title: Preoperative atrial fibrillation decreases event-free survival following cardiac surgery.
abstract: OBJECTIVE
  To investigate the relationship between preoperative atrial fibrillation and early and late clinical outcomes following cardiac surgery.
  
  
  METHODS
  A retrospective cohort including all consecutive coronary artery bypass graft and/or valve surgery patients between 1995 and 2005 was identified (n = 9796). No patient had a concomitant surgical AF ablation. The association between preoperative atrial fibrillation and in-hospital outcomes was examined. We also determined late death and cardiovascular-related re-hospitalization by linking to administrative health databases. Median follow-up was 2.9 years (maximum 11 years).
  
  
  RESULTS
  The prevalence of preoperative atrial fibrillation was 11.3% (n = 1105), ranging from 7.2% in isolated CABG to 30% in valve surgery. In-hospital mortality, stroke, and renal failure were more common in atrial fibrillation patients (all p < 0.0001), although the association between atrial fibrillation and mortality was not statistically significant in multivariate logistic regression. Longitudinal analyses showed that preoperative atrial fibrillation was associated with decreased event-free survival (adjusted hazard ratio 1.55, 95% confidence interval 1.42-1.70, p < 0.0001).
  
  
  CONCLUSIONS
  Preoperative atrial fibrillation is associated with increased late mortality and recurrent cardiovascular events post-cardiac surgery. Effective management strategies for atrial fibrillation need to be explored and may provide an opportunity to improve the long-term outcomes of cardiac surgical patients.
authors.affiliation: Department of Surgery, Division of Cardiac Surgery, Dalhousie University, Queen Elizabeth II Health Sciences Centre, 1796 Summer Street, Room 2269, Halifax, Nova Scotia, Canada, B3H 3A7.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Kalavrouziotis
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Buth
authors.forename: Tarren
authors.initials: T
authors.lastname: Vyas
authors.forename: Imtiaz S
authors.initials: IS
authors.lastname: Ali