Prognostic Value of Iron-Homeostasis Regulating Peptide Hepcidin in Coronary Heart Disease-Evidence from the Large AtheroGene Study

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.

Iron deficiency and all-cause mortality after myocardial infarction

BACKGROUND

Data on the clinical significance of iron deficiency (ID) in patients with myocardial infarction (MI) are conflicting. This may be related to the use of various ID criteria. We aimed to compare the association of different ID criteria with all-cause mortality after MI.

METHODS

Consecutive patients hospitalized for their first MI at a large tertiary heart center were included. We evaluated the association of different iron metabolism parameters measured on the first day after hospital admission with all-cause mortality.

RESULTS

From the 1,156 patients included (aged 64±12 years, 25 % women), 194 (16.8 %) patients died during the median follow-up of 3.4 years. After multivariate adjustment, iron level ≤13 µmol/L (HR 1.67, 95 % CI 1.19-2.34) and the combination of iron level ≤12.8 µmol/L and soluble transferrin receptor (sTfR) ≥3 mg/L (HR 2.56, 95 % CI 1.64-3.99) termed as PragueID criteria were associated with increased mortality risk and had additional predictive value to the GRACE score. Compared to the model including iron level, the addition of sTfR improved risk stratification (net reclassification improvement 0.61, 95 % CI 0.52-0.69) by reclassifying patients into a higher-risk group. No association between ferritin level and mortality was found. 51 % of patients had low iron levels, and 58 % fulfilled the PragueID criteria.

CONCLUSION

Iron deficiency is common among patients with the first MI. The PragueID criteria based on iron and soluble transferrin receptor levels provide the best prediction of mortality and should be evaluated in future interventional studies for the identification of patients potentially benefiting from intravenous iron therapy.

suPAR as a risk Prediction Biomarker in Extracorporeal Membrane Oxygenation

suPAR is a promising biomarker of cardiovascular diseases, as it reflects “low-grade inflammation” and is associated with lifestyle factors such as smoking, alcohol, and an inactive lifestyle. suPAR is expressed in various cells involved in the development of atherosclerosis, including macrophages, endothelial cells, and smooth muscle cells, and an accumulation of suPAR in the atheroma has also been found. suPAR plays a role in the coagulation cascade during plasminogen activation and fibrinolysis. This abstract provides description of three case series showing the utility of suPAR as a risk prediction biomarker on VA extracorporeal membrane oxygenation (ECMO). We used SUPAR in 15 patients undergoing cardiac surgery of which three went on VA ECMO. Herein, we describe in detail three such patients and discuss each with good review of the literature.

Ferroptosis: A Potential Target in Cardiovascular Disease

Ferroptosis is a new form of regulatory cell death characterized by iron-dependent and intracellular lipid peroxidation. Ferroptosis can be divided into two stages. The first stage is iron overload in the cell, which generates a large amount of reactive oxygen species through the Fenton reaction, and the second stage results from an imbalance of the intracellular antioxidant system. Excessive phospholipid hydroperoxides cannot be removed by reduction reactions, as this could destroy the cell membrane structure and interfere with mitochondrial function, eventually leading to ferroptosis of the cell. Cardiovascular diseases have gradually become the leading cause of death in modern society. The relationship between ferroptosis and the occurrence and progression of cardiovascular disease has become a research hotspot in recent years. In this review, we summarize the mechanism of ferroptosis and its specific role in cardiovascular disease.

