This study investigated the short- and long-term outcome of children with pulmonary arterial hypertension (PAH) treated with inhaled iloprost.
Background
Inhaled iloprost has been approved for the treatment of adults with PAH, but little is known about the effects in children with PAH.
Methods
We evaluated the acute effects of inhaled iloprost on hemodynamic status and lung function and the response to long-term therapy in 22 children (range 4.5 to 17.7 years) with PAH (idiopathic, n = 12; congenital heart disease, n = 10). Cardiac catheterization, standard lung function testing before and after iloprost inhalation, 6-min walk test, World Health Organization functional class, and hemodynamic parameters were monitored.
Results
Acute administration of inhaled iloprost lowered mean pulmonary artery pressure equivalent to the response to inhaled nitric oxide with oxygen. Acute iloprost inhalation reduced forced expiratory volume in 1 s and mid-volume forced expiratory flow by 5% and 10%, respectively, consistent with acute bronchoconstriction. At 6 months, functional class improved in 35%, decreased in 15%, and remained unchanged in 50% of children. Sixty-four percent of patients continued receiving long-term iloprost therapy, 36% stopped iloprost, due to lower airway reactivity, clinical deterioration, or death. In 9 patients on chronic intravenous prostanoids, 8 transitioned from intravenous prostanoids to inhaled iloprost, which continued during follow-up.
Conclusions
Inhaled iloprost caused sustained functional improvement in some children with PAH, although inhaled iloprost occasionally induced bronchoconstriction. Most patients tolerated the transition from intravenous to inhaled prostanoid therapy. Clinical deterioration, side effects, and poor compliance, owing to the frequency of treatments, could limit chronic treatment in children.
Abbreviations and Acronyms
6MW
6-min walk
FEV1
forced expiratory volume in 1 s
FEF25–75
mid-volume forced expiratory flow
FVC
forced vital capacity
IV
intravenous
NO
nitric oxide
PAH
pulmonary arterial hypertension
PAP
pulmonary arterial pressure
PVR
pulmonary vascular resistance
TLC
total lung capacity
WHO
World Health Organization
Cited by (0)
Supported in part by grant M01-RR00069 from the General Clinical Research Center branch of the National Center for Research Resources, National Institutes of Health.