title: Association of rate-controlled persistent atrial fibrillation with clinical outcome and ventricular remodelling in recipients of cardiac resynchronization therapy.
abstract: BACKGROUND
  Whether patients with persistent atrial fibrillation (AF) obtain the same degree of benefit with cardiac resynchronization therapy (CRT) as those in sinus rhythm remains unclear.
  
  
  METHODS
  We enrolled 93 patients undergoing CRT implantation, 20 (22%) of whom had rate-controlled persistent AF. The primary endpoint was CRT response defined as 1 class improvement in Specific Activity Scale and 15% reduction in left ventricular end-systolic volume (LVESV) during 12 months. Other endpoints included changes in 6-minute walk distance, quality of life, B-type natriuretic peptide, and survival.
  
  
  RESULTS
  Baseline characteristics were similar in those with and without AF. Response to CRT was observed in 42% vs 54% of those with and without AF, respectively (P=0.3). Both groups had significant improvements in 6-minute walk distance, quality of life, and LVESV, but the improvement in LVESV was smaller in those with AF (13.7%±14.9% vs 27.7%±23.7%; P=0.02). During 2.8±1.4 years of follow-up, AF was associated with a 2.2-fold increased risk of death or transplantation (95% confidence interval, 1.2-3.9; P=0.01).
  
  
  CONCLUSIONS
  Compared with patients without rate-controlled persistent AF, those with rate-controlled persistent AF had similar rates of clinical improvement but less left ventricular reverse remodelling in the first year after CRT. AF was associated with a markedly higher risk of death or transplantation in long-term follow-up. Given these findings, randomized studies assessing CRT efficacy in those with AF are warranted.
authors: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada. sbwilton@ucalgary.ca
authors: Stephen B
authors: SB
authors: Wilton
authors: Katherine M
authors: KM
authors: Kavanagh
authors: Sandeep G
authors: SG
authors: Aggarwal
authors: François
authors: F
authors: Philippon
authors: Raymond
authors: R
authors: Yee
authors: Karen
authors: K
authors: Cowan
authors: Derek V
authors: DV
authors: Exner
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D010865:Pilot Projects; D011446:Prospective Studies; D013318:Stroke Volume; D016896:Treatment Outcome; D020257:Ventricular Remodeling / Q000502:physiology*