β-Blockers Improve Survival of Patients With Chronic Obstructive Pulmonary Disease After Coronary Artery Bypass Grafting
BACKGROUND: β-Blockers are known to improve survival of patients with cardiovascular disease, but their administration in patients with chronic obstructive pulmonary disease (COPD) remains controversial. The aim of the present study was to assess the effect of β-blocker administration in patients with COPD undergoing coronary artery bypass grafting.
METHODS: A total of 388 consecutive patients with COPD who underwent isolated coronary artery bypass grafting were studied, and clinical follow-up was completed. Diagnosis of COPD was based on preoperative forced expiration volume; exacerbation episodes were defined as a pulsed-dose prescription of prednisolone or a hospital admission for an exacerbation. Two propensity-matched cohorts of 104 patients each either receiving or not receiving β-blockers were identified.
RESULTS: At baseline, there was no significant difference among groups. After a median follow-up of 36 months, there were 8 deaths in 104 patients (7.7%) receiving β-blockers versus 19 deaths in 104 patients (18.3%) who did not receive β-blockers (p = 0.03). Kaplan-Meyer analysis showed a survival of 91.8% ± 2.8% for patients taking β-blockers versus 80.6% ± 4.0% for control subjects (χ(2), 29.4; p = 0.003; hazard ratio, 0.38). In addition, β-blocker administration did not increase rates of COPD exacerbation, which was experienced by 46 of 104 patients (44.2%) receiving β-blockers versus 45 of 104 patients (43.3%) not receiving β-blockers (p = 0.99).
CONCLUSIONS: This study showed that in patients with COPD undergoing coronary artery bypass grafting the administration of β-blockers is safe and significantly improves survival at mid-term follow-up. Further randomized studies are needed to confirm these findings.