The recent article by Viethen and colleagues examines the potential role of intravenous iron in a clinical scenario that has not been widely studied, but which has previously yielded some positive data. It builds on a previous publication by Smith and colleagues1 that intravenous iron may be of potential benefit in pulmonary arterial hypertension (PAH).
The study by Viethen and colleagues examined the effects of up to one gram of intravenous ferric carboxymaltose in a cohort of 20 patients with iron deficiency and PAH. There was a significant improvement in both exercise capacity, as assessed with the 6-minute walk test and quality of life; results from the 6-minute walk test improved from 346.5 ± 28.3 to 374.0 ± 25.5 minutes (p=0.007), and this was associated with an improvement in quality of life (SF-36 score from 44.3 ± 3.7 to 50.6 ± 3.6; p=0.01). The study was not randomised, but there was a control group of patients who did not have iron deficiency.
The population was clearly very iron deficient, as defined by a serum iron level <10 μmol/L, a serum ferritin <150 μg/L and a transferrin saturation <15%. Nevertheless, iron repletion with intravenous iron resulted in fairly striking effects. Although this was a relatively small cohort, the study was conducted prospectively and there was absolutely no change in the control group. How much the positive results were due to a slight improvement in anaemia is not certain but, as with the FAIR-HF study2, even patients who were not anaemic benefited from intravenous iron.
This study provides additional evidence that intravenous iron therapy can improve exercise capacity and quality of life in iron-deficient patients independent of its effects on haemoglobin. This paves the way for further randomised controlled trials in this therapeutic area, including patients with less pronounced iron deficiency.
The full article is available in the August 2014 issue of the International Journal of Cardiology. For further information on iron deficiency in patients with cardiovascular disease, please click here.