Disordered iron homeostasis in chronic heart failure: prevalence, predictors, and relation to anemia, exercise capacity, and survival

The treatment of chronic anemia in heart failure: a global approach

Chronic anemia is an independent risk factor for mortality in patients with heart failure (HF). Restoring physiological hemoglobin (Hb) levels is essential to increase oxygen transport capacity to tissues and improve cell metabolism as well as physical and cardiac performance. Nutritional deficits and iron deficiency are the major causes of chronic anemia, but other etiologies include chronic kidney disease, inflammatory processes, and unexplained anemia. Hormonal therapy, including erythropoietin (EPO) and anabolic treatment in chronic anemia HF patients, may contribute to improving Hb levels and clinical outcomes. Although preliminary studies showed a beneficial effect of EPO therapy on cardiac efficiency and in HF, more recent studies have not confirmed this positive impact of EPO, alluding to its side effect profile. Physical exercise significantly increases Hb levels and the response of anemia to treatment. In malnourished patients and chronic inflammatory processes, low levels of anabolic hormones, such as testosterone and insulin-like growth factor-1, contribute to the development of chronic anemia. This paper aims to review the effect of nutrition, EPO, anabolic hormones, standard HF treatments, and exercise as regulatory mechanisms of chronic anemia and their cardiovascular consequences in patients with HF.

Iron metabolism biomarkers and mortality risk in U.S. patients with congestive heart failure: NHANES 1999-2018 analysis

BACKGROUND AND AIMS

Iron deficiency is a major public health concern. We aimed to assess the predictive capability of 4 iron metabolism biomarkers for all-cause and cardiovascular disease-specific mortality in U.S. patients with congestive heart failure (CHF).

METHODS AND RESULTS

1904 CHF patients aged ≥20 years were enrolled from NHANES, 1999-2000 to 2017-2018. All analyses were weighted to provide nationally representative estimates. Among 1905 CHF patients, mean age was 71 years, and 1024 (53.8%), 459 (24.1%), 206 (10.8%), and 216 (11.3%) were Non-Hispanic Black, Non-Hispanic White, Hispanic-Mexican American, and Hispanic-Other Hispanic, respectively. During follow-ups, 1080 deaths occurred. Median follow-up time was 5.08 years. Per-unit increase in natural-logarithmic-transformed iron and transferrin saturation decreased all-cause mortality risk separately by 33.0% (adjusted hazard ratio: 0.670, 95% confidence interval: 0.563 to 0.797, P < 0.001) and 32.6% (0.674, 0.495 to 0.917, 0.013), and per-unit increase in transferrin receptor increased mortality risk by 33.7% (1.337, 1.104 to 1.618, 0.004). Two derivates from 3 significant iron biomarkers were generated - transferrin receptor to natural-logarithmic-transformed iron ratio (TRI) and transferrin receptor to natural-logarithmic-transformed transferrin saturation ratio (TRTS), which were significantly associated with all-cause mortality, with per-unit increase corresponding to 2.692- and 1.655-fold increased all-cause mortality risk (P: 0.003 and 0.023). Only iron and TRTS were associated with the significant risk of cardiovascular disease-specific mortality (P: 0.004 and 0.017).

CONCLUSIONS

Our findings identified 3 iron metabolism biomarkers that were individually, significantly, and independently associated with all-cause mortality in patients with CHF, and importantly 2 derivates generated exhibited stronger predictive capability.

Low-density lipoprotein cholesterol, erythrocyte, and platelet in heart failure with preserved ejection fraction

AIMS

Low-density lipoprotein cholesterol (LDL-C), anaemia and low platelets have been associated with worse clinical outcomes in heart failure patients. We investigated the relationship between the combination of these three components and clinical outcome in patients with heart failure with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

We examined the data of 1021 patients with HFpEF hospitalized with acute decompensated heart failure (HF) from the PURSUIT-HFpEF registry, a prospective, multicenter observational study. The enrolled patients were classified into four groups by an LEP (LDL-C, Erythrocyte, and Platelet) score of 0 to 3 points, with 1 point each for LDL-C, erythrocyte and platelet values less than the cut-off values as calculated by receiver operating characteristic curve analysis. The endpoint, a composite of all-cause death and HF readmission, was evaluated among the four groups. Median follow-up duration was 579 [300, 978] days. Risk of the composite endpoint significantly differed among the four groups (P < 0.001). Kaplan-Meier analysis showed that the groups with an LEP score of 2 had higher risk of the composite endpoint than those with an LEP score of 0 or 1 (P < 0.001, and P = 0.013, respectively), while those with an LEP score of 3 had higher risk than those with an LEP score of 0, 1 or 2 (P < 0.001, P < 0.001 and P = 0.020, respectively). Cox proportional hazards analysis showed that an LEP score of 3 was significantly associated with the composite endpoint (P = 0.030). Kaplan-Meier analysis showed that risk of the composite of all-cause death and HF readmission was significantly higher in low LDL values (less than the cut-off values as calculated by receiver operating characteristic curve analysis) patients with statin use than in those without statin use (log rank P = 0.002).

CONCLUSIONS

LEP score, which comprehensively reflects extra-cardiac co-morbidities, is significantly associated with clinical outcomes in HFpEF patients.

Iron deficiency in new onset heart failure: association with clinical factors and quality of life

AIMS

The prevalence of iron deficiency (ID) in newly diagnosed heart failure (HF) and the progression of ID in patients after initiation of HF therapy are unknown. We aimed to describe the natural trajectory of ID in patients with new onset HF during the first year after HF diagnosis, assessing associations between ID, clinical factors, and quality of life (QoL).

METHODS AND RESULTS

A prospective cohort of patients with new onset HF in hospitals or outpatient clinics at five major hospitals in Stockholm, Sweden, during 2015-2018 were analysed with clinical assessment, electrocardiogram, blood samples including iron levels, Minnesota living with heart failure questionnaire (MLHFQ), and echocardiogram at baseline and after 12 months. Of 547 patients with new-onset HF, 482 (88%) had complete iron data at baseline. Mean age was 70 years (interquartile range 61-77) and 311 (65%) were men; 55% of patients had ejection fraction (EF) ≤ 40%, 19% had EF 41-49%, and 26% had HF with preserved EF (HFpEF). At baseline, 163 patients (34%) had ID defined as ferritin <100 μg/L or ferritin 100-299 μg/L and transferrin saturation <20%. After 12 months of follow-up, 119 (32%) had ID of the 368 patients who had complete iron data both at baseline and after 12 months and did not receive intravenous (i.v.) iron during follow-up. During the first year after HF diagnosis, 19% had persistent ID, 13% developed ID, 11% resolved ID, and 57% never had ID, consequently 24% changed their classification. Anaemia at baseline was the strongest independent predictor of ID 1 year after diagnosis [odds ratio (OR) 3.91, 95% confidence interval (CI) 1.88-8.13, P < 0.001], followed by HF hospitalization (OR 2.21, 95% CI 1.24-3.95, P < 0.01), female sex (OR 2.04, 95% CI 1.25-3.32, P < 0.01), HFpEF (OR 1.96, 95% CI 1.13-3.39, P < 0.05), and diabetes mellitus (OR 1.92, 95% CI 1.06-3.48, P < 0.05). ID was associated with low QoL at baseline (MLHFQ score mean difference 7.4 points, 95% CI 3.1-11.7, P < 0.001), but not at follow-up.

CONCLUSIONS

About one third of patients with new onset HF had ID both at the time of HF diagnosis and after 1 year, though a quarter of the patients changed their ID status. Patients with anaemia, HF hospitalization, female gender, HFpEF, or diabetes mellitus at baseline were more likely to have ID after 1 year implying that these should be carefully screened for ID to find those in need of i.v. iron treatment.

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.

Intravenous iron in patients with iron deficiency and heart failure: a review of modern evidence

PURPOSE OF REVIEW

Iron deficiency is common in patients with heart failure, affecting up to half of ambulatory patients and an even greater percentage of patients admitted for acute decompensation. Iron deficiency in this population is also associated with poor outcomes, including worse quality of life in addition to increased hospitalizations for heart failure and mortality. Evidence suggests that patients with iron deficiency in heart failure may benefit from repletion with IV iron.

