The chest CT signs for pulmonary veno-occlusive disease correlate with pulmonary haemodynamics in systemic sclerosis

Objectives Pulmonary arterial hypertension associated with systemic sclerosis (PAH-SSc) sometimes accompanies pulmonary veno-occlusive disease (PVOD). We aimed to reveal the relationship between clinical signs of PVOD and severity of pulmonary vasculopathy in SSc. Methods This study included 52 consecutive SSc patients who had pulmonary haemodynamic abnormalities [mean pulmonary arterial pressure (mPAP) >20mmHg, pulmonary vascular resistance >2 WU or pulmonary artery wedge pressure (PAWP) >15mmHg]. A chest CT scan was evaluated in all patients. Patients were divided into two groups, the 0-1 group and the 2-3 group, according to the number of chest CT signs for PVOD, including mediastinal lymph node enlargement, thickened interlobular septal wall and ground glass opacity. Pulmonary haemodynamics, echocardiography and MRI-based cardiac function, pulmonary function and serum biomarkers were compared between the two groups. Results Mediastinal lymph node enlargement, thickened interlobular septal wall and ground glass opacity were observed in 11 (21%), 32 (62%) and 11 (21%) patients, respectively. The 2-3 group (n=15) had higher mPAP (P=0.02) but lower diffusing capacity of carbon monoxide (DLCO)/alveolar volume (P=0.02) compared with the 0-1 group (n=37). Other parameters, including PAWP, cardiac output, left ventricular ejection fraction, left atrial diameter, forced vital capacity, brain natriuretic peptide and Krebs von den Lunge-6 were not different between the two groups. Conclusions The CT signs for PVOD had a positive correlation with mPAP but a negative correlation with DLCO in SSc patients, indicating that PAH-SSc may reflect a spectrum of pulmonary vascular disease that ranges from the pulmonary artery to the vein.