Objective: Childhood idiopathic pulmonary arterial hypertension (IPAH) is a devastating and rapidly progressive disease. Combination medical therapies are frequently employed, despite limited data about efficacy. We reviewed outcomes for all children aged 0-18 years with IPAH, referred to a single state-wide cardiology service since 1998 (current patients).
Methods: Standard statistical methods were used to assess survival. Freedom from initiation of intravenous epoprostenol was calculated for those started on first-line oral therapies. Historic controls comprised children with IPAH diagnosed between 1980-1997.
Results: The mean (SD) age at diagnosis for 15 current IPAH patients was 7.3 (4.2) years compared to 6.9 (4.2) years for 13 historic controls (p=0.83). The two groups were matched for haemodynamic parameters at right heart catheterisation. A PDE5 inhibitor was administered to 12 of 15 (80%) current patients, an endothelin receptor antagonist in 14 (93.3%) patients, epoprostenol in 9 (66.7%) and a calcium channel blocker in 2 (13.3%) patients. Eight current patients have been treated with a combination of 3 PAH specific therapies, 6 patients with two therapies, and one patient is receiving monotherapy. Survival free from lung transplantation for current patients was 100% at 1 year after diagnosis and 56.4% at 5 years, compared to 50% at 1 year and 33.3% at 5 years for historic controls (p=0.06). Survival free from epoprostenol initiation for current patients was only 22.4% at 5 years.
Conclusions: Combination therapies are associated with modestly improved survival in children with IPAH. The probability of epoprostenol utilisation within 5 years of diagnosis remains high.