Iron deficiency in pulmonary arterial hypertension: prevalence and potential usefulness of oral supplementation

Background: The aim of this study was to evaluate the prevalence of iron depletion in a prevalent population of patients with pulmonary arterial hypertension (PAH) and to gain preliminary insights on the possibility of its treatment with oral drugs. Methods: Iron status was determined in 31 consecutive prevalent idiopathic patients with PAH. Iron depletion was defined as serum iron <10 mmol/L and decreased transferrin saturation irrespective of the coexistence of anaemia. Patients underwent laboratory examinations, 6-min walking test and echocardiography in the same day. A subgroup of iron depleted patients received one oral capsule/day containing 30 mg of pyrophosphate liposomal iron for 16 weeks. After this period all patients were re-evaluated. Results: Iron depletion was observed in 22 patients (71%), of whom 6 were also anaemic and 16 were not anaemic. Iron depletion was associated with higher systolic pulmonary artery pressure (60 [50-90] vs. 45 [40-50] mmHg, p = .007), greater prevalence of moderate to severe tricuspid regurgitation (36% vs. 0%, p = .039), lower tricuspid annular plane systolic excursion (23 [21-24] vs. 19 [18-20] mm; p = .025]) and higher left ventricular eccentricity index (1.35 vs. 1, p = .042). After 16 weeks of treatment, 6-min walking distance significantly improved (500 [390-500] vs. 530 [410-550] metres; p = .043). Conclusions: Iron deficiency is highly prevalent in patients with PAH and is associated with worse clinical conditions. Treatment with oral liposomal iron is a therapeutic option which should be further investigated in future trials.