Impact of Radiographic Bronchiectasis in COPD

BACKGROUND: COPD and bronchiectasis frequently coexist, which creates an emerging phenotype with a worse prognosis. However, the impact of bronchiectasis on the natural history of COPD has not been fully evaluated and is still controversial. This meta-analysis was performed to clarify the associations of the presence of bronchiectasis with the prognosis and quality of life of patients with COPD. METHODS: A systematic review and meta-analysis was performed following a search of medical databases, and included articles published up to April 2019. The following outcome measures were analyzed: age, sex, smoking history, body mass index, exacerbation rate, lung function, inflammatory biomarkers, albumin, colonization by potentially pathogenic microorganisms, Pseudomonas aeruginosa isolates, Haemophilus influenzae isolates, hospital admissions, and mortality. RESULTS: A total of 415,257 subjects with COPD from 18 observational studies were eligible; bronchiectasis was present in 25,929 subjects (6.24%). The coexistence of COPD and bronchiectasis occurred more often in older subjects with lower body mass index. The presence of bronchiectasis in the subjects with COPD increased the risk of daily sputum production (odds ratio [OR] 1.80, 95% CI 1.24-2.61), exacerbation (weighted mean difference [WMD] 0.72 times, 95% CI 0.59-0.85), frequent hospital admissions (WMD 0.35 times, 95% CI 0.21-0.49), and follow-up (>3 years) mortality (OR 2.26, 95% CI 0.95-5.36). The subjects with COPD and bronchiectasis showed poorer pulmonary function (FEV1/FVC: WMD -3.37%, 95% CI -5.63 to -1.11), lower albumin (Standardized mean difference [SMD] -0.17, 95% CI -0.26 to -0.08), elevated C-reactive protein (SMD 0.40, 95% CI 0.06-0.74), a greater proportion of chronic colonization by potentially pathogenic microorganisms (OR 6.65, 95% CI 4.44-9.95), and a higher isolation rate of P. aeruginosa (OR 5.13, 95% CI 4.89-5.38) or II. influenzae (OR 1.90, 95% CI 1.29-2.79) than the subjects with COPD without bronchiectasis. CONCLUSIONS: This meta-analysis confirmed the significant associations of the presence of bronchiectasis with the natural history, disease course, and outcomes in COPD. The COPD-bronchiectasis phenotype had adverse effects on subjects' health condition and prognosis.