Intravenous iron in patients with heart failure and iron deficiency: an updated meta-analysis

Iron deficiency and supplementation in heart failure

Non-anaemic iron deficiency (NAID) is a strategic target in cardiovascular medicine because of its association with a range of adverse effects in various conditions. Endeavours to tackle NAID in heart failure have yielded mixed results, exposing knowledge gaps in how best to define 'iron deficiency' and the handling of iron therapies by the body. To address these gaps, we harness the latest understanding of the mechanisms of iron homeostasis outside the erythron and integrate clinical and preclinical lines of evidence. The emerging picture is that current definitions of iron deficiency do not assimilate the multiple influences at play in patients with heart failure and, consequently, fail to identify those with a truly unmet need for iron. Additionally, current iron supplementation therapies benefit only certain patients with heart failure, reflecting differences in the nature of the unmet need for iron and the modifying effects of anaemia and inflammation on the handling of iron therapies by the body. Building on these insights, we identify untapped opportunities in the management of NAID, including the refinement of current approaches and the development of novel strategies. Lessons learned from NAID in cardiovascular disease could ultimately translate into benefits for patients with other chronic conditions such as chronic kidney disease, chronic obstructive pulmonary disease and cancer.

Intravenous Iron Repletion for Patients With Heart Failure and Iron Deficiency: JACC State-of-the-Art Review

Iron deficiency and heart failure frequently co-occur, sparking clinical research into the role of iron repletion in this condition over the last 20 years. Although early nonrandomized studies and subsequent moderate-sized randomized controlled trials showed an improvement in symptoms and functional metrics with the use of intravenous iron, 3 recent larger trials powered to detect a difference in hard cardiovascular outcomes failed to meet their primary endpoints. Additionally, there are potential concerns related to side effects from intravenous iron, both in the short and long term. This review discusses the basics of iron biology and regulation, the diagnostic criteria for iron deficiency and the clinical evidence for intravenous iron in heart failure, safety concerns, and alternative therapies. We also make practical suggestions for the management of patients with iron deficiency and heart failure and outline key areas in need of future research.

Association between dietary inflammatory index and NT-proBNP levels in US adults: A cross-sectional analysis

BACKGROUND

With cardiovascular diseases standing as a leading cause of mortality worldwide, the interplay between diet-induced inflammation, as quantified by the Dietary Inflammatory Index (DII), and heart failure biomarker NT-proBNP has not been investigated in the general population.

METHODS

This study analyzed data from the National Health and Nutrition Examination Survey (NHANES) 1999-2004, encompassing 10,766 individuals. The relationship between the DII and NT-proBNP levels was evaluated through multivariable-adjusted regression models. To pinpoint crucial dietary components influencing NT-proBNP levels, the LASSO regression model was utilized. Stratified analyses were then conducted to examine the associations within specific subgroups to identify differential effects of the DII on NT-proBNP levels across diverse populations.

RESULTS

In individuals without heart failure, a unit increase in the DII was significantly associated with an increase in NT-proBNP levels. Specifically, NT-proBNP levels rose by 9.69 pg/mL (95% CI: 6.47, 12.91; p < 0.001) without adjustments, 8.57 pg/mL (95% CI: 4.97, 12.17; p < 0.001) after adjusting for demographic factors, and 5.54 pg/mL (95% CI: 1.75, 9.32; p = 0.001) with further adjustments for health variables. In participants with a history of heart failure, those in the second and third DII quartile showed a trend towards higher NT-proBNP levels compared to those in the lowest quartile, with increases of 717.06 pg/mL (95% CI: 76.49-1357.63, p = 0.030) and 855.49 pg/mL (95% CI: 156.57-1554.41, p = 0.018). Significant interactions were observed in subgroup analyses by age (<50: β = 3.63, p = 0.141; 50-75: β = 18.4, p<0.001; >75: β = 56.09, p<0.001), gender (men: β = 17.82, p<0.001; women: β = 7.43, p = 0.061),hypertension (β = 25.73, p<0.001) and diabetes (β = 38.94, p<0.001).

CONCLUSION

This study identified a positive correlation between the DII and NT-proBNP levels, suggesting a robust link between pro-inflammatory diets and increased heart failure biomarkers, with implications for dietary modifications in cardiovascular risk management.

