title: Does preoperative atrial fibrillation reduce survival after coronary artery bypass grafting?
abstract: BACKGROUND
  Preoperative atrial fibrillation has been identified as a risk factor for reduced long-term survival after coronary artery bypass grafting. This study sought to determine whether atrial fibrillation is merely a marker for high-risk patients or an independent risk factor for time-related mortality.
  
  
  METHODS
  From 1972 to 2000, 46,984 patients underwent primary isolated coronary artery bypass grafting; 451 (0.96% prevalence) had electrocardiogram-documented preoperative atrial fibrillation (n = 411) or flutter (n = 40). Characteristics of patients with and without atrial fibrillation were contrasted by multivariable logistic regression to form a propensity score. With this, comparable groups with and without atrial fibrillation were formed by pairwise propensity-matching to assess survival.
  
  
  RESULTS
  Patients with preoperative atrial fibrillation were older (67 +/- 9.0 versus 59 +/- 9.8 years, p < 0.0001), had more left ventricular dysfunction (66% versus 52%, p < 0.0001) and hypertension (73% versus 59%, p < 0.0001), but less severe angina (39% moderate or severe versus 49%, p < 0.0001). Many of these factors are themselves predictors of increased time-related mortality. In propensity-matched patients, survival at 30 days and at 5 and 10 years for patients with versus without atrial fibrillation was 97% versus 99%, 68% versus 85%, and 42% versus 66%, respectively, a survival difference at 10 years of 24%. Median survival in patients with atrial fibrillation was 8.7 years versus 14 years for those without it.
  
  
  CONCLUSIONS
  Atrial fibrillation in patients undergoing coronary artery bypass grafting is a marker for high-risk patients; in addition, atrial fibrillation itself substantially reduces long-term survival. Thus, if patients in atrial fibrillation require surgical revascularization, it is appropriate to consider performing a concomitant surgical ablation procedure.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic Foundation, Ohio 44195, USA.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Quader
authors.forename: Patrick M
authors.initials: PM
authors.lastname: McCarthy
authors.forename: A Marc
authors.initials: AM
authors.lastname: Gillinov
authors.forename: Joan M
authors.initials: JM
authors.lastname: Alster
authors.forename: Delos M
authors.initials: DM
authors.lastname: Cosgrove
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Lytle
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Blackstone
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology*; D001830:Body Surface Area; D015897:Comorbidity; D001026:Coronary Artery Bypass / Q000401:mortality*; D003327:Coronary Disease / Q000453:epidemiology* / Q000401:mortality / Q000601:surgery*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D016019:Survival Analysis