Short-Term Changes in Left and Right Ventricular Cardiac Magnetic Resonance Feature Tracking Strain Following Ferric Carboxymaltose in Patients With Heart Failure: A Substudy of the Myocardial-IRON Trial

Ferric carboxymaltose for iron deficiency in patients with heart failure: a systematic review and meta-analysis

Aim: Iron deficiency (ID) is associated with heart failure (HF) in a considerable proportion of patients. To improve the quality of life, lower the frequency of hospitalizations, and lower mortality rates of chronic HF patients (HF), this meta-analysis will look into the role of iron supplementation using ferric carboxymaltose (FCM). Methods & results: From inception until 1 October 2023, we conducted a thorough literature search of electronic databases for peer-reviewed publications. Around 5229 HF patients were included, of which 2691 received FCM while 2538 received placebo. Conclusion: FCM reduces HF-related hospitalizations but doesn't improve overall or cardiovascular mortality in those with HF and ID. The overall results support FCM's role in managing iron deficiency in heart failure.

Iron Deficiency in Patients with Left Ventricular Assist Devices

Iron deficiency is a common and independent predictor of adverse outcomes in patients with heart failure. The implications of iron deficiency in patients implanted with a left ventricular assist device (LVAD) are less established. This review recaps data on the prevalence, characteristics and impact of Iron deficiency in the LVAD population. A systematic search yielded eight studies involving 517 LVAD patients, with iron deficiency prevalence ranging from 40% to 82%. IV iron repletion was not associated with adverse events and effectively resolved iron deficiency in most patients. However, the effects of iron deficiency and iron repletion on post-implant survival and exercise capacity remain unknown. Although iron deficiency is highly prevalent in LVAD patients, its true prevalence and adverse effects may be misestimated due to inexact diagnostic criteria. Future randomised controlled trials on IV iron treatment in LVAD patients are warranted to clarify the significance of this common comorbidity.

Identification of three mechanistic pathways for iron-deficient heart failure

Current understanding of iron-deficient heart failure is based on blood tests that are thought to reflect systemic iron stores, but the available evidence suggests greater complexity. The entry and egress of circulating iron is controlled by erythroblasts, which (in severe iron deficiency) will sacrifice erythropoiesis to supply iron to other organs, e.g. the heart. Marked hypoferraemia (typically with anaemia) can drive the depletion of cardiomyocyte iron, impairing contractile performance and explaining why a transferrin saturation < ≈15%-16% predicts the ability of intravenous iron to reduce the risk of major heart failure events in long-term trials (Type 1 iron-deficient heart failure). However, heart failure may be accompanied by intracellular iron depletion within skeletal muscle and cardiomyocytes, which is disproportionate to the findings of systemic iron biomarkers. Inflammation- and deconditioning-mediated skeletal muscle dysfunction-a primary cause of dyspnoea and exercise intolerance in patients with heart failure-is accompanied by intracellular skeletal myocyte iron depletion, which can be exacerbated by even mild hypoferraemia, explaining why symptoms and functional capacity improve following intravenous iron, regardless of baseline haemoglobin or changes in haemoglobin (Type 2 iron-deficient heart failure). Additionally, patients with advanced heart failure show myocardial iron depletion due to both diminished entry into and enhanced egress of iron from the myocardium; the changes in iron proteins in the cardiomyocytes of these patients are opposite to those expected from systemic iron deficiency. Nevertheless, iron supplementation can prevent ventricular remodelling and cardiomyopathy produced by experimental injury in the absence of systemic iron deficiency (Type 3 iron-deficient heart failure). These observations, taken collectively, support the possibility of three different mechanistic pathways for the development of iron-deficient heart failure: one that is driven through systemic iron depletion and impaired erythropoiesis and two that are characterized by disproportionate depletion of intracellular iron in skeletal and cardiac muscle. These mechanisms are not mutually exclusive, and all pathways may be operative at the same time or may occur sequentially in the same patients.

