Treprostinil in the treatment of pediatric patients with severe Idiopathic and Heritable Pulmonary Arterial Hypertension

Abstract

Abstract Introduction: Data have been accumulating that parental treprostinil is safe and effective in pediatric PAH patients. This study was designed to evaluate the efficacy of treprostinil in severe pediatric patients with IPAH and HPAH (IPAH/HPAH). Methods: Children diagnosed with IPAH/HPAH between August 2018 to April 2022 treated with treprostinil at a single center were included in this study. Clinical data including World Health Organization Functional Class (WHO-FC), echocardiography, BNP level and invasive hemodynamics were collected at baseline, short-term follow-up, and at the last available follow-up. Results: Thirty-four children (mean age 9.55 ± 4.90 years, female 65%) were included in this study. Twenty-eight patients (82% of the cohort) carried PAH-related genes mutations with a dominance of BMPR2 mutations. Thirty patients were in WHO-FC III/IV at baseline and most had severely depressed right ventricle systolic function. At short-term follow-up (3.89 months IQR 3.01, 6.39), all patients were alive with significant improvements in clinical symptoms, echocardiographic parameters, and hemodynamics. Eighteen patients who reached WHO-FC I/II discontinued treprostinil during follow-up. One-year and two-year survival rates of the cohort were 90.6% and 68.2%, respectively. Cox regression analysis identified BNP at short-term follow-up and change of peak tricuspid valve regurgitant velocity (TRV) between baseline and short-term follow-up as predictors for survival. Conclusion: Treprostinil can significantly improve clinical condition, right ventricle function, hemodynamics, and prognosis in children with severe IPAH/HPAH. However, for the children with reduced response to initial treatment non-pharmacological treatments should be considered. Larger, randomized studies using treprostinil in pediatric IPAH/HPAH patients are warranted.