title: Adding Defibrillation Therapy to Cardiac Resynchronization on the Basis of the Myocardial Substrate.
abstract: BACKGROUND
  Patients with nonischemic dilated cardiomyopathy (DCM) may be at lower risk for ventricular arrhythmias compared with those with ischemic cardiomyopathy (ICM). In addition, DCM has been identified as a predictor of positive response to cardiac resynchronization therapy (CRT).
  
  
  OBJECTIVE
  The aim of this study was to investigate the impact of an additional implantable cardioverter-defibrillator over CRT, according to underlying heart disease, in a large study group of primary prevention patients with heart failure.
  
  
  METHODS
  This was an observational, multicenter, European cohort study of 5,307 consecutive patients with DCM or ICM, no history of sustained ventricular arrhythmias, who underwent CRT implantation with (n = 4,037) or without (n = 1,270) a defibrillator. Propensity-score and cause-of-death analyses were used to compare outcomes.
  
  
  RESULTS
  After a mean follow-up period of 41.4 ± 29.0 months, patients with ICM had better survival when receiving CRT with a defibrillator compared with those who received CRT without a defibrillator (hazard ratio for mortality adjusted on propensity score and all mortality predictors: 0.76; 95% confidence interval [CI]: 0.62 to 0.92; p = 0.005), whereas in patients with DCM, no such difference was observed (hazard ratio: 0.92; 95% CI: 0.73 to 1.16; p = 0.49). Compared with recipients of defibrillators, the excess mortality in patients who did not receive defibrillators was related to sudden cardiac death in 8.0% among those with ICM but in only 0.4% of those with DCM.
  
  
  CONCLUSIONS
  Among patients with heart failure with indications for CRT, those with DCM may not benefit from additional primary prevention implantable cardioverter-defibrillator therapy, as opposed to those with ICM.
authors.affiliation: Cardiology Department, Papworth Hospital NHS Foundation Trust, Cambridge, United Kingdom. Electronic address: sergioncbarra@gmail.com.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Barra
authors.affiliation: Cardiology Department, Clinique Pasteur, Toulouse, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Boveda
authors.affiliation: Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Rui
authors.initials: R
authors.lastname: Providência
authors.affiliation: Cardiology Department, Nancy University Hospital, Nancy, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Sadoul
authors.affiliation: Cardiology Department, Papworth Hospital NHS Foundation Trust, Cambridge, United Kingdom.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Duehmke
authors.affiliation: Arrhythmia Clinic, Lund University, Skane University Hospital, Lund, Sweden.
authors.forename: Christian
authors.initials: C
authors.lastname: Reitan
authors.affiliation: Arrhythmia Clinic, Lund University, Skane University Hospital, Lund, Sweden.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Borgquist
authors.affiliation: MaxCure Hospitals, Hyderabad, India; Paris Cardiovascular Research Center, Paris, France.
authors.forename: Kumar
authors.initials: K
authors.lastname: Narayanan
authors.affiliation: La Pitie Salpetriere University Hospital, Paris, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Hidden-Lucet
authors.affiliation: Cardiology Department, Lille University Hospital, Lille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Klug
authors.affiliation: Cardiology Department, Grenoble University Hospital, Grenoble, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Defaye
authors.affiliation: Nouvelles Cliniques Nantaises, Nantes, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Gras
authors.affiliation: Rouen University Hospital, Rouen, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Anselme
authors.affiliation: Rennes University Hospital, Rennes, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
authors.affiliation: Amiens University Hospital, Amiens, France.
authors.forename: Jean-Sébastien
authors.initials: JS
authors.lastname: Hermida
authors.affiliation: Marseille University Hospital, Marseille, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Deharo
authors.affiliation: Green Lane Cardiovascular Services, Level 3, Auckland City Hospital, Grafton, Auckland, New Zealand.
authors.forename: Khang-Li
authors.initials: KL
authors.lastname: Looi
authors.affiliation: Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Chow
authors.affiliation: Cardiology Department, Papworth Hospital NHS Foundation Trust, Cambridge, United Kingdom.
authors.forename: Munmohan
authors.initials: M
authors.lastname: Virdee
authors.affiliation: Cardiology Department, Papworth Hospital NHS Foundation Trust, Cambridge, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Fynn
authors.affiliation: Paris Cardiovascular Research Center, Paris, France; Cardiology Department, European Georges Pompidou Hospital, Paris, France; Paris Descartes University, Paris, France.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Le Heuzey
authors.affiliation: Paris Cardiovascular Research Center, Paris, France; Cardiology Department, European Georges Pompidou Hospital, Paris, France; Paris Descartes University, Paris, France.
authors.forename: Eloi
authors.initials: E
authors.lastname: Marijon
authors.affiliation: Cardiology Department, Papworth Hospital NHS Foundation Trust, Cambridge, United Kingdom.
authors.forename: Sharad
authors.initials: S
authors.lastname: Agarwal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy; D058409:Cardiac Resynchronization Therapy Devices; D002311:Cardiomyopathy, Dilated / Q000401:mortality / Q000628:therapy*; D015331:Cohort Studies; D017147:Defibrillators, Implantable; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000401:mortality / Q000628:therapy*
keywords: all-cause mortality; cause of death analysis; dilated cardiomyopathy; implantable cardioverter-defibrillator; ischemic cardiomyopathy; sudden cardiac death