Intravenous iron supplementation improves energy metabolism of exercising skeletal muscles without effect on either oxidative stress or inflammation in male patients with heart failure with reduced ejection fraction.

BACKGROUND: Skeletal muscle dysfunction is a feature of heart failure (HF). Iron deficiency (ID) is prevalent in patients with HF associated with exercise intolerance and poor quality of life. Intravenous iron in iron deficient patients with HF has attenuated HF symptoms, however the pathomechanisms remain unclear. The aim of study was to assess whether intravenous iron supplementation as compared to placebo improves energy metabolism of skeletal muscles in patients with HF. METHODS: Men with heart failure with reduced ejection fraction (HFrEF) and ID were randomised in 1:1 ratio to either intravenous ferric carboxymaltose (IV FCM) or placebo. In vivo reduction of lactates by exercising skeletal muscles of forearm was analyzed. A change in lactate production between week 0 and 24 was considered as a primary endpoint of the study. RESULTS: There were two study arms: the placebo and the IV FCM (12 and 11 male patients with HFrEF). At baseline, there were no differences between these two study arms. IV FCM therapy as compared to placebo reduced the exertional production of lactates in exercising skeletal muscles. These effects were accompanied by a significant increase in both serum ferritin and transferrin saturation in the IV FCM arm which was not demonstrated in the placebo arm. CONCLUSIONS: Intravenous iron supplementation in iron deficient men with HFrEF improves the functioning of skeletal muscles via an improvement in energy metabolism in exercising skeletal muscles, limiting the contribution of anaerobic reactions generating ATP as reflected by a lower in vivo lactate production in exercising muscles in patients with repleted iron stores.

Iron Status and Short-Term Recovery after Non-Severe Acute Myocarditis: A Prospective Observational Study.

Pathomechanisms responsible for recovery from acute myocarditis (MCD) or progression to non-ischemic cardiomyopathy have not been comprehensively investigated. Iron, positioned at the crossroads of inflammation and the energy metabolism of cardiomyocytes, may contribute to the pathophysiology of inflammatory myocardial disease. The aim of this study was to evaluate whether systemic iron parameters are related to myocardial dysfunction in MCD patients. We prospectively enrolled 42 consecutive patients hospitalized for MCD. Their iron status and their clinical, laboratory, and echocardiographic indices were assessed during hospitalization and during ambulatory visits six weeks after discharge. A control group comprising healthy volunteers was recruited. The MCD patients had higher serum ferritin and hepcidin and lower serum iron concentration and transferrin saturation (TSAT) than the healthy controls (all p < 0.01). Six weeks after discharge, the iron status of the MCD patients was already comparable to that of the control group. During hospitalization, lower serum iron and TSAT correlated with higher NT-proBNP (both p < 0.05). In-hospital lower serum iron and TSAT correlated with both a lower left ventricular ejection fraction (LVEF) and worse left ventricular global longitudinal strain at follow-up visits (all p < 0.05). In conclusion, in patients with acute MCD, iron status is altered and normalizes within six weeks. Low serum iron and TSAT are related to greater in-hospital neurohormonal activation and subtle persistent left ventricular dysfunction.

Pathophysiology and Treatment Opportunities of Iron Deficiency in Heart Failure: Is There a Need for Further Trials?

PURPOSE OF REVIEW: Iron deficiency (ID) complicates heart failure (HF) at different stages of the natural history of the disease; however, this frequent comorbidity is still not comprehensively understood and investigated in terms of pathophysiology. Intravenous iron therapy with ferric carboxymaltose (FCM) should be considered to improve the quality of life, exercise capacity, and symptoms in stable HF with ID, as well as to reduce HF hospitalizations in iron-deficient patients stabilized after an episode of acute HF. The therapy with intravenous iron, however, continues to generate important clinical questions for cardiologists. RECENT FINDINGS: In the current paper, we discuss the class effect concept for intravenous iron formulations beyond FCM, based on the experiences of nephrologists who administer different intravenous iron formulations in advanced chronic kidney disease complicated with ID and anemia. Furthermore, we discuss the neutral effects of oral iron therapy in patients with HF, because there are still some reasons to further explore this route of supplementation. The different definitions of ID applied in HF studies and new doubts regarding possible interactions of intravenous iron with sodium-glucose co-transporter type 2 inhibitors are also emphasized. The experiences of other medical specializations may provide new information on how to optimally replenish iron in patients with HF and ID.

