Rationale: Iron deficiency is common in kidney transplant recipients. The presence of iron deficiency is associated with an unfavourable prognosis in these patients. In patients with heart failure and iron deficiency, treatment with intravenous iron improved exercise capacity and quality of life. Whether such beneficial effects may also occur in kidney transplant recipients is unknown.~Objective: Our main objective is to address whether correction of iron deficiency with ferric(III) carboxymaltose improves exercise tolerance and quality of life in iron-deficient kidney-transplant recipients.~Study design: A multicentre double-blind, placebo-controlled randomized controlled clinical trial will be performed to compare the effects of ferric(III) carboxymaltose with placebo.~Study population: 158 iron-deficient kidney transplant recipients. The intervention arm will receive 10 mL of ferric(III) carboxymaltose (50 mg Fe3/mL, intravenously) every six weeks, with a total of four dosages. The control arm receives an intravenous placebo solution (saline).~Main study parameters/endpoints: The primary endpoint is the distance walked in six minutes, as quantified by the six-minute-walking-test at the end of follow-up.~The investigators expect that iron-deficient kidney transplant recipients will benefit from ferric(III) carboxymaltose treatment as a result of an improvement in exercise tolerance and general wellbeing.
Iron deficiency is common in kidney transplant recipients and is associated with impaired exercise tolerance and an unfavourable prognosis.~This multicentre double-blind, placebo-controlled randomized controlled clinical trial will allow the investigators to analyse the effects of intravenous iron correction with ferric(III) carboxymaltose on exercise tolerance and other parameters, in comparison to a placebo.