Triad role of hepcidin, ferroportin, and Nrf2 in cardiac iron metabolism: From health to disease

Iron is an essential trace element required for several vital physiological and developmental processes, including erythropoiesis, bone, and neuronal development. Iron metabolism and oxygen homeostasis are interlinked to perform a vital role in the functionality of the heart. The metabolic machinery of the heart utilizes almost 90 % of oxygen through the electron transport chain. To handle this tremendous level of oxygen, the iron metabolism in the heart is utmost crucial. Iron availability to the heart is therefore tightly regulated by (i) the hepcidin/ferroportin axis, which controls dietary iron absorption, storage, and recycling, and (ii) iron regulatory proteins 1 and 2 (IRP1/2) via hypoxia inducible factor 1 (HIF1) pathway. Despite iron being vital to the heart, recent investigations have demonstrated that iron imbalance is a common manifestation in conditions of heart failure (HF), since free iron readily transforms between Fe²⁺ and Fe³⁺via the Fenton reaction, leading to reactive oxygen species (ROS) production and oxidative damage. Therefore, to combat iron-mediated oxidative stress, targeting Nrf2/ARE antioxidant signaling is rational. The involvement of Nrf2 in regulating several genes engaged in heme synthesis, iron storage, and iron export is beginning to be uncovered. Consequently, it is possible that Nrf2/hepcidin/ferroportin might act as an epicenter connecting iron metabolism to redox alterations. However, the mechanism bridging the two remains obscure. In this review, we tried to summarize the contemporary insight of how cardiomyocytes regulate intracellular iron levels and discussed the mechanisms linking cardiac dysfunction with iron imbalance. Further, we emphasized the impact of Nrf2 on the interplay between systemic/cardiac iron control in the context of heart disease, particularly in myocardial ischemia and HF.

Association of iron deficiency with incident cardiovascular diseases and mortality in the general population

Aims

Although absolute (AID) and functional iron deficiency (FID) are known risk factors for patients with cardiovascular (CV) disease, their relevance for the general population is unknown. The aim was to assess the association between AID/FID with incident CV disease and mortality in the general population.

Methods and results

In 12 164 individuals from three European population‐based cohorts, AID was defined as ferritin < 100 μg/L or as ferritin < 30 μg/L (severe AID), and FID was defined as ferritin < 100 μg/L or ferritin 100–299 μg/L and transferrin saturation < 20%. The association between iron deficiency and incident coronary heart disease (CHD), CV mortality, and all‐cause mortality was evaluated by Cox regression models. Population attributable fraction (PAF) was estimated. Median age was 59 (45–68) years; 45.2% were male. AID, severe AID, and FID were prevalent in 60.0%, 16.4%, and 64.3% of individuals. AID was associated with CHD [hazard ratio (HR) 1.20, 95% confidence interval (CI) 1.04–1.39, P = 0.01], but not with mortality. Severe AID was associated with all‐cause mortality (HR 1.28, 95% CI 1.12–1.46, P < 0.01), but not with CV mortality/CHD. FID was associated with CHD (HR 1.24, 95% CI 1.07–1.43, P < 0.01), CV mortality (HR 1.26, 95% CI 1.03–1.54, P = 0.03), and all‐cause mortality (HR 1.12, 95% CI 1.01–1.24, P = 0.03). Overall, 5.4% of all deaths, 11.7% of all CV deaths, and 10.7% of CHD were attributable to FID.

Conclusions

In the general population, FID was highly prevalent, was associated with incident CHD, CV death, and all‐cause death, and had the highest PAF for these events, whereas AID was only associated with CHD and severe AID only with all‐cause mortality. This indicates that FID is a relevant risk factor for CV diseases in the general population.

Immunoadsorption for heart failure is associated with normalization of iron metabolism

AIMS

In heart failure (HF) patients, early stages are associated with increased iron levels, whereas iron deficiency is a common feature of chronic HF. We investigated the acute and long-term changes in iron metabolism in HF patients after immunoadsorption treatment and intravenous immunoglobulin (IVIG) administration.