Iron Deficiency and Deranged Myocardial Energetics in Heart Failure.

Among different pathomechanisms involved in the development of heart failure, adverse metabolic myocardial remodeling closely related to ineffective energy production, constitutes the fundamental feature of the disease and translates into further progression of both cardiac dysfunction and maladaptations occurring within other organs. Being the component of key enzymatic machineries, iron plays a vital role in energy generation and utilization, hence the interest in whether, by correcting systemic and/or cellular deficiency of this micronutrient, we can influence the energetic efficiency of tissues, including the heart. In this review we summarize current knowledge on disturbed energy metabolism in failing hearts as well as we analyze experimental evidence linking iron deficiency with deranged myocardial energetics.

Iron deficiency as an emerging therapeutic target in patients stabilized after an episode of acute heart failure.

Acute heart failure (AHF) syndromes are among the most frequent causes of hospitalization in the elderly and put a heavy financial burden on healthcare systems, mainly due to high early readmission rates. The understanding of AHF has evolved over the years from a significant hemodynamic failure to a multi-organ disease in the course of which peripheral mechanisms such as dysregulated cardiorenal axis or inflammation also play essential roles. A few available observational studies investigating iron deficiency (ID) in patients hospitalized for AHF indicate that this comorbidity is more prevalent than in chronic heart failure, and iron status presents some dynamics in these subjects. ID in AHF predicts increased mortality, greater risk for early readmission and is related to prolonged hospitalization. This paper reviews the results of the first multicenter, double-blind, randomized clinical trial on ferric carboxymaltose in patients who were stabilized after an episode of AHF who had concomitant ID (AFFIRM-AHF), and potential pathophysiological links between dysregulated iron status and AHF syndromes are discussed.

Iron deficiency contributes to resistance to endogenous erythropoietin in anaemic heart failure patients.

AIMS: Abnormal endogenous erythropoietin (EPO) constitutes an important cause of anaemia in chronic diseases. We analysed the relationships between iron deficiency (ID) and the adequacy of endogenous EPO in anaemic heart failure (HF) patients, and the impact of abnormal EPO on 12-month mortality. METHODS AND RESULTS: We investigated 435 anaemic HF patients (age: 74 ± 10 years; males: 60%; New York Heart Association class I or II: 39%; left ventricular ejection fraction: 43 ± 17%). Patients with EPO higher than expected for a given haemoglobin were considered EPO-resistant whereas those with EPO lower than expected - EPO-deficient. ID was defined as serum ferritin <100 µg/L or 100-299 µg/L with transferrin saturation <20%. EPO-resistant patients (22%) had more advanced HF whereas those with EPO deficiency (57%) were more frequently females and had worse renal function. Lower serum ferritin (indicating depleted body iron stores) was related to higher EPO observed/predicted ratio when adjusted for significant clinical confounders, including C-reactive protein. One year all-cause mortality was 28% in patients with EPO resistance compared to 17% in patients with EPO deficiency and 10% in patients with adequate EPO (log-rank test for the comparison EPO resistance vs. adequate EPO: P = 0.02). When adjusted for other prognosticators, there was still a trend towards increased 12-month mortality in patients with higher EPO level. CONCLUSION: Anaemic HF patients with endogenous EPO deficiency vs. resistance have different clinical and laboratory characteristics. In such patients, ID contributes to EPO resistance independently of inflammation.

Primary Human Cardiomyocytes and Cardiofibroblasts Treated with Sera from Myocarditis Patients Exhibit an Increased Iron Demand and Complex Changes in the Gene Expression.

