Pulmonary vascular features on chest computed tomography differentially associate with adverse outcomes in smokers in...

In smokers with and without chronic obstructive pulmonary disease (COPD), the differential strengths of association between chest computed tomography (CT)-based metrics of pulmonary vascular disease and adverse outcomes are unknown.

We aimed to quantify the differential strengths of association of CT features, from the distal pulmonary arteries to the central great vessels and cardiac chambers, with acute respiratory exacerbations (AREs) and mortality in smokers with and without COPD.

Smokers with and without COPD with pulmonary vascular morphology and outcomes data were identified in COPDGene. Negative binominal and multivariable Cox proportional hazard models were used to investigate the association of CT features, including volume of the distal pulmonary arterial vasculature or pruning (<5 mm2 normalized to total arterial blood vessel volume [aBV5/aTBV]), preacinar vessels (5-20 mm2), and pulmonary artery to aorta (PA/Ao) and right to left ventricular epicardial volume (RV/LV) ratios, with outcomes. Kaplan-Meier curves were used to describe pruning risk on mortality.

A total of 3169 smokers with COPD and 2530 smokers without COPD were analyzed. Among smokers with COPD, PA/Ao was the only imaging feature significantly associated with AREs (incidence rate ratio, 1.08 [95% CI, 1.04-1.12]), even after adjusting for aBV5/aTBV. Conversely, pruning demonstrated the strongest association with mortality, even in smokers without COPD (hazard ratio, 1.22 [95% CI, 1.14-1.30] and 1.26 [95% CI, 1.11-1.42], respectively). The association of preacinar vessels with mortality in smokers with COPD and in those without COPD, but with significant emphysema on imaging (≥5%), was novel.

Pruning is significantly associated with mortality risk in smokers with and without COPD; however, PA/Ao selectively associates with AREs in COPD, even when accounting for distal vasculopathy.