METHODS AND RESULTS

Twenty-seven patients with HF with reduced ejection fraction (HFrEF) received a single cycle of immunoadsorption followed by IVIG administration. Left ventricular ejection fraction (LVEF) and iron biomarker (ferritin, hepcidin and interleukin-6) were evaluated at baseline, after immunoadsorption and during long-term follow-up of 29.3 months. LVEF improved significantly after immunoadsorption treatment from baseline 27% to 43% at long-term follow-up. Ferritin decreased from baseline 300.2 to 201.3 ng/mL (p < 0.0001) during immunoadsorption treatment and normalized during long-term to 207.9 ng/mL. Hepcidin showed a V-shaped course, with a significant decrease after immunoadsorption and normalization during long-term. Interleukin-6 levels showed no relevant inflammation.

CONCLUSIONS

Our data suggest that initial high serum ferritin and hepcidin levels indicate elevated iron levels characteristic of early stages of HFrEF, without inflammation. Normalization of hepcidin and ferritin was paralleled by restoration of systolic cardiac function after immunoadsorption treatment, without development of iron deficiency, as usually observed in chronic HF.

In-depth review: is hepcidin a marker for the heart and the kidney?

Iron is an essential trace element involved in oxidation-reduction reactions, oxygen transport and storage, and energy metabolism. Iron in excess can be toxic for cells, since iron produces reactive oxygen species and is important for survival of pathogenic microbes. There is a fine-tuning in the regulation of serum iron levels, determined by intestinal absorption, macrophage iron recycling, and mobilization of hepatocyte stores versus iron utilization, primarily by erythroid cells in the bone marrow. Hepcidin is the major regulatory hormone of systemic iron homeostasis and is upregulated during inflammation. Hepcidin metabolism is altered in chronic kidney disease. Ferroportin is an iron export protein and mediates iron release into the circulation from duodenal enterocytes, splenic reticuloendothelial macrophages, and hepatocytes. Systemic iron homeostasis is controlled by the hepcidin-ferroportin axis at the sites of iron entry into the circulation. Hepcidin binds to ferroportin, induces its internalization and intracellular degradation, and thus inhibits iron absorption from enterocytes, and iron release from macrophages and hepatocytes. Recent data suggest that hepcidin, by slowing or preventing the mobilization of iron from macrophages, may promote atherosclerosis and may be associated with increased cardiovascular disease risk. This article reviews the current data regarding the molecular and cellular pathways of systemic and autocrine hepcidin production and seeks the answer to the question whether changes in hepcidin translate into clinical outcomes of all-cause and cardiovascular mortality, and cardiovascular and renal end-points.

Low testosterone concentrations and prediction of future heart failure in men and in women: evidence from the large FINRISK97 study

Aims

The increased incidence of heart failure in men suggests that endogenous sex hormones might play a role in the development of heart failure, but epidemiological data remain sparse. Here, we evaluated the predictive value of low testosterone levels on future heart failure in the large population‐based FINRISK97 study.

Methods and results

Baseline serum testosterone concentrations were measured in 7855 subjects (3865 men and 3990 women) of the FINRISK97 study. During a median follow‐up (FU) of 13.8 years, a total of 564 heart failure events were recorded. The age‐adjusted baseline testosterone levels did not differ significantly between subjects developing incident heart failure during FU and those without incident events during FU (men: 16.6 vs. 17.1 nmol/L, P = 0.75; women: 1.15 vs. 1.17 nmol/L, P = 0.32). Relevant statistically significant correlations of testosterone levels were found with high‐density lipoprotein cholesterol levels (R = 0.22; P < 0.001), body mass index (R = −0.23; P < 0.001), and waist‐to‐hip ratio (R = −0.21; P < 0.001) in men, while statistically significant correlations in women were negligible in effect size. In sex‐stratified Cox regression analyses, taking age into account, a quite strong association between low testosterone and incident heart failure was found in men [hazard ratio (HR) 1.51 (95% confidence interval, CI: 1.09–2.10); P = 0.020 for lowest vs. highest quarter], but not in women [HR 0.70 (95% CI: 0.49–0.98); P = 0.086 for lowest vs. highest quarter]. Nevertheless, this association turned non‐significant after full adjustment including body mass index and waist‐to‐hip ratio, and testosterone levels were no longer predictive for incident heart failure—neither in men [HR 0.99 (95% CI: 0.70–1.42); P = 0.77 for lowest vs. highest quarter] nor in women [HR 0.92 (95% CI: 0.64–1.33); P = 0.99 for lowest vs. highest quarter]. Accordingly, Kaplan–Meier analyses did not reveal significant association of testosterone levels with heart failure.