RECENT FINDINGS

In this review, we outline the etiology and pathophysiology of iron deficiency in heart failure as well as various iron formulations available. We discuss evidence for intravenous iron repletion with a particular focus on recent studies that have evaluated its effects on hospitalizations and mortality. Finally, we discuss areas of uncertainty and future study and provide practical guidance for iron repletion.

SUMMARY

In summary, there is overwhelming evidence that intravenous iron repletion in patients with iron deficiency in heart failure is both beneficial and safe. However, further evidence is needed to better identify which patients would most benefit from iron repletion as well as the ideal repletion strategy.

Exercise training response according to baseline ferrokinetics in heart failure with preserved ejection fraction: A substudy of the TRAINING-HF trial

BACKGROUND

Iron deficiency (ID) is associated with impaired functional capacity in patients with heart failure (HF), even in those with preserved ejection fraction (HFpEF). This study aimed to evaluate the effect of baseline ferrokinetics on peak oxygen consumption (peakVO2) improvement after a 12-week physical therapy programme in patients with stable HFpEF.

METHODS

This study is a post-hoc sub-analysis of a randomized clinical trial in which 59 stable patients with HFpEF were randomized to receive a 12-week programme of inspiratory muscle training (IMT), functional electrical stimulation (FES), IMT + FES or usual care (UC) to evaluate change in peakVO2 (NCT02638961). Serum ferritin and transferrin saturation (TSAT) determinations were assessed at baseline. ID was defined as ferritin <100 ng/mL and/or TSAT <20% if ferritin was within 100-299 ng/mL. We used a linear mixed regression model to analyse between-treatment changes in peakVO2 across ferrokinetics status at 12 and 24 weeks.

RESULTS

The mean age was 74 ± 9 years, and 36 (61%) had ID. The mean of peakVO2 was 9.9 ± 2.5 mL/kg/min. The median of ferritin and transferrin saturation (TSAT) was 91 (50-181) ng/mL and 23% (16-30), respectively. A total of 52 patients completed the trial (13 patients per arm). Compared with those patients on UC, patients allocated to any of the active arms showed less improvement in peak VO2 when they showed ID (P-value for interaction <0.001), lower values of ferritin (P-value for interaction <0.001), or TSAT (P-value for interaction <0.001).

CONCLUSIONS

Ferrokinetics status plays an essential role in modifying the aerobic capacity response to physical therapies in patients with HFpEF. Further studies are required to confirm these findings.

Iron Deficiency, Anemia, and Iron Supplementation in Patients With Heart Failure: A Population-Level Study

BACKGROUND

Studies have shown an association between iron deficiency (ID) and clinical outcomes in patients with heart failure (HF), irrespective of the presence of ID anemia (IDA). The current study used population-level data from a large, single-payer health care system in Canada to investigate the epidemiology of ID and IDA in patients with acute HF and those with chronic HF, and the iron supplementation practices in these settings.

METHODS

All adult patients with HF in Alberta between 2012 and 2019 were identified and categorized as acute or chronic HF. HF subtypes were determined through echocardiography data, and ID (serum ferritin concentration <100 μg/L, or ferritin concentration between 100 and 300 μg/L along with transferrin saturation <20%), and IDA through laboratory data. Broad eligibility for 3 clinical trials (AFFIRM-AHF [Study to Compare Ferric Carboxymaltose With Placebo in Patients With Acute HF and ID], IRONMAN [Intravenous Iron Treatment in Patients With Heart Failure and Iron Deficiency], and HEART-FID [Randomized Placebocontrolled Trial of Ferric Carboxymaltose as Treatment for HF With ID]) was determined.

RESULTS

Among the 17 463 patients with acute HF, 38.5% had iron studies tested within 30 days post-index-HF episode (and 34.2% of the 11 320 patients with chronic HF). Among tested patients, 72.6% of the acute HF and 73.9% of the chronic HF were iron-deficient, and 51.4% and 49.0% had IDA, respectively. Iron therapy was provided to 41.8% and 40.5% of patients with IDA and acute or chronic HF, respectively. Of ID patients without anemia, 19.9% and 21.7% were prescribed iron therapy. The most common type of iron therapy was oral (28.1% of patients). Approximately half of the cohort was eligible for each of the AFFIRM-AHF, intravenous iron treatment in patients with HF and ID, and HEART-FID trials.

CONCLUSIONS

Current practices for investigating and treating ID in patients with HF do not align with existing guideline recommendations. Considering the gap in care, innovative strategies to optimize iron therapy in patients with HF are required.

Benefits of intravenous iron supplementation in heart failure

Introduction: Iron deficiency (ID) is one of the most frequent comorbidities in patients with heart failure (HF) and is estimated to be present in up to 80% of acute patients regardless of their ejection fraction. Randomized controlled trials have shown that supplementary intravenous iron results in improved clinical outcomes; however, the current understanding of the effects of intravenous iron on morbidity and mortality remains limited. Study and results: The meta-analysis pooled individual participant data from three randomized placebo-controlled trials of ferric carboxymaltose (FCM) in adult patients (n = 4,501) with heart failure and iron deficiency (CONFIRM-HF, AFFIRM-AHF, and HEART-FID). FCM therapy significantly reduced the co-primary composite endpoint of total cardiovascular hospitalizations and cardiovascular death, with a rate ratio (RR 0.86; 95% CI 0.75 to 0.98; p = 0.029). FCM therapy was associated with a 17% relative rate reduction in total cardiovascular hospitalizations (RR 0.83; 95% CI 0.73 to 0.96; p = 0.009) and a 16% relative rate reduction in total heart failure hospitalizations (RR 0.84; 95% CI 0.71 to 0.98; p = 0.025). Lessons learned: The meta-analysis shows that in iron-deficient patients with heart failure and reduced or mildly reduced left ventricular ejection fraction, intravenous ferric carboxymaltose (FCM) is associated with a reduced risk of total cardiovascular hospitalization and cardiovascular mortality. These findings indicate that intravenous FCM should be considered in iron-deficient patients with heart failure and reduced or mildly reduced ejection fractions.

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.

Clinical outcomes of intravenous iron therapy in patients with heart failure and iron deficiency: Meta-analysis and trial sequential analysis of randomized clinical trials

BACKGROUND

Iron deficiency in patients with heart failure (HF) is underdiagnosed and undertreated. The role of intravenous (IV) iron is well-established to improve quality of life measures. Emerging evidence also supports its role in preventing cardiovascular events in patients with HF.

METHODOLOGY

We conducted a literature search of multiple electronic databases. Randomized controlled trials that compared IV iron to usual care among patients with HF and reported cardiovascular (CV) outcomes were included. Primary outcome was the composite of first heart failure hospitalization (HFH) or CV death. Secondary outcomes included HFH (first or recurrent), CV death, all-cause mortality, hospitalization for any cause, gastrointestinal (GI) side effects, or any infection. We performed trial sequential and cumulative meta-analyses to evaluate the effect of IV iron on the primary endpoint, and on HFH.

RESULTS

Nine trials enrolling 3337 patients were included. Adding IV iron to usual care significantly reduced the risk of first HFH or CV death [risk ratio (RR) 0.84; 95 % confidence interval (CI) 0.75-0.93; I2 = 0 %; number needed to treat (NNT) 18], which was primarily driven by a reduction in the risk of HFH of 25 %. IV iron also reduced the risk of the composite of hospitalization for any cause or death (RR 0.92; 95 % CI 0.85-0.99; I2 = 0 %; NNT 19). There was no significant difference in the risk of CV death, all-cause mortality, adverse GI events, or any infection among patients receiving IV iron compared to usual care. The observed benefits of IV iron were directionally consistent across trials and crossed both the statistical and trial sequential boundaries of benefit.

CONCLUSION

In patients with HF and iron deficiency, the addition of IV iron to usual care reduces the risk of HFH without affecting the risk of CV or all-cause mortality.

Efficacy of ferric carboxymaltose in heart failure with iron deficiency: an individual patient data meta-analysis

BACKGROUND AND AIMS

Whereas a beneficial effect of intravenous ferric carboxymaltose (FCM) on symptoms and exercise capacity among patients with iron deficiency and heart failure (HF) has been consistently demonstrated, the effects of treatment on clinical events remain the subject of research. This meta-analysis aimed to characterize the effects of FCM therapy on hospitalizations and mortality.

