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Article of Interest

Bhatt S et al. β -bl ockers are associated with a reduction in COPD exacerbations. Thorax. 2016.

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Context and Study Objective

Conventional wisdom holds chronic obstructive pulmonary disease (COPD) to be a contraindication to β - blocker therapy as it can precipitate bronchospasm. However, the exclusion of an entire class of agents renders achieving BP control difficult, particularly when 120/80 mg may be the goal. This publication by Bhatt explored whether individuals receiving β - antagonist therapy were in fact more like to suffer a COPD exacerbation.

Design, Setting, Participants

Participant data from the observational COPDGene study were analyzed retrospectively. Persons aged 45-80 were eligible if they suffered from COPD, currently/previously smoked, and were either African American or Hispanic. Those experiencing a COPD flare or cardiac event less than 1 month prior to recruitment were excluded. Persons with lung disease other than COPD or asthma were ineligible. COPD was diagnosed via pulmonary function testing (PFT).

Results

-Study characteristics: 3500 subjects. Mean age 63. 45% women. 20% Black. 80% Hispanic. 40% current smokers. 25% asthmatic. 30% on supplemental oxygen. 50% hypertensive.

-Most participants had moderate-to-severe COPD; 15% suffered from very severe disease.

-Only one-third of those with coronary artery disease or heart failure received β- blockers.

-Individuals with more severe COPD, higher flare rates, or a greater number of respiratory medications were less likely to be on β- antagonists.

-After 2 years, surveillance, β- blocker usage was associated with 25% fewer exacerbations, a finding that persisted after adjustment for confounders such as cardiovascular disease, COPD severity, and the number of respiratory agents.

Clinical Perspective

-Contrary to conventional wisdom, β -blockers do not increase exacerbation frequency and may well reduce it. As demonstrated, this favorable profile persisted in those with advanced COPD. β -antagonists are also safe for administration during flares requiring hospitalization .

-Importantly, β- 1 selective (metoprolol, nebivolol) rather than non-specific β- 1/2 agents (propranolol) should be prescribed. Carvedilol, a mixed α/ β - antagonist, lacks sufficient data to comment on its safety.

-I regularly prescribe β- blockers in this population to control BP, particularly among patients with a cardiac indication, the leading cause of mortality in this population. By contrast, I believe the evidence insufficient to endorse their use with the sole intention of reducing COPD flares.

-It is curious that one can simultaneously prescribe a β -antagonist and β -agonist (eg albuterol) with each not negating the other's efficacy.

-Criticism: This observational study does not prove causality. However, patients with COPD are excluded from randomized trials of β -blockers. Moreover, this publication is consistent with the literature.

-Disclosures: I have no conflicts to declare. The study was researcher-funded but the authors received honoraria from Merck or GlaxoSmithKline.