The findings of a service evaluation on the practice of assessment and treatment of iron deficiency in people admitted to a UK hospital with decompensated Heart Failure

BACKGROUND

Iron Deficiency (ID) is common in Heart Failure (HF) and associated with poor outcomes. Replacement with intravenous (IV) iron can improve functional status, quality of life and risk of unplanned admission. In 2015/16 a local service evaluation was performed which found that of people admitted with HF, only 27.5 % had assessment of iron status, and when identified, replacement occurred in fewer than half. Education strategies were employed to increase awareness of the importance of assessment and correction.

OBJECTIVES

To assess if practice had improved following education strategies.

METHODS

A review of 220 patient records for people admitted with HF in 2020/21 to establish if iron status assessed, presence of ID, and whether if ID identified it was treated, and by which route. Trends in 2020/21 data were explored in sub-groups by age, sex, type of HF, anaemia status, input from HF specialists and type of ID.

RESULTS

Compared to 2015/16, more assessments of iron status were performed (45% vs 27.5 %), ID was corrected more frequently (57% vs 46 %) and increased use of the IV route for replacement (83% vs 58 %) CONCLUSIONS: Despite the impact of COVID-19 on usual care in 2020/21, improvement was seen in proportion of assessment and treatment of ID following simple education strategies for key stakeholders. There may be scope to improve practice further if the findings remain similar post pandemic. If so, a formal Quality Improvement approach may be helpful.

Iron Deficiency and Incident Heart Failure in Older Community-Dwelling Individuals

AIMS

Among persons with prevalent heart failure (HF), iron deficiency has been linked to HF admissions, and intravenous iron replacement improves HF outcomes. Recent studies in persons with chronic kidney disease (CKD) demonstrate that iron deficiency is associated with incident HF. This study aimed to determine the relationship of iron status with incident HF in community-dwelling older adults irrespective of their kidney function.

METHODS

In this case-cohort study, 1,006 Cardiovascular Health Study participants (785 from the random sub-cohort [including 193 HF cases] and 221 additional HF cases [N = 414 total HF cases]) aged ≥ 65 years without HF (41% with CKD), we used weighted Cox models to evaluate associations of iron status with incident HF. Participants were categorized based on quartiles of transferrin saturation and ferritin as "iron replete" (27.3%), "functional iron deficiency" (7.7%), "iron deficiency" (11.8%), "mixed iron deficiency" (5.6%), "high iron" (9.3%) and "non-classified" (38.1%), consistent with prior studies.

RESULTS

Compared to older persons who were iron replete, those with iron deficiency were at higher risk of incident HF (HR 1.47; 1.02-2.11) in models adjusting for demographics, HF risk factors, and estimated glomerular filtration rate. Other iron categories did not associate with incident HF. The relationship of iron deficiency with incident HF did not differ by CKD status (interaction P value 0.2).

CONCLUSIONS

Among community-dwelling elders, iron deficiency is independently associated with incident HF, an association that was similar irrespective of CKD status. Our findings support conduct of clinical trials of iron replacement for prevention of HF in older adults with iron deficiency.

2024 update in heart failure

In the last years, major progress has occurred in heart failure (HF) management. The 2023 ESC focused update of the 2021 HF guidelines introduced new key recommendations based on the results of the last years of science. First, two drugs, sodium-glucose co-transporter-2 (SGLT2) inhibitors and finerenone, a novel nonsteroidal, selective mineralocorticoid receptor antagonist (MRA), are recommended for the prevention of HF in patients with diabetic chronic kidney disease (CKD). Second, SGLT2 inhibitors are now recommended for the treatment of HF across the entire left ventricular ejection fraction spectrum. The benefits of quadruple therapy in patients with HF with reduced ejection fraction (HFrEF) are well established. Its rapid and early up-titration along with a close follow-up with frequent clinical and laboratory re-assessment after an episode of acute HF (the so-called 'high-intensity care' strategy) was associated with better outcomes in the STRONG-HF trial. Patients experiencing an episode of worsening HF might require a fifth drug, vericiguat. In the STEP-HFpEF-DM and STEP-HFpEF trials, semaglutide 2.4 mg once weekly administered for 1 year decreased body weight and significantly improved quality of life and the 6 min walk distance in obese patients with HF with preserved ejection fraction (HFpEF) with or without a history of diabetes. Further data on safety and efficacy, including also hard endpoints, are needed to support the addition of acetazolamide or hydrochlorothiazide to a standard diuretic regimen in patients hospitalized due to acute HF. In the meantime, PUSH-AHF supported the use of natriuresis-guided diuretic therapy. Further options and most recent evidence for the treatment of HF, including specific drugs for cardiomyopathies (i.e., mavacamten in hypertrophic cardiomyopathy and tafamidis in transthyretin cardiac amyloidosis), device therapies, cardiac contractility modulation and percutaneous treatment of valvulopathies, with the recent finding from the TRILUMINATE Pivotal trial, are also reviewed in this article.

