Absolute iron deficiency without anaemia in patients with chronic systolic heart failure is associated with poorer functional capacity

Arch Cardiovasc Dis. 2017 Feb;110(2):99-105. doi: 10.1016/j.acvd.2016.06.003. Epub 2017 Feb 8.

Abstract

Background: Functional status is one of the main concerns in the management of heart failure (HF). Recently, the FAIR-HF and CONFIRM-HF trials showed that correcting anaemia using intravenous iron supplementation improved functional variables in patients with absolute or relative iron deficiency. Relative iron deficiency is supposed to be a marker of HF severity, as ferritin concentration increases with advanced stages of HF, but little is known about the impact of absolute iron deficiency (AID).

Aims: To study the impact of AID on functional variables and survival in patients with chronic systolic HF.

Methods: One hundred and thirty-eight non-anaemic patients with chronic systolic HF were included retrospectively. Patients were divided into two groups according to iron status: the AID group, defined by a ferritin concentration<100μg/L and the non-AID group, defined by a ferritin concentration≥100μg/L. Functional, morphological and biological variables were collected, and survival was assessed.

Results: Patients in the AID group had a poorer 6-minute walking test (342 vs. 387m; P=0.03) and poorer peak exercise oxygen consumption (13.8 vs. 16.0mL/min/kg; P=0.01). By multivariable analysis, ferritin<100μg/L was associated with impaired capacity of effort, assessed by peak exercise oxygen consumption. By multivariable analysis, there was no difference in total mortality between groups, with a mean follow-up of 5.1±1.1 years.

Conclusions: The poorer functional evaluations in iron-deficient patients previously reported are not caused by the merging of two different populations (i.e. patients with absolute or relative iron deficiency). Our study has confirmed that non-anaemic HF patients with AID have poorer peak oxygen consumption. However, AID has no impact on the survival of these patients.

Keywords: Ferritinémie; Functional evaluation; Heart failure; Insuffisance cardiaque; Iron deficiency; Évaluation fonctionnelle.

MeSH terms

  • Anemia, Iron-Deficiency
  • Biomarkers / blood
  • Disease Management*
  • Exercise Test
  • Exercise Tolerance / physiology*
  • Female
  • Follow-Up Studies
  • Heart Failure, Systolic / blood
  • Heart Failure, Systolic / physiopathology*
  • Humans
  • Iron / blood
  • Iron Deficiencies*
  • Male
  • Middle Aged
  • Retrospective Studies

Substances

  • Biomarkers
  • Iron