Baseline characteristics of patients with initial diagnosis of IPAH
| Characteristic | IPAH-noLD | IPAH-CGG | IPAH-LD | p-value |
| Subjects n | 151 | 46 | 130 | |
| Age at diagnosis | 56±18# | 48±19# | 70±9¶,+ | <0.001 |
| Male sex | 48 (32)# | 11 (24)# | 69 (53)¶,+ | <0.001 |
| WHO functional class | # | # | ¶,+ | 0.011 |
| II | 25 (17) | 9 (20) | 9 (6.9) | |
| III | 98 (65) | 29 (64) | 81 (62) | |
| IV | 27 (18) | 7 (16) | 40 (31) | |
| Smoker, ever | 66 (49)# | 19 (42)# | 81 (86)¶,+ | <0.001 |
| CT – centrilobular ground-glass | 0 (0)+ | 46 (100)¶,# | 0 (0)+ | <0.001 |
| CT – ground-glass opacification | 9 (6.0)+ | 39 (85)¶,# | 8 (6.2)+ | <0.001 |
| CT – honeycombing | 0 (0)# | 0 (0)¶,# | 5 (3.8)¶ | 0.021 |
| CT – consolidation | 5 (3.3) | 2 (4.3) | 2 (1.5) | 0.4 |
| CT – fibrosis | 0 (0)# | 0 (0)# | 68 (52)¶,+ | <0.001 |
| CT – fibrosis (by severity) | # | # | ¶,+ | <0.001 |
| None | 151 (100) | 46 (100) | 62 (48) | |
| Mild | 0 (0) | 0 (0) | 52 (40) | |
| Moderate | 0 (0) | 0 (0) | 9 (6.9) | |
| Unknown | 0 (0) | 0 (0) | 7 (5.4) | |
| CT – emphysema | 0 (0)# | 0 (0)# | 94 (72)¶,+ | <0.001 |
| CT – emphysema (by severity) | # | # | ¶,+ | |
| None | 151 (100) | 46 (100) | 36 (28) | |
| Mild | 0 (0) | 0 (0) | 44 (34) | |
| Moderate | 0 (0) | 0 (0) | 38 (29) | |
| Severe | 0 (0) | 0 (0) | 5 (3.8) | |
| Unknown | 0 (0) | 0 (0) | 7 (5.4) | |
| CT – CPFE | 0 (0)# | 0 (0)# | 32 (25)¶,+ | <0.001 |
| mPAP mmHg | 54±12+,# | 62±13¶,# | 49±8¶,+ | <0.001 |
| mRAP mmHg | 12±6 | 10±5 | 11±5 | 0.3 |
| PAWP mmHg | 10.91±3.10 | 9.72±2.77 | 11.03±3.21 | 0.055 |
| Cardiac output L·min−1 | 4.64±1.87+,# | 3.85±0.98¶ | 4.08±1.44¶ | 0.014 |
| Cardiac index L·min−1·m−2 | 2.47±0.95# | 2.13±0.52 | 2.23±0.73¶ | 0.031 |
| PVR Wood Units | 10.7±5.2+ | 14.6±6.2¶,# | 10.3±4.4+ | <0.001 |
| SvO2% | 61±10 | 62±7 | 59±8 | 0.030 |
| FEV1 % predicted | 82±17 | 88±15 | 83±20 | 0.124 |
| FEV1 severity | 0.056 | |||
| Normal (>80% predicted) | 83 (58) | 31 (70) | 67 (53) | |
| Mild (70–80% predicted) | 21 (15) | 8 (18) | 24 (19) | |
| Moderate (50–70% predicted) | 34 (24) | 5 (11) | 29 (23) | |
| Severe (<50% predicted) | 5 (3.5) | 0 (0) | 6 (4.8) | |
| FVC % predicted | 93±20 | 101±18 | 99±21 | 0.016 |
| FEV1/FVC % | 74±10# | 74±8# | 67±10¶,+ | <0.001 |
| DLCO % predicted | 52±20# | 56±17# | 31±14¶,+ | <0.001 |
Data are presented as n (%) or mean±sd unless otherwise stated. Between-group comparisons performed using one-way ANOVA with Bonferroni post hoc correction. Eight patients with both CGG and LD not included. IPAH: idiopathic pulmonary arterial hypertension; IPAH-noLD: idiopathic pulmonary arterial hypertension with no computed tomography features of lung disease; IPAH-CGG: idiopathic pulmonary arterial hypertension with centrilobular ground-glass changes; IPAH-LD: idiopathic pulmonary arterial hypertension with CT features of lung disease; 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; CGG: centrilobular ground-glass; LD: lung disease. Difference between groups noted – #: significant difference to IPAH-LD; ¶: significant difference to IPAH-noLD; +: significant difference to IPAH-CGG.