title: Long-Term Results of Cardiac Resynchronization Therapy: A Comparison between CRT-Pacemakers versus Primary Prophylactic CRT-Defibrillators.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) with or without a defibrillator has a positive effect on mortality and morbidity for patients with heart failure. However, comparisons between CRT-defibrillators (CRT-D) and CRT-pacemakers (CRT-P) are relatively scarce outside the clinical trial setting. This study aimed to assess baseline characteristics in relation to long-term prognosis in patients treated with CRT, and to investigate the potential benefit of CRT-D versus CRT-P.
  
  
  METHODS
  Data were retrospectively collected from the medical records of all consecutive patients treated with CRT-P or primary prophylactic CRT-D at a large tertiary care center between 1999 and 2012. Predictors of mortality were investigated, and time-dependent analysis was performed with all-cause mortality as the primary end point.
  
  
  RESULTS
  A total of 705 patients were included (69.6 ± 10 years, 78% New York Heart Association classes III-IV, left ventricular ejection fraction median 25%, 16% female, 36% CRT-D). The patients were followed for a median of 59 months. Annual mortality differed between CRT-D primary prophylactic and CRT-P groups (5.3% and 11.8%, respectively), but when adjusted for covariates, CRT-D treatment (compared to CRT-P) was not associated with better long-term survival. Independent predictors of survival were: age, use of loop diuretics, hemoglobin levels, and use of renin angiotensin aldosterone system blockers.
  
  
  CONCLUSIONS
  In CRT treatment outside of the clinical trial setting, CRT-D treatment was not an independent predictor of long-term survival. Future research should focus on correct selection of the patients who receive enough benefit of an added defibrillator to justify CRT-D implantation instead of CRT-P treatment only.
authors: Lund University, Arrhythmia Clinic, Skane University Hospital, Lund, Sweden.
authors: Christian
authors: C
authors: Reitan
authors: Lund University, Arrhythmia Clinic, Skane University Hospital, Lund, Sweden.
authors: Uzma
authors: U
authors: Chaudhry
authors: Lund University, Arrhythmia Clinic, Skane University Hospital, Lund, Sweden.
authors: Zoltan
authors: Z
authors: Bakos
authors: Lund University, Arrhythmia Clinic, Skane University Hospital, Lund, Sweden.
authors: Johan
authors: J
authors: Brandt
authors: Lund University, Arrhythmia Clinic, Skane University Hospital, Lund, Sweden.
authors: Lingwei
authors: L
authors: Wang
authors: Lund University, Arrhythmia Clinic, Skane University Hospital, Lund, Sweden.
authors: Pyotr G
authors: PG
authors: Platonov
authors: Lund University, Arrhythmia Clinic, Skane University Hospital, Lund, Sweden.
authors: Rasmus
authors: R
authors: Borgquist
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D002423:Cause of Death; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate
keywords: cardiac resynchronization therapy; heart failure; implantable defibrillator; long-term follow-up; prognostic factors