METHODS

Patient-level data from randomized, placebo-controlled FCM trials including adults with HF and iron deficiency with ≥52 weeks follow-up were analysed. The co-primary efficacy endpoints were (i) composite of total/recurrent cardiovascular hospitalizations and cardiovascular death and (ii) composite of total HF hospitalizations and cardiovascular death, through 52 weeks. Key secondary endpoints included individual composite endpoint components. Event rates were analysed using a negative binomial model. Treatment-emergent adverse events were also examined.

RESULTS

Three FCM trials with a total of 4501 patients were included. Ferric carboxymaltose was associated with a significantly reduced risk of co-primary endpoint 1 (rate ratio 0.86; 95% confidence interval 0.75-0.98; P = .029; Cochran Q: 0.008), with a trend towards a reduction of co-primary endpoint 2 (rate ratio 0.87; 95% confidence interval 0.75-1.01; P = .076; Cochran Q: 0.024). Treatment effects appeared to result from reduced hospitalization rates, not improved survival. Treatment appeared to have a good safety profile and was well tolerated.

CONCLUSIONS

In iron-deficient patients with HF with reduced left ventricular ejection fraction, intravenous FCM was associated with significantly reduced risk of hospital admissions for HF and cardiovascular causes, with no apparent effect on mortality.

Hydrogen Attenuates Chronic Intermittent Hypoxia-Induced Cardiac Hypertrophy by Regulating Iron Metabolism

The present study aimed to investigate the impact of hydrogen (H2) on chronic intermittent hypoxia (CIH)-induced cardiac hypertrophy in mice by modulating iron metabolism. C57BL/6N mice were randomly allocated into four groups: control (Con), CIH, CIH + H2, and H2. The mice were exposed to CIH (21-5% FiO2, 3 min/cycle, 8 h/d), and received inhalation of a hydrogen-oxygen mixture (2 h/d) for 5 weeks. Cardiac and mitochondrial function, levels of reactive oxygen species (ROS), and iron levels were evaluated. The H9C2 cell line was subjected to intermittent hypoxia (IH) and treated with H2. Firstly, we found H2 had a notable impact on cardiac hypertrophy, ameliorated pathological alterations and mitochondrial morphology induced by CIH (p < 0.05). Secondly, H2 exhibited a suppressive effect on oxidative injury by decreasing levels of inducible nitric oxide synthase (i-NOS) (p < 0.05) and 4-hydroxynonenal (4-HNE) (p < 0.01). Thirdly, H2 demonstrated a significant reduction in iron levels within myocardial cells through the upregulation of ferroportin 1 (FPN1) proteins (p < 0.01) and the downregulation of transferrin receptor 1 (TfR1), divalent metal transporter 1 with iron-responsive element (DMT1(+ire)), and ferritin light chain (FTL) mRNA or proteins (p < 0.05). Simultaneously, H2 exhibited the ability to decrease the levels of Fe2+ and ROS in H9C2 cells exposed to IH (p < 0.05). Moreover, H2 mediated the expression of hepcidin, hypoxia-inducible factor-1α (HIF-1α) (p < 0.01), and iron regulatory proteins (IRPs), which might be involved in the regulation of iron-related transporter proteins. These results suggested that H2 may be beneficial in preventing cardiac hypertrophy, a condition associated with reduced iron toxicity.

Correlation between serum iron levels and pulmonary function: A cross-sectional analysis based on NHANES database 5319 cases

Pulmonary function, one of the main indicators of respiratory system assessment, is difficult to measure in specific cases. The study investigated the association between serum iron levels and pulmonary function. The cross-sectional study was conducted using data from 5319 participants from the 2010-2012 National Health and Nutrition Examination Survey. Forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and forced expiratory flow from 25% to 75% of FVC were used as indicators of pulmonary function to analyze the relationship of serum iron and pulmonary function. Univariate and stratified analyses, multiple equation regression analysis, smoothed curve fitting analysis, and threshold effect analysis were performed to explore the relationship between pulmonary function and serum iron concentrations. Threshold effect analysis revealed a nonlinear relationship between serum iron levels and FVC, as well as FEV1, with inflection points observed at 8.1 (µmol/L) and 8.4 (µmol/L), respectively. When serum iron concentrations fell below the inflection point, there was no statistically significant relationship between serum iron and FVC (P = .065) or FEV1 (P = .095) (P > .005). However, when serum iron concentrations exceeded the inflection point, both FVC (β = 6.87; 95% confidence interval [CI] = 3.95, 9.79; P < .0001) and FEV1 (β = 7.09; 95% CI = 4.54, 9.64; P < .0001) exhibited a positive correlation with increasing serum iron levels. Additionally, forced expiratory flow from 25% to 75% of FVC (mL/s) demonstrated a positive association with serum iron (β = 6.72; 95% CI = 2.30, 11.13; P = .0029). Serum iron level was positively correlated with pulmonary function within a certain range of serum iron concentration. Serum iron level may be a protective factor for pulmonary function.

The anaemia treatment journey of CKD patients: from epoetins to hypoxia-inducible factor-prolyl hydroxylase inhibitors

The discovery and development of erythropoiesis-stimulating agents was a journey lasting more than a century, leading to the cloning and approval of recombinant human erythropoietin (rHuEpo). This was an impressive clinical advance, providing the possibility of correcting the symptoms associated with anaemia in chronic kidney disease. Associated iron use was needed to produce new haemoglobin-containing blood red cells. Partial anaemia correction became the standard of care since trials aiming for near-normal haemoglobin levels showed a higher risk of adverse cardiovascular events. Hoping to reduce the cardiovascular risks, a new category of drugs was developed and tested. Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are small molecules than can be formulated into orally active pills. They simulate reduced tissue oxygen pressure, thus stimulating the production of endogenous erythropoietin (Epo) by the kidneys and liver. Clinical trials with these compounds demonstrated that HIF-PHIs are at least as effective as rHuEpo in treating or correcting anaemia in non-dialysis and dialysis patients. Trials with HIF-PHIs did not demonstrate superiority in safety outcomes and in some trials, outcomes were worse. There was also a focus on oral delivery, a possible beneficial iron-sparing effect and the ability to overcome Epo resistance in inflamed patients. A negative effect is possible iron depletion, which may explain adverse outcomes.

Improving the Outcome of Patients With Heart Failure: Assessment of Iron Deficiency and Intravenous Iron Replacement

Background Iron deficiency (ID) has been shown to be a significant co-morbidity in patients with heart failure (HF), independent of their anaemia status. Correction of ID has been shown to improve quality of life, recurrent heart failure hospitalizations and morbidity. A quality improvement project was designed to improve the assessment and treatment of iron deficiency in HF patients in our tertiary care centre. Methods and results An initial baseline dataset was collected, followed by two cycles of interventions to help improve the care of HF patients admitted to our hospital over a two-month period. The Plan-Do-Study-Act (PDSA) cycle approach was applied, with the first intervention involving raising awareness of the importance and need to assess the iron status of HF patients through education provided to doctors, nurses and patients. Furthermore, information leaflets were produced and disseminated across the medical wards and through social media forums. The post-intervention datasets were collected and compared to the baseline outcomes. Baseline data showed that only four (20%) of heart failure patients had their iron status checked. Following the interventions, screening for ID increased to 80% (16), of which 85% (11) of those who identified as iron deficient received intravenous iron replacement. Conclusion The project was successful in improving the practice of screening for iron deficiency and intravenous replacement of iron in patients with HF.

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.

Ferric Carboxymaltose in Iron-Deficient Patients with Hospitalized Heart Failure and Reduced Kidney Function

BACKGROUND

Reduced kidney function is common among patients with heart failure. In patients with heart failure and/or kidney disease, iron deficiency is an independent predictor of adverse outcomes. In the AFFIRM-AHF trial, patients with acute heart failure with iron deficiency treated with intravenous ferric carboxymaltose demonstrated reduced risk of heart failure hospitalization, with improved quality of life. We aimed to further characterize the impact of ferric carboxymaltose among patients with coexisting kidney impairment.

METHODS

The double-blind, placebo-controlled AFFIRM-AHF trial randomized 1132 stabilized adults with acute heart failure (left ventricular ejection fraction <50%) and iron deficiency. Patients on dialysis were excluded. The primary end point was a composite of total heart failure hospitalizations and cardiovascular death during the 52-week follow-up period. Additional end points included cardiovascular hospitalizations, total heart failure hospitalizations, and days lost to heart failure hospitalizations or cardiovascular death. For this subgroup analysis, patients were stratified according to baseline eGFR.

