Performance of the Seattle Heart Failure Model in Implantable Defibrillator Patients Treated With Cardiac Resynchronization Therapy

The Seattle Heart Failure Model (SHFM) is a validated multivariate risk prediction model for mortality in patients with heart failure, using widely available clinical variables. The aim of this study was to assess the performance of the SHFM when applied to patients with heart failure who received cardiac resynchronization therapy devices with defibrillation. A total of 413 patients were identified from 2 prospective implantable cardioverter-defibrillator registries who received cardiac resynchronization therapy devices with defibrillation for the primary prevention of sudden death. Baseline laboratory and clinical data were entered in the SHFM to calculate predicted survival. The end point was all-cause mortality. During a median follow-up period of 2.8 years, 78 patients died and 9 underwent heart transplantation. Observed versus predicted 5-year mortality rates were 11.6% versus 11.4%, 21.5% versus 22.1%, and 41.4% versus 46.1% by ascending tertile of Seattle Heart Failure Score, respectively. No systematic or substantial errors of risk estimation were observed. Discrimination was excellent; the C-statistic ranged from 0.78 at 1-year follow-up to 0.70 at 5-year follow-up, and the Hosmer-Lemeshow chi-square statistic was 0.87 (p = 0.65). In conclusion, in patients with heart failure who received cardiac resynchronization therapy devices with defibrillation, the SHFM offers adequate discrimination of risk for all-cause mortality and estimation of mortality risk without substantial or systematic errors.