| Completed | 3 | 10 | Europe | Bosentan, Bosentan = Tracleer, Placebo | Universitaire Ziekenhuizen Leuven | Heart Septal Defects, Atrial | 03/14 | 03/14 | | |
| Completed | 3 | 20 | Europe | bosentan, Ro 47.0203, placebo | University Teaching Hospital Hall in Tirol | Heart Failure, Diastolic, Hypertension, Pulmonary | 06/14 | 06/14 | | |