Treprostinil Effectiveness in Higher-Risk Pediatric Patients With Idiopathic and Heritable Pulmonary Arterial Hypertension.

Background: Little is known about the effectiveness of treprostinil in higher-risk paediatric patients with various pulmonary arterial hypertension genotypes. This study was designed to investigate the prognosis of higher-risk paediatric patients with idiopathic or heritable pulmonary arterial hypertension (IPAH/HPAH) after treprostinil therapy.

Methods: Children with IPAH/HPAH who were stratified as higher risk and treated with treprostinil in our centre were included as the study cohort. Those who received only oral medications were included as the reference cohort. All patients in the study cohort received PAH-related genotyping. Survival was defined as no death. Event-free survival was defined as no death, Potts shunt, or atrial septostomy.

Results: Forty-nine children (median age 7.7 years [interquartile range (IQR) 4.2-11.5 years], 65% female) were included in the study cohort and 48 children were included in the reference cohort; 84% of the study cohort had genetic disorders after genetic testing with a dominance of BMPR2 and ACVRL1 mutations. After a median therapy duration of 5.56 months (IQR 2.66-11.12 months), all patients were alive with significant improvements in clinical characteristics. One-, 2-, and 3-year survival rates were 91%, 84%, and 69%, respectively with a median follow-up duration of 19.17 months (IQR 9.7-29.79 months), which was significantly superior to the reference cohort (P = 0.038). Multivariate Cox regression analysis identified World Health Organisation functional class after therapy as a predictor for survival. There was no significant difference in survival among patients with different genotypes.

Conclusions: Treprostinil can significantly improve the prognosis in children with IPAH/HPAH who are at higher risk, despite genetic backgrounds.