Defining iron deficiency in patients with heart failure

For patients with heart failure and reduced left ventricular ejection fraction, intravenous iron is likely to deliver clinical and prognostic benefits for those with anaemia and transferrin saturation <20%, especially if serum ferritin exceeds 100 mu g/l. A serum ferritin of <100 mu g/l does not appear to be useful as a marker of iron deficiency.