Medium doses seem to have best risk-benefit ratio for children with pulmonary artery hypertension
MONDAY, Oct. 24 (HealthDay News) -- Medium doses of sildenafil may be beneficial for children with pulmonary artery hypertension (PAH), according to a study presented at the annual meeting of the American College of Chest Physicians, held from from Oct. 22 to 26 in Honolulu.
Robyn Barst, M.D., from Columbia University in New York City, and colleagues investigated the outcomes of sildenafil therapy for 234 children with PAH. Participants, aged 1 to 17 years, received low, medium, or high-dose sildenafil, or placebo for 16 weeks. Of these, 106 who could reliably exercise on a bicycle were evaluated at baseline and week 16 for cardiopulmonary exercise testing, peak oxygen consumption (pVO2), and minute ventilation to carbon dioxide output (VE/VCO2) levels. The percent change in pVO2 was the primary end point of the study.
The investigators found that, although the primary end point did not meet the predefined criteria (P = 0.056), the pVO2 and VE/VCO2 slope improved more in children who received medium and high dose of sildenafil than in those who received placebo. Sildenafil made it easier for children to exercise, increased the amount of exercise they could perform, and improved the gas exchange efficiency of the lungs during exercise. Patients with idiopathic/heritable PAH had more favorable outcomes than those with congenital heart defect-associated PAH. There was a concern for increased mortality in the high-dose group in long-term follow up three years after the initial trial.
"The goal in treating the children is to improve their overall quality of life, in addition to hopefully improving their survival," Barst said in a statement.