Table 1. Patient demographics and baseline characteristics.
| IPAH (n = 798) | PH-IIP (n = 151) | p value | |
|---|---|---|---|
| Female (n, %) | 478 (59.9%) | 56 (37.1%) | <0.001 |
| Age, years (mean, SD) | 64.5±15.8 | 71.1±10.7 | <0.001 |
| BMI, kg/m2 (mean/SD) | 28.0±6.7 | 26.9±5.0 | 0.033 |
| 6MWD, m (mean, SD) | 303±129 | 251±116 | <0.001 |
| WHO Class I (n, %) | 3 (0.4%) | 0 | * |
| WHO Class II (n, %) | 98 (12.5%) | 4 (2.7%) | * |
| WHO Class III (n, %) | 568 (72.4%) | 106 (71.6%) | * |
| WHO Class IV (n, %) | 115 (14.7%) | 38 (25.7%) | * |
| TLC (% pred) | 95.3±17.2 | 68.8±17.0 | <0.001 |
| FVC (% pred) | 82.1±21.6 | 62.9±20.0 | <0.001 |
| FEV1 (% pred) | 76.7±21.4 | 67.7±20.2 | 0.001 |
| DLCO (% pred) | 50.1±20.5 | 28.5±15.8 | <0.001 |
| paO2 (mmHg) a | 62.4±13.4 | 56.3±10.4 | <0.001 |
| paCO2 (mmHg) a | 34.5±7.1 | 37.4±5.5 | 0.001 |
| RAP, mmHg | 8.6±5.0 | 5.9±4.8 | <0.001 |
| mPAP, mmHg | 45±13 | 37±9 | <0.001 |
| PAWP, mmHg | 9.6±3.4 | 8.0±3.8 | <0.001 |
| PVR, dyn.s.cm-5 | 793±433 | 649±268 | 0.001 |
| CI, L/min/m2 | 2.2±0.7 | 2.1±0.6 | 0.438 |
| SvO2, % | 63±9 | 64±8 | 0.063 |
| Bilirubin (mg/dl) | 0.7 (0.5–1.0) | 0.6 (0.5–0.9) | 0.011 |
| Creatinine (mg/dl) | 1.0 (0.8–1.3) | 1.0 (0.8–1.3) | 0.755 |
| Uric acid (mg/dl) | 7.2 (5.7–9.0) | 7.1 (5.7–8.3) | 0.224 |
| NT-proBNP (ng/L) | 1,627 (577–3,487) | 1,029 (373–2901) | 0.065 |
| BNP (ng/L) | 233 (93–469) | 114 (59–256) | 0.009 |
All baseline variables were more than 90% complete except for PaO2 at room air and serum levels of BNP/NT-proBNP.
Abbreviations: IPAH, idiopathic pulmonary arterial hypertension; PH-IIP, pulmonary hypertension associated with idiopathic interstitial pneumonia; 6MWD, 6 min walking distance; BMI, body mass index; WHO, world health organization; TLC, total lung capacity; FVC, forced vital capacity; FEV1, forced expiratory capacity in one second; DLCO, diffusion capacity of the lung for carbon monoxide; RAP, right atrial pressure; PAPm, mean pulmonary arterial pressure; PAWP, pulmonary arterial wedge pressure; CI, cardiac index, SvO2, mixed venous oxygen saturation; PVR, pulmonary vascular resistance; mixed-venous oxygen saturation; BNP, brain natriuretic peptide; NT-proBNP, N-terminal fragment of pro-brain natriuretic peptide; Q1, 25th percentile; Q3, 75th percentile; pred, predicted normal value;
aroom air measurements only
*p<0.001 for all WHO functional classes combined