Selecting patients for heart transplantation: Comparison of the Heart Failure Survival Score (HFSS) and the Seattle Heart Failure Model (SHFM)

Background: The Heart Failure Survival Score (HFSS) risk-stratifies patients with chronic heart failure (CHF) referred for heart transplantation using 7 parameters, including peak VO ₂. The Seattle Heart Failure Model (SHFM) is a 20-variable model that combines clinical, laboratory and therapeutic data. Although both models have excellent accuracy, only the HFSS was derived and validated in patients referred for transplantation, and the HFSS and SHFM have not been directly compared. Methods: We tested the accuracy of the SHFM and compared the HFSS and SHFM in 715 patients referred for heart transplantation. Results: Over a follow-up of 962 ± 912 days, 354 patients died or received an urgent heart transplantation or a ventricular assist device. One-year event-free survival was 89%, 72% and 60%, respectively, for the low-, medium- and high-risk HFSS strata, and 93%, 76%, and 58%, respectively, for the low-, medium- and high-risk SHFM strata. The HFSS and SHFM were modestly correlated (R = -0.48, p < 0.001). In receiver operating characteristic curve analysis, areas under the curves (AUCs) for the HFSS and SHFM were comparable (1 year: 0.72 vs 0.73; 2-year: 0.70 vs 0.74, respectively) and incremental to New York Heart Association class. The 1- and 2-year combined HFSS+SHFM AUCs were 0.77 and 0.76, respectively, significantly better than the HFSS or SHFM alone. Conclusions: The HFSS and SHFM provide accurate and comparable risk stratification in CHF patients referred for transplantation. Combining the HFSS and SHFM improves predictive ability.