Iron deficiency in heart failure: why so frequent and which mechanisms?

Redox homeostasis in cardiac fibrosis: Focus on metal ion metabolism

Cardiac fibrosis is a major public health problem worldwide, with high morbidity and mortality, affecting almost all patients with heart disease worldwide. It is characterized by fibroblast activation, abnormal proliferation, excessive deposition, and abnormal distribution of extracellular matrix (ECM) proteins. The maladaptive process of cardiac fibrosis is complex and often involves multiple mechanisms. With the increasing research on cardiac fibrosis, redox has been recognized as an important part of cardiac remodeling, and an imbalance in redox homeostasis can adversely affect the function and structure of the heart. The metabolism of metal ions is essential for life, and abnormal metabolism of metal ions in cells can impair a variety of biochemical processes, especially redox. However, current research on metal ion metabolism is still very limited. This review comprehensively examines the effects of metal ion (iron, copper, calcium, and zinc) metabolism-mediated redox homeostasis on cardiac fibrosis, outlines possible therapeutic interventions, and addresses ongoing challenges in this rapidly evolving field.

Diagnosis and Treatment of Iron Deficiency in Heart Failure: OFICSel study by the French Heart Failure Working Group

AIMS

Iron deficiency (ID) occurs in about 50% of patients with heart failure (HF). The European Society of Cardiology (ESC) recommends ID diagnostic testing in newly diagnosed patients with HF and during follow-up, with intravenous iron supplementation (IS) only recommended in patients with HF with reduced ejection fraction (HFrEF). This study aimed to assess prevalence, clinical characteristics, and application of ESC guidelines for ID and IS in patients with HF in the real-life clinical setting.

METHODS AND RESULTS

The French transversal multicentre OFICSel registry (300 cardiologists) conducted in 2017 included patients hospitalized for HF at least once in the previous 5 years. Diverse adult patients were eligible including inpatients and outpatients and those with acute and chronic HF. Data were collected from cardiologists and patients using study-specific surveys. Data included demographic and clinical data, as well as HF and ID management data. Overall, 2822 patients, mainly male (69.3%) with a median age of 69 years (interquartile range 58-78), were included. A total of 1075 patients (38.1%) were tested for ID, with 364 (33.9%) diagnosed. Of these, 168 (46.2%) received IS: 128 (76.2%) intravenous IS and 40 (23.8%) oral. Among the 201 patients with HFrEF diagnosed with ID, 99 (49.3%) received IS: 79 (79.8%) intravenous IS and 20 (20.2%) oral.

CONCLUSIONS

In clinical practice, only one-third of patients with HF had a diagnostic test for ID. In patients with ID with HFrEF, only 39.3% received intravenous IS as recommended. Thus, in general, cardiologists should be encouraged to follow the ESC guidelines to ensure optimal treatment for patients with HF.

Low serum iron levels and risk of cardiovascular disease in high risk elderly population: Nested case-control study in the PREvención con DIeta MEDiterránea (PREDIMED) trial

BACKGROUND & AIMS

Epidemiological data on iron status and cardiovascular disease (CVD) are still controversial. The aim of this study was to determine whether low serum iron (SI) levels are associated with an increased odds of first CVD event in a population at high cardiovascular risk.

METHODS

Case-control study design nested within the "PREvención con DIeta MEDiterránea" (PREDIMED) trial. A total of 207 participants diagnosed with CVD (myocardial infarction, stroke or cardiovascular death) during follow-up period (2003-2010) were matched by sex, age and intervention group to 436 controls by incidence density sampling. Median time between serum sample collection and subsequent CVD event occurrence was 0.94 years. Inductively coupled plasma mass spectrometry analysis was used to determine SI levels. In-person interviews, medical record reviews, and validated questionnaires were used to assess covariates. Multivariable-adjusted odds ratios (ORs) of CVD were calculated with conditional logistic regression.

RESULTS

Mean SI levels were higher in men than in women (1224.0 μg/L vs. 1093.8 μg/L; p < 0.001). Among women, but not in men, the mean SI concentration was lower in cases than in controls (1008.5 μg/L vs. 1132.9 μg/L; p = 0.030). There was a gradual decrease in the multivariable-adjusted ORs of CVD with increasing SI levels (highest vs. lowest quartile: OR = 0.55, 95% CI: 0.32-0.93; p_trend = 0.020). This inverse relationship was more pronounced among women (highest vs. lowest quartile: OR = 0.15, 95% CI: 0.03-0.69; p_trend = 0.011).

CONCLUSIONS

The present findings are consistent with previously reported inverse associations between SI and CVD. SI levels as an independent marker of short-term cardiovascular risk may be useful for risk assessment in older populations.

TRIAL REGISTRATION

www.controlled-trials.com; International Standard Randomized Controlled Trial Number (ISRCTN): 35,739,639. Registered 5 October 2005. Retrospectively registered.