Critical re-evaluation of the identification of iron deficiency states and effective iron repletion strategies in patients with chronic heart failure

According to current guidelines, iron deficiency is defined by a serum ferritin level <100 ng/ml or a transferrin saturation (TSAT) <20% if the serum ferritin level is 100-299 μg/L. These criteria were developed to encourage the use of intravenous iron as an adjunct to erythropoiesis-stimulating agents in the treatment of renal anaemia. However, in patients with heart failure, these criteria are not supported by any pathophysiological or clinical evidence that they identify an absolute or functional iron deficiency state. A low baseline TSAT-but not serum ferritin level-appears to be a reliable indicator of the effect of intravenous iron to reduce major heart failure events. In randomized controlled trials, intravenous iron decreased the risk of cardiovascular death or total heart failure hospitalization in patients with a TSAT <20% (risk ratio 0.67 [0.49-0.92]) but not in patients with a TSAT ≥20% (risk ratio 0.99 [0.74-1.30]), with the magnitude of the risk reduction being proportional to the severity of hypoferraemia. Patients who were enrolled in clinical trials solely because they had a serum ferritin level <100 μg/L showed no significant benefit on heart failure outcomes, and it is noteworthy that serum ferritin levels of 20-300 μg/L lie entirely within the range of normal values for healthy adults. Current guidelines reflect the eligibility criteria of clinical trials, which inadvertently adopted unvalidated criteria to define iron deficiency. Reliance on these guidelines would lead to the treatment of many patients who are not iron deficient (serum ferritin level <100 μg/L but normal TSAT) and ignores the possibility of iron deficiency in patients with a low TSAT but with serum ferritin level of >300 μg/L. Importantly, analyses of benefit based on trial eligibility-driven guidelines substantially underestimate the magnitude of heart-failure-event risk reduction with intravenous iron in patients who are truly iron deficient. Based on all available data, we recommend a new mechanism-based and trial-tested approach that reflects the totality of evidence more faithfully than the historical process adopted by clinical investigators and by the guidelines. Until additional evidence is forthcoming, an iron deficiency state in patients with heart failure should be defined by a TSAT <20% (as long as the serum ferritin level is <400 μg/L), and furthermore, the use of a serum ferritin level <100 μg/L alone as a diagnostic criterion should be discarded.

Improvement in left atrial strain following ferric carboxymaltose in heart failure: an analysis of the Myocardial-IRON trial

AIMS

Iron deficiency (ID) is associated with an impaired cardiac function and remodelling in heart failure (HF). Treatment with ferric carboxymaltose (FCM) has been showed recently to improve biventricular systolic function and ventricular strain parameters in patients with HF with reduced ejection fraction and ID, but there is no evidence on the benefit of FCM on the left atrium (LA). In this study, we aimed to evaluate the effect of FCM on LA longitudinal strain (LA-LS).

METHODS AND RESULTS

This is a post hoc subanalysis of a double-blind, placebo-controlled, randomized clinical trial that enrolled 53 ambulatory patients with HF, left ventricular ejection fraction (LVEF) < 50%, and ID [Myocardial-IRON trial (NCT03398681)], treated with FCM or placebo. Cardiac magnetic resonance-featured tracking (CMR-FT) strain changes were evaluated before and 7 and 30 days after randomization using linear mixed regression analysis. The median age of the sample was 68 years (interquartile range: 64-76), and 20 (69%) were men. Mean ± standard deviation of LVEF was 39 ± 11%, and most (97%) were in stable New York Heart Association class II. At baseline, mean LA-LS was -8.9 ± 3.5%. At 30 days, and compared with placebo, LA-LS significantly improved in those allocated to FCM treatment arm (LA-LS = -12.0 ± 0.5 and -8.5 ± 0.6, respectively; - ∆ 3.55%, P < 0.001).

CONCLUSIONS

In patients with stable HF, LVEF < 50%, and ID, treatment with FCM was associated with short-term improvements in LA-LS assessed by CMR-FT. Future works should assess the potential benefit of iron repletion on LA function.

