Included variables from the “risk table” in the 2015 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines for the diagnosis and treatment of pulmonary hypertension and their cut-off values
| Determinants of prognosis | Low risk | Intermediate risk | High risk |
| WHO functional class | I, II | III | IV |
| 6MWD m | >440 | 165–440 | <165 |
| NT-proBNP levels ng·L−1 | <300 | 300–1400 | >1400 |
| Imaging (echocardiography) | RA area <18 cm2 | RA area 18–26 cm2 | RA area >26 cm2 |
| No pericardial effusion | Pericardial effusion | ||
| Haemodynamics | |||
| RAP mmHg | <8 | 8–14 | >14 |
| CI L·min−1·m−2 | ≥2.5 | 2.0–2.4 | <2.0 |
| SvO2 % | >65 | 60–65 | <60 |
Adopted from the “risk table” in the 2015 ESC/ERS guidelines for the diagnosis and treatment of pulmonary hypertension [6]. WHO: World Health Organization; 6MWD: 6-min walk distance; NT-proBNP: N-terminal pro-hormone of brain natriuretic peptide; RA: right atrium; RAP: right atrial pressure; CI: cardiac index; SvO2: mixed venous oxygen saturation.