The efficacy and safety of sildenafil in patients with pulmonary arterial hypertension associated with the different types of congenital heart disease.

Background: The difference in underlying pathophysiology in different congenital heart disease (CHD) may have an influence on clinical outcome. It remains unclear whether the effect of sildenafil on pulmonary arterial hypertension (PAH) varies in different types of CHD.

Hypothesis: The potential effect of sildenafil on pulmonary arterial hypertension related to CHD may be associated with shunt location.

Methods: In this 12-week, prospective, open label, multicenter trial, 55 patients with CHD were divided into the 3 groups: atrial septal defects group (ASD, n = 15), ventricular septal defects group (VSD, n = 24), and patent ductus arteriosus group (PDA, n = 16). Exercise capacity, hemodynamic parameters, and arterial oxygen saturation were assessed at baseline and after sildenafil therapy (25 mg, 3 times daily).

Results: Six-minute walk distance significantly increased from 377.2 ± 68.7 m to 436.0 ± 70.4 m in patients with ASD, from 371.2 ± 66.0 m to 413.7 ± 83.1 m in VSD, and from 384.3 ± 90.2 m to 440.9 ± 71.8 m in PDA (P<0.01, respectively). Moreover, sildenafil also improved the pulmonary vascular resistance and pulmonary blood flow index in the 3 groups, whereas no significant changes in systemic vascular resistance and systemic arterial pressure were observed. However, arterial oxygen saturation was significantly improved in the ASD group only. The incidence of adverse events was similar among the 3 groups.

Conclusions: Sildenafil therapy seems to be effective and safe for PAH secondary to ASD, VSD, and PDA, although some clinical and hemodynamic parameters were changed in a different manner among the 3 groups.