Which Functional Classification Scale is Optimal for Children with Pulmonary Hypertension (PAH)?

Functional status assessed by the WHO-FC scale derived from adults is a known prognostic factor for pulmonary hypertension. Data on the usefulness of the Panama-FC scale in assessing children with pulmonary hypertension are limited. The study was performed to compare functional status results (WHO-FC and Panama-FC) and to assess the usefulness of these scales in various clinical situations. The reliability of the Panama-FC questionnaire method for facilitating patient evaluation was also examined. 26 functional status assessments (7 in disease progression/after treatment intensification) in both scales were analyzed in 19 patients with PAH confirmed in RHC. WHO-FC, Panama-FC scales, and questionnaire-based on Panama-FC were conducted independently by three different physicians. Results of assessments were compared with each other and with 6MWD, NTproBNP level, and echo parameters (TAPSE, RV/LV ratio). The Panama-FC scale results obtained using the medical interview method and questionnaire did not differ. Both WHO-FC and Panama-FC classes well-reflected disease advancement confirmed by non-invasive parameters (NTproBNP, 6MWD, TAPSE, RV/LV ratio). Differences between grading the class in both scales were observed: 5pts were classified to II (Panama-FC) vs I (WHO-FC), 2pts were in lower risk group in WHO-FC (II) vs Panama (IIIa). Worsening or improvement after treatment intensification in functional status in both scales was connected with the significant change of NTproBNP level. The 6-min walking distance did not change. TAPSE, RV/LV ratio changed significantly in 3pts with IPAH, accordingly to change in WHO-FC and Panama-FC. WHO-FC and Panama-FC well reflect the disease advancement. The questionnaire method simplified the use of the Panama-FC scale. The Panama-FC scale appears to be better for assessing functional status during long-term follow-up, while the WHO-FC scale was more useful in short-term treatment monitoring.