for such patients.

Methods and results

Within this retrospective cohort study, 2223 patients (1601 men and 622 women) with CHF, referred to our department, between 2000 and 2018, were followed for a median time of 84 months. Anaemia was found in 393 patients and was an independent predictor for an adverse outcome [HR 2.164 (95% CI 1.865–2.512), P < 0.001]. In 674 patients with available parameters of iron metabolism, ID was present in 228 patients and was associated with an unfavourable outcome [HR 1.499 (95% CI 1.158–1.940), P = 0.002]. ID was best predicting an adverse outcome in men ≤59 years, with heart failure with reduced ejection fraction, preserved kidney function, no inflammation, and a body mass index (BMI) ≥25.5 kg/m². Functional ID in women and absolute ID in men were associated with poor prognosis. Of note, TSAT <20% but not low ferritin levels were predictive for an adverse outcome. Anaemic patients with high ferritin levels, advanced inflammation, older age, low BMI, male gender, and reduced glomerular filtration rate had the worst prognosis.

Conclusions

Anaemia and low tissue iron availability as reflected by TSAT <20% are negative predictors of outcome in patients with CHF. Systemic inflammation, renal function, BMI, age, and gender are important contributors for the clinical course.

Iron Deficiency: Impact on Functional Capacity and Quality of Life in Heart Failure with Preserved Ejection Fraction

The effects of iron deficiency (ID) have been widely studied in heart failure (HF) with reduced ejection fraction. On the other hand, studies in HF with preserved ejection fraction (HFpEF) are few and have included small numbers of participants. The aim of this study was to assess the role that ID plays in functional capacity and quality of life (QoL) in HFpEF while comparing several iron-related biomarkers to be used as potential predictors. ID was defined as ferritin <100 ng/mL or transferrin saturation <20%. Submaximal exercise capacity, measured by the 6-min walking test (6MWT), and QoL, assessed by the Minnesotta Living with Heart Failure Questionnaire (MLHFQ), were compared between iron deficient patients and patients with normal iron status. A total of 447 HFpEF patients were included in the present cross-sectional study, and ID prevalence was 73%. Patients with ID performed worse in the 6MWT compared to patients with normal iron status (ID 271 ± 94 m vs. non-ID 310 ± 108 m, p < 0.01). They also scored higher in the MLHFQ, denoting worse QoL (ID 49 ± 22 vs. non-ID 43 ± 23, p = 0.01). Regarding iron metabolism biomarkers, serum soluble transferrin receptor (sTfR) was the strongest independent predictor of functional capacity (β = −63, p < 0.0001, R² 0.39) and QoL (β = 7.95, p < 0.0001, R² 0.14) in multivariate models. This study postulates that ID is associated with worse functional capacity and QoL in HFpEF as well, and that sTfR is the best iron-related biomarker to predict both. Our study also suggests that the effects of ID could differ among HFpEF patients by left ventricular ejection fraction.

Association Between Norepinephrine Levels and Abnormal Iron Status in Patients With Chronic Heart Failure: Is Iron Deficiency More Than a Comorbidity?

Background

Mechanisms underlying iron homeostasis dysregulation in patients with chronic heart failure remain unsettled. In cardiomyocyte models, norepinephrine may lead to intracellular iron depletion, but the potential association between catecholamines (sympathetic activation markers) and iron metabolism biomarkers in chronic heart failure is unknown.

Methods and Results

In this cross‐sectional analysis, we studied the association between plasma norepinephrine levels and serum iron status biomarkers indicating iron storage (ferritin), iron transport (transferrin saturation), and iron demand (soluble transferrin receptor) in a prospective cohort of 742 chronic heart failure patients (mean age, 72±11 years; 56% male). Impaired iron status was defined as ferritin <100 μg/L or transferrin saturation <20%. Impaired iron status was observed in 69% of patients. In multivariate models, greater norepinephrine levels were associated with impaired iron transport (transferrin saturation <20%, odds ratio=2.28; 95% CI [1.19–4.35]; P=0.013), but not with impaired iron storage (ferritin <100 μg/L, odds ratio=1.25; 95% CI [0.73–2.16]; P=0.415). Norepinephrine was a significant predictor of increased iron demand (soluble transferrin receptor, standardized β‐coefficient=0.12; P=0.006) and low transferrin saturation (standardized β‐coefficient=−0.12; P=0.003). However, norepinephrine levels were not associated with iron or ferritin levels (P>0.05). Adjusted norepinephrine marginal means were significantly higher in patients with impaired iron status compared with those with normal iron status (528 pg/mL [505–551] versus 482 pg/mL [448–518], respectively; P=0.038).

Conclusions

In chronic heart failure patients, increased sympathetic activation estimated with norepinephrine levels is associated with impaired iron status and, particularly, dysregulation of biomarkers suggesting impaired iron transport and increased iron demand. Whether the relationship between norepinephrine and iron metabolism is bidirectional and entails causality need to be elucidated in future research.

Noncardiac Versus Cardiac Mortality in Heart Failure With Preserved, Midrange, and Reduced Ejection Fraction

Background

A thorough analysis of noncardiac determinants of mortality in heart failure (HF) is missing. Furthermore, evidence conflicts on the outcome of patients with HF and no or mild systolic dysfunction. We aimed to investigate the prevalence of noncardiac and cardiac causes of death in a cohort of chronic HF patients, covering the whole spectrum of systolic function.

