title: Cardiovascular outcomes with atrial-based pacing compared with ventricular pacing: meta-analysis of randomized trials, using individual patient data.
abstract: BACKGROUND
  Several randomized trials have compared atrial-based (dual-chamber or atrial) pacing with ventricular pacing in patients with bradycardia. No trial has shown a mortality reduction, and only 1 small trial suggested a reduction in stroke. The goal of this review was to determine whether atrial-based pacing prevents major cardiovascular events.
  
  
  RESULTS
  A systematic review was performed of publications since 1980. For inclusion, trials had to compare an atrial-based with a ventricular-based pacing mode; use a randomized, controlled, parallel design; and have data on mortality, stroke, heart failure, or atrial fibrillation. Individual patient data were obtained from 5 of the 8 identified studies, representing 95% of patients in the 8 trials, and a total of 35 000 patient-years of follow-up. There was no significant heterogeneity among the results of the individual trials. There was no significant reduction in mortality (hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.87 to 1.03; P=0.19) or heart failure (HR, 0.89; 95% CI, 0.77 to 1.03; P=0.15) with atrial-based pacing. There was a significant reduction in atrial fibrillation (HR, 0.80; 95% CI, 0.72 to 0.89; P=0.00003) and a reduction in stroke that was of borderline significance (HR, 0.81; 95% CI, 0.67 to 0.99; P=0.035). There was no convincing evidence that any patient subgroup received special benefit from atrial-based pacing.
  
  
  CONCLUSIONS
  Compared with ventricular pacing, the use of atrial-based pacing does not improve survival or reduce heart failure or cardiovascular death. However, atrial-based pacing reduces the incidence of atrial fibrillation and may modestly reduce stroke.
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada, L8L 2X2. healeyj@hhsc.ca
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Healey
authors.forename: William D
authors.initials: WD
authors.lastname: Toff
authors.forename: Gervasio A
authors.initials: GA
authors.lastname: Lamas
authors.forename: Henning R
authors.initials: HR
authors.lastname: Andersen
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Thorpe
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Ellenbogen
authors.forename: Kerry L
authors.initials: KL
authors.lastname: Lee
authors.forename: Allan M
authors.initials: AM
authors.lastname: Skene
authors.forename: Eleanor B
authors.initials: EB
authors.lastname: Schron
authors.forename: J Douglas
authors.initials: JD
authors.lastname: Skehan
authors.forename: Lee
authors.initials: L
authors.lastname: Goldman
authors.forename: Robin S
authors.initials: RS
authors.lastname: Roberts
authors.forename: A John
authors.initials: AJ
authors.lastname: Camm
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Connolly
mesh_terms: D001145:Arrhythmias, Cardiac / Q000628:therapy; D001281:Atrial Fibrillation / Q000150:complications / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D006325:Heart Atria; D006352:Heart Ventricles; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*; D016896:Treatment Outcome