Conclusions

Low levels of testosterone do not independently predict future heart failure.

Iron deficiency is a common disorder in general population and independently predicts all-cause mortality: results from the Gutenberg Health Study

BACKGROUND

Iron deficiency is now accepted as an independent entity beyond anemia. Recently, a new functional definition of iron deficiency was proposed and proved strong efficacy in randomized cardiovascular clinical trials of intravenous iron supplementation. Here, we characterize the impact of iron deficiency on all-cause mortality in the non-anemic general population based on two distinct definitions.

METHODS

The Gutenberg Health Study is a population-based, prospective, single-center cohort study. The 5000 individuals between 35 and 74 years underwent baseline and a planned follow-up visit at year 5. Tested definitions of iron deficiency were (1) functional iron deficiency-ferritin levels below 100 µg/l, or ferritin levels between 100 and 299 µg/l and transferrin saturation below 20%, and (2) absolute iron deficiency-ferritin below 30 µg/l.

RESULTS

At baseline, a total of 54.5% of participants showed functional iron deficiency at a mean hemoglobin of 14.3 g/dl; while, the rate of absolute iron deficiency was 11.8%, at a mean hemoglobin level of 13.4 g/dl. At year 5, proportion of newly diagnosed subjects was 18.5% and 4.8%, respectively. Rate of all-cause mortality was 7.2% (n = 361); while, median follow-up was 10.1 years. After adjustment for hemoglobin and major cardiovascular risk factors, the hazard ratio with 95% confidence interval of the association of iron deficiency with mortality was 1.3 (1.0-1.6; p = 0.023) for the functional definition, and 1.9 (1.3-2.8; p = 0.002) for absolute iron deficiency.

CONCLUSIONS

Iron deficiency is very common in the apparently healthy general population and independently associated with all-cause mortality in the mid to long term.

Iron Metabolism Contributes to Prognosis in Coronary Artery Disease: Prognostic Value of the Soluble Transferrin Receptor Within the AtheroGene Study

Background

Coronary heart disease is a leading cause of mortality worldwide. Iron deficiency, a frequent comorbidity of coronary heart disease, causes an increased expression of transferrin receptor and soluble transferrin receptor levels (sTfR) levels, while iron repletion returns sTfR levels to the normal physiological range. Recently, sTfR levels were proposed as a potential new marker of iron metabolism in cardiovascular diseases. Therefore, we aimed to evaluate the prognostic value of circulating sTfR levels in a large cohort of patients with coronary heart disease.

Methods and Results

The disease cohort comprised 3423 subjects who had angiographically documented coronary heart disease and who participated in the AtheroGene study. Serum levels of sTfR were determined at baseline using an automated immunoassay (Roche Cobas Integra 400). Two main outcomes were considered: a combined end point of myocardial infarction and cardiovascular death and cardiovascular death alone. During a median follow‐up of 4.0 years, 10.3% of the patients experienced an end point. In Cox regression analyses for sTfR levels, the hazard ratio (HR) for future cardiovascular death and/or myocardial infarction was 1.27 (95% CI, 1.11–1.44, P<0.001) after adjustment for sex and age. This association remained significant (HR, 1.23; 95% CI, 1.03–1.46, P=0.02) after additional adjustment for body mass index, smoking status, hypertension, diabetes mellitus, dyslipidemia, C‐reactive protein, and surrogates of cardiac function, size of myocardial necrosis (hs‐Tnl), and hemoglobin levels.

Conclusions

In this large cohort study, sTfR levels were strongly associated with future myocardial infarction and cardiovascular death. This implicates a role for sTfR in secondary cardiovascular risk prediction.

