Long-Term Subcutaneous Treprostinil in Pediatric Pulmonary Arterial Hypertension at a Latin American Referral Center: A Retrospective Cohort Study.

Abstract

Pediatric pulmonary arterial hypertension is a progressive vasculopathy with substantial early mortality. Subcutaneous treprostinil is an established prostacyclin-pathway therapy for higher-risk disease, but long-term pediatric data from Latin American referral centers remain limited. This retrospective cohort included all nine consecutive children with World Symposium on Pulmonary Hypertension Group 1 pulmonary arterial hypertension who initiated subcutaneous treprostinil at a Colombian referral center and were followed from diagnosis until death or last known contact. Outcomes included survival, pediatric risk category transitions, N-terminal pro-B-type natriuretic peptide levels, tricuspid annular plane systolic excursion, systolic pulmonary artery pressure, eccentricity index, and structured patient-/caregiver-reported domains. Exploratory comparisons were performed by maintenance dose (≤ 60 vs. > 60 ng/kg/min) and therapy duration. Kaplan-Meier survival at 1, 3, and 5 years was 88.9%, 55.6%, and 55.6%, respectively. Eccentricity index decreased from a median of 2.8 at diagnosis to 1.5 at 5 years, with paired comparisons showing reductions at 1 and 3 years. By Year 5, four of five children with paired risk data had transitioned to a lower pediatric risk category. Doses > 60 ng/kg/min were associated descriptively with more favorable final risk profiles, whereas structured patient-/caregiver-reported domains showed heterogeneous patterns; schooling was the only domain with a statistically detectable association by both dose and duration. In this small Latin American referral-center cohort, subcutaneous treprostinil treatment was accompanied by favorable risk transitions and stabilization of right ventricular geometry among long-term survivors. These findings are exploratory and should be interpreted in light of the small sample size, retrospective design, missing longitudinal data, and potential confounding by disease severity, survival, and treatment escalation.