title: The effect of ablation technology on surgical outcomes after the Cox-maze procedure: a propensity analysis.
abstract: OBJECTIVE
  Since its introduction in 1987, the Cox-maze procedure has been the gold standard for the surgical treatment of atrial fibrillation. At our institution, this procedure has evolved from the cut-and-sew technique (Cox-maze III procedure) to one using bipolar radiofrequency energy and cryoablation as ablative sources to replace most incisions (Cox-maze IV procedure). This study compared surgical outcomes of patients undergoing the Cox-maze III procedure versus those of patients undergoing the Cox-maze IV procedure by using propensity analysis.
  
  
  METHODS
  From April 1992 through July 2005, 242 patients underwent the Cox-maze procedure for atrial fibrillation. Of these, 154 patients had the Cox-maze III procedure, and 88 had the Cox-maze IV procedure. Logistic regression analysis was used to identify covariates among 7 baseline patient variables. Using the significant regression coefficients, each patient's propensity score was calculated, allowing selectively matched subgroups of 58 patients each. Operative outcomes were analyzed for differences. Late follow-up was available for 112 (97%) patients. Freedom from atrial fibrillation recurrence and survival was calculated at 1 year by using Kaplan-Meier analysis.
  
  
  RESULTS
  The Cox-maze III procedure had significantly longer crossclamp times. There was no significant difference in intensive care unit and hospital stay, 30-day mortality, permanent pacemaker placement, early atrial tachyarrhythmias, late stroke, and survival. Freedom from atrial fibrillation recurrence was greater than 90% in both groups at 1 year.
  
  
  CONCLUSIONS
  The use of bipolar radiofrequency ablation has simplified the Cox-maze procedure, making it applicable to virtually all patients with atrial fibrillation undergoing concomitant cardiac surgery. The Cox-maze IV procedure produces similar surgical outcomes to the Cox-maze III procedure at 1 year of follow-up.
authors.affiliation: Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, Saint Louis, Mo 63110, USA.
authors.forename: Shelly C
authors.initials: SC
authors.lastname: Lall
authors.forename: Spencer J
authors.initials: SJ
authors.lastname: Melby
authors.forename: Rochus K
authors.initials: RK
authors.lastname: Voeller
authors.forename: Andreas
authors.initials: A
authors.lastname: Zierer
authors.forename: Marci S
authors.initials: MS
authors.lastname: Bailey
authors.forename: Tracey J
authors.initials: TJ
authors.lastname: Guthrie
authors.forename: Marc R
authors.initials: MR
authors.lastname: Moon
authors.forename: Nader
authors.initials: N
authors.lastname: Moazami
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Lawton
authors.forename: Ralph J
authors.initials: RJ
authors.lastname: Damiano
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D002315:Cardiopulmonary Bypass / Q000379:methods; D016022:Case-Control Studies; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D003452:Cryosurgery / Q000009:adverse effects / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000401:mortality / Q000503:physiopathology; D011336:Probability; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate; D016896:Treatment Outcome