322 Subcutaneous treprostinil in pediatric idiopathic pulmonary arterial hypertension

Abstract

Therapeutic options at time of worsening remain unclear in children who do worse but remain in functional class III while being on combined oral therapy with endothelin receptor antagonists and PDE-5 inhibitors. To evaluate the use of a subcutaneous prostanoid as an ad-on therapy in pediatric PAH. Five children with PAH (median age 4 years, range 1.5–9 y) received subcutaneous treprostinil at time of worsening PAH. Two had idiopathic PAH, one being familial. Three patients had PAH associated with but not caused by congenital heart defect. All had severe PAH and were non responsive to inhaled nitric oxide. They were all on combined oral therapy with bosentan and sildenafil. Indication to add treprostinil was clinical deterioration with right ventricular failure in 4 patients and switch from IV epoprostenol in one. Treprostinil was initiated at a fixed dose of 1.25 ng/kg/min and then daily increased by 1.25 ng/kg/min to reach an average dose of 20 ng/kg/min. Local tolerance was good with tailored management of site injection. No serious adverse events was noted during the median 6 months follow-up. All patients were clinically improved with significant increase in 6MWT distance in the 3 oldest children and change from WHO functional class III to class II. Echocardiography showed an improved right ventricular function, increased pulmonary flow with increased acceleration time. Subcutaneous treprostinil can be a valuable alternative in pediatric PAH patients already receiving combined oral therapy. It may help to avoid complications of central lines and to improve quality of life.