Methods and Results

We enrolled 2791 stable HF patients, classified into HF with reduced ejection fraction (HFrEF; left ventricular ejection fraction [EF] <40%), HR with midrange EF (HFmrEF; left ventricular EF 41–49%), or HF with preserved EF (HFpEF; left ventricular EF ≥50%), and followed up for all‐cause, cardiac, and noncardiac mortality (adjudicated as due to cancer, sepsis, respiratory disease, renal disease, or other causes). Over follow‐up of 39 months, adjusted mortality was lower in HFpEF and HFmrEF versus HFrEF (hazard ratio: 0.75 [95% CI, 0.67–0.84], P<0.001 for HFpEF; hazard ratio: 0.78 [95% CI, 0.63–0.96], P=0.017 for HFmrEF). HFrEF had the highest rates of cardiac death, whereas noncardiac mortality was similar across left ventricular EF categories. Noncardiac causes accounted for 62% of deaths in HFpEF, 54% in HFmrEF and 35% in HFrEF; cancer was twice as frequent as a cause of death in HFpEF and HFmrEF versus HFrEF. Yearly rates of noncardiac death exceeded those of cardiac death since the beginning of follow‐up in HFpEF and HFmrEF.

Conclusions

Noncardiac death is a major determinant of outcome in stable HF, exceeding cardiac‐related mortality in HFpEF and HFmrHF. Comorbidities should be regarded as main therapeutic targets and objects of dedicated quality improvement initiatives, especially in patients with no or mild systolic dysfunction.

The Burden of Iron Deficiency in Heart Failure: Therapeutic Approach

Heart failure (HF) is highlighted by its burdening symptom-limited exercise capacity and recurrent hospitalizations. Despite substantial advances regarding disease-modifying drugs in HF with reduced ejection fraction, additional therapeutic strategies to improve quality of life are invaluable. Currently, iron deficiency (ID) is overwhelmingly recognized in over 30% to 50% of patients with stable chronic HF, which worsens prognosis. The established pathophysiological mechanisms of progressive HF may be intertwined with increasing myocardial iron scarcity, wherein one begets the other. Most importantly, ID constitutes a novel target for symptom relief in carefully selected patients. In this regard, intravenous iron may be a safe and efficacious intervention, potentially reducing HF hospitalizations. We discuss the evidence and gaps in knowledge concerning iron therapy in HF and propose a practical, comprehensive, clinically oriented algorithm for timely adequate iron replenishment in different clinical scenarios. Finally, we further debate imperative decision-making before intervention and the drawbacks of such a strategy.

Definition of Iron Deficiency Based on the Gold Standard of Bone Marrow Iron Staining in Heart Failure Patients

BACKGROUND

The most commonly used definition of iron deficiency (ID; ferritin <100 ng/mL or ferritin 100-300 ng/mL and transferrin saturation [TSAT] <20%) has not been validated in patients with heart failure (HF). We aimed to define and validate the biomarker-based definition of ID in HF, using bone marrow iron staining as the gold standard. Second, we aimed to assess the prognostic value of the optimized definition.

METHODS AND RESULTS

Bone marrow aspiration with iron staining was performed in 42 patients with HF and a reduced left ventricular ejection fraction (≤45%) undergoing median sternotomy for coronary artery bypass grafting. Patients were mostly male (76%) with mild-to-moderate HF and a mean age of 68±10 years. Bone marrow ID was found in 17 (40%) of the HF patients. The most commonly used definition of ID had a sensitivity of 82% and a specificity of 72%. A definition solely based on TSAT ≤19.8% or serum iron ≤13 µmol/L had a sensitivity of 94% and specificity of 84% and 88%, respectively (P<0.05 compared with the former definition). Subsequently, we assessed the incidence of all-cause mortality in 387 consecutive outpatient HF patients (left ventricular ejection fraction ≤45%). In these patients, TSAT ≤19.8% and serum iron ≤13 µmol/L, and not ferritin, were independently associated with mortality.

CONCLUSIONS

A TSAT ≤19.8% or a serum iron ≤13 µmol/L shows the best performance in selecting patients with ID and identifies HF patients at the highest risk of death. Our findings validate the currently used TSAT cutoff of <20% for the identification of ID in HF patients, but question the diagnostic value of ferritin.

Iron deficiency in chronic and acute heart failure: A contemporary review on intertwined conditions

Iron Deficiency (ID) is increasingly recognized as a prevalent comorbid condition in Heart Failure (HF). Despite this, the pathophysiological mechanisms for progressive ID in either chronic or acute HF are still poorly understood. Beyond the traditional factors for iron deficit in the general population, we ought to review the specificities of such paucity in the HF patient, particularly focusing on the interplay between heightened inflammation, overactivity of the sympathetic nervous system and the so-called cardio-renal-anaemia-ID syndrome. Currently, ID constitutes not only an independent prognostic marker but also a novel safe therapeutic target. Particularly, in selected stable HF patients with reduced left ventricular ejection fraction, intravenous (IV) iron improves symptomatic burden and reduces hospitalizations due to worsening HF. On this topic, the main trials of IV iron with either iron sucrose (Toblli et al., FERRIC-HF and IRON-HF) or ferric carboxymaltose (FAIR-HF, CONFIRM-HF and EFFECT-HF) will be summarized and discussed. Finally, we debate the gaps in knowledge of ID in special populations, namely the unreliability of routine plasmatic surrogate markers to assess iron status in acute and advanced HF, the challenging patient with both HF and Chronic Kidney Disease, as well as efficacy and safety concerns in these settings and the potential role of iron correction in cardiac resynchronization therapy candidates.