Tracheobronchial Colonization Found to Significantly Increase Mortality Risk Among Patients With COPD

Tracheobronchial colonization by pseudomonas aeruginosa (PA) was shown to increase the mortality risk of outpatients with chronic obstructive pulmonary disease (COPD) by 47%, according to study results published in the journal Open Forum Infectious Diseases.

PA infection has been linked to negative outcomes in cystic fibrosis and bronchiectasis causing higher rates of exacerbations and hospitalizations for patients. However, the uncertainty on whether this association applies to patients with COPD, especially in the outpatient setting, warranted further investigation, noted the study authors.

Researchers analyzed the association between COPD and PA isolation through data derived from monthly sputum cultures in a prospective cohort of 181 patients with COPD from 1994 to 2014. The primary objectives examined PA infection association with patient mortality and changes in exacerbation and hospitalization rates within the longitudinal cohort of outpatients with COPD. In addition, all-cause mortality was compared between patients colonized during follow-up (PA positive [PA+]) and those who remained free of colonization (PA negative [PA-]) using Cox proportional hazard models, and exacerbation and hospitalization rates were evaluated by 2-rate chi-square and segmented regression analysis 12 months before and 24 months after PA isolation

In the study cohort, 73 patients (40%) were found to be PA+, in which the PA was isolated from their sputum, with the remaining 108 patients represented as PA-. Study results showed that within this subgroup, increased mortality was reported with PA isolation, as 77% (n = 56) of the PA+ patients died compared with 68% (n = 73) of the PA- patients (P = .004). After adjusting for variables such age, baseline smoking status, and race, PA+ patients had a 47% higher risk of mortality compared with PA- patients (adjusted HR, 1.47; 95% CI, 1.03-2.11, P = .04).

Exacerbation and hospitalization rates were higher for the PA+ group compared with the PA- group during postisolation periods (exacerbation rates: 15.7 vs 7.5 per 100 person-months; P <.001; hospitalization rates: 6.25 vs 2.44; P <.001), with exacerbation rates also higher among PA+ patients during the pre-isolation period as well (15.4 vs. 9.0; P <.001).

As reported by ContagionLive, lead study author David Jacobs, PharmD, PhD, assistant professor in the School of Pharmacy and Pharmaceutical Sciences at the University at Buffalo, highlighted the study’s research as one of the first to support the association of higher morbidity and mortality for PA+ outpatients with COPD. “For COPD outpatients, clinicians and healthcare providers may want to pay closer attention to those patients that isolate Pseudomonas,” said Jacobs.

He noted that further research is needed to validate study findings. “As research on this topic continues, early intervention for P aeruginosa isolation may be proposed in order to minimize long-term sequelae."

Reference

Jacobs DM, Ochs-Balcom HM, Noyes K, et al. Impact of Pseudomonas aeruginosa Isolation on Mortality and Outcomes in an Outpatient COPD Cohort [published online January 4, 2020]. Open Forum Infect Dis. doi: 10.1093/ofid/ofz546.