NPPB and pulmonary arterial hypertension: In this cross-sectional study, we aim to investigate its impact on children with PAH and their caregivers, medical care, and doctor–patient communication, in addition to anxiety levels and specific COVID-19-related concerns based on the Polish registry of pulmonary hypertension—The Database of Pulmonary Hypertension in the Polish Population [18,19] (BNP-PL, ClinicalTrials.gov Identifier: NCT03959748).