Univariate analysis relating survival to selected baseline variables
| Variables | Hazard ratio | 95% CI | p-value |
| Age yrs | 1.04 | 0.97–1.11 | 0.297 |
| NYHA class (II–III/IV) | 2.25 | 0.86–5.87 | 0.096 |
| DL,CO % pred | 0.93 | 0.87–1.00 | 0.049 |
| KCO % pred | 0.94 | 0.88–1.01 | 0.071 |
| Pa,O2 kPa | 0.80 | 0.35–1.84 | 0.604 |
| 6MWD m | 0.99 | 0.99–1.00 | 0.157 |
| Sa,O2 6MWD % | 0.97 | 0.91–1.04 | 0.444 |
| fC beats·min−1 | 1.07 | 1.01–1.12 | 0.010 |
| Pra mmHg | 0.99 | 0.84–1.17 | 0.904 |
| Mean Ppa mmHg | 1.07 | 1.00–1.14 | 0.049 |
| CI L·min−1·m−2 | 0.23 | 0.05–1.02 | 0.054 |
| PVR dyn·s·cm−5 | 1.01 | 1.00–1.01 | 0.002 |
| SV,O2 % | 1.02 | 0.95–1.10 | 0.513 |
| Medical treatment of PH (yes/no) | 1.32 | 0.39–4.93 | 0.656 |
A value of hazard ratio >1 indicates an increased risk of death. NYHA: New York Heart Association; DL,CO: diffusing capacity of the lung for carbon monoxide; % pred; % predicted; KCO: transfer factor of the lung for carbon monoxide; Pa,O2: arterial oxygen tension; 6MWD: 6-min walk distance; Sa,O2: arterial oxygen saturation; fC: cardiac frequency; Pra: right atrial pressure; Ppa: pulmonary arterial pressure; CI: cardiac index; PVR: pulmonary vascular resistance; SV,O2: venous oxygen saturation; PH: pulmonary hypertension.