RESULTS

Overall, 60% of patients had an eGFR <60 ml/min per 1.73 m 2 (the lower eGFR subgroup). These patients were significantly older, more likely to be female and to have ischemic heart failure, and had higher baseline serum phosphate levels and higher rates of anemia. For all end points, event rates were higher in the lower eGFR group. In the lower eGFR group, the annualized event rates for the primary composite outcome were 68.96 and 86.30 per 100 patient-years in the ferric carboxymaltose and placebo arms, respectively (rate ratio, 0.76; 95% confidence interval, 0.54 to 1.06). The treatment effect was similar in the higher eGFR subgroup (rate ratio, 0.65; 95% confidence interval, 0.42 to 1.02; Pinteraction = 0.60). A similar pattern was observed for all end points ( Pinteraction > 0.05).

CONCLUSIONS

In a cohort of patients with acute heart failure, left ventricular ejection fraction <50%, and iron deficiency, the safety and efficacy of ferric carboxymaltose were consistent across a range of eGFR values.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Study to Compare Ferric Carboxymaltose With Placebo in Patients With Acute Heart Failure and Iron Deficiency (Affirm-AHF), NCT02937454 .

Iron deficiency in young basketball players: Is a 100 μg/L ferritin cut-off appropriate for iron supplementation?: Results of a randomized placebo-controlled study

BACKGROUND

Iron deficiency (ID) is one of the most common factors that may reduce sports performance, supplementation forms and doses are still not standardized in athletes. Our aim was to assess the iron status of young male basketball players and to study the effect of iron supplementation in a randomized placebo-controlled study.

HYPOTHESIS

We hypothesized that due to the higher iron demand of athletes, the 100 μg/L ferritin cut-off may be appropriate to determine the non-anemic ID.

METHODS

During a sports cardiology screening, questionnaires, laboratory tests, electrocardiograms, echocardiography exams, and cardiopulmonary exercise tests were performed. Athletes with ID (ferritin <100 μg/L) were randomized into iron and placebo groups. Ferrous sulfate (containing 100 mg elemental iron [II] and 60 mg ascorbic acid) or placebo (50 mg vitamin C) was administered for 3 months. All exams were repeated after the supplementation period.

RESULTS

We included 65 (age 15.8 ± 1.7 years) basketball players divided into four age groups. Non-anemic ID was observed in 60 (92%) athletes. After supplementation, ferritin levels were higher in the iron group (75.5 ± 25.9 vs. 54.9 ± 10.4 μg/L, p < .01). Ferritin >100 μg/L level was achieved only in 15% of the athletes. There were no differences in performance between the groups (VO2 max: 53.6 ± 4.3 vs. 54.4 ± 5.7 mL/kg/min, p = .46; peak lactate: 9.1 ± 2.2 vs. 9.1 ± 2.6 mmol/L, p = .90).

CONCLUSIONS

As a result of the 3-month iron supplementation, the ferritin levels increased; however, only a small portion of the athletes achieved the target ferritin level, while performance improvement was not detectable.

Iron deficiency in heart failure: screening, prevalence, incidence and outcome data from the Swedish Heart Failure Registry and the Stockholm CREAtinine Measurements collaborative project

AIMS

Iron deficiency (ID) is common in heart failure (HF) and linked with poor prognosis regardless of anaemia. We assessed temporal trends in ID testing, ID prevalence, ID incidence, iron need, and outcomes associated with ID in HF across the ejection fraction (EF) spectrum.

METHODS AND RESULTS

From the Swedish HF registry, we enrolled 15 197 patients from Region Stockholm with available EF and collected laboratory tests from routine practice. Iron screening improved since 2016 but remained <25% as of 2018. In 1486 patients with iron biomarkers at baseline, the prevalence of ID was 55% (HF with reduced EF 54%; mildly reduced EF 51%; preserved EF 61%). Iron need was ≥1500 mg in 72% of patients. ID was independently associated with higher risk for HF rehospitalizations (incidence rate ratio [IRR] 1.62, 95% confidence interval [CI] 1.13-2.31) and with cardiovascular (CV) death or repeated HF hospitalizations (IRR 1.63, 95% CI 1.15-2.30) regardless of EF (p-interaction 0.21 and 0.26, respectively), but not with all-cause death, CV death, or first HF hospitalization. Among 96 patients without ID at baseline and with follow-up iron biomarkers, 21% developed ID within 6 months.

CONCLUSIONS

Iron deficiency screening improved over time but is still limitedly implemented, despite being highly prevalent and incident, and independently associated with CV death or HF rehospitalizations regardless of EF. Most patients with ID had an iron need necessitating either repeated administrations of intravenous iron or a preparation permitting >1000 mg doses. These data highlight the need for improved screening for ID in HF.

Iron Deficiency in Heart Failure: A Scientific Statement from the Heart Failure Society of America

Iron deficiency is present in approximately 50% of patients with symptomatic heart failure and is independently associated with worse functional capacity, lower quality of, life and increased mortality. The purpose of this document is to summarize current knowledge of how iron deficiency is defined in heart failure and its epidemiology and pathophysiology, as well as pharmacological considerations for repletion strategies. This document also summarizes the rapidly expanding array of clinical trial evidence informing when, how, and in whom to consider iron repletion.

Treatment of Iron Deficiency in Heart Failure

PURPOSE OF REVIEW

Heart failure (HF) is commonly associated with iron deficiency (ID), defined as insufficient levels of iron to meet physiological demands. ID's association with anaemia is well understood but it is increasingly recognised as an important comorbidity in HF, even in the absence of anaemia. This review summarises contemporary evidence for the measurement and treatment of ID, in both HFrEF and HFpEF, and specific HF aetiologies, and highlights important gaps in the evidence-base.

RECENT FINDINGS

ID is common among patients with HF and associated with increased morbidity and mortality. Correcting ID in patients with HF can impact upon functional status, exercise tolerance, symptoms, and overall quality of life, irrespective of anaemia status. ID is a modifiable comorbidity in HF. Therefore, recognising and treating ID has emerging therapeutic potential and is important for all clinicians who care for patients with HF to understand the rationale and approach to treatment.

Efficacy and safety of intravenous iron repletion in patients with heart failure: a systematic review and meta-analysis

INTRODUCTION

AFFIRM-AHF and IRONMAN demonstrated lower rates of the combined endpoint recurrent heart failure (HF) hospitalizations and cardiovascular death (CVD) using intravenous (IV) ferric carboxymaltose (FCM) and ferric derisomaltose (FDI), respectively in patients with HF and iron deficiency (ID) utilizing prespecified COVID-19 analyses.

MATERIAL AND METHODS

We meta-analyzed efficacy, between trial heterogeneity and data robustness for the primary endpoint and CVD in AFFIRM-AHF and IRONMAN. As sensitivity analysis, we analyzed data from all eligible exploratory trials investigating FCM/FDI in HF.

RESULTS

FCM/FDI reduced the primary endpoint (RR = 0.81, 95% CI 0.69-0.95, p = 0.01, I2 = 0%), with the number needed to treat (NNT) being 7. Power was 73% and findings were robust with fragility index (FI) of 94 and fragility quotient (FQ) of 0.041. Effects of FCM/FDI were neutral concerning CVD (OR = 0.88, 95% CI 0.71-1.09, p = 0.24, I2 = 0%). Power was 21% while findings were fragile with reverse FI of 14 and reversed FQ of 0.006. The sensitivity analysis from all eligible trials (n = 3258) confirmed positive effects of FCM/FDI on the primary endpoint (RR = 0.77, 95% CI 0.66-0.90, p = 0.0008, I2 = 0%), with NNT being 6. Power was 91% while findings were robust (FI of 147 and FQ of 0.045). Effect on CVD was neutral (RR = 0.87, 95% CI 0.71-1.07, p = 0.18, I2 = 0%). Power was 10% while findings were fragile (reverse FI of 7 and reverse FQ of 0.002). Rate of infections (OR = 0.85, 95% CI 0.71-1.02, p = 0.09, I2 = 0%), vascular disorder (OR = 0.84, 95% CI 0.57-1.25, p = 0.34, I2 = 0%) and general or injection-site related disorders (OR = 1.39, 95% CI 0.88-1.29, p = 0.16, I2 = 30%) were comparable between groups. There was no relevant heterogeneity (I2 > 50%) between the trials for any of the analyzed outcomes.

