title: Positive response to cardiac resynchronization therapy reduces arrhythmic events after elective generator change in patients with primary prevention CRT-D.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) and implantable cardioverter-defibrillators (ICD) are effective therapies for heart failure (HF) patients with cardiac dyssynchrony. Patients receiving primary prevention CRT-defibrillator that positively remodel might no longer qualify for ICD indication due to CRT-induced left ventricular ejection fraction (LVEF) improvement. We aimed to evaluate the outcome of CRT-D patients at the time of device replacement (DR).
  
  
  RESULTS
  Patients undergoing primary prevention CRT-D DR were prospectively included from November 2007 to March 2011 in 2 centers. CRT response was as defined as ≥1 NYHA class improvement and an increase in LVEF ≥10%. Before DR, all patients underwent echocardiography and device interrogation. Patients without theoretical ongoing ICD indication (TOII) at DR were defined as those with LVEF ≥40% without appropriate ICD therapy (appropriate therapy) during the first ICD service-life. A total of 107 consecutive patients were enrolled. Sixty-one patients (57%) were considered CRT responders after the index procedure. At the time of DR (56.4 ± 14.4 months from initial implant), 87% of CRT responders were free of appropriate therapy, compared with 70% of CRT nonresponders (P = 0.02). Thirty-nine patients (37%) did not meet the criteria for TOII. During follow-up (mean 26.4 ± 14.4 months after DR), 37 patients (95%) without TOII were free of appropriate therapy versus 49 of 68 patients (72%) with ongoing TOII (P = 0.007). By multivariable analysis, the only independent predictor of appropriate therapy after DR was TOII (hazard ratio = 6.43; P = 0.01).
  
  
  CONCLUSIONS
  Absence of theoretical ICD indication occurs in more than one-third of CRT-D patients undergoing DR. In addition, appropriate therapy rate is relatively low (2.2% per year) in this subgroup of patients.
authors: Fédération de cardiologie, Hôpital Henri Mondor, Assistance Publique Hôpitaux de Paris et INSERMU955, Créteil, France; Division of Cardiovascular Medicine, St. Thomas' Hospital, Guy's and Saint Thomas NHS Trust, London, UK.
authors: Frederic A
authors: FA
authors: Sebag
authors: Nicolas
authors: N
authors: Lellouche
authors: Zhong
authors: Z
authors: Chen
authors: Amine
authors: A
authors: Tritar
authors: Mark D
authors: MD
authors: O'Neill
authors: Jaswinder
authors: J
authors: Gill
authors: Matthew
authors: M
authors: Wright
authors: Christophe
authors: C
authors: Leclercq
authors: Christopher A
authors: CA
authors: Rinaldi
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000175:diagnosis* / Q000517:prevention & control*; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D003131:Combined Modality Therapy / Q000379:methods; D017147:Defibrillators, Implantable; D005260:Female; D005602:France; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D011322:Primary Prevention / Q000379:methods; D016896:Treatment Outcome; D006113:United Kingdom
keywords: cardiac resynchronization therapy; heart failure; implantable cardioverter-defibrillator; remodeling; sudden death; ventricular arrhythmia