Bronchiectasis alone predicted mortality in patients with moderate to severe chronic obstructive pulmonary disease, independent of pulmonary function and other risk factors, a study by Spanish investigators has shown.
That finding means that "bronchiectasis could be a new prognostic factor" for COPD, the study’s authors predicted.
Confirmation of bronchiectasis "would have a major clinical impact," because high-resolution CT can readily diagnose the condition, and effective therapy is available to treat the chronic bronchial inflammation and infection that plague patients, said lead investigator Dr. Miguel Angel Martínez-García of the Polytechnic and University La Fe Hospital in Valencia, Spain, and his colleagues (Am. J. Respir. Crit. Care Med. 2013 Feb. 7 [doi:10.1164/rccm.201208-1518OC]).
Conceivably, those patients could be "subject to different diagnostic and therapeutic approaches and, therefore, define a new phenotype": COPD with bronchiectasis, Dr. Martínez-García said.
Bronchiectasis is already known to be associated with worse exacerbations, more frequent bacterial colonizations, and greater degrees of impairment in COPD patients. But its relationship to mortality – or its utility as a prognostic factor – hasn’t been demonstrated until now, the researchers noted.
The investigators followed 115 patients with moderate to severe COPD and with bronchiectasis and 86 COPD patients without bronchiectasis for a median of 48 months. A total of 43 patients (37%) died in the bronchiectasis group, but only 8 patients (9%) in the nonbronchiectasis group died. COPD exacerbations were the most common cause of death.
COPD patients with bronchiectasis were 2.5 times more likely to die than those without bronchiectasis, after adjustment for factors such as dyspnea, body mass index, the presence of potentially pathogenic respiratory microorganisms, and other potential confounders (hazard ratio, 2.54; 95%CI: 1.16-5.56; P = .02).
Patients with bronchiectasis also presented with "a more severe form of COPD in clinical and functional terms, as well as a greater concentration of parameters of systemic inflammation and a greater presence of" potentially pathogenic microorganisms (PPMs) in their airways, the investigators said.
Bacterial respiratory colonization and subsequent inflammation probably play an important role in dilating the bronchioles and causing bronchiectasis – which leads to more colonization and a vicious cycle. But that cycle might "be broken by the early identification of this subgroup of patients" and the use of oral moxifloxacin or inhaled antibiotics, they said.
A total of 59% (68) of patients with bronchiectasis, but only 20% (17) of those without it, had PPM respiratory isolates, most commonly Haemophilus influenzae, followed by Pseudomonas aeruginosa.
Most of the patients were men and, on average, around 70 years old and overweight. Overall, they had an average smoking history of 60.7 pack-years and had COPD for more than decade. A minority of patients had tuberculosis histories or active pneumonia.
The authors said they had no relevant financial disclosures. Praxis Pharmaceutical funded the study.