Metoprolol vs. carvedilol or carvedilol plus N-acetyl cysteine on post-operative atrial fibrillation: a randomized, double-blind, placebo-controlled study

Eur Heart J. 2013 Feb;34(8):597-604. doi: 10.1093/eurheartj/ehs423. Epub 2012 Dec 11.


Aims: Carvedilol and N-acetyl cysteine (NAC) have antioxidant and anti-inflammatory properties. Aim was to evaluate the efficacy of metoprolol, carvedilol, and carvedilol plus NAC on the prevention of post-operative atrial fibrillation (POAF).

Methods and results: Patients undergoing cardiac surgery (n = 311) were randomized to metoprolol, carvedilol, or carvedilol plus NAC. Baseline characteristics were similar. The incidence of POAF was lower in the carvedilol plus NAC group compared with the metoprolol group (P < 0.0001) or the carvedilol group (P = 0.03). There was a borderline significance for lower POAF rates in the carvedilol group compared with the metoprolol group (P = 0.06). Duration of hospitalization was lower in the carvedilol plus NAC group compared to the metoprolol group (P = 0.004). Multivariate independent predictors of POAF included left-atrial diameter, hypertension, bypass duration, pre-randomization and pre-operative heart rates, carvedilol plus NAC group vs. metoprolol group, and carvedilol plus NAC group vs. carvedilol group.

Conclusion: Carvedilol plus NAC decreased POAF incidence and duration of hospitalization compared with metoprolol and decreased POAF incidence compared with carvedilol.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Acetylcysteine / therapeutic use*
  • Adult
  • Aged
  • Analysis of Variance
  • Anti-Arrhythmia Agents / therapeutic use*
  • Atrial Fibrillation / drug therapy*
  • Carbazoles / therapeutic use*
  • Carvedilol
  • Coronary Artery Bypass
  • Double-Blind Method
  • Drug Therapy, Combination
  • Humans
  • Length of Stay
  • Metoprolol / therapeutic use*
  • Middle Aged
  • Postoperative Complications / drug therapy*
  • Propanolamines / therapeutic use*
  • Treatment Outcome
  • Young Adult


  • Anti-Arrhythmia Agents
  • Carbazoles
  • Propanolamines
  • Carvedilol
  • Metoprolol
  • Acetylcysteine