Objectives: We aimed to investigate the prevalence of iron deficiency (ID) in congenital heart disease associated with pulmonary arterial hypertension (CHD-PAH) and to explore the influence of ID on CHD-PAH patients. What was associated with ID in these patients was also looked into.
Design: One hundred and fifty-three patients who were newly diagnosed with CHD-PAH were enrolled. Patients were divided into iron-deficient and iron-replete groups according to the following criteria. ID was defined as transferrin saturation <20% in male and transferrin saturation <25% in female. Clinical data of all participants were collected and compared. Logistic regression was performed to explore factors associated with ID in CHD-PAH.
Results: Thirty-nine percent of 153 CHD-PAH patients were founded with ID. Iron-deficient group had greater proportion of female patients, shorter six minutes walking distance (6-MWD), higher N-terminal pro-brain natriuretic peptide levels, lower creatinine levels, greater ratio of diastolic right ventricle diameter to left ventricle diameter. Female (OR = 15.44, 95%CI 4.91-48.54, p < .01), 6-MWD (OR = 0.99, 95%CI 0.98-1.00, p = .02) and mean right atrial pressure (OR = 1.13, 95%CI 1.02-1.26, p = .02) were independently associated with ID in the overall CHD-PAH patients. Menstruation was independently associated with ID in the female subgroup (OR = 3.88, 95%CI 1.09-13.84, p = .04).
Conclusions: ID was highly prevalent in CHD-PAH patients. Worse exercise tolerance and right heart function were observed in iron-deficient patients with CHD-PAH. Female, 6-MWD, mean right atrial pressure and menstruation are important variables indicating the presence of ID in CHD-PAH.
Keywords: Congenital heart disease; Iron deficiency; Pulmonary arterial hypertension; Transferrin saturation.