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.

Expert recommendations for the management of iron deficiency in patients with heart failure in Asia

BACKGROUND

Iron deficiency is a common comorbidity in heart failure (HF) and is independently associated with a worse quality-of-life and exercise capacity, as well as increased risk of hospitalization, regardless of anemia status. Although international guidelines have provided recommendations for the management of iron deficiency in patients with HF, guidelines in Asia are less established, and practical use of guidelines for management of iron deficiency is limited in the region.

METHODS

A panel comprising cardiologists from China, Hong Kong, India, Japan, Malaysia, Pakistan, Philippines, Singapore, South Korea, Taiwan, and Thailand convened to share insights and provide guidance for the optimal management of iron deficiency in patients with HF, tailored for the Asian community.

RESULTS

Expert opinions were provided for the screening, diagnosis, treatment and monitoring of iron deficiency in patients with HF. It was recommended that all patients with HF with reduced ejection fraction should be screened for iron deficiency, and iron-deficient patients should be treated with intravenous iron. Monitoring of iron levels in patients with HF should be carried out once or twice yearly. Barriers to the management of iron deficiency in patients with HF in the region include low awareness of iron deficiency amongst general physicians, lack of reimbursement for screening and treatment, and lack of proper facilities for administration of intravenous iron.

CONCLUSIONS

These recommendations provide a structured approach to the management of iron deficiency in patients with HF in Asia.

The complementary roles of iron and estrogen in menopausal differences in cardiometabolic outcomes

Biological hormonal changes are frequently cited as an explanatory factor of sex and menopause differences in cardiometabolic diseases (CMD) and its associated risk factors. However, iron metabolism which varies between sexes and among women of different reproductive stages could also play a role. Recent evidence suggest that iron may contribute to CMD risk by modulating oxidative stress pathways and inflammatory responses, offering insights into the mechanistic interplay between iron and CMD development. In the current review, we provide a critical appraisal of the existing evidence on sex and menopausal differences in CMD, discuss the pitfall of current estrogen hypothesis as sole explanation, and the emerging role of iron in CMD as complementary pathway. Prior to menopause, body iron stores are lower in females as compared to males, but the increase during and after menopause, is tandem with an increased CMD risk. Importantly, basic science experiments show that an increased iron status is related to the development of type 2 diabetes (T2D), and different cardiovascular diseases (CVD). While epidemiological studies have consistently reported associations between heme iron intake and some iron biomarkers such as ferritin and transferrin saturation with the risk of T2D, the evidence regarding their connection to CVD remains controversial. We delve into the factors contributing to this inconsistency, and the limitation of relying on observational evidence, as it does not necessarily imply causation. In conclusion, we provide recommendations for future studies on evaluating the potential role of iron in elucidating the sex and menopausal differences observed in CMD.

The Impact of Ferric Derisomaltose on Cardiovascular and Noncardiovascular Events in Patients With Anemia, Iron Deficiency, and Heart Failure With Reduced Ejection Fraction

BACKGROUND

In some countries, intravenous ferric derisomaltose (FDI) is only licensed for treating iron deficiency with anemia. Accordingly, we investigated the effects of intravenous FDI in a subgroup of patients with anemia in the IRONMAN (Effectiveness of Intravenous (IV) Iron Treatment Versus Standard Care in Patients With Heart Failure and Iron Deficiency) trial.

