The Relationship Between Computed Tomography Derived Thoracic Metrics and Echocardiographic Systolic Pulmonary Arterial Pressure in Patients with Pulmonary Hypertension

Abstract

Introduction: Doppler echocardiography-derived systolic pulmonary artery pressure (sPAP) is the first-line examination in evaluating patients with suspected pulmonary hypertension (PH). We aimed to determine the relationship between the contrast-enhanced chest computed tomography (CT)-derived dimensions of pulmonary vessels/right heart chambers and echocardiographic sPAP in patients with PH. Patients and Methods: Overall, 68 patients (44 female, 24 male) with sPAP > 35 mmHg who underwent CT within 3 days of echocardiographic examination were included. The diameters of the main pulmonary artery (MPA), right and left pulmonary arteries, and right and left interlobar branch arteries and the wall thicknesses and diameters of the right ventricle were measured. Pulmonary arterial measurements were adjusted based on diameters of the ascending aorta, descending aorta, and thorax length. The right ventricular measurements were adjusted by left ventricular internal dimensions and wall thicknesses and by thorax length. The relationships between sPAP and all primary and adjusted measurements were assessed by correlation analyses. Results: The dimensions of MPA, left and right pulmonary arteries, left and right interlobar arteries, right ventricular chamber, and wall thickness were all related to sPAP. Adjustment of these measurements lessened the relationship with sPAP. By multivariate analysis, MPA was the only independent variable related to sPAP (r= 0.65, p< 0.001). Subgroup analysis of 48 (71%) patients with sPAP elevation not caused by left heart pathology revealed a stronger correlation between MPA and sPAP (r= 0.72, p< 0.001). Conclusion: MPA was the strongest single independent correlator of sPAP among various CT measurements. The relationship between sPAP and MPA was more pronounced in patients with precapillary PH.