Comparisons between hyperinflator and non-hyperinflator pulmonary hypertension patients

Subjects n179
Age years47±1742±150.4
Pulmonary hypertension aetiology n
 PAH (idiopathic/heritable/HIV-associated)11 (7/2/2)6 (3/3/0)0.44
NYHA I/II/III/IV7/7/3/03/2/4/00.67
6MWD m500±103538±990.37
 Right atrial pressure mmHg8±37±30.31
 mPAP mmHg51±1345±160.31
 Pulmonary artery wedge pressure mmHg10±39±20.19
 Cardiac output L·min−15.9±1.85.6±1.70.62
 Cardiac index L·min−1·m−23.3±0.83.1±0.90.57
 Pulmonary vascular resistance Wood units7.3±2.97.1±3.60.89
 Mixed venous oxygen saturation %68±665±140.49
 mPAP/cardiac output slope5.8 (3.5–6.8)7.9 (4.8–9.7)p<0.001
Lung function tests
 FEV1/FVC %81±984±100.47
 FEV1 L2.7±0.53.1±1.00.26
 FEV1 % pred93±18101±180.20
 FVC L3.6±0.73.9±1.10.38
 FVC % pred105±26103±140.67
 FEF75% L·s−1 (% pred)1.1±0.5 (55±14)1.8±0.7 (90±20)0.004
 TLC L5.0±0.75.4±1.20.30
 TLC % pred94±1796±140.72
 RV L1.3±0.51.4±0.90.90
 RV % pred84±2781±300.88
DLCO % pred64±1668±140.54
Work rate peak W94±3397±410.42
Work rate at anaerobic/ventilatory threshold W61±2157±290.32
VO2 peak mL·kg−116.8±4.418.0±4.90.54
VO2 peak % pred59±2155±150.57
VO2 at anaerobic/ventilatory threshold mL·kg−1·min−113.4±3.113.0±3.70.77
VE at rest L·min−116.3±6.221.8±8.70.058
VE at anaerobic/ventilatory threshold L·min−145±1246±160.87
VE at peak L·min−171.9±15.383.5±26.30.12
VE/VCO2 slope52 (41–48)57 (44–68)p<0.001
fR at peak breaths·min−142±940±70.27
VD/VT at rest0.45±0.130.52±0.120.070
VD/VT at peak0.55±0.080.57±0.150.36
VT at rest L0.8±0.21.1±0.60.10
VT at VT inflection L1.5±0.41.8±0.50.11
VT at peak L1.7±0.42.1±0.60.054
IC at rest L2.4±0.52.6±0.60.18
IC at VT inflection L2.1±0.42.6±0.60.018
IC at peak L2.0±0.42.6±0.60.011
IRV at rest L1.6±0.51.5±0.50.37
IRV at VT inflection L0.5±0.20.8±0.30.017
IRV at peak L0.3±0.30.5±0.40.07
Dyspnoea Borg at rest a.u.0.4±0.70.3±0.70.47
Dyspnoea Borg at VT inflection a.u.4.4±1.53.3±1.30.036
Dyspnoea Borg at peak a.u.7.2±1.66.4±1.40.11
RER at peak1.17±0.091.14±0.080.20

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; VO2: oxygen uptake; VE: minute ventilation; VCO2: 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.