Effect of β-blockers on the risk of COPD exacerbations according to indication of use: The Rotterdam study

Observational studies report a reduction of COPD exacerbations in patients treated with β-blockers. In contrast, the BLOCK COPD RCT which excluded COPD patients with cardiovascular (CV) conditions showed an increase in COPD exacerbations. It is unclear whether this discrepancy could be explained by underlying CV comorbidity. We examined whether the association between use of β-blockers and risk of COPD exacerbations differed between patients with and without a CV indication for β-blockers use. Within the Rotterdam Study, we followed COPD subjects until the first COPD exacerbation, or end of follow-up. Cardiovascular indication for β-blocker use was defined as a history of hypertension, coronary heart disease, atrial fibrillation, or heart failure at baseline. The association between β-blockers use and COPD exacerbations was assessed using Cox proportional hazards models adjusted for age, sex, smoking, incident CV disease (i.e., heart failure, hypertension, atrial fibrillation, and coronary heart disease during follow-up), respiratory drugs, and nitrates. In total 1312 COPD patients with a mean age=69.7±9.2 years were included. In patients with a CV indication (n=755, mean age=70.4±8.8 years), current use of cardioselective β-blockers was significantly associated with a reduced risk of COPD exacerbations (HR=0.69, 95% CI: 0.57–0.85). In contrast, in subjects without a CV indication (n=557, mean age=68.8±9.7 years), cardioselective β-blockers was not associated with an altered risk of COPD exacerbations (HR=0.94, 95% CI: 0.55–1.62). Use of cardioselective β-blockers reduced the risk of exacerbations in COPD patients with concomitant cardiovascular diseases. Therefore, the potential benefits of β-blockers might be confined to COPD patients with cardiovascular disease.