Prevalence of iron deficiency in pulmonary hypertension and comparison according etiology

Abstract

Background and objectives: Although iron is a pivotal player in several critical enzymes, limited data is available on the prevalence of iron deficiency in pulmonary hypertension (PH). We sought to assess the prevalence of iron deficiency in a population with PH. Methods: We performed a clinical, hemodynamic and echocardiographic characterization of all PH patients currently being followed in PH clinic between 2008 and 2012. We have assessed the prevalence of iron deficiency in this population by the evaluation of ferritin and transferrin saturation at baseline, nadir values and latest assessment on outpatient clinic. We also compared the different groups of PH. A total of 114 patients (68.4% female, mean age 44±18.3 years) were included. Results: Most patients were from group 1 PH (40.6%) whereas chronic thromboembolic PH comprised 23.8% patients, followed by congenital heart disease-associated PH in 22,8% (18.3% with Eisenmenger's Syndrome). At baseline, most patients were in NYHA 3 (44%) and NYHA 4 (28.4%). Mean brain natriuretic peptide was 355 pg/mL, mean pulmonary artery pressure was 51 mmHg, mean capillary wedge pressure was 9 mmHg and cardiac output was 3.0 L/min. Approximately one-third of patients were receiving warfarin and 14% patients required continuous oxygen. We have found that all the three groups showed transferrin saturation values lower than the reference values. The difference between the groups was statistically significant (DADOS p=0,009). The lowest values were found in group 1, with a mean value of 12%. Serial ferritin values were normal or elevated and no difference between groups was found. After follow-up, there was a favorable outcome when assessing the final transferrin saturation with respect to the minimum value (p<0,0001). Conclusion: The prevalence of iron deficiency is significantly high in PH, particularly in groups 1 and 2. However, there is a good response to treatment.