This multicentre observational trial used data from the COPDGene Study to investigate whether pulmonary vascular disease is associated with acute exacerbations of chronic obstructive pulmonary disease (COPD). Although severe pulmonary hypertension is a well recognised late complication of the disease, the study questioned whether earlier radiological changes could be used as a predictor for exacerbations. CT was used to provide a measure of pulmonary artery (PA) enlargement, using the ratio of PA diameter as compared with the diameter of the aorta (A).

The study population included 3464 patients with a diagnosis of Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II–IV COPD. These patients were longitudinally followed up for a median duration of 2.1years, as was an external validation cohort from the US ECLIPSE trial. Multivariate logistic regression analysis demonstrated a significant association between those with PA enlargement (PA:A ratio >1) and a history of severe...