Group comparison of computed tomography-derived vessel parameters in patients with mild to moderate PH (mPAP 21–34 mmHg) versus patients with severe PH (mPAP ≥35 mmHg) in PH-COPD/emphysema and PH-ILD

Mild–moderate PHSevere PHMild–moderate PHSevere PH
Subjects n20243016
 Age years65±1367±1164±1269±16
 Sex %60% female50% male63% female56% male
 WHO functional class (I/II/III/IV) n0/3/16/10/0/18/61/4/23/10/0/10/6
Right heart catheter data
 mRAP, mmHg6±412±6*6±311±11*
 mPAP, mmHg27±550±10**26±448±9**
 PAWP, mmHg11±315±7*11±311±5
 Cardiac output, L·min−15.75±1.144.44±1.65*5.16±1.263.95±0.93*
 Cardiac index, L·min−1·m−23.30±0.742.36±0.70**2.81±0.732.09±0.53*
 PVR, mmHg233±90709±405**257±143777±242**
SaO2, %95±293±497±293±3**
SvO2, %74±662±9**70±463±10*
ISWT - distance, m231±153105±74**228±15270±85**
Pulmonary function tests
 FEV1, % pred66±2462±2067±1954±14*
 FVC, % pred94±2181±18*68±2055±17*
 FEV1/FVC ratio, %55±1158±1677±978±9
TLCO, % pred49.2±23.121.6±11.637.6±20.817.8±11.8*
All vessel parameters
 Pulmonary vessels <0.8 mm, mL·m−210.6±3.98.1±2.7*6.3±3.34.4±2.3*
 Pulmonary vessels <1.2 mm, mL·m−222.6±7.717.2±5.4*13.2±6.59.4±4.9*
 Pulmonary vessels <1.6 mm, mL·m−234.5±1127±8*20.7±9.415±7.5*
 Lung volume, mL2884±6432395±524*1841±5591526±510
 Total vessel volume, mL91±1779±21*55±1749±24

Data expressed as mean±sd unless otherwise indicated. PH: pulmonary hypertension; ILD: interstitial lung disease; mPAP: mean pulmonary arterial pressure; WHO: World Health Organization; mRAP: mean right atrial pressure; PAWP: pulmonary artery wedge pressure; PVR: pulmonary vascular resistance; SaO2: oxygen saturation; SvO2: mixed venous oxygen saturation; ISWT: incremental shuttle walk test; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; TLCO: transfer capacity of the lung for the uptake of carbon monoxide (CO). *: significant change between mild to moderate PH and severe PH (p<0.05); **: significant change between mild to moderate PH and severe PH (p<0.01).