title: Four-year efficacy of cardiac resynchronization therapy on exercise tolerance and disease progression: the importance of performing atrioventricular junction ablation in patients with atrial fibrillation.
abstract: OBJECTIVE
  The goal of this study was to investigate the effects of cardiac resynchronization therapy (CRT) in heart failure patients with permanent atrial fibrillation (AF) and the role of atrioventricular junction (AVJ) ablation.
  
  
  BACKGROUND
  Cardiac resynchronization therapy has been proven effective in heart failure patients with sinus rhythm (SR). However, little is known about the effects of CRT in heart failure patients with permanent AF.
  
  
  METHODS
  Efficacy of CRT on ventricular function, exercise performance, and reversal of maladaptive remodeling process was prospectively compared in 48 patients with permanent AF in whom ventricular rate was controlled by drugs, thus resulting in apparently adequate delivery of biventricular pacing (>85% of pacing time), and in 114 permanent AF patients, who had undergone AVJ ablation (100% of resynchronization therapy delivery). The clinical and echocardiographic long-term outcomes of both groups were compared with those of 511 SR patients treated with CRT.
  
  
  RESULTS
  Both SR and AF groups showed significant and sustained improvements of all assessed parameters (model p < 0.001 for all parameters). However, within the AF group, only patients who underwent ablation showed a significant increase of ejection fraction (p < 0.001), reverse remodeling effect (p < 0.001), and improved exercise tolerance (p < 0.001); no improvements were observed in AF patients who did not undergo ablation.
  
  
  CONCLUSIONS
  Heart failure patients with ventricular conduction disturbance and permanent AF treated with CRT showed large and sustained long-term (up to 4 year) improvements of left ventricular function and functional capacity, similar to patients in SR, only if AVJ ablation was performed.
authors.affiliation: Department of Cardiology, IRCCS, Istituto Clinico Humanitas Rozzano-Milano, Milan, Italy. maurizio.gasparini@humanitas.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gasparini
authors.forename: Angelo
authors.initials: A
authors.lastname: Auricchio
authors.forename: François
authors.initials: F
authors.lastname: Regoli
authors.forename: Cecilia
authors.initials: C
authors.lastname: Fantoni
authors.forename: Mihoko
authors.initials: M
authors.lastname: Kawabata
authors.forename: Paola
authors.initials: P
authors.lastname: Galimberti
authors.forename: Daniela
authors.initials: D
authors.lastname: Pini
authors.forename: Carlo
authors.initials: C
authors.lastname: Ceriotti
authors.forename: Edoardo
authors.initials: E
authors.lastname: Gronda
authors.forename: Catherine
authors.initials: C
authors.lastname: Klersy
authors.forename: Simona
authors.initials: S
authors.lastname: Fratini
authors.forename: Helmut H
authors.initials: HH
authors.lastname: Klein
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000601:surgery*; D001283:Atrioventricular Node / Q000601:surgery*; D017147:Defibrillators, Implantable; D018450:Disease Progression; D004452:Echocardiography; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000473:pathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D016896:Treatment Outcome; D016277:Ventricular Function, Left
chemical_list: D000889:Anti-Arrhythmia Agents