Baseline characteristics of the study population
| Characteristic | Result |
| Age years | 63±11 |
| Female gender % | 82 |
| BMI kg·m−2 | 31.4±7.8 |
| Aetiology | |
| Non-CTD associated PAH | 40 |
| Idiopathic | 39 |
| HIV associated | 1 |
| CTD associated PAH | 42 |
| Systemic sclerosis spectrum | 39 |
| Rheumatoid arthritis | 2 |
| Systemic lupus erythematosus | 1 |
| Comorbidities | |
| Diabetes mellitus | 20 (24) |
| Hypertension | 45 (55) |
| Dyslipidaemia | 36 (44) |
| Ischaemic heart disease | 22 (27) |
| Peripheral vascular disease | 5 (6) |
| Current smoker | 3 (4) |
| Ex-smoker | 26 (32) |
| OSA | 20 (24) |
| Baseline haemodynamics | |
| Mean PAP mmHg | 27 (25–30) |
| PAWP mmHg | 13 (11–14) |
| PVR Wood units | 2.2 (1.9–2.7) |
| Cardiac output L·min−1 | 6.7 (5.8–7.9) |
| Cardiac index L·min−1·m−2 | 3.55 (3.1–4.2) |
| RAP mmHg | 8.0 (5.2–10.0) |
| Mean SAP mmHg | 98 (83–106) |
| SVR dynes·sec·cm−5 | 1078 (852–1240) |
| HR beats·min−1 | 72 (67–87) |
| Baseline 6MWD m | 352 (280–416) |
| PFT | |
| FEV1 % predicted | 91 (75–96) |
| FVC % predicted | 90 (81–105) |
| TLC % predicted | 93 (80–98) |
| DLCO % predicted | 53 (45–62) |
| NYHA functional class | |
| 1 | 1 (1) |
| 2 | 19 (23) |
| 3 | 60 (73) |
| 4 | 2 (3) |
Data are presented as n, n (%), mean±sd or median (IQR), unless otherwise stated. BMI: body mass index; CTD: connective tissue disease; PAH: pulmonary arterial hypertension; OSA: obstructive sleep apnoea; PAP: pulmonary arterial pressure; PAWP: pulmonary arterial wedge pressure; PVR: pulmonary vascular resistance; RAP: right-atrial pressure; SAP: systemic arterial pressure; SVR: systemic vascular resistance; HR: heart rate; 6MWD: 6-min walk distance; PFT: pulmonary function test; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; TLC: total lung capacity; DLCO: diffusing capacity of the lung for carbon monoxide; NYHA: New York Heart Association.