title: Comparison of 1-year effects of left ventricular and biventricular pacing in patients with heart failure who have ventricular arrhythmias and left bundle-branch block: the Bi vs Left Ventricular Pacing: an International Pilot Evaluation on Heart Failure Patients with Ventricular Arrhythmias (BELIEVE) multicenter prospective randomized pilot study.
abstract: BACKGROUND
  Little is known on the chronic effects of left ventricular pacing (LV) in heart failure.
  
  
  METHODS
  Seventy-four patients with LBBB, QRS >130 milliseconds, New York Heart Association class (Bradley DJ, Bradley EA, Braughman KL, et al. Cardiac resynchronization and death from progressive heart failure: a meta-analysis of randomized controlled trials. JAMA 2003;289:730-40.) II, LV ejection fraction (LVEF) <35%, and a class I cardioverter/defibrillator indication were implanted with CRT-D devices and were randomized to either LV or biventricular (BiV) pacing. Response (defined as increases of >5 points increase of LVEF and/or > or = 10% 6-minute walking test [6MWT]) between LV and BiV pacing were compared in an attempt to define the number of patients needed to claim noninferiority of LV pacing. In addition, absolute change in LVEF at 12 months in heart failure patients treated with LV pacing was evaluated. The safety of LV pacing was assessed comparing the total number of ventricular arrhythmia episodes, of hospitalizations, and of deaths between the two pacing modes.
  
  
  RESULTS
  The percentage of responders was comparable for both groups (LV = 75%, BiV = 70%, P = .788); based on the 95% CI of the difference between the groups, 1100 patients would be needed to claim noninferiority of LV pacing (with a 5% CI lower limit). LV pacing induced siginificant LVEF increase (5.2%, P = .002). These results remained unchanged after performing adjustment analyses. There were no differences in the numbers of ventricular arrhythmias, hospitalizations, and death events between the 2 pacing modes.
  
  
  CONCLUSIONS
  At 12 months, percentage of responders to LV pacing was similar to BIV pacing. Furthermore, LV pacing achieved a significant increase of ejection fraction. LV pacing is both safe and feasible.
authors.affiliation: IRCCS Istituto Clinico Humanitas, Rozzano-MILANO, Italy. maurizio.gasparini@humanitas.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gasparini
authors.forename: Mario
authors.initials: M
authors.lastname: Bocchiardo
authors.forename: Maurizio
authors.initials: M
authors.lastname: Lunati
authors.forename: Pier Antonio
authors.initials: PA
authors.lastname: Ravazzi
authors.forename: Massimo
authors.initials: M
authors.lastname: Santini
authors.forename: Marco
authors.initials: M
authors.lastname: Zardini
authors.forename: Silvia
authors.initials: S
authors.lastname: Signorelli
authors.forename: Micaela
authors.initials: M
authors.lastname: Passardi
authors.forename: Catherine
authors.initials: C
authors.lastname: Klersy
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000628:therapy; D002037:Bundle-Branch Block / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods; D015897:Comorbidity; D005260:Female; D006333:Heart Failure / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012107:Research Design; D016037:Single-Blind Method; D013318:Stroke Volume; D016896:Treatment Outcome