title: Increased late mortality after coronary artery bypass surgery complicated by isolated new-onset atrial fibrillation: a comprehensive propensity-matched analysis.
abstract: OBJECTIVE
  The association of new-onset postoperative atrial fibrillation (POAF) and late death after coronary artery bypass grafting (CABG) has been confounded by the frequent concomitant serious complications that co-occur with POAF. We aimed to define the magnitude and time dependence of the effect of isolated POAF on late survival after uncomplicated CABG to comprehensively account for comorbidity and perioperative confounding factors.
  
  
  METHODS
  Nonsalvage CABG patients with no history of AF, no concomitant aortic or valvular surgery, and no perioperative complications other than POAF were studied (n=6305). Patients were divided into AF (n=1211, 68 years old, 72% male) and no-AF (n=5094, 63 years old, 70% male) groups. Propensity matching was done using 55 patient variables, including coronary grafts, completeness of revascularization, and transfusion data. The AF effect was quantified using time-segmented hazard ratios by Cox regression analysis.
  
  
  RESULTS
  Single (1-to-1), double (1-to-2), and triple (1-to-3) propensity matching of the AF and no-AF was achieved for 1196, 993, and 719 cases, respectively. The AF group showed significantly worse, yet time-varying, 0- to 18-year survival: 0 to 1 year, HR, 1.18 (95% confidence interval, 0.77-1.81); 1 to 6 years, HR, 1.37 (95% confidence interval, 1.12 to 1.67); and 6 to 17 years, HR, 1.25 (95% confidence interval, 1.05 to 1.49).
  
  
  CONCLUSIONS
  Isolated POAF was associated with a time-varying increase in mortality after CABG. Given these findings and the high incidence of POAF, efforts to reduce POAF should be pursued to potentially improve resource usage, morbidity, and mortality.
authors.affiliation: Vascular Medicine Program, American University of Beirut, Beirut, Lebanon.
authors.forename: Laila
authors.initials: L
authors.lastname: Al-Shaar
authors.affiliation: Department of Surgery, University of Toledo College of Medicine, Toledo, Ohio.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Schwann
authors.affiliation: Mercy Saint Vincent Medical Center, Toledo, Ohio.
authors.forename: Ameer
authors.initials: A
authors.lastname: Kabour
authors.affiliation: Vascular Medicine Program, American University of Beirut, Beirut, Lebanon; Outcomes Research Unit and Department of Internal Medicine, American University of Beirut, Beirut, Lebanon. Electronic address: rh106@aub.edu.lb.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Habib
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000401:mortality*; D016009:Chi-Square Distribution; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000401:mortality*; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D057216:Propensity Score; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome