Patient demographics and baseline characteristics.

All baseline variables were more than 90% complete except for PaO2 at room air and serum levels of BNP/NT-proBNP.Abbreviations: IPAH, idiopathic pulmonary arterial hypertension; PH-IIP, pulmonary hypertension associated with idiopathic interstitial pneumonia; 6MWD, 6 min walking distance; BMI, body mass index; WHO, world health organization; TLC, total lung capacity; FVC, forced vital capacity; FEV1, forced expiratory capacity in one second; DLCO, diffusion capacity of the lung for carbon monoxide; RAP, right atrial pressure; PAPm, mean pulmonary arterial pressure; PAWP, pulmonary arterial wedge pressure; CI, cardiac index, SvO2, mixed venous oxygen saturation; PVR, pulmonary vascular resistance; mixed-venous oxygen saturation; BNP, brain natriuretic peptide; NT-proBNP, N-terminal fragment of pro-brain natriuretic peptide; Q1, 25th percentile; Q3, 75th percentile; pred, predicted normal value;aroom air measurements only*pPatient demographics and baseline characteristics.