Optimal beta-blocker for prevention of atrial fibrillation after on-pump coronary artery bypass graft surgery: carvedilol versus metoprolol

Heart Rhythm. 2007 Sep;4(9):1170-4. doi: 10.1016/j.hrthm.2007.04.022. Epub 2007 May 5.


Background: Atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass graft (CABG) surgery. It has been shown that prophylactic oral beta-blocker administration reduces the incidence of post-CABG AF. However, the optimal beta-blocker has not been identified.

Objective: This study sought to determine whether oral carvedilol (with its unique anti-inflammatory and antioxidant properties) is more effective than oral metoprolol for prevention of AF after CABG surgery.

Methods: Between April 2006 and December 2006, 120 patients (63 men, mean age 61 +/- 9.4 years) who were scheduled to undergo their first on-pump CABG were enrolled in this study. The patients were randomized in a prospective 1:1 manner to receive either oral carvedilol (n = 60) or oral metoprolol (n = 60). The end point of the study was the occurrence of the new-onset AF during the first 5 days after CABG.

Results: AF occurred in 29 of 120 patients (24.0%). The incidence of postoperative AF was 15.0% (9 of 60) in the carvedilol group and 33% (20 of 60) in the metoprolol group (P = .022). The carvedilol group was treated with mean daily dose of 46 +/- 9 mg and metoprolol group with mean daily dose of 93 +/- 11 mg. There were no differences between the study groups regarding any known preoperative, perioperative, or postoperative characteristics (all values were P >.05). No significant adverse effect was observed in either group.

Conclusion: This prospective study suggested that oral carvedilol is more effective than oral metoprolol in the prevention of AF after on-pump CABG. It is well tolerated when started before and continued after the surgery. However, further prospective studies are needed to clarify this issue.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adrenergic beta-Antagonists / therapeutic use*
  • Aged
  • Atrial Fibrillation / etiology
  • Atrial Fibrillation / prevention & control*
  • Carbazoles / therapeutic use*
  • Carvedilol
  • Coronary Artery Bypass / adverse effects*
  • Coronary Artery Bypass / methods
  • Double-Blind Method
  • Female
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Metoprolol / therapeutic use*
  • Middle Aged
  • Postoperative Complications
  • Propanolamines / therapeutic use*
  • Prospective Studies
  • Time Factors


  • Adrenergic beta-Antagonists
  • Carbazoles
  • Propanolamines
  • Carvedilol
  • Metoprolol