CONCLUSIONS

Use of FCM/FDI is safe and reduces the composite of recurrent HF hospitalizations and CVD, while effects on CVD alone are based on available level of data indeterminate. Findings concerning composite outcomes exhibit a high level of robustness without heterogeneity between trials with FCM and FDI.

Intravenous iron therapy among patients with heart failure and iron deficiency: An updated meta-analysis of randomized controlled trials

Background

Randomized clinical trials (RCTs) evaluating the role of intravenous (IV) iron administration in patients with heart failure (HF) and iron deficiency (ID) have yielded inconsistent results.

Methods

Electronic search of MEDLINE, EMBASE and OVID databases was performed until November 2022 for RCTs that evaluated the role of IV iron administration in patients with HF and ID. The main study outcomes were the composite of HF hospitalization or cardiovascular mortality, and individual outcome of HF hospitalization. Summary estimates were evaluated using random effects model.

Results

The final analysis included 12 RCTs with 3,492 patients (1,831 patients in the IV iron group and 1,661 patients in the control group). The mean follow-up was 8.3 months. IV iron was associated with a lower incidence in the composite of HF hospitalization or cardiovascular mortality (31.9% vs. 45.3%; relative risk [RR] 0.72; 95% confidence interval [CI] 0.59-0.88) and individual outcome of HF hospitalization (28.4% vs. 42.2; RR 0.69; 95% CI 0.57-0.85). There was no significant difference between both groups in cardiovascular mortality (RR 0.88; 95% CI 0.75-1.04) and all-cause mortality (RR 0.95; 95% CI 0.83-1.09). IV iron was associated with lower New York Heart Association class and higher left ventricular ejection fraction (LVEF). Meta-regression analyses showed no effect modification for the main outcomes based on age, hemoglobin level, ferritin level or LVEF.

Conclusion

Among patients with HF and ID, IV iron administration was associated with reduction in the composite of HF hospitalization or cardiovascular mortality and driven by a reduction in HF hospitalization.

Preoperative anemia and associated factors in women undergoing cesarean section at a comprehensive specialized referral hospital in Ethiopia

Background

Anemia is a common public health burden during pregnancy. Severe maternal and fetal complications have been associated with anemia. Despite many studies on anemia during pregnancy have been conducted in Ethiopia at any time of antenatal care visits, the prevalence of preoperative anemia among women awaiting cesarean delivery and its contributing factors have not been determined. The aim of this study was to determine the prevalence and associated factors of preoperative anemia in women awaiting cesarean section at a comprehensive specialized hospital in Ethiopia.

Methods

An institution-based cross-sectional study was done from April to June 2022 to determine preoperative anemia in women undergoing cesarean delivery. Data were obtained using a standardized questionnaire that included the women’s background characteristics. Bi-variable and multi-variable logistic regression analyses were performed to identify variables related to preoperative anemia. With a 95% confidence level, the estimated crude odds ratio and adjusted odds ratio were calculated. In a multivariate analysis, variables were considered statistically significant if their p-value was less than 0.05.

Results

A total of 424 pregnant women with a 100% response rate were included in this study. The prevalence of preoperative anemia among women awaiting cesarean delivery was 28.3% (95% CI: 23.8–32.5%). Previous history of abortion, lack of iron supplementation, human immunodeficiency virus infection, previous cesarean section, and American Society of Anesthesiology class III were significantly associated with preoperative anemia among women awaiting cesarean section.

Conclusion and recommendation

Preoperative anemia was diagnosed in a significant proportion of women awaiting cesarean-delivery. Anemia was linked to a lack of iron supplementation, American Society of Anesthesiology class III, previous history of abortion, human immunodeficiency virus infection, and previous cesarean section. Therefore, early detection of high-risk pregnancies, iron supplementation, prevention of HIV infection and due attention to people living with HIV/AIDs are paramount.

A Role of Sodium-Glucose Co-Transporter 2 in Cardiorenal Anemia Iron Deficiency Syndrome

Heart failure, renal dysfunction, anemia, and iron deficiency affect each other and form a vicious cycle, a condition referred to as cardiorenal anemia iron deficiency syndrome. The presence of diabetes further accelerates this vicious cycle. Surprisingly, simply inhibiting sodium-glucose co-transporter 2 (SGLT2), which is expressed almost exclusively in the proximal tubular epithelial cells of the kidney, not only increases glucose excretion into the urine and effectively controls blood glucose levels in diabetes but can also correct the vicious cycle of cardiorenal anemia iron deficiency syndrome. This review describes how SGLT2 is involved in energy metabolism regulation, hemodynamics (i.e., circulating blood volume and sympathetic nervous system activity), erythropoiesis, iron bioavailability, and inflammatory set points in diabetes, heart failure, and renal dysfunction.

Markers of Iron Metabolism and Outcomes in Patients with Heart Failure: A Systematic Review

Iron deficiency (ID) in conjunction with heart failure (HF) poses a challenge for clinicians and is associated with worse HF outcomes. Treatment of ID with IV iron supplementation for patients with HF has demonstrated benefits in quality of life (QoL) and HF-related hospitalizations. The aim of this systematic review was to summarize the evidence linking iron metabolism biomarkers with outcomes in patients with HF to assist in the optimal use of these biomarkers for patient selection. A systematic review of observational studies in English from 2010 to 2022 was conducted using PubMed, with keywords of “Heart Failure” and respective iron metabolism biomarkers (“Ferritin”, “Hepcidin”, “TSAT”, “Serum Iron”, and “Soluble Transferrin Receptor”). Studies pertaining to HF patients, with available quantitative data on serum iron metabolism biomarkers, and report of specific outcomes (mortality, hospitalization rates, functional capacity, QoL, and cardiovascular events) were included, irrespective of left ventricular ejection fraction (LVEF) or other HF characteristics. Clinical trials of iron supplementation and anemia treatment were removed. This systematic review was conducive to formal assessment of risk of bias via Newcastle-Ottawa Scale. Results were synthesized based on their respective adverse outcomes and iron metabolism biomarker(s). Initial and updated searches identified 508 unique titles once duplicates were removed. The final analysis included 26 studies: 58% focused on reduced LVEF; age range was 53–79 years; males composed 41–100% of the reported population. Statistically significant associations of ID were observed with all-cause mortality, HF hospitalization rates, functional capacity, and QoL. Increased risk for cerebrovascular events and acute renal injury have also been reported, but these findings were not consistent. Varying definitions of ID were utilized among the studies; however, most studies employed the current European Society of Cardiology criteria: serum ferritin < 100 ng/mL or the combination of ferritin between 100–299 ng/mL and transferrin saturation (TSAT) < 20%. Despite several iron metabolism biomarkers demonstrating strong association with several outcomes, TSAT better predicted all-cause mortality, as well as long-term risk for HF hospitalizations. Low ferritin was associated with short-term risk for HF hospitalizations, worsening functional capacity, poor QoL, and development of acute renal injury in acute HF. Elevated soluble transferrin receptor (sTfR) levels were associated with worse functional capacity and QoL. Finally, low serum iron was significantly associated with increased risk for cardiovascular events. Considering the lack of consistency among the iron metabolism biomarkers for association with adverse outcomes, it is important to incorporate additional biomarker data, beyond ferritin and TSAT, when assessing for ID in HF patients. These inconsistent associations question how best to define ID to ensure proper treatment. Further research, potentially tailored to specific HF phenotypes, is required to optimize patient selection for iron supplementation therapy and appropriate targets for iron stores replenishment.

Interpreting Iron Homeostasis in Congenital and Acquired Disorders

Mammalian cells require iron to satisfy their metabolic needs and to accomplish specialized functions, such as hematopoiesis, mitochondrial biogenesis, energy metabolism, or oxygen transport. Iron homeostasis is balanced by the interplay of proteins responsible for iron import, storage, and export. A misbalance of iron homeostasis may cause either iron deficiencies or iron overload diseases. The clinical work-up of iron dysregulation is highly important, as severe symptoms and pathologies may arise. Treating iron overload or iron deficiency is important to avoid cellular damage and severe symptoms and improve patient outcomes. The impressive progress made in the past years in understanding mechanisms that maintain iron homeostasis has already changed clinical practice for treating iron-related diseases and is expected to improve patient management even further in the future.

