Pulmonary artery size on computed tomography associates with mean pulmonary artery pressure and mortality.

Overview

abstract

RATIONALE: Pulmonary artery (PA) dilation on computed tomography (CT) has been associated with moderate-to-severe -pulmonary hypertension (PH) using outdated diagnostic criteria. The association between PA size and mean PA pressure (mPAP) in mild PH and the prognostic implications of PA dilation remain unclear. OBJECTIVES: To investigate associations between PA size, mPAP, and survival in subjects without significant lung disease aside from PH. METHODS: PA size on CT was measured for individuals with group 1 or 2 PH and matched controls in the Pulmonary Vascular Disease Phenomics cohort. Outcomes included mPAP on right heart catheterization (RHC) and time to heart and/or lung -transplantation or death. MEASUREMENTS AND MAIN RESULTS: A total of 691 subjects were included, with 595 undergoing RHC. PA diameter and PA:aorta ratio demonstrated significant association with mPAP (ρ = 0.557 and 0.564, respectively). Size increased incrementally from no PH to mild PH to moderate-severe PH for PA diameter (27.64 [95% CI, 17.64-37.64] mm to 30.65 [95% CI, 18.99-42.31] mm to 36.00 [95% CI, 22.46-49.54] mm) and PA:aorta (0.89 [95% CI, 0.53-1.24] to 0.99 [95% CI, 0.63-1.35] to 1.19 [95% CI, 0.60-1.78]). PA diameter and PA:aorta demonstrated good discrimination of mPAP >20 mm Hg (area under the curve: 0.834 and 0.816, respectively). Transplant-free survival decreased across the continuum of PA diameter and PA:aorta (P <.001). Adjusted hazard ratio of third versus first quartile values was 2.36 (95% CI, 1.58-3.54) for PA diameter and 2.24 (95% CI, 1.52-3.30) for PA:aorta. CONCLUSIONS: In subjects without significant lung disease outside of PH, PA size on CT was associated with increased mPAP and decreased transplant-free survival across the spectrum of PH severity and demonstrated modest diagnostic discriminatory ability using updated hemodynamic criteria.