METHOD AND RESULTS

IRONMAN enrolled patients with heart failure, a left ventricular ejection fraction of ≤45%, and iron deficiency (ferritin <100 µg/L or transferrin saturation of <20%), 771 (68%) of whom had anemia (hemoglobin <12 g/dL for women and <13 g/dL for men). Patients were randomized, open label, to FDI (n = 397) or usual care (n = 374) and followed for a median of 2.6 years. The primary end point, recurrent hospitalization for heart failure and cardiovascular death, occurred less frequently for those assigned to FDI (rate ratio 0.78, 95% confidence interval 0.61-1.01; P = .063). First event analysis for cardiovascular death or hospitalization for heart failure, less affected by the coronavirus disease 2019 pandemic, gave similar results (hazard ratio 0.77, 95% confidence interval 0.62-0.96; P = .022). Patients randomized to FDI reported a better Minnesota Living with Heart Failure quality of life, for overall (P = .013) and physical domain (P = .00093) scores at 4 months.

CONCLUSIONS

In patients with iron deficiency anemia and heart failure with reduced left ventricular ejection fraction, intravenous FDI improves quality of life and may decrease cardiovascular events.

Intravenous iron for heart failure, iron deficiency definitions, and clinical response: the IRONMAN trial

BACKGROUND AND AIMS

What is the relationship between blood tests for iron deficiency, including anaemia, and the response to intravenous iron in patients with heart failure?

METHODS

In the IRONMAN trial, 1137 patients with heart failure, ejection fraction ≤ 45%, and either serum ferritin < 100 µg/L or transferrin saturation (TSAT) < 20% were randomized to intravenous ferric derisomaltose (FDI) or usual care. Relationships were investigated between baseline anaemia severity, ferritin and TSAT, to changes in haemoglobin from baseline to 4 months, Minnesota Living with Heart Failure (MLwHF) score and 6-minute walk distance achieved at 4 months, and clinical events, including heart failure hospitalization (recurrent) or cardiovascular death.

RESULTS

The rise in haemoglobin after administering FDI, adjusted for usual care, was greater for lower baseline TSAT (Pinteraction < .0001) and ferritin (Pinteraction = .028) and more severe anaemia (Pinteraction = .014). MLwHF scores at 4 months were somewhat lower (better) with FDI for more anaemic patients (overall Pinteraction = .14; physical Pinteraction = .085; emotional Pinteraction = .043) but were not related to baseline TSAT or ferritin. Blood tests did not predict difference in achieved walking distance for those randomized to FDI compared to control. The absence of anaemia or a TSAT ≥ 20% was associated with lower event rates and little evidence of benefit from FDI. More severe anaemia or TSAT < 20%, especially when ferritin was ≥100 µg/L, was associated with higher event rates and greater absolute reductions in events with FDI, albeit not statistically significant.

CONCLUSIONS

This hypothesis-generating analysis suggests that anaemia or TSAT < 20% with ferritin > 100 µg/L might identify patients with heart failure who obtain greater benefit from intravenous iron. This interpretation requires confirmation.

Effect of anaemia and iron deficiency in heart failure with mildly reduced ejection fraction

OBJECTIVE

The present study aims to clarify the prevalence and prognostic impact of anaemia and iron deficiency in patients with heart failure with mildly reduced ejection fraction (HFmrEF).

BACKGROUND

The prognostic impact of anaemia and iron deficiency in HFmrEF has not yet been clarified.

METHODS

Consecutive patients with HFmrEF were retrospectively included at one institution from 2016 to 2022. Patients with anaemia (i.e. haemoglobin <13 g/dL in males and < 12 g/dL in females) were compared to patients without, respectively patients with or without iron deficiency. The primary endpoint was all-cause mortality at 30 months (median follow-up), secondary endpoints comprised HF-related rehospitalisation.

RESULTS

Two thousand one hundred and fifty four patients with HFmrEF with a median haemoglobin level of 12.2 g/dL were included. Anaemia was present in 52% of patients with HFmrEF and associated with a higher risk of all-cause mortality (44% vs. 18%; HR = 3.021; 95% CI 2.552-3.576; p =.001) and HF-related rehospitalisation (18% vs. 8%; HR = 2.351; 95% CI 1.819-3.040; p =.001) at 30 months, which was confirmed after multivariable adjustment. Although iron status was infrequently assessed in anaemics with HFmrEF (27%), the presence of iron deficiency was associated with higher risk of rehospitalisation for worsening HF (25% vs. 15%; HR = 1.746; 95% CI 1.024-2.976; p =.038), but not all-cause mortality (p =.279) at 30 months.