Ferumoxytol: an emerging therapeutic for iron deficiency anemia

INTRODUCTION

Iron deficiency anemia (IDA) is common worldwide, and various iron replacement therapies are available. Ferumoxytol is an injectable, high-dose iron formulation (510 mg) that can be administered over a short period (15 min) without test administration. The drug was approved by the Food and Drug Administration in 2009 for the treatment of IDA in patients with chronic kidney disease (CKD), and in 2018, the indication was expanded to include patients without CKD.

AREAS COVERED

This paper reviews studies testing the efficacy and safety of ferumoxytol in treating IDA compared with other iron formulations.

EXPERT OPINION

There is substantial evidence that ferumoxytol is effective for the treatment of IDA. The efficacy of ferumoxytol in improving anemia is comparable to that of iron sucrose and ferric carboxymaltose (FCM) and superior to that of oral iron or a placebo in replenishing iron stores. Treatment with ferumoxytol, although more expensive, is cost-effective for outpatients requiring parenteral administration because it requires fewer doses and shorter dosing times per dose. Ferumoxytol also causes less frequent hypophosphatemia than FCM. Currently, its use in children and pregnant women is under consideration, which may provide important information for the future applications of ferumoxytol in larger numbers of patients.

Mean corpuscular haemoglobin concentration and outcomes in heart failure with preserved ejection fraction

AIMS

This study aims to evaluate the prognostic value of mean corpuscular haemoglobin concentration (MCHC) on clinical outcomes in patients with heart failure with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

We analysed HFpEF participants from the Americas in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial with available baseline data (n = 1747). Patients were grouped into hypochromia or non-hypochromia group according to a MCHC cut-off level of 330 g/L. Cox proportional hazard model was used to explore the prognostic value of hypochromia on the long-term clinical outcomes (the primary endpoint [composite of cardiovascular mortality, HF hospitalization and aborted cardiac arrest], any-cause and HF hospitalization, all-cause and cardiovascular mortality). Patients were further stratified according to baseline estimated glomerular filtration rate (eGFR) to explore the impact of renal dysfunction on the prognostic value of hypochromia. Baseline hypochromia was prevalent (n = 662, 37.9%) and strongly associated with worse clinical outcomes. In patients with worse renal function (eGFR < 60 mL/min per 1.73 m² ), hypochromia was independently associated with primary endpoint (hazard ratio [HR], 1.56; 95% confidence interval [CI], 1.23-1.98; P < 0.001), any-cause hospitalization (HR, 1.43; 95% CI, 1.20-1.71, P < 0.001) and HF hospitalization (HR, 1.40; 95% CI, 1.07-1.84; P = 0.015), whereas no significant association between hypochromia and these outcomes was found in patients with better renal function.

CONCLUSIONS

Among HFpEF patients, hypochromia (i.e. MCHC ≤ 330 g/L) is independently associated with adverse clinical outcomes, especially when in the presence of co-morbidity renal dysfunction.

Role of Iron Deficiency in Heart Failure-Clinical and Treatment Approach: An Overview

BACKGROUND

The association of chronic heart failure (CHF) and iron deficiency (ID) with or without anemia is frequently encountered in current medical practice and has a negative prognostic impact, worsening patients' exercise capacity and increasing hospitalization costs. Moreover, anemia is common in patients with chronic kidney disease (CKD) and CHF, an association known as cardio-renal anemia syndrome (CRAS) possessing a significantly increased risk of death.

AIM

This review aims to provide an illustrative survey on the impact of ID in CHF patients-based on physiopathological traits, clinical features, and the correlation between functional and absolute ID with CHF-and the benefit of iron supplementation in CHF.

METHOD

We selected the most recent publications with important scientific content covering the association of CHF and ID with or without anemia.

DISCUSSIONS

An intricate physiopathological interplay is described in these patients-decrease in erythropoietin levels, activation of the renin-angiotensin-aldosterone system, systemic inflammation, and increases in hepcidin levels. These mechanisms amplify anemia, CHF, and CKD severity and worsen patients' outcomes.

CONCLUSIONS

Anemia is frequently encountered in CHF and represents a negative prognostic factor. Data from randomized controlled trials have underlined the administration of intravenous iron therapy (ferric carboxymaltose) as the only viable treatment option, with beneficial effects on quality of life and exercise capacity in patients with ID and systolic heart failure.

Association of myocardial iron deficiency based on T2* CMR with the risk of mild left ventricular dysfunction in HIV-1-infected patients

Objectives

This study sought to noninvasively determine myocardial iron levels in HIV-1-infected patients using CMR and explore the association between T2* values and mild left ventricular systolic dysfunction (LVSD).

Methods

This prospective study was conducted from June 2019 to July 2021. HIV-1-infected adults and healthy controls were consecutively enrolled for CMR exam. CMR exam included the assessment of myocardium iron content (T2*), cardiac function (cine), inflammation (T2), and fibrosis (through extracellular volume fraction [ECV] and late gadolinium enhancement [LGE]) measurements. Mild LVSD is defined as a left ventricular ejection fraction (LVEF) between 40% and 49%.

Results

Of 47 HIV-1-infected patients enrolled, 12 were diagnosed with mild LVSD (HIV-1+/LEVF+) and 35 were diagnosed with preserved LV function (HIV-1+/LEVF-). Compared with healthy controls, HIV-1-infected patients displayed higher T2*, T1, T2, ECV values and lower global circumferential strain (GCS) and global radial strain (GRS) (all P < 0.05). However, between patients with and without mild LVSD, only the T2* values and ECV (all P <0.05) were different. The association between increased T2* values (>26 ms) and mild LVSD remained significant after adjusting for the established univariate predictors (ECV >32.9%, T1 values >1336 ms) of mild LVSD (odds ratio [OR], 10.153; 95% confidence interval [CI] 1.565-65.878, P = 0.015).

Conclusions

Myocardial T2* values were elevated in HIV-1-infected patients, supporting the notion that ID was associated with mild LVSD. Our findings highlight the potential for ID in HIV-1-infected patients as an auxiliary biomarker to monitor the course of LVSD.

Impact of Structural Abnormalities in Left Ventricle and Left Atrium on Clinical Outcomes in Heart Failure with Preserved Ejection Fraction

Two key echocardiographic parameters, left ventricular mass index (LVMI) and left atrial volume index (LAVI), are important in assessing structural myocardial changes in heart failure (HF) with preserved ejection fraction (HFpEF). However, the differences in clinical characteristics and outcomes among groups classified by LVMI and LAVI values are unclear.We examined the data of 960 patients with HFpEF hospitalized due to acute decompensated HF from the PURSUIT-HFpEF registry, a prospective, multicenter observational study. Four groups were classified according to the cut-off values of LVMI and LAVI [LVMI = 95 g/m2 (female), 115 g/m2 (male) and LAVI = 34 mL/m2]. Clinical endpoints were the composite of HF readmission and all-cause death. Study endpoints among the 4 groups were evaluated. The composite endpoint occurred in 364 patients (37.9%). Median follow-up duration was 445 days. Kaplan-Meier analysis revealed significant differences in the composite endpoint among the 4 groups (P < 0.001). Cox proportional hazards analysis demonstrated that patients with increased LAVI alone were at significantly higher risk of HF readmission and the composite endpoints than those with increased LVMI alone (P = 0.030 and P = 0.024, respectively). Age, male gender, systolic blood pressure at discharge, atrial fibrillation (AF) hemoglobin, renal function, and LAVI were significant determinants of LVMI and female gender, AF, hemoglobin, and LVMI were significant determinants of LAVI.In HFpEF patients, increased LAVI alone was more strongly associated with HF readmission and the composite of HF readmission and all-cause death than those with increased LVMI alone.

Iron deficiency and cardiovascular disease

Iron deficiency (ID) is common in patients with cardiovascular disease. Up to 60% of patients with coronary artery disease, and an even higher proportion of those with heart failure (HF) or pulmonary hypertension have ID; the evidence for cerebrovascular disease, aortic stenosis and atrial fibrillation is less robust. The prevalence of ID increases with the severity of cardiac and renal dysfunction and is probably more common amongst women. Insufficient dietary iron, reduced iron absorption due to increases in hepcidin secondary to the low-grade inflammation associated with atherosclerosis and congestion or reduced gastric acidity, and increased blood loss due to anti-thrombotic therapy or gastro-intestinal or renal disease may all cause ID. For older people in the general population and patients with HF with reduced ejection fraction (HFrEF), both anaemia and ID are associated with a poor prognosis; each may confer independent risk. There is growing evidence that ID is an important therapeutic target for patients with HFrEF, even if they do not have anaemia. Whether this is also true for other HF phenotypes or patients with cardiovascular disease in general is currently unknown. Randomized trials showed that intravenous ferric carboxymaltose improved symptoms, health-related quality of life and exercise capacity and reduced hospitalizations for worsening HF in patients with HFrEF and mildly reduced ejection fraction (<50%). Since ID is easy to treat and is effective for patients with HFrEF, such patients should be investigated for possible ID. This recommendation may extend to other populations in the light of evidence from future trials.

