Population characteristics; discrete variables are expressed as counts (%) and continuous variables as mean ± standard deviation.

BMI denotes body mass index, CI cardiac index, DLCOcarbon monoxide diffusing capacity, FEV1 forced expiratory volume in one second, FVC forced vital capacity, LVEF left ventricular ejection fraction, MMRC medical research council dyspnea scale, mPAP mean pulmonary artery pressure, pCO2 partial pressure of carbon dioxide after exercise, PCWP pulmonary capillary wedge pressure, pO2 partial pressure of oxygen, PVR pulmonary vascular resistance, RV residual volume, spa systolic pulmonary artery pressure (estimated), TAPSE tricuspid annular plane systolic excursion, TLC total lung capacity.