Rubin DB, et al. - With an intent to gain a better understanding of pneumonia risk in COPD, researchers, herein, determined the predictors of pneumonia on routine chest X-rays (CXRs) in patients with COPD. They found that findings on routine CXR that relate to pathophysiological mechanisms of pneumonia could offer aid as far as the determination of pneumonia risk in COPD patients was concerned.

Methods

• In this post hoc exploratory analysis, researchers used data from 2 replicate year-long clinical trials assessing the impact of fluticasone furoate–vilanterol vs vilanterol alone on COPD exacerbations.
• Blinded consensus readings conducted by 2 radiologists identified abnormalities on baseline CXRs from 179 patients who developed pneumonia and 50 randomly selected patients who did not.
• For assessing the markers for subsequent pneumonia development during the 1-year study period, positive and negative likelihood ratios and diagnostic odds ratios (ORs) were calculated.

Results

• A lower body mass index (24.9 vs 27.5 kg/m², >P=0.008), more severe airflow obstruction (mean post-bronchodilator forced expiratory volume in 1 second [FEV₁]/forced vital capacity ratio: 42.3% vs 47.6%,>P=0.003), and prior pneumonia (36% vs 20%, >P=0.030) were identified as baseline features distinguishing the pneumonia and non-pneumonia groups.
• The following comprised the baseline CXR findings with the highest diagnostic ORs: elevated hemi-diaphragm (OR: 6.87; 95% CI: 0.90, 52.26), thick tracheal-esophageal stripe (OR: 4.39 [0.25, 78.22]), narrow cardiac silhouette (OR: 2.91 [0.85, 9.99]), calcified pleural plaque/mid-chest pleural thickening (OR: 2.82 [0.15, 53.76]), and large/prominent pulmonary artery shadow (OR: 1.94 [0.95, 3.97]).
• In findings, the presence of a narrow cardiac silhouette at baseline was shown to be associated with a statistically significant lower mean pre-bronchodilator FEV₁ (>P=0.040).
• Additionally, researchers noted a trend for a lower mean pre-bronchodilator FEV₁ in patients with a large/prominent pulmonary artery shadow at baseline (>P=0.095).