Pulmonary Artery Dilation on Chest CT Across the Spectrum of Chronic Lung Disease.

Abstract

Background: Pulmonary artery (PA) dilation on CT has been associated with pulmonary hypertension (PH) in subjects without lung disease using outdated PH criteria. The relationship between PA size and PH in chronic lung disease is unclear.

Research question: Is PA size associated with PH in subjects with chronic lung disease, and does association differ by disease etiology?

Methods: PA diameter and PA/aorta ratio (PA/A) were measured on CT for all group 3 PH subjects and comparators in the PVDOMICS Cohort. Subjects were categorized into obstructive, interstitial, or non-parenchymal subgroups. Mean PA pressure (mPAP) was measured on right heart catheterization. Associations and diagnostic performance were assessed using multivariable linear and logistic regression and receiver operating curve analysis.

Results: Among 252 subjects (81 obstructive, 125 interstitial, 46 non-parenchymal), PA size associated with PH (Q3 vs Q1 OR 4.30 [2.32-8.00] for diameter, 5.66 [2.86-11.18] for PA/A) and mPAP (ρ = 0.516 for diameter, 0.494 for PA/A; p < 0.001) and possessed moderate ability to detect PH (AUC 0.794 for diameter, 0.765 for PA/A). Association between PA/A and mPAP was strongest in non-parenchymal subjects (ρ = 0.750) and weakest in interstitial subjects (ρ = 0.373). PA/A diagnostic performance was lower in interstitial subjects (AUC 0.704) than in obstructive (AUC 0.865) and non-parenchymal (AUC 0.822) subjects. PA dilation between Q1 and Q3 mPAP was lower in interstitial (3.9 [95% CI 2.3-5.4] mm) compared to obstructive (4.9 [2.4-7.4] mm) and non-parenchymal (4.8 [1.8-7.8] mm) subjects.