Abstract 4353: Impact of Beta-Blocker Use on Outcomes After Discharge in Patients Who Underwent Cardiac Surgery
Background: Beta-blockers improve outcomes in patients with heart failure or history of myocardial infarction (MI), but it remains uncertain whether they are beneficial for post-cardiac surgery patients without these conditions. Therefore, we sought to determine whether discharge beta-blocker prescription is associated with long-term outcomes in patients after cardiac surgery.
Methods: We analyzed outcomes in a prospective cohort of 3102 patients discharged alive after cardiac surgery (2547 of whom had undergone coronary artery bypass graft surgery [CABG]) between September 2002 and August 2005.
Results: Of 3120 patients, 2580 (83%) were prescribed a beta-blocker at hospital discharge. These patients were more likely to be male, have prior MI, hypertension, diabetes mellitus, hyperlipidemia, or discharge prescriptions for aspirin, angiotensin-converting enzyme inhibitors, and/or statins, but were less likely to have a history of heart failure, chronic pulmonary disease, or chronic kidney disease (all p≤0.02). Over a mean follow-up of 75 months (SD 20 months), 10% (259/2580) of patients discharged on beta-blockers and 19% (97/522) not prescribed beta-blockers at time of hospital discharge died (hazard ratio 0.65, 95% confidence interval [CI] 0.49 – 0.87, after adjustment for covariates). This total includes 95 patients (57/2580 beta-blocker users vs. 38/522 non-users, unadjusted odds ratio 0.29, 95% CI 0.19 – 0.44) who died within one year of discharge after their index cardiac surgery. After adjusting for covariates, discharge beta-blocker prescription was associated with lower one year mortality in patients post-CABG: adjusted odds ratio 0.54, 95% CI 0.30 – 0.97. The association between beta-blocker use and lower mortality was consistent across all examined subgroups, including patients without prior MI or without heart failure (all p<0.01).
Conclusions: Patients discharged on beta-blocker after cardiac surgery exhibit a substantially lower mortality rate during long-term follow-up, even in those without a history of MI or heart failure.