| SSc 0 PVOD | SSc 1+ PVOD | SSc 2+ PVOD | IPAH | PVOD | p-value | |
| Patients | 3 | 9 | 6 | 3 | 3 | |
| Age years | 50.3±14 | 52.2±9.5 | 54±8.4 | 42.6±15 | 38.3±14 | 0.38 |
| Females | 1 (33.3%) | 4 (44.4%) | 2 (33.3%) | 2 (66.7%) | 2 (66.7%) | 0.9 |
| Caucasians | 1 (33.3%) | 8 (88.9%) | 5 (83.3%) | 3 (100%) | 3 (100%) | 0.2 |
| NYHA class III | 2 (66.7%) | 7 (77.8%) | 5 (83.3%) | 2 (66.7%) | 2 (66.7%) | 0.4 |
| NYHA class IV | 0 | 2 (22.2%) | 1 (16.7%) | 0 | 0 | |
| Smoking history pack-years | 2.3±2 | 13±20 | 3.3±8 | 0 | 0 | 0.3 |
| Diffuse SSc | 2 | 3 | 1 | 0.2 | ||
| Limited SSc | 0 | 3 | 4 | |||
| RVSP mmHg | 68±20 | 43.8±24 | 75.4±32 | 83±12 | 61.3±32 | 0.18 |
| FVC % predicted | 45.6±21 | 51.3±20 | 48.3±20 | 77.9±17 | 63.5±20 | 0.2 |
| TLC | 24±13 | 27.3±7 | 26.6±18 | 73.6±14 | 47.2±28 | 0.1 |
| DLCO % predicted | 63.1±19 | 54.6±24 | 56.6±19 | 90.6±9 | 72.1±18 | 0.05 |
| Right heart catheterisation | ||||||
| PA systolic mmHg | 78±6.2 | 52±16.2 | 63.3±22 | 84±8.4 | 84.3±17 | 0.04 |
| PA diastolic mmHg | 23±9.6 | 18±7 | 19.3±7 | 32.5±4.9 | 35.6±8 | 0.03 |
| PA mean mmHg | 43.6±5.1 | 32.2±10.5 | 36±11.2 | 57±5.5 | 55.3±11 | 0.01 |
| PAWP mmHg | 9±5.5 | 10.6±3.5 | 9.6±3.1 | 12±2.6 | 4.7±2 | 0.1 |
| TPG mmHg | 34.6±0.5 | 21.5±12 | 26.3±11 | 45±8 | 50.6±12 | 0.01 |
| PVR WU | 4.9±0.9 | 4.9±3.3 | 4.5±1.7 | 14.9±8.7 | 10.1±4 | 0.07 |
| Pathology | ||||||
| Pulmonary veins | ||||||
| Intimal thickening | 0 | 1 (11.1%) | 5 (100%) | 0 | 3 (100%) | <0.001 |
| Obstructive fibrous luminal septa or recanalisation | 0 | 4 (44.4%) | 5 (100%) | 1 (33.3%) | 3 (100%) | 0.002 |
| Arterialisation of pulmonary veins | 0 | 7 (77.8%) | 5 (100%) | 1 (33.3%) | 3 (100%) | 0.02 |
| Capillaries | ||||||
| Angioma-like lesions in capillaries | 0 | 0 | 1 (20%) | 1 (33.3%) | 3 (100%) | 0.006 |
| Pulmonary arteries | ||||||
| Plexiform lesions | 0 | 0 | 0 | 3 (100%) | 0 | 0.002 |
| Eccentric intimal fibrosis | 2 (66.7%) | 3 (33.3%) | 5 (100%) | 1 (33.3%) | 1 (33.3%) | 0.1 |
| Concentric intimal fibrosis | 1 (33.3%) | 4 (44.4%) | 4 (80%) | 3 (100%) | 2 (66.7%) | 0.1 |
| Recanalising thrombosis | 0 | 3 (33.3%) | 1 (20%) | 2 (66.7%) | 2 (66.7%) | 0.5 |
| Muscularisation of small arteries | 2 (66.7%) | 6 (66.7%) | 5 (100%) | 2 (66.7%) | 2 (66.7%) | 0.8 |
| Morphometric analysis | ||||||
| Pulmonary veins | ||||||
| Ratio of lumen to external diameter | 0.5±0.009 | 0.3±0.07 | 0.4±0.07 | 0.5±0.13 | 0.6±0.1 | 0.05 |
| Smooth muscle % | 10.1 | 11.1±2.3 | 6.7±1.1 | 10.4±6.2 | 7.9±1.7 | 0.09 |
| Pulmonary arteries | ||||||
| Smooth muscle % | 25.4±2.5 | 29.7±4 | 31.7±7.5 | 36.0±10 | 26.0±4.4 | 0.2 |
| Intima % | 36.4±0.2 | 32.0±8.7 | 45.7±16.5 | 30.5±8 | 30.4±19.4 | 0.4 |
| Ratio of intima to smooth muscle | 1.6±0.09 | 2.0±2.7 | 1.5±0.2 | 1.0±0.3 | 1.2±0.8 | 0.4 |
Comparison of the demographics, haemodynamics and pathology of scleroderma (SSc)-pulmonary hypertension (PH)-interstitial lung disease patients. Idiopathic pulmonary arterial hypertension (IPAH) and pulmonary veno-occlusive disease (PVOD) were used as controls. Data are presented as mean±sd, unless otherwise stated. p-values were obtained by comparing all cases and controls using Kruskal–Wallis for continuous variables and Fisher's exact test for categorical variables. Bold indicates statistically significant p-values. NYHA: New York Heart Association; RVSP: right ventricular systolic pressure; FVC: forced vital capacity; TLC: total lung capacity; DLCO: diffusing capacity of the lung for carbon monoxide; PA: pulmonary artery; PAWP: pulmonary arterial wedge pressure; TPG: transpulmonary pressure gradient; PVR: pulmonary vascular resistance; WU: Wood units.