Abstract: Objective To investigate the effect of oral bosentan in the treatment of congenital heart disease-associated
pulmonary arterial hypertension. Methods 24 patients with congenital heart disease-associated pulmonary arterial
hypertension, including 4 receiving heart surgery and 20 with surgical contraindications, were enrolled in this study. All the
patients were given oral bosentan and followed up regularly for analyzing the outcomes and side effects. Results One patient
was lost to follow up and one patient died. Systolic pulmonary artery pressure showed no significant changes at 2 (93.6±17.2
mmHg) and 4 months (85.7±25.5 mmHg) of bosentan treatment compared to that before the medication (97.8±14.9 mmHg) (P=
0.096), but decreased significantly after a 6-month therapy (80.9 ± 25.0 mmHg, P=0.029). The 6-minute walking distance
increased significantly after a 2, 4, and 6-month therapy [(488±98.8, 496.3±89.0, and 491.3±114.2 m, respectively; P=0.004, 0.003,
and 0.004 vs the distance before medication (317.0 ± 134.1)]. The New York heart functional classification was improved
significantly after a 2, 4, and 6-month therapy [(2.0±0.5, 1.8±0.4, and 1.7±0.5, respectively; P<0.001 vs pre-medication score (2.9±
0.5)). Hepatic and renal function remained normal, and ALT and AST showed no significant variations during the medication
(P>0.05). Conclusion Oral bosentan can effectively relieve the symptoms, decrease pulmonary artery hypertension, and
improve exercise tolerance and cardiac function classification in patients with pulmonary artery hypertension associated with
congenital heart disease with good safety and mild side effects.