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) >20 mmHg, pulmonary vascular resistance >2 WU or pulmonary artery wedge pressure (PAWP) >15 mmHg]. 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.