title: Comparing the outcome of on-pump versus off-pump coronary artery bypass grafting in patients with preoperative atrial fibrillation.
abstract: OBJECTIVE
  Around 5-15% of patients undergoing coronary artery bypass grafting (CABG) suffer from preoperative/pre-existing atrial fibrillation (PAF). This is a benign arrhythmia but can affect the outcome of the surgery. The aim of this study was to assess the effect of PAF on the immediate postoperative course of patients undergoing on-pump (ONCAB) vs. off-pump (OPCAB) CABG.
  
  
  METHODS
  Over a 10-year period, data were prospectively entered into the database of our institution. A total of 10,461 patients underwent CABG, of whom 477 (4.6%) were in PAF. We analyzed these patients in two separate groups: group A (n=310) who underwent ONCAB and group B (n=167) who underwent OPCAB. After 4:1 propensity matching and adjusting for the preoperative and operative characteristics of these two groups with patients in SR (sinus rhythm), early, mid- and long-term outcomes of PAF patients were analyzed.
  
  
  RESULTS
  After adjusting for preoperative characteristics, postoperative complications were significantly higher in patients who had ONCAB when there was PAF compared to those in SR (P<0.001). In the OPCAB patients, on the other hand, there was no statistically significant difference in the postoperative complications between the patients with preoperative SR or PAF. In-hospital and short-term mortality were no different in the PAF group undergoing OPCAB compared to those in SR; however, the mid- and long-term survival rates in PAF patients who underwent OPCAB/ONCAB were worse compared than was seen in SR.
  
  
  CONCLUSIONS
  PAF is associated with a higher incidence of postoperative complications. Our results have demonstrated that patients in PAF undergoing ONCAB are more susceptible to the postoperative complications compared to those in SR. However, there were no differences in mid- and long-term outcomes.
authors.affiliation: Liverpool Heart and Chest Hospital, Thomas Drive, Liverpool L14 3PE, UK. saina.attaran@kcl.ac.uk
authors.forename: Saina
authors.initials: S
authors.lastname: Attaran
authors.forename: Hesham Z
authors.initials: HZ
authors.lastname: Saleh
authors.forename: Matthew
authors.initials: M
authors.lastname: Shaw
authors.forename: Laura
authors.initials: L
authors.lastname: Bond
authors.forename: Mark D
authors.initials: MD
authors.lastname: Pullan
authors.forename: Brian M
authors.initials: BM
authors.lastname: Fabri
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications* / Q000401:mortality; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000401:mortality; D016009:Chi-Square Distribution; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000401:mortality; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects / Q000401:mortality; D003324:Coronary Artery Disease / Q000150:complications / Q000401:mortality / Q000601:surgery*; D004739:England; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome