- Subjects aged 18 and over above with PAH and for which bosentan therapy is indicated
according to national license
- Subjects with a mean pulmonary artery pressure of >25mmHg and a pulmonary artery wedge
pressure of randomization.
- Subjects whose baseline 6 Minute Walk Test distance is >100m and
- PAH secondary to any aetiology including congenital heart disease other than those
specified in the inclusion criteria
- Subjects whose 6 Minute Walk Test may be limited by conditions other than PAH related
dyspnoea or fatigue eg. claudication from vascular insufficiency or arthritis.