title: Maze surgery normalizes left ventricular function in patients with persistent lone atrial fibrillation.
abstract: OBJECTIVE
  The aim of this study is to evaluate the mid-term clinical and functional outcomes of maze surgery in symptomatic refractory lone atrial fibrillation (AF) patients.
  
  
  METHODS
  Between March 2008 and January 2013, 39 highly symptomatic patients [mean age 51 ± 10 (mean ± standard deviation); 95% CI, European Heart Rhythm Association class III-IV] underwent maze surgery for lone AF. Biatrial ablations were performed with bipolar radiofrequency and cryoenergy, according to a maze III lesion set (modified by omitting the intercaval line in 5 of 39 patients). Mean ejection fraction was 51 ± 9% (range 17-60), <45% in 10 patients (26%). Seventeen of 39 patients (44%) had persistent, 22 of 39 patients (56%) long-standing persistent AF, and 35 of 39 patients (90%) had previous transvenous ablations (median = 2; range 0-8). No patient had concomitant structural heart disease.
  
  
  RESULTS
  A minimally invasive approach was adopted in 22 patients (56%). Major complications were 1 mediastinitis, 1 re-exploration for bleeding and 2 pacemaker (5%) implantation. At a mean follow-up of 29.4 ± 14.2 months, freedom from arrhythmias was 92 and 93% at 24 and 36 months, respectively. Freedom without antiarrhythmic drugs was 75 and 85% at 24 and 36 months, respectively. Ejection fraction normalized in all cases, from 51.3 ± 9% to 61.1 ± 3% (P < 0.001) overall, and from 37.0 ± 10% to 60.3 ± 3% (P < 0.001) when ≤ 45% preoperatively. AF-related symptoms score decreased to class I in 36 patients (93%). No early or late stroke occurred.
  
  
  CONCLUSIONS
  Within a dedicated AF centre, maze surgery grants excellent outcomes, with symptoms relief and negligible risk. It provides a complete reversal of arrhythmia-related myocardial dysfunction and is therefore a convenient alternative to His bundle ablation and lifelong pacemaker dependency in symptomatic refractory patients.
authors.affiliation: Department of Cardiothoracic Surgery, San Raffaele University Hospital, Milan, Italy albertopozzoli@gmail.com.
authors.forename: Alberto
authors.initials: A
authors.lastname: Pozzoli
authors.affiliation: Department of Cardiothoracic Surgery, San Raffaele University Hospital, Milan, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Taramasso
authors.affiliation: Department of Cardiothoracic Surgery, San Raffaele University Hospital, Milan, Italy.
authors.forename: Giuditta
authors.initials: G
authors.lastname: Coppola
authors.affiliation: Department of Cardiothoracic Surgery, San Raffaele University Hospital, Milan, Italy.
authors.forename: Mikel
authors.initials: M
authors.lastname: Kamami
authors.affiliation: Department of Cardiothoracic Surgery, San Raffaele University Hospital, Milan, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: La Canna
authors.affiliation: Arrhythmia Unit and Electrophysiology Laboratories, San Raffaele University Hospital, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Della Bella
authors.affiliation: Department of Cardiothoracic Surgery, San Raffaele University Hospital, Milan, Italy.
authors.forename: Ottavio
authors.initials: O
authors.lastname: Alfieri
authors.affiliation: Department of Cardiothoracic Surgery, San Raffaele University Hospital, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Benussi
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000601:surgery*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000601:surgery; D006352:Heart Ventricles / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Arrhythmias; Atrial fibrillation ablation; Congestive heart failure; Electrophysiology; Maze surgery; Minimally invasive surgery; Transcatheter ablation