Cardio-Renal Biomarker Soluble Urokinase-Type Plasminogen Activator Receptor Is Associated With Cardiovascular Death and Myocardial Infarction in Patients With Coronary Artery Disease Independent of Troponin, C-Reactive Protein, and Renal Function

Background Risk stratification among patients with coronary artery disease (CAD) is of considerable interest due to the potential to guide secondary preventive therapies. Thus, we evaluated the predictive value of soluble urokinase-type plasminogen activator receptor (suPAR) levels for cardiovascular mortality and nonfatal myocardial infarction in patients with CAD. Methods and Results Plasma levels of suPAR were measured in a cohort of 1703 patients with documented CAD as evidenced by coronary angiography-including 626 patients with acute coronary syndrome and 1077 patients with stable angina pectoris. Cardiovascular death and/or nonfatal myocardial infarction were defined as main outcome measures. During a median follow-up of 3.5 years, suPAR levels reliably predicted cardiovascular death or myocardial infarction in CAD, evidenced by survival curves stratified for tertiles of suPAR levels. In Cox regression analyses, the hazard ratio for the prediction of cardiovascular death and/or myocardial infarction was 2.19 (P<0.001) in the overall cohort and 2.56 in the acute coronary syndrome cohort (P<0.001). Even after adjustment for common cardiovascular risk factors, renal function and the biomarkers C-reactive protein, N-terminal pro-B-type natriuretic peptide and high-sensitivity troponin I suPAR still enabled a reliable prediction of cardiovascular death or myocardial infarction with a hazard ratio of 1.61 (P=0.022) in the overall cohort and 2.22 (P=0.005) in the acute coronary syndrome cohort. Conclusions SuPAR has a strong and independent prognostic value in secondary prevention settings, and thereby might represent a valuable biomarker for risk estimation in CAD.

Iron deficiency is a common disorder in general population and independently predicts all-cause mortality: results from the Gutenberg Health Study

Background

Iron deficiency is now accepted as an independent entity beyond anemia. Recently, a new functional definition of iron deficiency was proposed and proved strong efficacy in randomized cardiovascular clinical trials of intravenous iron supplementation. Here, we characterize the impact of iron deficiency on all-cause mortality in the non-anemic general population based on two distinct definitions.

Methods

The Gutenberg Health Study is a population-based, prospective, single-center cohort study. The 5000 individuals between 35 and 74 years underwent baseline and a planned follow-up visit at year 5. Tested definitions of iron deficiency were (1) functional iron deficiency—ferritin levels below 100 µg/l, or ferritin levels between 100 and 299 µg/l and transferrin saturation below 20%, and (2) absolute iron deficiency—ferritin below 30 µg/l.

Results

At baseline, a total of 54.5% of participants showed functional iron deficiency at a mean hemoglobin of 14.3 g/dl; while, the rate of absolute iron deficiency was 11.8%, at a mean hemoglobin level of 13.4 g/dl. At year 5, proportion of newly diagnosed subjects was 18.5% and 4.8%, respectively. Rate of all-cause mortality was 7.2% (n = 361); while, median follow-up was 10.1 years. After adjustment for hemoglobin and major cardiovascular risk factors, the hazard ratio with 95% confidence interval of the association of iron deficiency with mortality was 1.3 (1.0–1.6; p = 0.023) for the functional definition, and 1.9 (1.3–2.8; p = 0.002) for absolute iron deficiency.

Conclusions

Iron deficiency is very common in the apparently healthy general population and independently associated with all-cause mortality in the mid to long term.

Graphic abstract

Predictive value of low testosterone concentrations regarding coronary heart disease and mortality in men and women - evidence from the FINRISK97 study

INTRODUCTION

The relevance of low testosterone concentrations for incident coronary heart disease (CHD) and mortality has been discussed in various studies. Here, we evaluate the predictive value of low baseline testosterone levels in a large population-based cohort.

