Ewa Jankowska, Professor and Head of laboratory of applied research on cardiovascular system, Wroclaw Medical University, Poland, talked to Cardio Debate about experiences in iron deficiency in patients with heart failure.
Why is iron deficiency important in patients with heart failure?
Iron deficiency is very common in patients with heart failure. We thought at the beginning that iron deficiency was just because of anaemia in this group of patients. However, later we discovered that iron deficiency itself is much more common than anaemia, and that iron deficiency beyond abnormal haemoglobin levels is related to poor exercise capacity and increased mortality in patients with heart failure.
At a later stage we came to the idea of supplementing iron in patients with heart failure.
Are there studies supporting the treatment of iron deficiency in heart failure?
As we know, iron deficiency has such significant effects on patients with heart failure, we decided to test if intravenous (IV) iron works in patients with heart failure.
Until now there have been several small clinical studies that assess the effect of intravenous iron in patients with heart failure, and among these studies two of them merit special attention.
One is Fair-HF trial, and the other is the CONFIRM-HF trial. Both the studies have been performed with intravenous ferric carobxymaltose in patients who were iron deficient, and patients who had heart failure with impaired systolic ejection fraction.
Importantly, in the Fair-HF trial it was shown that patients with heart failure benefit from IV iron, regarding clinical symptoms and mainly quality of life, regardless of haemoglobin levels. I mean both anaemic and non-anaemic patients benefit from this kind of treatment.
In CONFIRM-HF trial, which was published just two years ago, it was shown that IV iron improves exercise capacity in patients with heart failure, increasing the six-minute walking test distance.
But what I think was extremely important to demonstrate in the study was one of the secondary end points, it has been shown that intravenous iron can reduce the rate of heart failure hospitalisations in patients with heart failure, which we consider as a very important clinical benefit.
What are the key points to highlight about iron deficiency, especially in patients with heart failure?
It’s really important to emphasise that iron deficiency works not only in patients with anaemia, but patients who are not anaemic.
And why could iron work in these patients? Maybe because iron deficiency is needed for functioning of skeletal muscles. We have more and more evidence showing that iron is needed for the optimal energy metabolism of exercising skeletal muscles, of working myocardium, before we believe that we should supplement iron. Also in patients with normal haemoglobin levels, but who remain iron deficient.
What other important aspects are worth mentioning?
It’s really important to also realize that the pathophysiology of iron deficiency is different to the iron deficiency in patients with chronic kidney disease.
Although many people think that iron deficiency in heart failure is due to augmented inflammation lag in patients with chronic kidney disease, there is no evidence supporting this concept.
We know that patients with heart failure who are iron deficient have very low ferritin, have extremely low hepcidin and do not have increased pro-inflammatory molecules in the circulation.
Therefore iron deficiency in heart failure is an example of absolute iron deficiency, where in fact body iron stores are almost completely depleted in these patients.
Therefore, there is really an urgent need to supplement iron, and the intravenous route is the only one which can quickly and sufficiently supplement the iron stores in these patients.