Iron deficiency: an ominous sign in patients with systolic chronic heart failure

Beyond erythropoiesis, iron is involved in numerous biological processes crucial for maintenance of homeostasis. Patients with chronic heart failure (CHF) are prone to develop iron deficiency (ID), and iron supplementation improves their functional status and quality of life. We sought to examine the relationship between ID and survival in patients with systolic CHF. In a prospective observational study, we evaluated 546 patients with stable systolic CHF [age: 55 +/- 11 (mean +/- standard deviation) years, males: 88%, left ventricular ejection fraction: 26 +/- 7%, New York Heart Association (NYHA) class (I/II/III/IV): 57/221/226/42]. Iron deficiency was defined as: ferritin < 100 mu g/L, or 100-300 mu g/L with transferrin saturation < 20%. The prevalence of ID was 37 +/- 4% [+/- 95% confidence intervals (CI)] in the entire CHF population (32 +/- 4 vs. 57 +/- 10%-in subjects without vs. with anaemia defined as haemoglobin level < 12 g/dL in women and < 13 g/dL in men, P < 0.001). In a multiple logistic model, ID was more prevalent in women, those in the advanced NYHA class, with higher plasma N-terminal pro-type B natriuretic peptide and higher serum high-sensitivity C-reactive protein (all P < 0.05). At the end of follow-up (mean duration: 731 +/- 350 days), there were 153 (28%) deaths and 30 (6%) heart transplantations (HTX). In multivariable models, ID (but not anaemia) was related to an increased risk of death or HTX (adjusted hazard ratio 1.58, 95% CI 1.14-2.17, P < 0.01). In patients with systolic CHF, ID is common and constitutes a strong, independent predictor of unfavourable outcome. Iron supplementation may be considered as a therapeutic approach in these patients to improve prognosis.