CONCLUSION

Anaemia and iron deficiency are very common in atleast half of patients with HFmrEF and independently associated with adverse long-term prognosis.

Meta-Analysis and Metaregression of the Treatment Effect of Intravenous Iron in Iron-Deficient Heart Failure

BACKGROUND

Guidelines recommend that intravenous iron should be considered to improve symptoms of heart failure (HF) and reduce the risk for HF admissions in patients after acute HF.

OBJECTIVES

This study sought to analyze the effect of intravenous iron on cardiovascular (CV) death and HF admissions in a broad population of HF patients with iron deficiency and the relation with baseline transferrin saturation (TSAT).

METHODS

A systematic review of all published randomized controlled trials assessing the effect of intravenous iron in patients with iron deficiency and HF between January 1, 2000, and August 26, 2023, was performed. The overall treatment effect was estimated using a fixed effect model for: 1) CV death; 2) CV death and HF admission; 3) first HF admission; and 4) total HF admissions. Metaregression through a mixed effect model was used to explore the impact of baseline TSAT in case of heterogeneity among trial results.

RESULTS

A total of 14 randomized controlled trials were identified in the systematic review and retained in the meta-analysis. Aggregate-level data were included on 6,624 HF patients, 3,407 of whom were randomized to intravenous iron and 3,217 to placebo. Treatment with intravenous iron resulted in a lower risk for CV death (OR: 0.867 [95% CI: 0.755-0.955]; P = 0.0427), combined CV death and HF admission (OR: 0.838 [95% CI: 0.751-0.936]; P = 0.0015), first HF admission (OR: 0.855 [95% CI: 0.744-0.983]; P = 0.0281), and total HF admissions (rate ratio: 0.739 [95% CI: 0.661-0.827]; P < 0.0001). Significant heterogeneity among trial results was observed for first and total HF admissions. Metaregression suggested that some of the heterogeneity was related to the baseline TSAT of the enrolled population, with trials enrolling patients with lower TSAT exhibiting a large effect size on HF-related events.

CONCLUSIONS

The totality of data suggests that treatment with intravenous iron reduces both CV death and HF-related events in a broad population with HF. A lower baseline TSAT might be important for the effect on HF-related events.

Plasma Ferritin Levels, Incident Heart Failure, and Cardiac Structure and Function: The ARIC Study

BACKGROUND

Whether iron deficiency contributes to incident heart failure (HF) and cardiac dysfunction has important implications given the prevalence of iron deficiency and the availability of several therapeutics for iron repletion.

OBJECTIVES

The aim of this study was to estimate the associations of plasma ferritin level with incident HF overall, HF phenotypes, and cardiac structure and function measures in older adults.

METHODS

Participants in the ongoing, longitudinal ARIC (Atherosclerosis Risk In Communities) study who were free of prevalent HF and anemia were studied. The associations of plasma ferritin levels with incident HF overall and heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) were estimated using Cox proportional hazards regression models. Linear regression models estimated the cross-sectional associations of plasma ferritin with echocardiographic measures of cardiac structure and function.

RESULTS

The cohort included 3,472 individuals with a mean age of 75 ± 5 years (56% women, 14% Black individuals). In fully adjusted models, lower ferritin was associated with higher risk for incident HF overall (HR: 1.20 [95% CI: 1.08-1.34] per 50% lower ferritin level) and higher risk for incident HFpEF (HR: 1.28 [95% CI: 1.09-1.50]). Associations with incident HFrEF were not statistically significant. Lower ferritin levels were associated with higher E/e' ratio and higher pulmonary artery systolic pressure after adjustment for demographics and HF risk factors but not with measures of left ventricular structure or systolic function.

CONCLUSIONS

Among older adults without prevalent HF or anemia, lower plasma ferritin level is associated with a higher risk for incident HF, HFpEF, and higher measures of left ventricular filling pressure.

