Objective: To investigate the preliminary efficacy and safety of bosentan, a dual endothelin-receptor antagonist, in Chinese pulmonary arterial hypertension (PAH) patients.
Methods: 21 patients with PAH, idiopathic or associated with congenital heart disease or connective-tissue disease received 62.5 mg of bosentan twice daily for 4 weeks, and then 125 mg twice daily for 8 weeks if without serious side effects. At week 12, the patients underwent 6 min walk test, hemodynamic variables examination, right heart catheterization, ultrasound cardiography, and electrocardiography.
Results: The six-minute walking distance 12 weeks after bosentan treatment was 461 m +/- 84 m, significantly longer than that before the therapy (374 m +/- 113 m, P < 0.001). The pulmonary vascular resistance 12 weeks after the bosentan treatment was (1236 +/- 729) dyn x s(-1) x cm(-5), significantly lower than that before [(1,440 +/- 766) dyn x s(-1) x cm(-5), P = 0.007]. The cardiac index 12 weeks after the bosentan treatment was (3.02 +/- 1.71) L x min(-1)xm(2), significantly higher than that before treatment [(2.35 +/- 1.20) L x min(-1)xm(2), P = 0.002]. No patient was withdrawn from this study for safety reason.
Conclusion: Improves the exercise capacity and hemodynamic parameters in Chinese PAH patients; bosentan is safe in treating PAH and can be well tolerated.