Results of Cox regression analysis relating survival time to individual selected variables
| Variable | Hazard ratio (95% CI) | p-value |
| NYHA class | 0.60 (0.11–3.20) | 0.55 |
| VC L | 0.97 (0.93–1.00) | 0.22 |
| FVC L | 0.99 (0.95–1.03) | 0.51 |
| FEV1 L | 0.98 (0.94–1.03) | 0.47 |
| DL,CO mL·min−1·mmHg−1 | 0.99 (0.93–1.05) | 0.74 |
| Arterial PO2 | 0.97 (0.91–1.03) | 0.28 |
| Arterial PCO2 | 0.86 (0.74–1.01) | 0.07 |
| Arterial pH | 1.28 (0.93–1.76) (per 0.01 increase in pH value) | 0.13 |
| Sa,O2-rest % | 0.91 (0.81–1.01) | 0.09 |
| Sa,O2-exercise % | 0.92 (0.85–0.99) | 0.03 |
| ΔSa,O2% | 1.26 (1.04–1.53) (per each 1% decrease) | 0.02 |
| Distance m | 0.82 (0.63–1.05) (per 50 meters increase in distance) | 0.11 |
| mRAP mmHg | 1.09 (0.95–1.24) | 0.19 |
| mPAP mmHg | 1.23 (1.03–1.47) | 0.33 |
| CO L·min−1 | 0.66 (0.38–1.14) | 0.14 |
| PVR Wood units | 1.12 (1.01–1.26) | 0.04 |
NYHA: New York Heart Association; VC: slow vital capacity; FVC: forced vital capacity; FEV1: forced expired volume in the first second; DL,CO: diffusing capacity for carbon monoxide; PO2: arterial oxygen tension; PCO2: arterial carbon dioxide tension; Sa,O2-rest: oxygen saturation rest; Sa,O2-exercise: trough of oxygen saturation during six-minute walk test; ΔSa,O2: difference between resting and trough oxygen saturation; mRAP: mean right atrial pressure; mPAP: man pulmonary artery pressure; CO: cardiac output; PVR: pulmonary vascular resistance.