[Current therapy of heart failure with mildly reduced or preserved left ventricular ejection fraction]

Based on the results of recent clinical trials investigating patients with heart failure and a mildly reduced (HFmrEF) or preserved (HFpEF) left ventricular ejection fraction, an update of the ESC guidelines on acute and chronic heart failure as well as the German `Nationale Versorgungsleitlinie Herzinsuffizienz' has been released. Consistently, they now recommend the use of SGLT2 inhibitors also in these patients' groups. Further, patients with diabetes mellitus and chronic renal failure should receive the non-steroidal mineralocorticoid antagonist finerenone to reduce the risk of heart failure related hospitalization. In patients with HFmrEF, intravenous application of iron can be considered to improve quality of life in iron-depleted patients. Patients experiencing a heart failure related hospitalization shall receive the foundational guideline-directed pharmacotherapy already while in hospital and undergo a timely post discharge visit to further optimize treatment.

2023 Focused Update of the 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the task force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC) With the special contribution of the Heart Failure Association (HFA) of the ESC

Document Reviewers: Rudolf A. de Boer (CPG Review Co-ordinator) (Netherlands), P. Christian Schulze (CPG Review Co-ordinator) (Germany), Elena Arbelo (Spain), Jozef Bartunek (Belgium), Johann Bauersachs (Germany), Michael A. Borger (Germany), Sergio Buccheri (Sweden), Elisabetta Cerbai (Italy), Erwan Donal (France), Frank Edelmann (Germany), Gloria Färber (Germany), Bettina Heidecker (Germany), Borja Ibanez (Spain), Stefan James (Sweden), Lars Køber (Denmark), Konstantinos C. Koskinas (Switzerland), Josep Masip (Spain), John William McEvoy (Ireland), Robert Mentz (United States of America), Borislava Mihaylova (United Kingdom), Jacob Eifer Møller (Denmark), Wilfried Mullens (Belgium), Lis Neubeck (United Kingdom), Jens Cosedis Nielsen (Denmark), Agnes A. Pasquet (Belgium), Piotr Ponikowski (Poland), Eva Prescott (Denmark), Amina Rakisheva (Kazakhstan), Bianca Rocca (Italy), Xavier Rossello (Spain), Leyla Elif Sade (United States of America/Türkiye), Hannah Schaubroeck (Belgium), Elena Tessitore (Switzerland), Mariya Tokmakova (Bulgaria), Peter van der Meer (Netherlands), Isabelle C. Van Gelder (Netherlands), Mattias Van Heetvelde (Belgium), Christiaan Vrints (Belgium), Matthias Wilhelm (Switzerland), Adam Witkowski (Poland), and Katja Zeppenfeld (Netherlands) All experts involved in the development of this Focused Update have submitted declarations of interest. These have been compiled in a report and simultaneously published in a supplementary document to the Focused Update. The report is also available on the ESC website www.escardio.org/guidelines See the European Heart Journal online for supplementary documents that include evidence tables.

Iron Dyshomeostasis and Mitochondrial Function in the Failing Heart: A Review of the Literature

Cardiac contraction and relaxation require a substantial amount of energy provided by the mitochondria. The failing heart is adenosine triphosphate (ATP)- and creatine-depleted. Studies have found iron is involved in almost every aspect of mitochondrial function, and previous studies have shown myocardial iron deficiency in heart failure (HF). Many clinicians advocated intravenous iron repletion for HF patients meeting the conventional criteria for systemic iron deficiency. While clinical trials showed improved quality of life, iron repletion failed to significantly impact survival or significant cardiovascular adverse events. There is evidence that in HF, labile iron is trapped inside the mitochondria causing oxidative stress and lipid peroxidation. There is also compelling preclinical evidence demonstrating the detrimental effects of both iron overload and depletion on cardiomyocyte function. We reviewed the mechanisms governing myocardial and mitochondrial iron content. Mitochondrial dynamics (i.e., fusion, fission, mitophagy) and the role of iron were also investigated. Ferroptosis, as an important regulated cell death mechanism involved in cardiomyocyte loss, was reviewed along with agents used to manipulate it. The membrane stability and iron content of mitochondria can be altered by many agents. Some studies are showing promising improvement in the cardiomyocyte function after iron chelation by deferiprone; however, whether the in vitro and in vivo findings will be reflected on on clinical grounds is still unclear. Finally, we briefly reviewed the clinical trials on intravenous iron repletion. There is a need for more well-simulated animal studies to shed light on the safety and efficacy of chelation agents and pave the road for clinical studies.