METHODS

We measured the serum levels of testosterone in 7671 subjects (3710 male, 3961 female) of the population-based FINRISK97 study.

RESULTS

The median follow-up (FU) was 13.8 years. During the FU, a total of 779 deaths from any cause, and 395 incident CHD events were recorded. The age-adjusted baseline testosterone levels were similar in subjects suffering incident events during FU and those without incident events during FU (men: 15.80 vs. 17.01 nmol L-1 ; P = 0.69, women: 1.14 vs. 1.15 nmol L-1 ; P = 0.92). Weak correlations of testosterone levels were found with smoking (R = 0.09; P < 0.001), HDL cholesterol levels (R = 0.22, P < 0.001), systolic blood pressure (R = -0.05; P = 0.011), BMI (R = -0.23; P < 0.001) and waist-hip-ratio (R = -0.21; P < 0.001) in men, and with eGFR (R = -0.05; P = 0.009) in women. Kaplan-Meier analyses did not reveal a positive association of testosterone levels with incident CHD or mortality. Accordingly, also in Cox regression analyses, testosterone levels were not predictive for incident CHD or mortality - neither in men (HR 1.02 [95%CI: 0.70-1.51]; P = 0.79 for lowest versus highest quarter regarding CHD and HR 1.06 [95%CI: 0.80-1.39]; P = 0.67 regarding mortality), nor in women (HR 1.13 [95%CI: 0.69-1.85]; P = 0.56 for lowest versus highest quarter regarding CHD and HR 0.99 [95%CI: 0.71-1.39]; P = 0.80 regarding mortality).

CONCLUSIONS

Low levels of testosterone are not predictive regarding future CHD or mortality - neither in men, nor in women.

Diagnostic Value of Soluble Urokinase-Type Plasminogen Activator Receptor in Addition to High-Sensitivity Troponin I in Early Diagnosis of Acute Myocardial Infarction

The soluble urokinase-type plasminogen activator receptor (suPAR) is a new marker for immune activation and inflammation and may provide diagnostic value on top of established biomarkers in patients with suspected acute myocardial infarction (AMI). Here, we evaluate the diagnostic potential of suPAR levels on top of high-sensitivity troponin I (hs-TnI) in a cohort of patients with suspected AMI. A total of 1220 patients presenting to the emergency department with suspected AMI were included, of whom 245 were diagnosed with AMI. Median suPAR levels at admission were elevated in subjects with AMI compared to non-AMI (3.8 ng/mL vs. 3.3 ng/mL, p = 0.001). In C-statistics, the area under the curve (AUC) regarding the diagnosis of AMI was low (0.57 at an optimized cut-off of 3.7 ng/mL). Moreover, baseline suPAR levels on top of troponin values at admission and hour 1 reduced the number of patients who were correctly ruled-out as non-AMI, and who were correctly ruled-in as AMI. Our study shows that circulating levels of suPAR on top of high-sensitivity troponin I do not improve the early diagnosis of AMI.

Testosterone Levels and Type 2 Diabetes-No Correlation with Age, Differential Predictive Value in Men and Women

Most studies reporting on the association of circulating testosterone levels with type 2 diabetes in men are of cross-sectional design. Reports on the relevance of altered testosterone levels in women are scarce. Here, we evaluate the role of low serum testosterone levels for incident diabetes in men and women in a population setting of 7706 subjects (3896 females). During a mean follow up time of 13.8 years, 7.8% developed type 2 diabetes. Significant correlations of testosterone with high density lipoprotein (HDL)-cholesterol (R = 0.21, p < 0.001), body-mass-index (R = −0.23, p < 0.001), and waist-to-hip-ratio (R = −0.21, p < 0.001) were found in men. No correlation was found with age in men; in women, the correlation was negligible (R = 0.04, p = 0.012). In men, low testosterone levels predicted high risk of type 2 diabetes, while in women this relationship was opposite. Men with low testosterone levels showed increased risk of future diabetes (hazard ratio (HR) 2.66, 95% confidence interval (CI) 1.91–3.72, p < 0.001 in basic model; HR 1.56 95%, CI 1.10–2.21, p = 0.003). In women, low testosterone levels indicated lower risk with (HR 0.53, 95% CI 0.37–0.77, p = 0.003), while the association lost significance in the fully adjusted model (HR 0.72, 95% CI 0.49–1.05, p = 0.09). Low levels of testosterone predicted future diabetes in men. A borderline opposite association was found in women.

