The state of vascular bed, parenchyma and perfusion of lungs in chronic thromboembolic pulmonary hypertension according to data of subtraction pulmonary angiography

Abstract

Aim: to assess the state of vascular bed, parenchyma, and perfusion of lungs in patients with chronic thromboembolic pulmonary hypertension (CTEPH) using the method of subtraction computed tomography (CT). Methods. CT pulmonary angiography (CTPA) was performed in 45 patients with verified CTEPH (18 men, 27 women, age 26-79 years) by CT scanner using the "Lung subtraction" standard protocol. Parameters analyzed were characteristics of the state of main pulmonary artery (MPA) and the right ventricle (RV), and calculated CT angiographic (CTA) obstruction and perfusion defect scores. Results. Significant correlation was found between CTA obstruction score and perfusion defect score (r=0.34, p=0.02). Mean pulmonary arterial pressure (mPAP) correlated with MPA diameter (r=0.4, p=0.02), RV wall thickness (r=0.6, p=0.0003) and the ratio of MPA diameter to ascending aortic diameter (r=0.5, p=0.002). Significant correlation was also found between RV wall thickness and pulmonary vascular resistance (PVR) (r=0.4, p=0.04). Neither CTA obstruction score nor perfusion defect score correlated with PVR and mPAP. The data of CT did not correlate with results of 6-minute walk test. Conclusion. In patients with CTEPH subtraction CTPA allows carrying out complex diagnostics of the state of vascular bed, parenchyma and perfusion of the lungs.