Association between pulmonary artery to aorta diameter ratio with pulmonary hypertension and outcomes in diffuse cystic lung diseases

Abstract

To investigate the importance of pulmonary vascular measurements on computed tomography (CT) in predicting pulmonary hypertension (PH) and worse outcomes in diffuse cystic lung diseases (DCLDs). We conducted a cross-sectional study of patients with DCLDs. Patients underwent pulmonary function tests, a six-minute walk test (6MWT), chest CT, transthoracic echocardiography, and right heart catheterization. Pulmonary artery (PA) diameter and PA-ascending aorta ratio (PA-Ao ratio) were obtained from CT. Mean pulmonary artery pressure (mPAP) from right heart catheterization was correlated with tomographic, functional, and echocardiographic variables. The association between the PA-Ao ratio with outcomes was determined by Kaplan–Meier curves. Thirty-four patients were included (18 with pulmonary Langerhans cell histiocytosis and 16 with lymphangioleiomyomatosis, mean age 46 ± 9 years). Forced expiratory volume in the first second and lung diffusing capacity for carbon monoxide were 47 ± 20% and 38 ± 21% predicted, respectively. PA diameter and PA-Ao ratio were 29 ± 6 mm and 0.95 ± 0.24, respectively. PA-Ao ratio > 1 occurred in 38.2% of patients. PA-Ao ratio was a good predictor of PH. mPAP correlated best with PA-Ao ratio, PA diameter, oxygen desaturation during six-minute walk test, and echocardiographic variables. Patients with PA-Ao ratio > 1 had greater mPAP, and a higher risk of death or lung transplantation (log-rank, P < .001) than those with PA-Ao ratio ≤ 1. The PA-Ao ratio measured on CT scan has a potential role as a non-invasive tool to predict the presence of PH and as a prognostic parameter in patients with DCLDs.

Investigation of Pulmonary Artery and Ascending Aorta Morphology in the Coronavirus Disease 2019: A Radioanatomical Study

“…Another study showed that patients with cystic lung disease had a MAo diameter of 31 mm. 26 In our study, the diameter was 32.01 ± 3.14 mm in women and 32.39 ± 4.18 mm in men, with a mean value of 32.21 ± 3.71 mm. Our findings were consistent with the results of these previous studies 22 , 26 , 27 ; the MAo diameter increased in the patient groups compared to the control group in both genders.…”

“… 26 In our study, the diameter was 32.01 ± 3.14 mm in women and 32.39 ± 4.18 mm in men, with a mean value of 32.21 ± 3.71 mm. Our findings were consistent with the results of these previous studies 22 , 26 , 27 ; the MAo diameter increased in the patient groups compared to the control group in both genders. Ground-glass opacity, pulmonary consolidation, air bronchogram and airway changes, pulmonary vascular enlargement, reticular pattern and linear opacification, pleural effusion, and pulmonary thromboembolism are considered the main chest CT findings of COVID-19.…”

“…The MPA diameter was reported as 35.3 mm in patients with COPD 22 and 29 mm in patients with cystic lung disease. 26 Another study conducted on patients with COVID-19 found the MPA diameter to be 26.3 ± 4.4 mm. 27 The mortality rate of individuals with pulmonary hypertension was reported to be high in the last 5 years in individuals with MPA diameter measurements of ≥37.7 mm, 28 while this rate was determined as ≥48 mm in another study.…”

“… 40 , 41 Other studies on patients with pulmonary hypertension reported that an MPA–MAo ratio of 1.0 or higher predicts worse outcomes. 42 , 43 Baldi et al 26 reported the MPA–MAo ratio as 0.95 in patients with cystic lung disease. Erdoğan et al 27 found the MPA–MAo ratio in patients with COVID-19 as 0.80 ± 1.2.…”

Pulmonary Artery Dilatation Due to Pressure or Volume Overload in Congenital Heart Disease

“…Usually, as pathology is defined the MPA/Ao asc ratio >0.9 [ 1 , 2 , 4 , 23 , 38 , 39 ], or up to >1.05–1.1 in some studies [ 3 , 20 ]. In severe PH, a high-risk situation for the development of complications is considered, when the MPA/Ao asc ratio exceeds 1.5–2 [ 8 , 28 , 40 ].…”