Ferric carboxymaltose improves exercise capacity and quality of life in patients with pulmonary arterial hypertension and iron deficiency: a pilot study

Abstract

Background: Pulmonary arterial hypertension (PAH) is a progressive condition harboring a poor prognosis. Iron deficiency in PAH correlates with disease severity and mortality. While replacement therapy may be beneficial, dietary iron absorption is impaired in PAH patients by hepcidin, a key regulatory protein of iron homoeostasis. We therefore assessed the therapeutic potential and safety of intravenous iron supplementation in patients with PAH and iron deficiency.

Methods: 20 patients with PAH and iron deficiency, who were on stable targeted PAH therapy, received a single infusion of ≤1000 mg ferric carboxymaltose. All patients were assessed at baseline and two months after iron treatment. Exercise capacity was evaluated based on the 6-minute-walking distance (6MWD), and quality of life (QoL) was assessed by the SF-36 questionnaire (100 point scale). The effects were compared to 20 matched patients with stable PAH without iron deficiency who did not receive ferric carboxymaltose.

Results: In iron deficient patients, iron supplementation led to a marked improvement of iron status (serum iron 5.7±0.4 to 11.1±1.1 μmol/L, ferritin 29.3±6.3 to 145.2±25.4 μg/L, transferrin saturation 7.5±0.7 to 19.3±2.3%, all p≤0.001). Iron-deficient patients receiving ferric carboxymaltose showed a significant increase of the 6MWD from 346.5±28.3 to 374.0±25.5 m (p=0.007), whereas no significant changes were found in the control group not receiving iron supplementation (6MWD 389.9±25.3 to 379.6±26.2 m; n.s.), resulting in a net increase in the 6MWD of 37.8m (p=0.003). This was associated with an improvement in QoL (SF-36 score from 44.3±3.7 to 50.6±3.6; p=0.01). Only minimal side-effects were reported.

Conclusions: These data indicate that parenteral iron supplementation with ferric carboxymaltose significantly improves exercise capacity and QoL and is well tolerated in patients with PAH and iron deficiency, and when administered in addition to targeted PAH therapies. Our results provide proof of concept for further studies evaluating the potential of iron as an adjunct in PAH treatment on a larger scale.

Keywords: Ferric carboxymaltose; Iron; Iron deficiency; Pulmonary arterial hypertension (PAH).