Effect of Intravenous Ferric Carboxymaltose on Exercise Capacity After Kidney Transplantation (EFFECT-KTx): rationale and study protocol for a double-blind, randomised, placebo-controlled trial

INTRODUCTION

Iron deficiency (ID) is common and has been associated with an excess mortality risk in kidney transplant recipients (KTRs). In patients with chronic heart failure and ID, intravenous iron improves exercise capacity and quality of life. Whether these beneficial effects also occur in KTRs is unknown. The main objective of this trial is to address whether intravenous iron improves exercise tolerance in iron-deficient KTRs.

METHODS AND ANALYSIS

The Effect of Ferric Carboxymaltose on Exercise Capacity after Kidney Transplantation study is a multicentre, double-blind, randomised, placebo-controlled clinical trial that will include 158 iron-deficient KTRs. ID is defined as plasma ferritin <100 µg/L or plasma ferritin 100-299 µg/L with transferrin saturation <20%. Patients are randomised to receive 10 mL of ferric carboxymaltose (50 mg Fe³⁺/mL, intravenously) or placebo (0.9% sodium chloride solution) every 6 weeks, four dosages in total. The primary endpoint is change in exercise capacity, as quantified by the 6 min walk test, between the first study visit and the end of follow-up, 24 weeks later. Secondary endpoints include changes in haemoglobin levels and iron status, quality of life, systolic and diastolic heart function, skeletal muscle strength, bone and mineral parameters, neurocognitive function and safety endpoints. Tertiary (explorative) outcomes are changes in gut microbiota and lymphocyte proliferation and function.

ETHICS AND DISSEMINATION

The protocol of this study has been approved by the medical ethical committee of the University Medical Centre Groningen (METc 2018/482;) and is being conducted in accordance with the principles of the Declaration of Helsinki, the Standard Protocol Items: Recommendations for Interventional Trials checklist and the Good Clinical Practice guidelines provided by the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use. Study results will be disseminated through publications in peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03769441.

High salt intake damages myocardial viability and induces cardiac remodeling via chronic inflammation in the elderly

Background

The heart is an important target organ for the harmful effects of high dietary salt intake. However, the effects and associations of high salt intake on myocardial viability, cardiac function changes, and myocardial remodeling are unclear.

Methods

A total of 3,810 participants aged 60 years and older were eligible and enrolled from April 2008 to November 2010 and from August 2019 to November 2019 in the Shandong area of China. Salt intake was estimated using 24-h urine collection consecutively for 7 days. Myocardial strain rates, cardiac function and structure, and serum high-sensitivity C-reactive protein (hsCRP) levels were assessed. Participants were classified into low (n = 643), mild (n = 989), moderate (n = 1,245), and high (n = 933) groups, corresponding to < 6, 6–9, 9–12, and >12 g/day of salt intake, respectively, depending on the salt intake estimation.

Results

The global early diastolic strain rate (SRe) and late diastolic strain rate (SRa) in the high group were 1.58 ± 0.26, 1.38 ± 0.24. respectively, and significantly lower compared with the low, mild, and moderate groups (all P < 0.05). The global systolic strain rate (SRs) in the high group was −1.24 ± 0.24, and it was higher than those in the low, mild, and moderate groups (all P < 0.05). Salt intake was independently and positively correlated with global SRs, Tei index, and the parameters of left ventricular structure separately; negatively correlated with global SRe and SRa, left ventricular short axis shortening rate, left ventricular ejection fraction after adjusting for confounders (all P_adjusted < 0.001). Hayes process analyses demonstrated that the mediating effects of hsCRP on global SRe, SRa, and SRs; Tei index; and left ventricular remodeling index were −0.013 (95% CI: −0.015 to −0.010), −0.010 (−0.012 to −0.008), 0.008 (0.006–0.010), 0.005 (0.003–0.006), and 0.010 (0.009–0.012), respectively (all P_adjusted < 0.001).

Conclusion

Our data indicate that excess salt intake is independently associated with the impairment in myocardial viability and cardiac function, as well as myocardial remodeling. Chronic inflammation might play a mediating role in the association between high salt intake and cardiac function damage and myocardial remodeling.