Secondary end-points
| Placebo | Bosentan | Treatment effect versus placebo | |
| Patients n | 175 | 159 | |
| Change in WHO functional class from baseline to 16 weeks | Relative risk of improvement# 0.98 (95% CI 0.60–1.61, p=1.000¶) | ||
| Worsened | 17 (9.7) | 13 (8.2) | |
| Unchanged | 130 (74.3) | 121 (76.1) | |
| Improved | 28 (16.0) | 25 (15.7) | |
| Time to death, hospitalisation for PAH, atrial septostomy or lung transplantation up to the end of the study | Hazard ratio 0.963 (95% CI 0.673–1.380, p=0.8385+) | ||
| Patients | 67 (38.3) | 54 (34.0) | |
| Time to death from any cause up to the end of the study | Hazard ratio 0.855 (95% CI 0.544–1.344, p=0.4974+) | ||
| Patients | 44 (25.1) | 33 (20.8) |
Data are presented as n (%) unless otherwise stated. WHO: World Health Organization; PAH: pulmonary arterial hypertension. #: versus no improvement; ¶: Fisher's exact test; +: log-rank test.