title: The impact of cardiac resynchronization therapy on the incidence of ventricular arrhythmias in mild heart failure.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular (LV) remodeling in selected populations. However, the effect of CRT on ventricular arrhythmias is controversial. This is particularly important among patients with mild heart failure (HF), in whom sudden death is a leading cause of mortality.
  
  
  OBJECTIVE
  This study sought to assess the impact of CRT on ventricular arrhythmias in mild HF.
  
  
  METHODS
  The REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) study is a multicenter randomized, double-blind trial of CRT among patients with mild systolic HF. The time to first appropriate, treated ventricular tachycardia/ventricular fibrillation (VT/VF) episode or spontaneous sustained VT in cardiac resynchronization therapy plus defibrillation device (CRT-D) patients was compared between groups, as were predictors of VT/VF.
  
  
  RESULTS
  The study randomized 508 patients who received CRT-D devices. There were no significant demographic differences between groups. There were no differences in VT/VF episodes or VT storm between groups. Specifically, in the CRT ON group, the estimated event rate was 18.7% at 2 years, compared with 21.9% in the CRT OFF group (hazard ratio 1.05, P = .84). However, among CRT ON patients, those with reverse remodeling had a reduced incidence of VT/VF compared with those without remodeling (5.6% vs. 16.3%, hazard ratio 0.31, P = .001).
  
  
  CONCLUSIONS
  CRT for up to 2 years does not impact VT/VF in mild HF despite marked clinical and remodeling effects of pacing. This neutral effect may be attributable to competing antiarrhythmic effects of reverse remodeling and proarrhythmic effect of pacing.
  
  
  BACKGROUND
  http://www.clinicaltrials.gov/ct2/show/NCT00271154.
authors.affiliation: Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina 29425-5920, USA. goldmr@musc.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Gold
authors.forename: Cecilia
authors.initials: C
authors.lastname: Linde
authors.forename: William T
authors.initials: WT
authors.lastname: Abraham
authors.forename: Ajmal
authors.initials: A
authors.lastname: Gardiwal
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Daubert
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D005260:Female; D006333:Heart Failure / Q000150:complications*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000628:therapy*; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000209:etiology / Q000628:therapy*