Pulmonary artery enlargement predicts poor outcome during acute exacerbations of fibrotic interstitial lung disease

Abstract

Background and objective: In fibrotic interstitial lung disease (f-ILD), pulmonary artery diameter to ascending aorta diameter ratio (PA/A) ≥ 1 during the stable stage is associated with worse outcomes; however, the effect of acute exacerbation (AE) on the PA/A is unknown. Methods: Patients with a diagnosis of AE of f-ILD and with a computed tomography (CT) scan performed during stable period to confirm background fibrosis, as well as a CT scan at admission, were included. The pulmonary arterial diameter, ascending aortic diameter and PA/A were measured using CT during AE and CT prior to AE, when available, to evaluate the changes. Demographic data, co-morbidities and clinical outcome (90-day mortality) were analysed. Results: Of the 123 patients included, 45 had a PA/A ≥ 1 during AE and compared to the PA/A < 1 group, they were younger, had lower % vital capacity (VC) and % forced vital capacity (FVC), required more long-term oxygen therapy and other treatments, and had lower PaO 2 /FiO 2 (P/F) ratios. During AE, the PA/A increased from that during stable periods (P < 0.001), and a PA/A ≥ 1 was significantly associated with 90-day mortality both before and after adjustment for age, the P/F ratio at admission, long-term oxygen therapy usage and the type of background f-ILD (P = 0.018 and 0.025). Conclusion: To the best of our knowledge, this is the first longitudinal examination of the PA/A ratio and evaluation during AE of f-ILD. Our data show that a PA/A ≥ 1 during AE predicted poor survival outcome in f-ILD.

Novel exploratory data in interstitial lung disease

“…Second, Kogo et al . explored the prognostic significance of enlargement of the pulmonary artery, quantified as the pulmonary artery/aorta (PA/A) ratio, in acute exacerbations of fibrotic interstitial lung disease (fILD) . The authors found that a PA/A ratio > 1.0 was associated with increased 90‐day mortality before and after adjustment for a number of factors (FVC reduction prior to the acute exacerbation age, AE‐fILD severity and type of fILD).…”

Contemporary Concise Review 2019: Interstitial lung disease

“…73 Kogo et al use the ratio of the pulmonary artery to aorta to prognosticate and report that a ratio of ≥1 predicts a greater risk of mortality associated with acute exacerbations. 74…”

The association between pulmonary artery enlargement and mortality in an Emergency Department population undergoing computed tomography pulmonary angiography

“…Enlargement of the pulmonary arteries as detected by contrast‐enhanced computed tomography pulmonary angiography (CTPA) provides prognostic information in patients with various forms of cardiopulmonary disease. Enlargement of the pulmonary artery diameter (PAd) or increased ratio of the PAd to aorta diameter (PA:AA) has been associated with increased mortality in patients with chronic obstructive pulmonary disease (COPD), 1 , 2 interstitial lung disease, 3 , 4 , 5 pulmonary arterial hypertension (PAH), 6 , 7 chronic thromboembolic pulmonary hypertension (CTEPH), 7 , 8 chronic systolic heart failure, 9 and severe COVID‐19 infection. 10 This is not surprising, as pulmonary artery enlargement on CTPA has been shown to correlate with other better defined assessments of pulmonary hypertension, including echocardiography and right heart catheterization, 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 and the presence of pulmonary hypertension is associated with a poor prognosis in many of these conditions.…”