Cardiac fibroblasts and cardiomyocytes are the main cells involved in the pathophysiology of myocarditis (MCD). These cells are especially sensitive to changes in iron homeostasis, which is extremely important for the optimal maintenance of crucial cellular processes. However, the exact role of iron status in the pathophysiology of MCD remains unknown. We cultured primary human cardiomyocytes (hCM) and cardiofibroblasts (hCF) with sera from acute MCD patients and healthy controls to mimic the effects of systemic inflammation on these cells. Next, we performed an initial small-scale (n = 3 per group) RNA sequencing experiment to investigate the global cellular response to the exposure on sera. In both cell lines, transcriptomic data analysis revealed many alterations in gene expression, which are related to disturbed canonical pathways and the progression of cardiac diseases. Moreover, hCM exhibited changes in the iron homeostasis pathway. To further investigate these alterations in sera-treated cells, we performed a larger-scale (n = 10 for controls, n = 18 for MCD) follow-up study and evaluated the expression of genes involved in iron metabolism. In both cell lines, we demonstrated an increased expression of transferrin receptor 1 (TFR1) and ferritin in MCD serum-treated cells as compared to controls, suggesting increased iron demand. Furthermore, we related TFR1 expression with the clinical profile of patients and showed that greater iron demand in sera-treated cells was associated with higher inflammation score (interleukin 6 (IL-6), C-reactive protein (CRP)) and advanced neurohormonal activation (NT-proBNP) in patients. Collectively, our data suggest that the malfunctioning of cardiomyocytes and cardiofibroblasts in the course of MCD might be related to alterations in the iron homeostasis.

Iron status, catabolic/anabolic balance, and skeletal muscle performance in men with heart failure with reduced ejection fraction.

BACKGROUND: Metabolic derangements related to tissue energetics constitute an important pathophysiological feature of heart failure. We investigated whether iron deficiency and catabolic/anabolic imbalance contribute to decreased skeletal muscle performance in men with heart failure with reduced ejection fraction (HFrEF), and whether these pathologies are related to each other. METHODS: We comprehensively examined 23 men with stable HFrEF (median age [interquartile range]: 63 [59-66] years; left ventricular ejection fraction: 28 [25-35]%; New York Heart Association class I/II/III: 17/43/39%). We analyzed clinical characteristics, iron status, hormones, strength and fatigability of forearm flexors and quadriceps (surface electromyography), and exercise capacity (6-minute walking test). RESULTS: None of the patients had anemia whereas 8 were iron-deficient. Flexor carpi radialis fatigability correlated with lower reticulocyte hemoglobin content (CHR, p < 0.05), and there was a trend towards greater fatigability in patients with higher body mass index and lower serum ferritin (both p < 0.1). Flexor carpi ulnaris fatigability correlated with lower serum iron and CHR (both p < 0.05). Vastus medialis fatigability was related to lower free and bioavailable testosterone (FT and BT, respectively, both p < 0.05), and 6-minute walking test distance was shorter in patients with higher cortisol/FT and cortisol/BT ratio (both p < 0.05). Lower ferritin and transferrin saturation correlated with lower percentage of FT and BT. Men with HFrEF and iron deficiency had higher total testosterone, but lower percentage of FT and BT. CONCLUSIONS: Iron deficiency correlates with lower bioactive testosterone in men with HFrEF. These two pathologies can both contribute to decreased skeletal muscle performance in such patients.

Multidimensional Approach to Frailty.

The concept of frailty syndrome (FS) was first described in the scientific literature three decades ago. For a very long time, we understood it as a geriatric problem, recently becoming one of the dominant concepts in cardiology. It identifies symptoms of FS in one in 10 elderly people. It is estimated that in Europe, 17% of elderly people have FS. The changes in FS resemble and often overlap with changes associated with the physiological aging process of the body. Although there are numerous scientific reports confirming that FS is age correlated, it is not an unavoidable part of the aging process and does not apply only to the elderly. FS is a reversible clinical condition. To maximize benefits of frailty-reversing activities for patient with frailty, identification of its determinants appears to be fundamental. Many of the determinants of the FS have already been known: reduction in physical activity, malnutrition, sarcopenia, polypharmacy, depressive symptom, cognitive disorders, and lack of social support. This review shows that insight into FS determinants is the starting point for building both the comprehensive definition of FS and the adoption of the assessment method of FS, and then successful clinical management.

Iron deficiency in heart failure: a 2020 update.

Iron deficiency (ID) constitutes an important comorbidity affecting symptoms and outcomes in patients with heart failure (HF). Recent experimental studies and randomized clinical trials have demonstrated important novel data regarding either the mechanisms of this comorbid condition or the beneficial effects of intravenous iron therapy in patients with HF. In this review we summarize new developments regarding ID in patients with HF with either reduced or preserved ejection fraction, along with brief description of ongoing morbidity and mortality trials in this field-4 years after the release of the 2016 European Society of Cardiology guidelines that clearly recommend to screen for, and consider treatment of, ID in patients with HF with reduced ejection fraction.

