The Hemodynamic Characteristics of Severe Chronic Lung Disease Referred for Lung Transplantation in Hong Kong

Background There is a lack of data on hemodynamic characteristics among patients with chronic lung disease (CLD) among Chinese population. Methods We retrospectively reviewed right heart catheterization (RHC) results of patients with severe CLD referred for lung transplant assessment and compared them with patients with pulmonary arterial hypertension (PAH) in our center from 2010 to 2020. Results There were 153 patients including 106 patients in the CLD group and 47 in the PAH group. Among the 106 patients who had CLD, 37 (34.9%) did not have pulmonary hypertension (PH) defined as mean pulmonary arterial pressure (PAPm) <21 mmHg or PAPm 21–24 mmHg with pulmonary vascular resistance (PVR) <3 Wood units (WU); 48 (45.3%) had CLD with PH defined as PAPm 21–24 mmHg with PVR ⩾3 WU, or PAPm 25–34 mmHg; and 21 (19.8%) had CLD with severe PH defined as PAPm ⩾35 mmHg, or PAPm ⩾25 mmHg with low cardiac index (<2.0 L·min−1·m2). PAPm and PVR have excellent power in discriminating between CLD and PAH groups, with area under curve (AUC) values of 0.970 and 0.938, respectively. Conclusion There were distinct hemodynamic characteristics between CLD and PAH groups. There is a lack of data on hemodynamic characteristics among patients with chronic lung disease (CLD) among Chinese population. We retrospectively reviewed right heart catheterization (RHC) results of patients with severe CLD referred for lung transplant assessment and compared them with patients with pulmonary arterial hypertension (PAH) in our center from 2010 to 2020. There were 153 patients including 106 patients in the CLD group and 47 in the PAH group. Among the 106 patients who had CLD, 37 (34.9%) did not have pulmonary hypertension (PH) defined as mean pulmonary arterial pressure (PAPm) <21 mmHg or PAPm 21–24 mmHg with pulmonary vascular resistance (PVR) <3 Wood units (WU); 48 (45.3%) had CLD with PH defined as PAPm 21–24 mmHg with PVR ⩾3 WU, or PAPm 25–34 mmHg; and 21 (19.8%) had CLD with severe PH defined as PAPm ⩾35 mmHg, or PAPm ⩾25 mmHg with low cardiac index (<2.0 L·min−1·m2). PAPm and PVR have excellent power in discriminating between CLD and PAH groups, with area under curve (AUC) values of 0.970 and 0.938, respectively. There were distinct hemodynamic characteristics between CLD and PAH groups.