title: Does defibrillation testing influence outcomes after CRT-D implantation? A cause-of-death analysis from the DAI-PP study.
abstract: BACKGROUND
  Little data address the usefulness of defibrillation testing in patients with prolonged QRS duration, known for more advanced myocardial disease. We aimed to compare baseline characteristics and outcomes between patients who underwent defibrillation testing (DT+) and those who did not (DT-), immediately after the implantation of a cardiac resynchronization therapy with defibrillator (CRT-D).
  
  
  METHODS
  Data from all patients with ischemic or non-ischemic cardiomyopathy implanted in primary prevention with a CRT-D in 12 French centers were considered for analysis (2002-2012).
  
  
  RESULTS
  Out of the 1516 patients with DT information available, DT was performed in 958(63%) patients. Compared to DT- patients, DT+ patients presented no significant differences in terms of age (65.1±10.8 vs 64.7±10.3years, p=0.45), LVEF (25%[20.0-30.0] vs 25%[20.5-30.0], p=0.30), or etiologies of heart failure (ischemic: 49.6% vs 46.9%, p=0.32). By contrast, DT+ patients were less likely to present atrial fibrillation (25.3% vs 33.4%, p=0.001), renal insufficiency (eGFR<60ml/min in 45.3% vs 51.7%, p=0.04) and NYHA functional class≥III (68.9% vs 77.4%, p=0.0006). All of the three perioperative deaths occurred in the DT+ group and were related to DT itself. After a mean follow-up of 3.1±2.1years, the adjusted incidence of overall mortality was lower among DT+ patients (adjusted HR 0.6, 95%CI 0.4-0.7, p<0.0001). However, ICD-unresponsive sudden deaths remained very rare and no more frequently observed among DT- patients (p=0.41).
  
  
  CONCLUSIONS
  In our cohort, the higher (up to 40%) mortality at midterm among DT- patients is mainly reflecting their more severe cardiac disease, rather than a higher rate of ICD-unresponsive sudden death.
authors.affiliation: CHU La Timone, Marseille, France.
authors.forename: Tilman
authors.initials: T
authors.lastname: Perrin
authors.affiliation: CHU La Timone, Marseille, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Mechulan
authors.affiliation: Clinique Pasteur, Toulouse, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Boveda
authors.affiliation: Paris Cardiovascular Research Center, Inserm U970, Paris, France.
authors.forename: Frankie
authors.initials: F
authors.lastname: Beganton
authors.affiliation: CHU Michallon, Grenoble, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Defaye
authors.affiliation: CHU Brabois, Nancy, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Sadoul
authors.affiliation: Centre Cardiologique du Nord, Saint Denis, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Piot
authors.affiliation: CHRU Lille, Lille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Klug
authors.affiliation: Nouvelles Cliniques Nantaises, Nantes, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Gras
authors.affiliation: Paris Cardiovascular Research Center, Inserm U970, Paris, France.
authors.forename: Marie-Cécile
authors.initials: MC
authors.lastname: Perier
authors.affiliation: CHU Antoine Béclère, Clamart, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Algalarrondo
authors.affiliation: CHU Haut Lévêque, Bordeaux, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bordachar
authors.affiliation: CHU Trousseau, Tours, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Babuty
authors.affiliation: CHU Trousseau, Tours, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Fauchier
authors.affiliation: CHU Pontchaillou, Rennes, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
authors.affiliation: Paris Cardiovascular Research Center, Inserm U970, Paris, France; European Georges Pompidou Hospital, Paris, France; Paris Descartes University, Paris, France.
authors.forename: Eloi
authors.initials: E
authors.lastname: Marijon
authors.affiliation: CHU La Timone, Marseille, France. Electronic address: jeanclaude.deharo@ap-hm.fr.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Deharo
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000401:mortality* / Q000639:trends*; D002423:Cause of Death / Q000639:trends; D017147:Defibrillators, Implantable / Q000639:trends*; D004554:Electric Countershock / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011322:Primary Prevention / Q000639:trends*; D012042:Registries; D012189:Retrospective Studies; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*
keywords: Cardiac resynchronization therapy; Cause-of-death analysis; Defibrillation testing; Implantable cardioverter-defibrillator; Primary prevention; Sudden death