Pulmonary Artery Enlargement on CT Scan Predicts COPD Exacerbation

Now we need data showing that computed tomography measurements improve chronic obstructive pulmonary disease outcomes.

Some patients with advanced chronic obstructive pulmonary disease (COPD) have enlargement of the pulmonary artery (PA), reflecting pulmonary hypertension. Using two cohorts of several thousand patients with COPD, researchers examined whether the diameter of the main pulmonary artery on noncontrast computed tomography (CT) predicts COPD exacerbations. Researchers evaluated the ratio of the diameter of the main pulmonary artery (at the level of its bifurcation) to the diameter of the ascending aorta (on the same axial CT image) — the PA:A ratio (figure).

At baseline, the proportion of patients with severe COPD exacerbations during the previous year was significantly higher in the group with a PA:A ratio >1 than in the group with a ratio 1 (53% vs. 13%). In analyses adjusted for potentially confounding variables, PA:A ratio was a highly significant predictor of previous exacerbations. During several years of follow-up, multivariable analysis showed that PA:A ratio remained a powerful independent predictor of exacerbations (odds ratio, 3).

CITATION(S):

Wells JM et al. Pulmonary arterial enlargement and acute exacerbations of COPD. N Engl J Med 2012 Sep 6; 367:913.