Beta-blockers in COPD: time for reappraisal

The combined effects on the heart of smoking and hypoxaemia may contribute to an increased cardiovascular burden in chronic obstructive pulmonary disease (COPD). The use of beta-blockers in COPD has been proposed because of their known cardioprotective effects as well as reducing heart rate and improving systolic function. Despite the proven cardiac benefits of beta-blockers post-myocardial infarction and in heart failure they remain underused due to concerns regarding potential bronchoconstriction, even with cardioselective drugs. Initiating treatment with beta-blockers requires dose titration and monitoring over a period of weeks, and beta-blockers may be less well tolerated in older patients with COPD who have other comorbidities. Medium-term prospective placebo-controlled safety studies in COPD are warranted to reassure prescribers regarding the pulmonary and cardiac tolerability of beta-blockers as well as evaluating their potential interaction with concomitant inhaled long-acting bronchodilator therapy. Several retrospective observational studies have shown impressive reductions in mortality and exacerbations conferred by beta-blockers in COPD. However, this requires confirmation from long-term prospective placebo-controlled randomised controlled trials. The real challenge is to establish whether beta-blockers confer benefits on mortality and exacerbations in all patients with COPD, including those with silent cardiovascular disease where the situation is less clear.