Red cell distribution width as a prognosticator in patients with heart failure

AIMS

Increased red cell distribution width (RDW) is a poor prognostic factor in patients with heart failure (HF). However, only a few large-scale studies have identified the clinical utility of RDW after adjusting for covariates affecting RDW.

METHODS AND RESULTS

From January 2010 to April 2021, we retrospectively enrolled patients diagnosed with HF from three referral hospitals with available RDW data (taken within 3 months of HF diagnosis) using an integrated clinical data system. Patients with an ejection fraction (EF) < 50% or HFA-PEFF (Heart Failure Association Pre-test assessment, Echocardiography and natriuretic peptide, Functional testing, Final aetiology) score ≥ 2 without severe valvular heart disease or coronary revascularization were enrolled. The primary endpoint was all-cause mortality, and cardiovascular mortality was also collected. Multivariable Cox regression analysis and stabilized inverse probability of treatment weighting (IPTW) were used to identify any association between RDW and all-cause death by balancing covariates or compounding factors. The global χ² score was calculated and discrimination analysis was performed to evaluate the incremental value of RDW in predicting prognosis. Among the 6599 participants enrolled in this study, 1256 (19.0%) cases of all-cause death occurred, and the median duration of follow-up was 887 (interquartile range 351-1589) days. Elevated RDW at the initial diagnosis was associated with poor prognosis [cumulative incidence: 819 (30.2%) vs. 437 (11.2%), relative risk 1.58, 95% confidence interval (CI) 1.51-1.67, log-rank P < 0.001]. Multivariable Cox analysis showed that elevated RDW was a poor prognostic factor for the primary endpoint [hazard ratio (HR) 1.11, 95% CI 1.06-1.16, P < 0.001], independent of clinical risk factors, N-terminal pro-brain natriuretic peptide (NT-proBNP), and EF, which was concordant with the stabilized IPTW (HR 1.29, 95% CI 1.10-1.49, P < 0.001). Adding RDW to model composed of traditional risk factors, NT-proBNP, and echocardiographic parameters showed incremental prognostic value for predicting poor prognosis (area under the receiver operating characteristic curve, 0.799-0.826; P < 0.001).

CONCLUSIONS

Increased RDW at the time of diagnosis is associated with poor prognosis in patients with HF, independent of clinical risk factors, such as NT-proBNP, and echocardiographic parameters. Therefore, RDW may aid in the management of these patients beyond traditional risk factors.

Iron deficiency in cardiac surgical patients

Iron is an essential element and involved in a variety of metabolic processes including oxygen transport, cellular energy production, energy metabolism of heart muscles, brain function, cell growth and cell differentiation. Preoperative anaemia is an independent risk factor for poor outcome. Recently, iron deficiency was considered only in the context of anaemia. However, negative consequences of iron deficiency in the absence of anaemia have been described for patients undergoing cardiac surgery. To date, the benefit of intravenous iron supplementation in these patients has been controversially debated. In this review, we discuss the latest progress in studies of intravenous iron supplementation in iron deficient cardiac surgical patients.

Preoperative Evaluation and Care of Heart Transplant Candidates

Heart transplantation is recommended for patients with advanced heart failure refractory to medical and device therapy, and who do not have absolute contraindications. When patients become eligible for heart transplantation, they undergo comprehensive evaluation and preparation to optimize their posttransplantation outcomes. This review provides an overview of the processes that are employed to enable the candidates to be transplant-ready when donor hearts are available.

Iron Deficiency in Patients with Advanced Heart Failure

Background and Objectives: Iron deficiency (ID) is a common comorbidity in patients with heart failure. It is associated with reduced physical performance, frequent hospitalisations for heart failure decompensation, and high cardiovascular and overall mortality. The aim was to determine the prevalence of ID in patients with advanced heart failure on the waiting list for heart transplantation. Methods and Materials: We included 52 patients placed on the waiting list for heart transplantation in 2021 at our centre. The cohort included seven patients with LVAD (left ventricle assist device) as a bridge to transplantation implanted before the time of results collection. In addition to standard tests, the parameters of iron metabolism were monitored. ID was defined as a ferritin value <100 µg/L, or 100−299 µg/L if transferrin saturation (T-sat) is <20%. Results: ID was present in 79% of all subjects, but only in 35% of these patients anaemia was expressed. In the group without LVAD, ID was present in 82%, a median (lower−upper quartile) of ferritin level was 95.4 (62.2−152.1) µg/mL and mean T-sat was 0.18 ± 0.09. In LVAD group, ID was present in 57%, ferritin level was 268 (106−368) µg/mL and mean T-sat was 0.14 ± 0.04. Haemoglobin concentration was the same in patients with or without ID (133 ± 16) vs. (133 ± 23). ID was not associated with anaemia defined with regard to patient’s gender. In 40.5% of cases, iron deficiency was accompanied by chronic renal insufficiency, compared to 12.5% of the patients without ID. In the patients with LVAD, ID was present in four out of seven patients, but the group was too small for reliable statistical testing due to low statistical power. Conclusions: ID was present in the majority of patients with advanced heart failure and was not always accompanied by anaemia and renal insufficiency. Research on optimal markers for the diagnosis of iron deficiency, especially for specific groups of patients with heart failure, is still ongoing.

The effect of ferric carboxymaltose treatment on the Tp-e interval and the Tp-e/QT and Tp-e/QTc ratios in heart failure patients with iron deficiency

Aim    In heart failure (HF) patients with iron deficiency, cardiac electrical irregularity is a cause of arrhythmias. The aim of our study was to evaluate the effect of ferric carboxymaltose (FCM) treatment on T wave peak to end (Tp-e) interval and the Tp-e / QT and Tp-e / corrected QT (QTc) ratios that reflect the transmural dispersion of repolarization in HF patients with iron deficiency.Material and methods    Forty HF patients with iron deficiency that were treated with FCM were included in our single center, observational study. Repolarization parameters on electrocardiograms recorded before and 12 wks after FCM treatment were compared. Additionally, these parameters were compared with ventricular repolarization parameters of 40 healthy age and gender matched individuals and with another group of 40 HF patients without iron deficiency.Results    In the HF patients with iron deficiency, the Tp-e interval and the Tp-e / QT and Tp-e / QTc ratios before FCM treatment were 103.7±19.1 ms, 0.25± 0.04, 0.23±0.04, respectively. These values were higher compared to the healthy the group and HF group without iron deficiency (p<0.001). In the HF patients with iron deficiency, the Tp-e interval and the Tp-e / QT and Tp-e / QTc ratios after FCM treatment were lower compared to pre-treatment and similar to the HF patients without iron deficiency (89.4±18.6 ms, 0.22±0.04, 0.20±0.04, respectively; p<0.001).Conclusion    FCM treatment of HF patients with iron deficiency corrects prolonged Tp-e interval and high Tp-e / QT and Tp-e / QTc ratios, which are risk factors for ventricular arrhythmias.

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.

Cost-effective heart failure management: Meta-analysis of IV iron therapy in iron-deficient heart failure patients

Background

Iron deficiency is an important co-morbidity in heart failure patients. IV iron may improve quality of life and reduce heart failure hospitalizations, but the results of the clinical trials are varied.

Objective

The purpose of this meta-analysis is to assess not only the effect of IV iron in iron-deficient heart failure patients but also the quality of evidence.

Methods

PubMed and Cochrane databases were searched from inception to Oct 2021. Randomized clinical trials in iron-deficient, heart failure patients assessing the effect of IV iron versus placebo and with at least 12 weeks of follow-up were included. The outcomes were pooled and analyzed using a random-effect model. The quality of evidence was assessed using the GRADE approach.

