Beta-blockers significantly reduce exacerbations in COPD patients regardless of the severity of their airflow obstruction and appear to be safe, data from the COPDGene study suggests.
Analysis of 3,464 patients in the study, just published in Thorax, found 474 (14%) were taking beta-blockers.
During two years of follow-up beta-blocker use was associated with a 27% reduction in all exacerbations and a 33% reduction in severe exacerbations.
The benefits were evident in the subgroup with GOLD stage 3 and 4 disease, and also in the 21% who were using home oxygen therapy.
There was no difference in mortality between those taking and not taking beta-blockers.
Professor Christine McDonald, Director of Respiratory and Sleep Medicine at Austin Health in Melbourne, told the limbic that cardiovascular disease is a frequent comorbidity in patients with COPD, and many patients with COPD die from cardiovascular causes.
“Beta-blockers markedly improve symptoms and survival in heart failure, but for many years they were deemed to be contraindicated in COPD because of the potential risk of bronchospasm,” she said.
“There is still a strong perception that they are contraindicated, despite short-term studies suggesting that cardioselective beta-blockers do not worsen lung function or symptoms.
“A previous cohort study suggested an increased mortality risk associated with beta-blocker therapy in patients with COPD who were on home oxygen therapy, although other studies have suggested a mortality benefit.”
Lower exacerbation rates in the COPDGene study persisted even after adjusting for the use of respiratory medicines, the presence of coronary artery disease, congestive heart failure and coronary artery calcification, and the propensity to prescribe beta-blockers.
“Prospective randomised placebo-controlled trials are required to further investigate their role in COPD,” Professor McDonald said.
Other cardiac medications including calcium channel blockers, ACE inhibitors, angiotensin receptor blockers were not associated with any reduction in exacerbation risk in the study, suggesting that beta-blockers had a specific class effect.
The researchers, led by Dr Surya Bhatt from the University of Birmingham in Alabama, said that beta-blockers are significantly under-prescribed in patients with COPD, even in those with established cardiovascular disease in whom the drugs have known mortality and morbidity benefits. The reason appears to be concern that they may trigger bronchoconstriction and worsening of lung function.
“There is also now clear evidence that COPD is associated with accelerated atherosclerosis and a greater frequency of subclinical coronary artery disease and cardiac dysfunction, and thus beta-blockers may also have benefits in patients without diagnosed cardiovascular disease,” they said.
“This is supported by our finding that the drugs reduced exacerbation rates regardless of the severity of coronary calcification.”