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.

Ferric Carboxymaltose in Heart Failure with Iron Deficiency

BACKGROUND

Ferric carboxymaltose therapy reduces symptoms and improves quality of life in patients who have heart failure with a reduced ejection fraction and iron deficiency. Additional evidence about the effects of ferric carboxymaltose on clinical events is needed.

METHODS

In this double-blind, randomized trial, we assigned ambulatory patients with heart failure, a left ventricular ejection fraction of 40% or less, and iron deficiency, in a 1:1 ratio, to receive intravenous ferric carboxymaltose or placebo, in addition to standard therapy for heart failure. Ferric carboxymaltose or placebo was given every 6 months as needed on the basis of iron indexes and hemoglobin levels. The primary outcome was a hierarchical composite of death within 12 months after randomization, hospitalizations for heart failure within 12 months after randomization, or change from baseline to 6 months in the 6-minute walk distance. The significance level was set at 0.01.

RESULTS

We enrolled 3065 patients, of whom 1532 were randomly assigned to the ferric carboxymaltose group and 1533 to the placebo group. Death by month 12 occurred in 131 patients (8.6%) in the ferric carboxymaltose group and 158 (10.3%) in the placebo group; a total of 297 and 332 hospitalizations for heart failure, respectively, occurred by month 12; and the mean (±SD) change from baseline to 6 months in the 6-minute walk distance was 8±60 and 4±59 m, respectively (Wilcoxon-Mann-Whitney P = 0.02; unmatched win ratio, 1.10; 99% confidence interval, 0.99 to 1.23). Repeated dosing of ferric carboxymaltose appeared to be safe with an acceptable adverse-event profile in the majority of patients. The number of patients with serious adverse events occurring during the treatment period was similar in the two groups (413 patients [27.0%] in the ferric carboxymaltose group and 401 [26.2%] in the placebo group).

CONCLUSIONS

Among ambulatory patients who had heart failure with a reduced ejection fraction and iron deficiency, there was no apparent difference between ferric carboxymaltose and placebo with respect to the hierarchical composite of death, hospitalizations for heart failure, or 6-minute walk distance. (Funded by American Regent, a Daiichi Sankyo Group company; HEART-FID ClinicalTrials.gov number, NCT03037931.).

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.

Mendelian randomization study reveals a causal relationship between serum iron status and coronary heart disease and related cardiovascular diseases

Background

Growing observational studies have shown that abnormal systemic iron status is associated with Coronary heart disease (CHD). However, these results from observational studies was not entirely consistent.It remains unclear whether this relationship represents causality.It is necessary to explore the causal relationship between iron status and CHD and related cardiovascular diseases (CVD).

Objective

We aimed to investigate the potential casual relationship between serum iron status and CHD and related CVD using a two-sample Mendelian randomization (MR) approach.

Methods

Genetic statistics for single nucleotide polymorphisms (SNPs) between four iron status parameters were identified in a large-scale genome-wide association study (GWAS) conducted by the Iron Status Genetics organization. Three independent single nucleotide polymorphisms (SNPs) (rs1800562, rs1799945, and rs855791) aligned with four iron status biomarkers were used as instrumental variables. CHD and related CVD genetic statistics We used publicly available summary-level GWAS data. Five different MR methods random effects inverse variance weighting (IVW), MR Egger, weighted median, weighted mode, and Wald ratio were used to explore the causal relationship between serum iron status and CHD and related CVD.

Results

In the MR analysis, we found that the causal effect of serum iron (OR = 0.995, 95% CI = 0.992-0.998, p = 0.002) was negatively associated with the odds of coronary atherosclerosis (AS). Transferrin saturation (TS) (OR = 0.885, 95% CI = 0.797-0.982, p = 0.02) was negatively associated with the odds of Myocardial infarction (MI).

Conclusion

This MR analysis provides evidence for a causal relationship between whole-body iron status and CHD development. Our study suggests that a high iron status may be associated with a reduced risk of developing CHD.

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.