Efficacy of Chronic β-Blocker Therapy for Secondary Prevention on Long-Term Outcomes After Coronary Artery Bypass Grafting Surgery
Background—Conflicting results from recent observational studies raised questions concerning the benefit of β-blockers for patients undergoing coronary artery bypass grafting (CABG). Furthermore, the efficacy of chronic β-blocker therapy in CABG patients after hospital discharge is uncertain.
Methods and Results—The study included 5926 consecutive patients who underwent CABG and were discharged alive. The prevalence and consistency of β-blocker use were determined in patients with and without a prior history of myocardial infarction (MI). β-Blockers were always used in 1280 patients (50.9%) with and 1642 (48.1%) without prior MI after CABG. Compared with always users (n=2922 [49.3%]), the risk of all-cause death was significantly higher among inconsistent β-blocker users (HR, 1.96; 95% CI, 1.50 to 2.57), and never using of β-blockers was associated with increased risk of both all-cause death (1.42; 1.01 to 2.00) and the composite of adverse cardiovascular events (1.29; 1.10 to 1.50). In the cohort without MI, the HR for all-cause death was 1.70 (95% CI, 1.17 to 2.48) in inconsistent users and 1.23 (0.76 to 1.99) in never users. In the MI cohort, mortality was higher for inconsistent users (HR, 2.14; 95% CI, 1.43 to 3.20) and for never users (1.59; 1.07 to 2.63). Consistent results were obtained in equivalent sensitivity analyses.
Conclusions—In patients with or without prior MI undergoing CABG, the consistent use of β-blockers was associated with a lower risk of long-term mortality and adverse cardiovascular events. Strategies should be developed to understand and improve discharge prescription of β-blockers and long-term patient adherence.
- Received November 8, 2014.
- Revision received March 11, 2015.
- Accepted April 3, 2015.
Circulation is published on behalf of the American Heart Association, Inc., by Wolters Kluwer. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial-NoDervis License (http://creativecommons.org/licenses/by-nc-nd/3.0/), which permits use, distribution, and reproduction in any medium, provided that the original work is properly cited, the use is noncommercial, and no modifications or adaptations are made.