β-Blockers are associated with a reduction in COPD exacerbations.
BACKGROUND
While some retrospective studies have suggested that β-blocker use in patients with COPD is associated with a reduction in the frequency of acute exacerbations and lower mortality, there is concern that their use in patients with severe COPD on home oxygen may be harmful.


METHODS
Subjects with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 2-4 COPD participating in a prospective follow-up of the COPDGene cohort, a multicentre observational cohort of current and former smokers were recruited. Total and severe exacerbation rates were compared between groups categorised by β-blocker use on longitudinal follow-up using negative binomial regression analyses, after adjustment for demographics, airflow obstruction, %emphysema on CT, respiratory medications, presence of coronary artery disease, congestive heart failure and coronary artery calcification, and after adjustment for propensity to prescribe β-blockers.


RESULTS
3464 subjects were included. During a median of 2.1 years of follow-up, β-blocker use was associated with a significantly lower rate of total (incidence risk ratio (IRR) 0.73, 95% CI 0.60 to 0.90; p=0.003) and severe exacerbations (IRR 0.67, 95% CI 0.48 to 0.93; p=0.016). In those with GOLD stage 3 and 4 and on home oxygen, use of β-blockers was again associated with a reduction in the rate of total (IRR 0.33, 95% CI 0.19 to 0.58; p<0.001) and severe exacerbations (IRR 0.35, 95% CI 0.16 to 0.76; p=0.008). Exacerbation reduction was greatest in GOLD stage B. There was no difference in all-cause mortality with β-blocker use.


CONCLUSIONS
β-Blockers are associated with a significant reduction in COPD exacerbations regardless of severity of airflow obstruction. The findings of this study should be tested in a randomised, placebo-controlled trial.


TRIAL REGISTRATION NUMBER
(ClinicalTrials.gov NCT00608764).