title: Very Low Ventricular Pacing Rates Can Be Achieved Safely in a Heterogeneous Pacemaker Population and Provide Clinical Benefits: The CANadian Multi-Centre Randomised Study-Spontaneous AtrioVEntricular Conduction pReservation (CAN-SAVE R) Trial.
abstract: BACKGROUND
  It is well recognized that right ventricular apical pacing can have deleterious effects on ventricular function. We performed a head-to-head comparison of the SafeR pacing algorithm versus DDD pacing with a long atrioventricular delay in a heterogeneous population of patients with dual-chamber pacemakers.
  
  
  RESULTS
  In a multicenter prospective double-blinded randomized trial conducted at 10 centers in Canada, 373 patients, age 71±11 years, with indications for dual chamber DC pacemakers were randomized 1:1 to SafeR or DDD pacing with a long atrioventricular delay (250 ms). The primary objective was twofold: (1) reduction in the proportion of ventricular paced beats at 1 year; and (2) impact on atrial fibrillation burden at 3 years, defined as the ratio between cumulative duration of mode-switches divided by follow-up time. Statistical significance of both co-primary end points was required for the trial to be considered positive. At 1 year of follow-up, the median proportion of ventricular-paced beats was 4.0% with DDD versus 0% with SafeR (P<0.001). At 3 years of follow-up, the atrial fibrillation burden was not significantly reduced with SafeR versus DDD (median 0.00%, interquartile range [0.00% to 0.23%] versus median 0.01%, interquartile range [0.00% to 0.44%], respectively, P=0.178]), despite a persistent reduction in the median proportion of ventricular-paced beats (10% with DDD compared to 0% with SafeR).
  
  
  CONCLUSIONS
  A ventricular-paced rate <1% was safely achieved with SafeR in a population with a wide spectrum of indications for dual-chamber pacing. However, the lower percentage of ventricular pacing did not translate into a significant reduction in atrial fibrillation burden.
  
  
  BACKGROUND
  URL: https://www.clinicaltrials.gov/ Unique identifier: NCT01219621.
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Bernard
authors.initials: B
authors.lastname: Thibault
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Anique
authors.initials: A
authors.lastname: Ducharme
authors.affiliation: Kingston General Hospital, Kingston, Ontario, Canada (A.B.).
authors.forename: Adrian
authors.initials: A
authors.lastname: Baranchuk
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Marc
authors.initials: M
authors.lastname: Dubuc
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Katia
authors.initials: K
authors.lastname: Dyrda
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Peter G
authors.initials: PG
authors.lastname: Guerra
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Laurent
authors.initials: L
authors.lastname: Macle
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Blandine
authors.initials: B
authors.lastname: Mondésert
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Léna
authors.initials: L
authors.lastname: Rivard
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Denis
authors.initials: D
authors.lastname: Roy
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Mario
authors.initials: M
authors.lastname: Talajic
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Jason
authors.initials: J
authors.lastname: Andrade
authors.affiliation: SORIN Group CRM, Montreal, Quebec, Canada (N.).
authors.forename: Rémi
authors.initials: R
authors.lastname: Nitzsché
authors.affiliation: Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (B.T., A.D., M.D., K.D., P.G.G., L.M., B.M., R., D.R., M.T., J.A., P.K.).
authors.forename: Paul
authors.initials: P
authors.lastname: Khairy
mesh_terms: D000200:Action Potentials; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D001283:Atrioventricular Node / Q000503:physiopathology*; D002170:Canada; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000379:methods*; D058409:Cardiac Resynchronization Therapy Devices; D004311:Double-Blind Method; D004867:Equipment Design; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right
keywords: adverse arrhythmic events; atrial fibrillation; dual‐chamber pacemaker; long atrioventricular delay; right ventricular pacing