Figure 4.

Relationship between PH assessed by echocardiography and lung diffusion capacity. (A) Correlation between eSPAP and %DL_CO in COPD patients. (B) ROC curves of %DL_CO for the prediction of PH assessed by echocardiography. Correlations between continuous variables were evaluated using Spearman’s rank correlation coefficient.

Abbreviations: PH, pulmonary arterial hypertension; eSPAP, estimated systolic pulmonary artery pressure; DL_CO, diffusing capacity of lung carbon monoxide; COPD, chronic obstructive pulmonary disease; ROC, receiver operating characteristic.