Background: Pulmonary hypertension (PH/ PAH) is a serious condition and can have many possible causes in childhood. The aim of the COMPERA registry (ClinTrials.gov: NCT01347216), which was established for adult patients with PH/PAH in 2007, is the characterization of patients of all ages with PH/ PAH and their treatment patterns. Since June 2013, paediatric patients can be included in the COMPERA-KIDS registry.

Results: Until July 2021, 227 patients <18 years with PH/PAH were enrolled. For 200 of them, at least one follow-up was available with a mean follow-up time of 46.7 months. Of these paediatric patients, 67.8 % had PAH due to congenital heart disease (PAH-CHD), 14.5% had idiopathic PAH (iPAH), 9.7% had PH due to lung diseases and/or hypoxia and 3.5% had persistent PH of the newborn (PPHN). The patients were median 3.0 (IQR 1.0-9.5) years old, 49.3% male; NYHA functional class I in 13.7%, II in 45.4%, III in 32.2%, and IV in 8.7%. If known, the average disease duration after diagnosis was median 2.1 (IQR 0.5-20.8) months. Invasive measurement data by right heart catheterization were available for 71.8% of the patients. Upon inclusion, monotherapy was received by 70% of the patients, 21.1% of the patients had a dual and 3.5% a triple therapy. Phosphodiesterase-5 inhibitors were administered to 82.4% of the patients, 33.5% of the patients received endothelin receptor antagonists and 6.6% received prostacyclin-analogues/ receptor agonists. Anticoagulation by oral vitamin K antagonists was prescribed to 15.9% of patients, and 20.1% of patients received anti-platelet aggregating agents, while 63.4% received no anticoagulation therapy.

Conclusion: The most common form of PH in this study cohort is PAH due to congenital heart disease, followed by idiopathic PAH. Invasively measured right heart pressure data were available for about 70% of the paediatric patients. Treatment options for children primarily comprise phosphodiesterase-5 inhibitors, although endothelin receptor antagonists are increasingly used. About one third of paediatric patients receive anticoagulation therapy.