Pulmonary function testing in patients with pulmonary arterial hypertension.
BACKGROUND
Although previous studies have shown that peripheral airway obstruction can occur in idiopathic PAH (IPAH), pulmonary function tests have not been well-studied in patients with PAH associated with congenital heart disease (CHD-PAH) and connective tissue disease (CTD-PAH).


METHODS
A multicenter prospective study was performed in PAH patients in China. Pulmonary function tests were evaluated in 190 PAH patients.


RESULTS
Total lung capacity (TLC), residual volume (RV) and total airway resistance (Rtot) were similar in PAH patients and controls. However, measures of airflow, including vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1s (FEV(1)), FEV(1)/FVC and MEF(50) were decreased in PAH group. Single-breath diffusion capacity for carbon monoxide (DL(CO)) was also decreased in PAH patients. Expiratory flow-volume curves showed reduction and a curvilinear appearance in patients with PAH. Similar changes were observed among the various subgroups of IPAH, CHD-PAH, and CTD-PAH patients. More CTD-PAH patients had abnormal DL(CO).


CONCLUSIONS
Airway obstruction is common in IPAH, CHD-PAH and CTD-PAH patients. CTD-PAH patients have lower DL(CO). Hemodynamics, serum markers and exercise capacity parameters did not correlate well with pulmonary function indices.
Jing
Zhi-Cheng
ZC
Shanghai Pulmonary Hospital, Tongji University, Shanghai, China. jingzhicheng@gmail.com
Xu
Xi-Qi
XQ
Badesch
David B
DB
Jiang
Xin
X
Wu
Yan
Y
Liu
Jin-Ming
JM
Wang
Yong
Y
Pan
Lei
L
Li
Hui-Ping
HP
Pu
Jie-Lin
JL
Zhang
Zhuo-Li
ZL
Yang
Yue-Jin
YJ
D000328:Adult; D000402:Airway Obstruction / Q000209:etiology / Q000503:physiopathology*; D000704:Analysis of Variance; D003240:Connective Tissue Diseases / Q000150:complications / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006330:Heart Defects, Congenital / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000503:physiopathology*; D008297:Male; D011446:Prospective Studies; D012129:Respiratory Function Tests; D014797:Vital Capacity / Q000502:physiology