Comparisons between hyperinflator and non-hyperinflator pulmonary hypertension patients
| Hyperinflator | Non-hyperinflator | p-value | |
| Subjects n | 17 | 9 | |
| Female/male | 11/6 | 5/4 | 0.65 |
| Age years | 47±17 | 42±15 | 0.4 |
| Pulmonary hypertension aetiology n | |||
| PAH (idiopathic/heritable/HIV-associated) | 11 (7/2/2) | 6 (3/3/0) | 0.44 |
| CTEPH | 6 | 3 | |
| NYHA I/II/III/IV | 7/7/3/0 | 3/2/4/0 | 0.67 |
| 6MWD m | 500±103 | 538±99 | 0.37 |
| Haemodynamics | |||
| Right atrial pressure mmHg | 8±3 | 7±3 | 0.31 |
| mPAP mmHg | 51±13 | 45±16 | 0.31 |
| Pulmonary artery wedge pressure mmHg | 10±3 | 9±2 | 0.19 |
| Cardiac output L·min−1 | 5.9±1.8 | 5.6±1.7 | 0.62 |
| Cardiac index L·min−1·m−2 | 3.3±0.8 | 3.1±0.9 | 0.57 |
| Pulmonary vascular resistance Wood units | 7.3±2.9 | 7.1±3.6 | 0.89 |
| Mixed venous oxygen saturation % | 68±6 | 65±14 | 0.49 |
| mPAP/cardiac output slope | 5.8 (3.5–6.8) | 7.9 (4.8–9.7) | p<0.001 |
| Lung function tests | |||
| FEV1/FVC % | 81±9 | 84±10 | 0.47 |
| FEV1 L | 2.7±0.5 | 3.1±1.0 | 0.26 |
| FEV1 % pred | 93±18 | 101±18 | 0.20 |
| FVC L | 3.6±0.7 | 3.9±1.1 | 0.38 |
| FVC % pred | 105±26 | 103±14 | 0.67 |
| FEF75% L·s−1 (% pred) | 1.1±0.5 (55±14) | 1.8±0.7 (90±20) | 0.004 |
| TLC L | 5.0±0.7 | 5.4±1.2 | 0.30 |
| TLC % pred | 94±17 | 96±14 | 0.72 |
| RV L | 1.3±0.5 | 1.4±0.9 | 0.90 |
| RV % pred | 84±27 | 81±30 | 0.88 |
| DLCO % pred | 64±16 | 68±14 | 0.54 |
| Work rate peak W | 94±33 | 97±41 | 0.42 |
| Work rate at anaerobic/ventilatory threshold W | 61±21 | 57±29 | 0.32 |
| V′O2 peak mL·kg−1 | 16.8±4.4 | 18.0±4.9 | 0.54 |
| V′O2 peak % pred | 59±21 | 55±15 | 0.57 |
| V′O2 at anaerobic/ventilatory threshold mL·kg−1·min−1 | 13.4±3.1 | 13.0±3.7 | 0.77 |
| V′E at rest L·min−1 | 16.3±6.2 | 21.8±8.7 | 0.058 |
| V′E at anaerobic/ventilatory threshold L·min−1 | 45±12 | 46±16 | 0.87 |
| V′E at peak L·min−1 | 71.9±15.3 | 83.5±26.3 | 0.12 |
| V′E/V′CO2 slope | 52 (41–48) | 57 (44–68) | p<0.001 |
| fR at peak breaths·min−1 | 42±9 | 40±7 | 0.27 |
| VD/VT at rest | 0.45±0.13 | 0.52±0.12 | 0.070 |
| VD/VT at peak | 0.55±0.08 | 0.57±0.15 | 0.36 |
| VT at rest L | 0.8±0.2 | 1.1±0.6 | 0.10 |
| VT at VT inflection L | 1.5±0.4 | 1.8±0.5 | 0.11 |
| VT at peak L | 1.7±0.4 | 2.1±0.6 | 0.054 |
| IC at rest L | 2.4±0.5 | 2.6±0.6 | 0.18 |
| IC at VT inflection L | 2.1±0.4 | 2.6±0.6 | 0.018 |
| IC at peak L | 2.0±0.4 | 2.6±0.6 | 0.011 |
| IRV at rest L | 1.6±0.5 | 1.5±0.5 | 0.37 |
| IRV at VT inflection L | 0.5±0.2 | 0.8±0.3 | 0.017 |
| IRV at peak L | 0.3±0.3 | 0.5±0.4 | 0.07 |
| Dyspnoea Borg at rest a.u. | 0.4±0.7 | 0.3±0.7 | 0.47 |
| Dyspnoea Borg at VT inflection a.u. | 4.4±1.5 | 3.3±1.3 | 0.036 |
| Dyspnoea Borg at peak a.u. | 7.2±1.6 | 6.4±1.4 | 0.11 |
| RER at peak | 1.17±0.09 | 1.14±0.08 | 0.20 |
Results are presented as mean±sd or median (interquartile range), unless otherwise stated. Bold type represents statistical significance. PAH: pulmonary arterial hypertension; CTEPH: chronic thromboembolic pulmonary hypertension; NYHA: New York Heart Association; 6MWD: 6-min walk distance; mPAP: mean pulmonary artery pressure; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; FEF75%: forced expiratory flow at 75% of the FVC; TLC: total lung capacity; RV: residual volume; DLCO: diffusing capacity of the lung for carbon monoxide; V′O2: oxygen uptake; V′E: minute ventilation; V′CO2: carbon dioxide output; fR: respiratory rate; VD: dead space volume; VT: tidal volume; IC: inspiratory capacity; IRV: inspiratory reserve volume; a.u.: arbitrary units; RER: respiratory exchange ratio.