Included variables and cut-off values used for simplified risk assessment instrument
| Variables | Low risk | Intermediate risk | High risk |
|---|---|---|---|
| WHO Functional Class | I-II | III | IV |
| 6MWD | >440 m | 165–440 m | <165 m |
| NT-proBNP plasma levels | <300 ng/L | 300–1400 ng/L | >1400 ng/L |
| Imaging (echocardiography) | No pericardial effusion | No or minimal pericardial effusion | Pericardial effusion |
| Haemodynamics | right atrial pressure<8 mmHg cardiac index≥2.5 L/min/m2 SvO2>65% | right atrial pressure 8–14 mmHg cardiac index 2.0–2.4 L/min/m2 SvO2 60%–65% | right atrial pressure>14 mmHg cardiac index<2.0 L/min/m2 SvO2<60% |
6MWD: 6 min walk distance; NT-proBNP: N-terminal pro-B-type natriuretic peptide; SvO2: mixed venous oxygen saturation.