title: Cardiac Resynchronization Therapy Reduces Ventricular Arrhythmias in Primary but Not Secondary Prophylactic Implantable Cardioverter Defibrillator Patients: Insight From the Resynchronization in Ambulatory Heart Failure Trial.
abstract: BACKGROUND
  The RAFT (Resynchronization in Ambulatory Heart Failure Trial) demonstrated that cardiac resynchronization therapy (CRT) reduced both mortality and heart failure hospitalizations in patients with functional class II or III heart failure and widened QRS. We examined the influence of CRT on ventricular arrhythmias in patients with primary versus secondary prophylaxis defibrillator indications.
  
  
  RESULTS
  All ventricular arrhythmias among RAFT study participants were downloaded and adjudicated by 2 blinded reviewers with an overreader for disagreements and committee review for remaining discrepancies. Incidence of ventricular arrhythmias among patients randomized to CRT-D versus implantable cardioverter defibrillator (ICD) were compared within the groups of patients treated for primary prophylaxis and for secondary prophylaxis. Of 1798 enrolled patients, 1764 had data available for adjudication and were included. Of these, 1531 patients were implanted for primary prophylaxis, while 233 patients were implanted for secondary prophylaxis; 884 patients were randomized to ICD and 880 to CRT-D. During 5953.6 patient-years of follow-up, there were 11 278 appropriate ICD detections of ventricular arrhythmias. In the primary prophylaxis group, CRT-D significantly reduced incidence ventricular arrhythmias in comparison to ICD (hazard ratio, 0.86; 95% confidence interval, 0.74-0.99;P=0.044). This effect was not seen in the secondary prophylaxis group (hazard ratio, 1.14; 95% confidence interval, 0.82-1.58;P=0.45). CRT-D was not associated with significant differences in overall ventricular arrhythmia burden in either group.
  
  
  CONCLUSIONS
  CRT reduced the rate of onset of new ventricular arrhythmias detected by ICDs in patients without a history of prior ventricular arrhythmias. This effect was not observed among patients who had prior ventricular arrhythmias.
  
  
  BACKGROUND
  URL: http://www.clinicaltrials.gov. Unique identifier: NCT00251251.
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.). John.sapp@cdha.nshealth.ca.
authors.forename: John L
authors.initials: JL
authors.lastname: Sapp
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Ratika
authors.initials: R
authors.lastname: Parkash
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: George A
authors.initials: GA
authors.lastname: Wells
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Yetisir
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Gardner
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Healey
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Bernard
authors.initials: B
authors.lastname: Thibault
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Sterns
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: David
authors.initials: D
authors.lastname: Birnie
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Pablo B
authors.initials: PB
authors.lastname: Nery
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Soori
authors.initials: S
authors.lastname: Sivakumaran
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Vidal
authors.initials: V
authors.lastname: Essebag
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Paul
authors.initials: P
authors.lastname: Dorian
authors.affiliation: From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).
authors.forename: Anthony S L
authors.initials: AS
authors.lastname: Tang
mesh_terms: D000368:Aged; D000553:Ambulatory Care; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D004311:Double-Blind Method; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011322:Primary Prevention / Q000379:methods; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*
keywords: cardiac resynchronization therapy; congestive heart failure; heart failure; implantable cardioverter-defibrillator; ventricular arrhythmia