Baseline characteristics
| Characteristic | Full cohort | Subgroups | p-value | |
| IPAH | PH-CLD | |||
| Subjects n | 660 | 335 | 325 | |
| Age at diagnosis years | 64±15 | 60±17 | 67±11 | <0.001 |
| Male sex | 318 (48) | 131 (39) | 187 (58) | <0.001 |
| WHO functional class | 0.020 | |||
| II | 78 (12) | 44 (13) | 34 (10) | |
| III | 398 (61) | 213 (64) | 185 (57) | |
| IV | 181 (28) | 76 (23) | 105 (32) | |
| CT – centrilobular ground-glass (CGG) | 54 (8.2) | 54 (16) | 0 (0) | <0.001 |
| CT – ground-glass opacification (GGO) | 93 (14) | 62 (19) | 31 (9.5) | <0.001 |
| CT – honeycombing | 15 (2.3) | 5 (1.5) | 10 (3.1) | 0.2 |
| CT – consolidation | 31 (4.7) | 9 (2.7) | 22 (6.8) | 0.013 |
| CT – fibrosis | 213 (32) | 72 (21) | 141 (43) | <0.001 |
| CT – fibrosis (by severity) | <0.001 | |||
| None | 447 (68) | 263 (79) | 184 (57) | |
| Mild | 82 (12) | 54 (16) | 28 (8.6) | |
| Moderate | 53 (8.0) | 9 (2.7) | 44 (14) | |
| Severe | 48 (7.3) | 0 (0) | 48 (15) | |
| Unknown | 30 (4.5) | 9 (2.7) | 21 (6.5) | |
| CT – emphysema | 302 (46) | 98 (29) | 204 (63) | <0.001 |
| CT – emphysema (by severity) | <0.001 | |||
| None | 358 (54) | 237 (71) | 121 (37) | |
| Mild | 77 (12) | 48 (14) | 29 (8.9) | |
| Moderate | 129 (20) | 38 (11) | 91 (28) | |
| Severe | 69 (10) | 5 (1.5) | 64 (20) | |
| Unknown | 27 (4.1) | 7 (2.1) | 20 (6.2) | |
| CT – CPFE | 101 (15) | 32 (9.6) | 69 (21) | <0.001 |
| mPAP mmHg | 47±13 | 53±12 | 42±10 | <0.001 |
| mRAP mmHg | 10.2±5.6 | 11.4±5.8 | 9.0±5.1 | <0.001 |
| PAWP mmHg | 11.3±3.8 | 10.8±3.3 | 11.8±4.2 | 0.002 |
| Cardiac output L·min−1 | 4.65±1.66 | 4.31±1.62 | 5.00±1.64 | <0.001 |
| Cardiac index L·min−1·m−2 | 2.53±0.87 | 2.32±0.81 | 2.73±0.87 | <0.001 |
| PVR Wood Units | 9.0±5.1 | 11.0±5.2 | 7.0±4.1 | <0.001 |
| SvO2% | 63±9 | 61±9 | 65±8 | <0.001 |
| FEV1 % predicted | 72±25 | 83±18 | 60±25 | <0.001 |
| FEV1 severity | <0.001 | |||
| Normal (>80% predicted) | 259 (41) | 187 (58) | 72 (24) | |
| Mild (70–80% predicted) | 87 (14) | 53 (17) | 34 (11) | |
| Moderate (50–70% predicted) | 139 (22) | 70 (22) | 69 (23) | |
| Severe (<50% predicted) | 140 (22) | 11 (3.4) | 129 (42) | |
| FEV1/FVC % | 66±15 | 71±10 | 61±18 | <0.001 |
| DLCO % predicted | 37±19 | 44±20 | 28±14 | <0.001 |
Data are presented as n (%) or mean±sd unless otherwise stated. IPAH: idiopathic pulmonary arterial hypertension; PH-CLD: PH due to chronic lung disease and/or hypoxia; CT: computed tomography; WHO: World Health Organisation; CPFE: combined pulmonary fibrosis and emphysema; mPAP: mean pulmonary arterial pressure; mRAP: mean right atrial pressure; PAWP: pulmonary arterial wedge pressure; PVR: pulmonary vascular resistance; SvO2: mixed venous oxygen saturation; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide.