title: Prognostic Impact of Implementation of QRS Characteristics in the Seattle Heart Failure Model in ICD and CRT-D Recipients.
abstract: The Seattle Heart Failure Model (SHFM) provides accurate estimates of survival in heart failure (HF) patients. The model is, however, not developed for HF patients with cardiac resynchronization therapy (CRT). The aim of this study was to assess the prognostic value of SHFM combined with QRS morphology and CRT-related change in QRS duration in implantable cardioverter defibrillator (ICD) and CRT defibrillator (CRT-D) recipients.
  
  
  
  All patients who underwent prophylactic ICD implantation at the Leiden University Medical Center since 1996 were included. Baseline SHFM, QRS morphology, and duration before and after device implantation were determined. The regression coefficients of the QRS characteristics derived from a Cox regression analysis were implemented in the SHFM. SHFM-estimated survival was compared with Kaplan-Meier observed survival.
  
  
  
  The current study includes 1,834 defibrillator recipients (63 ± 11 years; 79% male; 53% CRT-D). In 585 (60%) CRT-D recipients a left bundle branch block was present, the mean QRS duration was 147 ± 31 ms before and 151 ± 27 ms after device implantation. After a median follow-up of 4.4 years (25(th) -75(th) percentile 2.7-6.4 years), 285 (29%) CRT-D recipients had died. CRT-related decrease in QRS duration adjusted for QRS morphology was associated with improved survival (hazard ratio 1.05/10 ms; 95% confidence interval [CI]: 1.01-1.09; P = 0.02). The estimated 5-year survival of CRT-D recipients after implementation of the QRS characteristic was 70%, and comparable with the observed 5-year survival of 68% (95% CI: 65-72).
  
  
  
  Implementation of native QRS morphology and change in QRS duration due to CRT in the SHFM improves the prognostic value of this model in HF patients with CRT-D.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Aafke C
authors.initials: AC
authors.lastname: VAN DER Heijden
authors.affiliation: Department of Cardiology, University of Washington, Seattle, Washington.
authors.forename: Wayne C
authors.initials: WC
authors.lastname: Levy
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Lieselot
authors.initials: L
authors.lastname: VAN Erven
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: C Jan Willem
authors.initials: CJ
authors.lastname: Borleffs
mesh_terms: D000368:Aged; D058409:Cardiac Resynchronization Therapy Devices; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate
keywords: QRS duration; QRS morphology; cardiac resynchronization therapy; implantable cardioverter defibrillator; survival