| All patients | Aetiology | p-value# | ||
| IPAH | CTDPH | |||
| Patients n | 137 | 86 | 51 | |
| Age¶ yrs | 60 (22) | 60 (29) | 62 (13) | 0.18 |
| Females | 95 (69) | 54 (63) | 41 (80) | <0.05 |
| Lung function¶ % pred | ||||
| FEV1 | 87 (22) | 88 (19) | 85 (24) | 0.84 |
| FVC | 99 (23) | 101 (22) | 98 (32) | 0.48 |
| DL,CO | 43 (32) | 45 (38) | 41 (18) | 0.22 |
| WHO FC | ||||
| I and II | 22 (16) | 17 (20) | 5 (10) | <0.05 |
| III | 104 (76) | 59 (69) | 45 (88) | |
| IV | 11 (8) | 10 (12) | 1 (2) | |
| Haemodynamics | ||||
| P̄ra¶ mmHg | 6 (7) | 6 (7) | 7 (8) | 0.40 |
| P̄pa ¶ mmHg | 48 (19) | 50 (18) | 42 (19) | <0.01 |
| CI¶ L·min−1·m−2 | 2.1 (0.9) | 2.2 (0.9) | 2.0 (0.9) | 0.92 |
| PVR¶ Wood units | 10.5 (8.4) | 10.6 (7.8) | 9.7 (9.9) | 0.36 |
| SV,O2 % | 63±8 | 64±8 | 63±9 | 0.60 |
| 6MWD+ | ||||
| Absolute 6MWD m | 264±111 | 271±117 | 251±102 | 0.33 |
| 6MWD % pred | ||||
| Enright 11 | 50±19 | 50±20 | 50±19 | 0.95 |
| Troosters 13 | 41±16 | 41±16 | 42±15 | 0.84 |
| Gibbons 12 | 41±16 | 41±16 | 40±15 | 0.81 |
| Chetta 10 | 49±19 | 49±20 | 49±18 | 0.92 |
Data are expressed as mean±sd or n (%), unless otherwise stated; ¶: median (interquartile range). IPAH: idiopathic pulmonary arterial hypertension; CTDPH: connective tissue disease-associated pulmonary hypertension; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; DL,CO: diffusing capacity of the lung for carbon monoxide; WHO FC: World Health Organization functional class; P̄ra: mean right atrial pressure; P̄pa: mean pulmonary artery pressure; CI: cardiac index; PVR: pulmonary vascular resistance; SV,O2: mixed venous oxygen saturation; 6MWD: 6-min walk distance. #: comparing IPAH versus CTDPH patients; +: n = 130.