Monitoring of iron status in patients with heart failure.

The 2016 ESC/HFA heart failure (HF) guidelines emphasize the importance of identifying and treating iron deficiency (ID) in patients with HF. Iron deficiency can occur in half or more of HF sufferers, depending on age and the phase of the disease. Iron deficiency can be a cause of anaemia, but it is also common even without anaemia, meaning that ID is a separate entity, which should be screened for within the HF population. Although assessment of iron stores in bone marrow samples is the most accurate method to investigate iron status, it is not practical in most HF patients. Levels of circulating iron biomarkers are an easily available alternative; especially, ferritin and transferrin saturation (Tsat). In patients with HF serum ferritin level <100 µg/L (regardless of Tsat value) or between 100 and 299 µg/L with Tsat <20% are considered as recommended criteria for the diagnosis of ID, criteria which have been used in the clinical trials in HF that have led to a recommendation to treat ID with intravenous iron. We discuss the optimal measures of iron biomarkers in patients with HF in order to screen and monitor iron status and introduce some novel ways to assess iron status.

Depleted iron stores are associated with inspiratory muscle weakness independently of skeletal muscle mass in men with systolic chronic heart failure.

BACKGROUND: Skeletal and respiratory muscle dysfunction constitutes an important pathophysiological feature of heart failure (HF). We assessed the relationships between respiratory muscle function, skeletal muscle mass, and physical fitness in men with HF with reduced left ventricular ejection fraction (HFrEF), and investigated the hypothesis of whether iron deficiency (ID) contributes to respiratory muscle dysfunction in these patients. METHODS: We examined 53 male outpatients with stable HFrEF without asthma or chronic obstructive pulmonary disease (age: 64 ± 10 years; New York Heart Association [NYHA] class I/II/III: 36/51/13%; ischaemic aetiology: 83%; all with left ventricular ejection fraction ≤40%) and 10 middle-aged healthy men (control group). We analysed respiratory muscle function (maximal inspiratory and expiratory pressure at the mouth [MIP and MEP, respectively]), appendicular lean mass/body mass index (ALM/BMI; ALM was measured using dual-energy X-ray absorptiometry), physical fitness (components of Functional Fitness Test for Older Adults), and iron status. RESULTS: MIP, MEP, and ALM/BMI (but not MIP adjusted for ALM/BMI) were lower in men with HFrEF vs. healthy men. MIP, MEP, and MIP adjusted for ALM/BMI (but not ALM/BMI) were lower in men with HFrEF with vs. without ID. In a multivariable linear regression model lower serum ferritin (but not transferrin saturation) was associated with lower MIP independently of ALM/BMI, left ventricular ejection fraction, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and haemoglobin concentration. In multivariable linear regression models, lower MIP was associated with worse results in Functional Fitness Test when adjusted for ALM/BMI or relevant clinical variables (NYHA class, estimated glomerular filtration rate, NT-proBNP, and haemoglobin concentration). CONCLUSIONS: In men with HFrEF, low ferritin reflecting depleted iron stores is associated with inspiratory muscle weakness independently of skeletal muscle mass. Inspiratory muscle dysfunction correlates with worse physical fitness independently of either skeletal muscle mass or disease severity.

Iron deficiency and red cell indices in patients with heart failure.

