title: Utility of the Seattle Heart Failure Model in patients with cardiac resynchronization therapy and implantable cardioverter defibrillator referred for heart transplantation.
abstract: BACKGROUND
  The Seattle Heart Failure Model (SHFM) predicts survival in heart failure but may underestimate risk in severe heart failure, and the performance has not been evaluated explicitly in patients with cardiac resynchronization therapy (CRT) and/or implantable cardioverter defibrillator (ICD) referred for heart transplantation. We aimed to assess the utility of the SHFM by validation in patients with CRT and/or ICD referred for heart transplantation.
  
  
  METHODS
  We assessed the SHFM performance in 382 patients with CRT and/or ICD referred for heart transplantation. Outcome was survival free from urgent transplantation or left ventricular assist device. Model discrimination and calibration were assessed graphically and by formal tests.
  
  
  RESULTS
  During a mean follow-up of 2.3 years, 195 events occurred. One-, 2-, and 3-year observed event-free survival was 77%, 62%, and 52%, and the observed to predicted event-free survival ratio was 0.89, 0.80, and 0.76. Calibration plots demonstrated results deviating from the ideal calibration line at 1, 2, and 3 years. The SHFM score adequately assigned patients in discrete risk strata, according to Kaplan-Meier estimated survival. Time-dependent receiver operating characteristic curve analyses demonstrated good discrimination overall, which was slightly better for 1-year (area under the curve [AUC] 0.774) compared with 2-year (AUC 0.742) and 3-year (AUC 0.728) event-free survival.
  
  
  CONCLUSIONS
  The SHFM has good discrimination but underestimates risk of adverse outcomes in patients with CRT and/or ICD referred for heart transplantation. The SHFM may be used to assess relative risk and changes over time, but when assessing absolute percentage of event-free survival, the overestimation of event-free survival should be accounted for.
authors.affiliation: Department of Cardiothoracic Surgery and Anesthesiology, Karolinska University Hospital, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. Electronic address: Ulrik.Sartipy@karolinska.se.
authors.forename: Ulrik
authors.initials: U
authors.lastname: Sartipy
authors.affiliation: Cardiology Department, Kyorin University, Tokyo, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Goda
authors.affiliation: Center for Advanced Cardiac Care, Columbia University Medical Center, New York, NY.
authors.forename: Melana
authors.initials: M
authors.lastname: Yuzefpolskaya
authors.affiliation: Center for Advanced Cardiac Care, Columbia University Medical Center, New York, NY.
authors.forename: Donna M
authors.initials: DM
authors.lastname: Mancini
authors.affiliation: Department of Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Lars H
authors.initials: LH
authors.lastname: Lund
mesh_terms: D000328:Adult; D000368:Aged; D058406:Cardiac Resynchronization Therapy; D017147:Defibrillators, Implantable; D006333:Heart Failure / Q000401:mortality* / Q000628:therapy*; D016027:Heart Transplantation; D006353:Heart-Assist Devices; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D010101:Oxygen Consumption; D011379:Prognosis; D012017:Referral and Consultation; D018570:Risk Assessment