The importance of iron deficiency in patients with heart failure is increasingly becoming the focus of scientific attention. Because the effects can be significant. Therefore, current ESC guidelines recommend checking iron status in all heart failure patients, regardless of the presence of anemia. Since oral iron therapy is usually insufficient to replenish iron stores, substitution should be intravenous.
Every second patient with heart failure also suffers from iron deficiency [1]. This has a significant impact on hospitalization and mortality. This is because iron plays a central role in the regulation of cardiac function and peripheral muscles. Chronic anemia, for example, can trigger a veritable vicious circle of peripheral vasodilation, blood pressure drop, and neurohormone activation. But it doesn’t even have to get that far to worsen the prognosis of heart failure patients. Even an iron deficiency is sufficient to increase symptoms and mortality, among other things, as well as
Reduce physical performance and quality of life. Iron deficiency is triggered by both gastrointestinal blood loss, malabsorption and malnutrition disorders, and especially inflammatory processes [1].
Iron deficiency is defined as a reduction in total body iron. It is differentiated into three stages depending on the severity [2]:
- Non-anemic iron deficiency
Hb and MCV normal, ferritin decreased; no effect on hematopoiesis. - Non-anemic iron deficiency with microcytosis and/or hypochromia.
Hb normal, ferritin, MCV, and MCH decreased; hematopoiesis and iron-dependent metabolic processes may be impaired. - Iron Deficiency Anemia
Hb <12 g/dl (women) or <13 g/dl (men), MCV, MCH and red cell count decreased.
Focus on iron substitution
Therefore, in view of the experience regarding morbidity and hospitalization, the extent to which therapy for iron deficiency might also affect heart failure was investigated. As early as 2009, a study showed that i.v. iron substitution resulted in positive effects on exercise capacity, symptoms, and quality of life, with a reduction in hospitalization rates and no serious side effects [3]. Similarly, patients could be classified lower in NYHA. In the meantime, these results have been substantiated in further studies. For example, 1132 patients who required hospitalization for acute heart failure and were found to be iron deficient received either min. Two injections of ferric carboxymaltose or placebo [4]. The combined primary end point was hospitalization for heart failure and cardiovascular death. Over the course of 52 weeks, iron therapy reduced this by 21%.
Guidelines recommend i.v. iron substitution
The positive results have led the guideline panel to revise the previous recommendation. Since 2016, i.v. administration of iron carboxymaltose should be considered in symptomatic patients (serum ferritin <100 µg/L or ferritin: 100-299 µg/L and transferrin saturation <20%) (Class IIa A recommendation). The 2021 updated ESC guidelines have now differentiated this [5]:
- Iron status should be checked regularly in all patients with heart failure.
- In symptomatic heart failure patients (LVEF <45%) with iron deficiency, iron therapy should be considered to relieve heart failure symptoms and improve physical performance and quality of life
- In symptomatic HI patients (LVEF <50%) with iron deficiency who have been recently hospitalized for heart failure, treatment should be considered to reduce the risk of heart failure-related hospitalizations
However, because there is limited clinical evidence from randomized clinical trials that have evaluated the use of oral iron in this clientele and these results did not improve exercise capacity or demonstrate adequate replenishment of iron stores, oral iron therapy is not considered effective. Rather, i.v. iron substitution with iron carboxymaltose should be resorted to.
Literature:
- www.universimed.com/ch/article/kardiologie-gefaessmedizin/herzinsuffizienz-und-eisenmangel-2108123 (last accessed on 10.02.2022)
- www.medix.ch/wissen/guidelines/blutkrankheiten/eisenmangel/ (last accessed on 10.02.2022)
- www.pressebox.de/inaktiv/galenica-ag/Ferinject-FAIR-HF-Studie-erreicht-primaere-Endpunkte-bei-Patienten-mit-Eisenmangel-und-Chronischer-Herzinsuffizienz/boxid/293385 (last accessed on 10.02.2022)
- www.kardiologie.org/herzinsuffizienz/aha-kongress-2020/herzinsuffizienz–wie-wirkt-sich-eisengabe-auf-die-prognose-aus-/18584112 (last accessed on 10.02.2022)
- https://academic.oup.com/eurheartj/article/42/36/3599/6358045 (last accessed on 10.02.2022)
CARDIOVASC 2022; 21(1): 22