AIMS: To investigate the prevalence of iron deficiency (ID) in heart failure (HF) patients with normal vs. abnormal red cell indices (RCI), the associations between iron parameters and RCI, and prognostic consequences of ID independently of RCI. METHODS AND RESULTS: We analysed clinical data of 1821 patients with HF [mean age 66 ± 13 years; 71% men; New York Heart Association class I/II/III/IV (11%/39%/44%/6%); left ventricular ejection fraction >45%: 19%]. Iron deficiency (ferritin <100 µg/L or ferritin 100-299 µg/L with transferrin saturation <20%) was common irrespective of the presence of anaemia (haemoglobin <12 g/dL in women and <13 g/dL in men) or low RCI, from 75% in anaemic subjects with low mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), and MCH concentration (MCHC), to 36% in non-anaemic subjects with MCV, MCH, and MCHC above the lower limit of normal. After adjustment for clinical variables, iron parameters remained independently associated with haemoglobin, MCV, MCH, MCHC, mean reticulocyte haemoglobin content (CHR), and red cell distribution width (RDW). In multivariable Cox proportional hazard regression models there was a trend towards higher mortality in patients with vs. without ID when adjusted for relevant HF prognosticators and MCH or MCHC (but not haemoglobin, CHR or RDW). CONCLUSIONS: Patients with HF should be routinely screened for ID irrespective of the presence of anaemia or abnormal RCI. The detrimental impact of ID on long-term survival in HF is partially independent of RCI.

The influence of iron deficiency on the functioning of skeletal muscles: experimental evidence and clinical implications.

Skeletal and respiratory myopathy not only constitutes an important pathophysiological feature of heart failure and chronic obstructive pulmonary disease, but also contributes to debilitating symptomatology and predicts worse outcomes in these patients. Accumulated evidence from laboratory experiments, animal models, and interventional studies in sports medicine suggests that undisturbed systemic iron homeostasis significantly contributes to the effective functioning of skeletal muscles. In this review, we discuss the role of iron status for the functioning of skeletal muscle tissue, and highlight iron deficiency as an emerging therapeutic target in chronic diseases accompanied by a marked muscle dysfunction.

Effects of intravenous iron therapy in iron-deficient patients with systolic heart failure: a meta-analysis of randomized controlled trials.

AIMS: The aim of this study was to assess the net clinical and prognostic effects of intravenous (i.v.) iron therapy in patients with systolic heart failure (HF) and iron deficiency (ID). METHODS AND RESULTS: We performed an aggregate data meta-analysis (random effects model) of randomized controlled trials that evaluated the effects of i.v. iron therapy in iron-deficient patients with systolic HF. We searched electronic databases up to September 2014. We identified five trials which fulfilled the inclusion criteria (509 patients received i.v. iron therapy in comparison with 342 controls). Intravenous iron therapy has been shown to reduce the risk of the combined endpoint of all-cause death or cardiovascular hospitalization [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.30-0.64, P < 0.0001], and the combined endpoint of cardiovascular death or hospitalization for worsening HF (OR 0.39, 95% CI 0.24-0.63, P = 0.0001). Intravenous iron therapy resulted in a reduction in NYHA class (data are reported as a mean net effect with 95% CIs for all continuous variables) (-0.54 class, 95% CI -0.87 to -0.21, P = 0.001); an increase in 6-min walking test distance (+31 m, 95% CI 18-43, P < 0.0001); and an improvement in quality of life [Kansas City Cardiomyopathy Questionnaire (KCCQ) score +5.5 points, 95% CI 2.8-8.3, P < 0.0001; European Quality of Life-5 Dimensions (EQ-5D) score +4.1 points, 95% CI 0.8-7.3, P = 0.01; Minnesota Living With Heart Failure Questionnaire (MLHFQ) score -19 points, 95% CI:-23 to -16, P < 0.0001; and Patient Global Assessment (PGA) +0.70 points, 95% CI 0.31-1.09, P = 0004]. CONCLUSION: The evidence indicates that i.v. iron therapy in iron-deficient patients with systolic HF improves outcomes, exercise capacity, and quality of life, and alleviates HF symptoms.

[Early bioprosthetic mitral valve thrombosis]. / Wczesna zakrzepica zastawki biologicznej w pozycji mitralnej.

We present a case of a 70 year-old woman operated due to severe mitral regurgitation. Early after surgery transthoracic echocardiography revealed the decreased effective orifice area of the implanted bioprosthetic valve and the stenotic features of transvalvular flow. Transesophageal echocardiography (TEE) disclosed a thrombotic cause of heterograft dysfunction. Due to the clinical deterioration and the unclear cause of prosthesis stenosis, the patient was reoperated. Intra-operatively bioprosthetic mitral valve thrombosis was confirmed. Precipitating factors of this rare complication including cardiac device related infective endocarditis (CDRIE) and the diagnostic applicability of TEE in this clinical scenario are discussed.