Table 1. Characteristics of pulmonary arterial hypertension according to New York Heart Association/World Health Organization functional class (NYHA/WHO FC) at diagnosis.
| Parameter | NYHA/WHO FC | p-value | ||
| I/II | III | IV | ||
| 6MWD n | 134 | 359 | 55 | |
| Distance m | 415±86 | 319±92 | 192±96 | <0.0001 |
| Haemodynamic variables n | 162 | 405 | 77 | |
| Pra mmHg | 6±4 | 9±5 | 11±7 | <0.0001 |
| P̄pa mmHg | 50±17 | 56±15 | 56±13 | 0.0002 |
| Ppcw mmHg | 8±3 | 8±3 | 8±4 | 0.75 |
| Cardiac index L·min−1·m−2 | 2.9±0.9 | 2.4±0.7 | 2.1±0.8 | <0.0001 |
| Sv,O2 | 67±8 | 62±8 | 54±9 | <0.0001 |
| PVRI mmHg·L·min·m−2 | 15.8±9.7 | 21.5±9.8 | 25.5±10.1 | <0.0001 |
Data are presented as mean±sd, unless otherwise stated. 6MWD: 6-min walk distance; Pra: right atrial pressure; P̄pa: mean pulmonary arterial pressure; Ppcw: pulmonary capillary wedge pressure; Sv,O2: venous oxygen saturation; PVRI: pulmonary vascular resistance index. Reproduced from [10] with permission from the publisher.