Elastic-to-Muscular Pulmonary Artery Area Ratio and Echocardiographic Pulmonary Arterial Systolic Pressure in the Prediction of Pulmonary Hypertension: A Retrospective Cohort Study

Objectives To evaluate the diagnostic accuracy of the elastic-to-muscular pulmonary artery area ratio (EM-AR), derived from 3D-printed digital models, for pulmonary hypertension (PH), both independently and in combination with echocardiographically estimated pulmonary arterial systolic pressure (PASP). Methods This retrospective diagnostic study enrolled 80 patients with suspected pulmonary hypertension, using invasive mean pulmonary arterial pressure (mPAP) from right heart catheterization as the reference standard. Cross-sectional areas of the elastic (third-order, right lower lobe) and muscular (sixth-order, right lower lobe) pulmonary arteries were measured from 3D-printed digital models to calculate the elastic-to-muscular artery ratio (EM-AR). A linear regression model integrating the calculated EM-AR and measured echocardiographic PASP was developed to predict mPAP (mPAP _predicted ). Results Quantitative analysis revealed significant remodeling of the pulmonary arterial tree in the PH group, characterized by enlargement of elastic arteries ( p  < 0.001), reduction in muscular artery area ( P  < 0.001), and a consequent elevation in the EM-AR ( P  < 0.001). The EM-AR showed the strongest correlation with invasive mPAP (r = 0.73, P  < 0.001) compared to its individual components (elastic artery: r = 0.54, P  < 0.001; muscular artery: r = -0.52, P  < 0.001). The composite mPAP, derived from a multiple linear regression model of EM-AR and PASP, correlated strongly with invasive mPAP (r = 0.82, P  < 0.001) and achieved superior diagnostic accuracy for PH (AUC = 0.95). At the optimal cut-off of 23.9 mmHg, it identified PH with 83.1% sensitivity and 95.2% specificity. Conclusions The EM-AR derived from 3D-printed digital models appears to be a promising indicator of pulmonary vascular remodeling. In our cohort, a multivariable model combining EM-AR with echocardiographic PASP demonstrated excellent diagnostic performance for the noninvasive prediction of pulmonary hypertension.