Background: Bosentan has an established role in the management of pulmonary arterial hypertension (PAH). This clinical trial assessed the benefits of bosentan in the Chinese population.
Methods: We investigated the efficacy and safety of bosentan in 92 Chinese citizens (mean +/- standard deviation age, 29.0 +/- 3.8 years) with PAH for a minimum of 12 weeks. All received bosentan (62.5 mg twice daily) for 4 weeks; then, patients who weighed <40 kg received 62.5 mg bosentan twice daily and patients who weighed >40 kg received 125 mg twice daily. All patients were eligible to continue bosentan beyond 12 weeks. The primary end point was a change in exercise capacity from baseline to 12 and 24 weeks. Secondary end points included a change in World Health Organization (WHO) functional class and changes in cardiopulmonary hemodynamics.
Results: At baseline, 66 patients (72%) were in WHO functional class III; presentation was 37 (40%) with idiopathic PAH (iPAH), 34 (37%) with PAH related to congenital heart disease (CHD), and 21 (23%) with PAH related to connective tissue disease (CTD). Exercise capacity increased to 67.8 m after 12 weeks and 92.6 m after 24 weeks (p < 0.001). After 24 weeks, WHO functional class decreased (-0.8 +/- 0.6; p < 0.001), mean pulmonary artery pressure and pulmonary vascular resistance decreased (p < 0.01), and cardiac output increased (p < 0.001). Twelve patients (13%) experienced at least 1 adverse event.
Conclusions: Bosentan improved exercise capacity, functional class, and cardiopulmonary hemodynamics in this patient cohort and was well tolerated.