Patients with idiopathic pulmonary fibrosis (IPF) who had a ratio of the diameter of the main pulmonary artery to that of the aorta (mPA/Ao) >1 on chest computed tomography (CT) had worse outcomes, according to the results of a recent study published in BMC Pulmonary Medicine.
The diameter of the mPA and Ao was measured by chest CT in patients after diagnosis of IPF. Associations between clinical outcomes and the ratio of the diameter of the mPA/Ao were examined retrospectively. The primary outcomes of interest were death and lung transplantation.
Among the 303 enrolled participants with IPF, 234 were men and 69 were women. The most common comorbidities were hypertension and diabetes mellitus. The median mPA/Ao ratio was 0.83. Of the 303 participants, 272 had an MPA/Ao ratio ≤1 whereas 31 had a ratio >1. The median main pulmonary artery diameter was 27.6 mm in the group with a ratio ≤1 and 32.9 mm in the group with a ratio >1. A lower body mass index; a higher score for sex, age, and physiologic variables; and a higher mPA/Ao ratio were significantly associated with a poor prognosis in patients with IPF.
The study authors wrote, “The results of this study indicate that an mPA/Ao ratio >1 is associated with worse outcomes, including death and lung transplantation, in patients with IPF.”
They added, “We suggest that the diameters of the mPA and Ao should be measured on chest CT at the time of initial diagnosis of IPF and that patients found to have a higher mPA/Ao ratio be kept under close observation.”
Choi JS, Lee SH, Leem AY, et al. Prognostic impact of the ratio of the main pulmonary artery to that of the aorta on chest computed tomography in patients with idiopathic pulmonary fibrosis. BMC Pulm Med. 2019;19(1):81.