Response to bosentan in children with pulmonary hypertension

Objective: To describe an early experience of treating 40 children with the dual endothelin receptor antagonist bosentan, which is known to be safe and effective in adults with pulmonary hypertension (PH). Design: In this retrospective, observational study the UK Service for Pulmonary Hypertension for children treated 40 children with bosentan, 20 with idiopathic pulmonary arterial hypertension (IPAH) (mean age 8.03 years, range 1.2-17) and 20 with PH associated with other conditions (congenital heart disease, parenchymal lung or connective tissue disease, or HIV). Their mean age was 8.3 years (range 0.6-16 years). Patients: 39 patients were in World Health Organization (WHO) class III and IV, and all had shown recent deterioration. In IPAH the mean pulmonary vascular resistance (PVR) was 21.7 units.m(2) (range 5.6-42.8). In secondary PH the mean PVR was 18 units.m(2) (range 4.9-49). No child had a positive response to vasodilator testing with nitric oxide. Interventions: Bosentan was given as first line treatment to 25. Nine were given intravenous epoprostenol. Children were treated for a mean of 12.7 months (range 2-24 months). Main outcome measures: Response to treatment was judged by WHO functional class, six minute walk test, weight, ECG and echocardiographic findings, and need to add additional treatment. Results: Bosentan was well tolerated. In the IPAH group 19 (95%) stabilised with bosentan treatment but 12 (60%) patients needed combined treatment with epoprostenol. In secondary PH, WHO class, six minute walk test, and weight gain improved significantly. Conclusion: Bosentan helped stabilise children with IPAH but intravenous epoprostenol was also needed by 60%. Children with secondary PH improved.