title: The Cox maze IV procedure: predictors of late recurrence.
abstract: OBJECTIVE
  The Cox maze III procedure achieved high cure rates and became the surgical gold standard for the treatment of atrial fibrillation. Because of its invasiveness, a more simplified ablation-assisted procedure, the Cox maze IV procedure, has been performed at our institution since January 2002. The study examined multiple preoperative and perioperative variables to determine predictors of late recurrence.
  
  
  METHODS
  Data were collected prospectively on 282 patients who underwent the Cox maze IV procedure from January 2002 through December 2009. Forty-two percent of patients had paroxysmal and 58% had either persistent or long-standing persistent atrial fibrillation. All patients were available for follow-up. Follow-up included electrocardiograms in all patients. Since 2006, 24-hour Holter monitoring was obtained in 94% of patients at 3, 6, and 12 months. Data were analyzed by means of logistic regression analysis at 12 months, with 13 preoperative and perioperative variables used as covariates.
  
  
  RESULTS
  Sixty-six percent of patients had a concomitant procedure. After an ablation-assisted Cox maze procedure, the freedom from atrial fibrillation was 89%, 93%, and 89% at 3, 6, and 12 months, respectively. The freedom from both atrial fibrillation and antiarrhythmic drugs was 63%, 79%, and 78% at 3, 6, and 12 months, respectively. The risk factors for atrial fibrillation recurrence at 1 year were enlarged left atrial diameter (P = .027), failure to isolate the entire posterior left atrium (P = .022), and early atrial tachyarrhythmias (P = .010).
  
  
  CONCLUSIONS
  The Cox maze IV procedure has a high success rate at 1 year, even with improved follow-up and stricter definitions of failure. In patients with large left atria, there might be a need for more extensive size reduction or expanded lesion sets.
authors.affiliation: Division of Cardiothoracic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, Saint Louis, Mo 63110, USA. damianor@wustl.edu
authors.forename: Ralph J
authors.initials: RJ
authors.lastname: Damiano
authors.forename: Forrest H
authors.initials: FH
authors.lastname: Schwartz
authors.forename: Marci S
authors.initials: MS
authors.lastname: Bailey
authors.forename: Hersh S
authors.initials: HS
authors.lastname: Maniar
authors.forename: Nabil A
authors.initials: NA
authors.lastname: Munfakh
authors.forename: Marc R
authors.initials: MR
authors.lastname: Moon
authors.forename: Richard B
authors.initials: RB
authors.lastname: Schuessler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D016009:Chi-Square Distribution; D015716:Electrocardiography, Ambulatory; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008923:Missouri; D011446:Prospective Studies; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D000889:Anti-Arrhythmia Agents