Postoperative atrial fibrillation and mortality after coronary artery bypass surgery

J Am Coll Cardiol. 2004 Mar 3;43(5):742-8. doi: 10.1016/j.jacc.2003.11.023.


Objectives: We sought to determine if the occurrence of postoperative atrial fibrillation (AF) affects early or late mortality following coronary artery bypass surgery (CABG).

Background: Atrial fibrillation is the most common arrhythmia seen following CABG.

Methods: The Texas Heart Institute Cardiovascular Research Database was used to identify all patients that developed AF after isolated initial CABG from January 1993 to December 1999 (n = 994). This population was compared with patients who underwent CABG during the same period but did not develop AF (n = 5,481). In-hospital end points were adjusted using logistic regression models to account for baseline differences. Long-term survival was evaluated using a retrospective cohort design, where Cox proportional hazards methods were used to adjust for baseline differences, and with case-matched populations (n = 390, 195 per arm).

Results: Atrial fibrillation was diagnosed in 16% of the population. Postoperative AF was associated with greater in-hospital mortality (odds ratio [OR] 1.7, p = 0.0001), more strokes (OR 2.02, p = 0.001), prolonged hospital stays (14 vs. 10 days, p < 0.0001), and a reduced incidence of myocardial infarction (OR 0.62, p = 0.01). At four to five years, survival was worse in patients who developed postoperative AF (74% vs. 87%, p < 0.0001 in the retrospective cohort; 80% vs. 93%, p = 0.003 in the case-matched population). On multivariate analysis, postoperative AF was an independent predictor of long-term mortality (adjusted OR 1.5, p < 0.001 in the retrospective cohort; OR 3.4, p = 0.0018 in the case-matched population).

Conclusions: The occurrence of AF following CABG identifies a subset of patients who have a reduced survival probability following CABG. The impact of various strategies, such as antiarrhythmics and warfarin, aimed at reducing AF and its complications deserves further study.

MeSH terms

  • Aged
  • Atrial Fibrillation / etiology*
  • Atrial Fibrillation / mortality*
  • Cardiac Care Facilities / statistics & numerical data
  • Cohort Studies
  • Coronary Artery Bypass / adverse effects*
  • Coronary Artery Bypass / mortality*
  • Databases as Topic
  • Female
  • Hospital Mortality
  • Humans
  • Length of Stay / statistics & numerical data
  • Male
  • Middle Aged
  • Myocardial Infarction / epidemiology
  • Proportional Hazards Models
  • Retrospective Studies
  • Stroke / epidemiology
  • Survival Analysis
  • Texas / epidemiology
  • Time Factors