Intrinsic Iron Release Is Associated with Lower Mortality in Patients with Stable Coronary Artery Disease-First Report on the Prospective Relevance of Intrinsic Iron Release

Intrinsic iron release is discussed to have favorable effects in coronary artery disease (CAD). The aim of this study was to evaluate the prognostic relevance of intrinsic iron release in patients with CAD. Intrinsic iron release was based on a definition including hepcidin and soluble transferrin receptor (sTfR). In a cohort of 811 patients with angiographically documented CAD levels of hepcidin and sTfR were measured at baseline. Systemic body iron release was defined as low levels of hepcidin (<24 ng/mL) and high levels of sTfR (≥2 mg/L). A commercially available ELISA (DRG) was used for measurements of serum hepcidin. Serum sTfR was determined by using an automated immunoassay (). Cardiovascular mortality was the main outcome measure. The criteria of intrinsic iron release were fulfilled in 32.6% of all patients. Significantly lower cardiovascular mortality rates were observed in CAD patients with systemic iron release. After adjustment for body mass index, smoking status, hypertension, diabetes, dyslipidemia, sex, and age, the hazard ratio for future cardiovascular death was 0.41. After an additional adjustment for surrogates of the size of myocardial necrosis (troponin I), anemia (hemoglobin), and cardiac function and heart failure severity (N-terminal pro B-type natriuretic peptide), this association did not change (Hazard ratio 0.37 (95% confidence interval 0.14⁻0.99), p = 0.047). In conclusion, significantly lower cardiovascular mortality rates were observed in CAD patients with intrinsic iron release shown during follow-up.

Adverse Outcome Prediction of Iron Deficiency in Patients with Acute Coronary Syndrome

Acute myocardial infarction remains a leading cause of morbidity and mortality. While iron deficient heart failure patients are at increased risk of future cardiovascular events and see improvement with intravenous supplementation, the clinical relevance of iron deficiency in acute coronary syndrome remains unclear. We aimed to evaluate the prognostic value of iron deficiency in the acute coronary syndrome (ACS). Levels of ferritin, iron, and transferrin were measured at baseline in 836 patients with ACS. A total of 29.1% was categorized as iron deficient. The prevalence of iron deficiency was clearly higher in women (42.8%), and in patients with anemia (42.5%). During a median follow-up of 4.0 years, 111 subjects (13.3%) experienced non-fatal myocardial infarction (MI) and cardiovascular mortality as combined endpoint. Iron deficiency strongly predicted non-fatal MI and cardiovascular mortality with a hazard ratio (HR) of 1.52 (95% confidence interval (CI) 1.03-2.26; p = 0.037) adjusted for age, sex, hypertension, smoking status, diabetes, hyperlipidemia, body-mass-index (BMI) This association remained significant (HR 1.73 (95% CI 1.07⁻2.81; p = 0.026)) after an additional adjustment for surrogates of cardiac function and heart failure severity (N-terminal pro B-type natriuretic peptide, NT-proBNP), for the size of myocardial necrosis (troponin), and for anemia (hemoglobin). Survival analyses for cardiovascular mortality and MI provided further evidence for the prognostic relevance of iron deficiency (HR 1.50 (95% CI 1.02⁻2.20)). Our data showed that iron deficiency is strongly associated with adverse outcome in acute coronary syndrome.