Results

Seven studies were included in our meta-analysis. IV iron was associated with a 13.8 % decreased risk of HF hospitalizations (OR 0.59; 0.35-0.98, p = 0.040, GRADE = Low). All-cause mortality and CV mortality were not different between IV iron and placebo. But a composite outcome of HF hospitalizations or CV mortality was 17.5 % lower with IV iron (OR 0.51;0.31-0.84, p = 0.008, GRADE = Moderate).

Conclusions

Among heart failure patients with iron deficiency, IV iron is associated with lower HF hospitalizations. It is a relatively inexpensive regimen that can potentially improve quality of life and decrease healthcare expenditure.

Ferroptosis: The Potential Target in Heart Failure with Preserved Ejection Fraction

Ferroptosis is a recently identified cell death characterized by an excessive accumulation of iron-dependent reactive oxygen species (ROS) and lipid peroxides. Intracellular iron overload can not only cause damage to macrophages, endothelial cells, and cardiomyocytes through responses such as lipid peroxidation, oxidative stress, and inflammation, but can also affect cardiomyocyte Ca²⁺ handling, impair excitation–contraction coupling, and play an important role in the pathological process of heart failure with preserved ejection fraction (HFpEF). However, the mechanisms through which ferroptosis initiates the development and progression of HFpEF have not been established. This review explains the possible correlations between HFpEF and ferroptosis and provides a reliable theoretical basis for future studies on its mechanism.

The Impact of Antithrombotic Therapy in Patients with De-compensated Heart Failure and Iron

Abstract: The iron deficient anaemia is a common medical condition in patients with heart failure receiving antithrombotic therapy. Especially during the COVID19 pandemic period the rate of bleeding complications associated with the antithrombotic therapy tend to be higher, as the patient’s referral to medical services is lower and the interaction doctor-patient is limited. In our retrospective observational study we included 300 consecutive patients with decompensated heat failure associating iron deficient anaemia. For defining the medical conditions we used the ESC guidelines terminology and diagnostic criteria. We assessed the association between the iron deficient anaemia and different antithrombotic therapies, recommended in concordance to ESC Guidelines. We found that aspirin 75mg/day was statistical significant associated with iron deficient anaemia (p 0.012) and anaemia severity (p 0.002), this association being assessed by Chi square and Pearson tests. Also, neither clopidogrel, ticagrelor, VKA or non-VKA were associated to the presence of anaemia. By assessing the mortality rate associated to anaemia severity, the severe anaemia was associated to higher mortality rate, meanwhile no antithrombotic therapy was associated with higher readmission or mortality rate (p<0.001). In conclusion, aspirin was the only antithrombotic therapy associated with the presence of anaemia and anaemia severity, while only severe anaemia was associated with statistic significant increase of patient’s mortality, with nonstatistical result regarding the readmission rate. This finding is concordant to the necessity of a permanent evaluation of the antithrombotic therapy in heart failure patients. Keywords: antithrombotic therapy, decompensated heart failure, iron deficient anaemia, COVID 19 pan-demic, mortality rate

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.

Neglected Comorbidity of Chronic Heart Failure: Iron Deficiency

Iron deficiency is a significant comorbidity of heart failure (HF), defined as the inability of the myocardium to provide sufficient blood flow. However, iron deficiency remains insufficiently detected. Iron-deficiency anemia, defined as a decrease in hemoglobin caused by iron deficiency, is a late consequence of iron deficiency, and the symptoms of iron deficiency, which are not specific, are often confused with those of HF or comorbidities. HF patients with iron deficiency are often rehospitalized and present reduced survival. The correction of iron deficiency in HF patients is associated with improved functional capacity, quality of life, and rehospitalization rates. Because of the inflammation associated with chronic HF, which complicates the picture of nutritional deficiency, only the parenteral route can bypass the tissue sequestration of iron and the inhibition of intestinal iron absorption. Given the negative impact of iron deficiency on HF progression, the frequency and financial implications of rehospitalizations due to decompensation episodes, and the efficacy of this supplementation, screening for this frequent comorbidity should be part of routine testing in all HF patients. Indeed, recent European guidelines recommend screening for iron deficiency (serum ferritin and transferrin saturation coefficient) in all patients with suspected HF, regular iron parameters assessment in all patients with HF, and intravenous iron supplementation in symptomatic patients with proven deficiency. We thus aim to summarize all currently available data regarding this common and easily improvable comorbidity.

Clinical and Laboratory Biomarkers in Paroxysmal Atrial Fibrillation: A Single Center Cross-Sectional Study

The clinical risk profile of paroxysmal atrial fibrillation (pAF) patients is inconclusive. We aimed to identify clinical and laboratory biomarkers in patients with pAF and the differences in biomarkers among genders. A cross-sectional study was conducted with a total of 181 participants in a single center in Beijing Anzhen Hospital. The participants were grouped according to the presence of pAF and sex differences, and clinical and laboratory results were collected and compared. The 181 participants had a mean age of 52.9 ± 15.1 years (pAF group, 60.4 ± 9.9 years, SR group, 48.3 ± 15.9 years, P < 0.05). Patients with pAF had significantly higher rates of age, left atrial (LA) diameter, haemoglobin (Hb) levels, tissue inhibitor of metalloproteinase-1 (TIMP-1), soluble tumour suppressor-2 (sST2), B-type natriuretic peptide (BNP) and indirect bilirubin (Ibil), mean haemoglobin concentration (MCHC), and hypertension (HTN) and smoking (P < 0.05). Multivariable logistic regression analysis revealed that age (OR = 1.075, 95% CI: 1.035–1.118, P < 0.0001), smoking (OR = 4.538, 95% CI: 1.559–13.205, P = 0.006), and MCHC (OR = 1.062, 95% CI: 1.019–1.106, P = 0.004) were independent predictive factors for pAF. Multivariable logistic regression analysis found that age (OR = 1.107, 95% CI: 1.016–1.206, P = 0.02) and Ibil level (OR = 2.303, 95% CI: 1.158–4.582, P = 0.017) were independent predictive factors of the occurrence of pAF in females; BNP (OR = 1.015, 95% CI: 1.002–1.029, P = 0.029) was an independent predictive variable of pAF in males. Age, smoking, and MCHC were independent predictive factors of pAF. BNP was an independent predictive biomarker of pAF in males, while in females, age and Ibil were independent predictive factors.

Oral iron supplementation in patients with heart failure: a systematic review and meta-analysis

AIMS

This review aimed to assess whether oral iron supplementation in a chronic heart failure (HF) population with iron deficiency (ID) or mild anaemia is safe and effective according to evidence-based medicine.

METHODS

We retrieved 1803 records from the PubMed, Embase, and the Cochrane Library databases from 1 January 1991 to 15 September 2021. The clinical outcome of oral iron supplementation for ID anaemia in patients with HF was the primary endpoint. The primary safety measures included adverse events and all-cause mortality, and efficacy measures included transferrin saturation (Tsat), ferritin levels, and the 6-min walk test (6MWT). The rate ratio (RR) was used to pool the efficacy measures.

RESULTS

Five randomized controlled trials that compared oral iron treatment for patients with the placebo group and included a combined total of 590 participants were analysed. No significant difference was found in all-cause death between oral iron treatment and placebo groups (RR = 0.77; 95% confidence intervals (CI), 0.46-1.29, Z = 0.98; P = 0.33). However, adverse events were not significantly higher in the iron treatment group (RR = 0.83; 95% CI, 0.60-1.16, Z = 1.07; P = 0.28). In addition, ferritin levels and Tsat were slightly increased after iron complex administration in patients with HF but were not statistically significant (ferritin: mean difference [MD] = 2.70, 95% CI, -2.41 to 7.81, Z = 1.04; P = 0.30; Tsat: MD = 27.42, 95% CI, -4.93 to 59.78, Z = 1.66; P = 0.10). No significant difference was found in exercise capacity, as indicated by the 6MWT results (MD = 59.60, 95% CI, -17.89 to 137.08, Z = 1.51; P = 0.13). We also analysed two non-randomized controlled trials with follow-up results showing that oral iron supplementation increased serum iron levels (MD = 28.87, 95% CI, 1.62-56.12, Z = 2.08; P = 0.04).

CONCLUSIONS

Based on the current findings, oral iron supplementation can increase serum iron levels in patients with HF and ID or mild anaemia but does not improve Tsat and 6MWT. In addition, oral iron supplementation is relatively safe.