Clinical characteristics of the study population at baseline
| Idiopathic PAH | Nonidiopathic PAH | |
| Subjects n | 46 | 37 |
| Demographics | ||
| Age yrs | 50±14 | 49±12 |
| Females/males n | 27/19 | 11/26 |
| Weight kg | 69±14 | 70±14 |
| Height cm | 165±9 | 169±8 |
| Body surface area m2 | 1.75±0.19 | 1.79±0.18 |
| NYHA n | ||
| II | 18 | 19 |
| III | 28 | 15 |
| IV | 0 | 3 |
| Resting haemodynamics | ||
| mRAP mmHg | 7±4 | 8±6 |
| mPAP mmHg | 55±16 | 40±15 |
| PAOP mmHg | 9±3 | 8±4 |
| CO L·min−1 | 4.72±1.11 | 5.56±1.64 |
| CI L·min−1·m−2 | 2.70±0.65 | 3.11±0.93 |
| SV mL | 60±17 | 70±24 |
| PVR mmHg·min·L−1 | 10.6±4.5 | 6.8 ±4.9 |
| Sv,O2 % | 64±8 | 63±12 |
| HR beats·min−1 | 81±13 | 81±14 |
| mSAP mmHg | 90±12 | 88±13 |
| 6MWT | ||
| Distance m | 431±87 | 423±104 |
| SP,O2,rest % | 95±3 | 95±3 |
| SP,O2,min % | 90±5 | 88±6 |
| ΔSP,O2 % | −5±4 | −8±5 |
| HRrest beats·min−1 | 85±14 | 89±16 |
| HRpeak beats·min−1 | 118±18 | 116±15 |
| ΔHR beats·min−1 | 33±15 | 27±11 |
| Borg scale | 3.4±1.6 | 3.1±1.3 |
Data are presented as mean±sd, unless otherwise specified. PAH: pulmonary arterial hypertension; NYHA: modified New York Heart Association; mRAP: mean right atrial pressure; mPAP: mean pulmonary arterial pressure; PAOP: pulmonary arterial occlusion pressure; CO: cardiac output; CI: cardiac index; SV: stroke volume; PVR: pulmonary vascular resistance; Sv,O2: mixed venous oxygen saturation; HR: heart rate; mSAP: mean systemic arterial pressure; 6MWT: 6-min walk test; SP,O2,rest: peripheral oxygen saturation measured at rest; SP,O2,min: minimal SP,O2 measured during 6MWT; ΔSP,O2: desaturation measured during the 6MWT (SP,O2,min–SP,O2,rest); HRrest: heart rate measured at rest; HRpeak: peak heart rate measured during the 6MWT; ΔHR: chronotropic response (HRpeak–HRrest). n = 83. 1 mmHg = 0.133 kPa.