Baseline demographics
| Parameter | Riociguat | Placebo |
| Patients n | 12 | 6 |
| Female | 8 (67) | 4 (67) |
| White race | 12 (100) | 6 (100) |
| Age years | 58±11 | 61±10 |
| Aetiology | ||
| Idiopathic PAH | 5 (42) | 4 (67) |
| Connective tissue disease | 5 (42) | 1 (17) |
| Portal hypertension | 1 (8) | 0 |
| Congenital heart disease | 1 (8) | 1 (17) |
| WHO functional class | ||
| I | 1 (8) | 0 |
| II | 6 (50) | 4 (67) |
| III | 4 (33) | 2 (33) |
| IV | 1 (8) | 0 |
| Baseline 6MWD ≥320 m | 7 (58) | 6 (100) |
| Baseline PVR dyn·s·cm−5 | 573±241 | 683±195 |
Data are presented as n (%) or mean±sd, unless otherwise stated. PAH: pulmonary arterial hypertension; WHO: World Health Organization; 6MWD: 6-min walking distance; PVR: pulmonary vascular resistance.