Effect of β-blocker use on outcomes after discharge in patients who underwent cardiac surgery

Abstract

Beta-blockers improve outcomes in patients with heart failure or a history of myocardial infarction, but it remains uncertain whether they are beneficial after the perioperative period in cardiac surgery patients without these conditions. This study was designed to examine whether discharge use of beta-blockers was associated with outcomes after hospitalization in patients who had undergone nontransplant cardiac surgery. We analyzed outcomes in a prospective cohort of 3102 patients discharged alive after cardiac surgery (2547 of whom had undergone coronary artery bypass grafting surgery) between September 2002 and August 2005. Beta-blockers were prescribed for 2580 (83%) patients at hospital discharge. Over a mean follow-up of 75 months (standard deviation, 20 months), 10% (259/2580) of patients discharged with beta-blockers and 19% (97/522) not prescribed beta-blockers at the time of hospital discharge died (hazard ratio of 0.65 [95% confidence interval, 0.49-0.87] after adjustment for covariates). One-year mortality was also lower in those discharged with beta-blockers: 2.2% (57/2580) in beta-blocker users versus 7.2% (38/522) in nonusers (adjusted odds ratio, 0.54 [95% confidence interval, 0.30-0.97]). The association between beta-blocker use and lower mortality was consistent across all examined subgroups, including patients without prior myocardial infarction or without heart failure (all P < .01). Patients discharged with beta-blockers after cardiac surgery exhibit a substantially lower mortality rate during long-term follow-up, even among those without a history of myocardial infarction or heart failure.