title: A randomized double-blind comparison of biventricular versus left ventricular stimulation for cardiac resynchronization therapy: the Biventricular versus Left Univentricular Pacing with ICD Back-up in Heart Failure Patients (B-LEFT HF) trial.
abstract: BACKGROUND
  Biventricular (BiV) stimulation is the preferred means of delivering cardiac resynchronization therapy (CRT), although left ventricular (LV)-only stimulation might be as safe and effective. B-LEFT HF is a prospective, multicenter, randomized, double-blind study aimed to examine whether LV-only is noninferior to BiV pacing regarding clinical and echocardiographic responses.
  
  
  METHODS
  B-LEFT HF randomly assigned 176 CRT-D recipients, in New York Heart Association class III or IV, with an LV ejection fraction < or =35% and QRS > or =130 milliseconds, to a BiV (n = 90) versus LV (n = 86) stimulation group. Clinical status and echocardiograms were analyzed at baseline and 6 months after CRT-D implant to test the noninferiority of LV-only compared with BiV stimulation.
  
  
  RESULTS
  The proportion of responders was in line with current literature on CRT, with improvement in heart failure composite score in 76.2% and 74.7% of patients in BiV and LV groups, respectively. Comparing LV versus BiV pacing, the small differences in response rates and corresponding 95% CI indicated that LV pacing was noninferior to BiV pacing for a series of response criteria (combination of improvement in New York Heart Association and reverse remodeling, improvement in heart failure composite score, reduction in LV end-systolic volume of at least 10%), both at intention-to-treat and at per-protocol analysis.
  
  
  CONCLUSIONS
  Left ventricular-only pacing is noninferior to BiV pacing in a 6-month follow-up with regard to clinical and echocardiographic responses. Left ventricular pacing may be considered as a clinical alternative option to BiV pacing.
authors.affiliation: Institute of Cardiology, University of Bologna, Azienda Ospedaliera S. Orsola-Malpighi, Bologna, Italy. giuseppe.boriani@unibo.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kranig
authors.forename: Erwan
authors.initials: E
authors.lastname: Donal
authors.forename: Leonardo
authors.initials: L
authors.lastname: Calo
authors.forename: Michela
authors.initials: M
authors.lastname: Casella
authors.forename: Nicolas
authors.initials: N
authors.lastname: Delarche
authors.forename: Ignacio Fernandez
authors.initials: IF
authors.lastname: Lozano
authors.forename: Gerardo
authors.initials: G
authors.lastname: Ansalone
authors.forename: Mauro
authors.initials: M
authors.lastname: Biffi
authors.forename: Eric
authors.initials: E
authors.lastname: Boulogne
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D017147:Defibrillators, Implantable; D004311:Double-Blind Method; D004452:Echocardiography; D004554:Electric Countershock / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D013318:Stroke Volume / Q000502:physiology*; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*