Usefulness of Red Cell Width Distribution (RDW) in the Assessment of Children with Pulmonary Arterial Hypertension (PAH)

Red cell width distribution (RDW) is known to be a prognostic marker in adults with pulmonary hypertension. The value of this test in the pulmonary arterial hypertension (PAH) pediatric population was not yet established. The aim of the study was to evaluate the prognostic value of RDW in children with PAH and utility of this parameter in the management. Data were collected retrospectively in 61 patients with PAH confirmed by right heart catheterization. RDW was measured at diagnosis, 3 and 12 months after initial therapy, during and after deterioration if occurred. Results were compared with NTproBNP, WHO-FC and oxygen blood saturation. Mean RDW at baseline was 15.3 ± 2.4% (12.1–24.4, median 14.7%) and was elevated in 29 patients (47%). There were no significant difference in clinical status, NTproBNP and hemodynamic parameters among patient with normal and elevated RDW at diagnosis. Poor negative correlation with SaO₂ and SvO₂ was shown. After 3 and 12 months of treatment no significant change of RDW level was found despite of statistically significant improvement of WHO-FC and decrease of NTproBNP level (NS). Episodes of clinical deterioration weren’t connected with change of RDW level (16 vs. 15.6% NS). Kaplan–Meier analysis did not show differences in prognosis between patients with normal and elevated RDW. Elevation of RDW was not associated with any measured parameters. Prognostic value of RDW in the pediatric PAH population was not confirmed. Usefulness of RDW in management in PAH pediatric population is limited and required further studies.