Background: The heart failure survival score (HFSS), a multivariable predictive index that has been shown to predict death or inotrope-dependent transplant in ambulatory patients referred for transplant evaluation has not been independently validated. We sought to independently assess the prognostic ability of the HFSS in a group of patients undergoing transplant evaluation in Italy, and to compare its prognostic value to that of peak exercise oxygen consumption (VO2), the standard tool for risk stratification in most transplant centers.
Methods: Data for the seven variables that constitute the HFSS, including peak VO2, were collected for 107 ambulatory patients referred to the heart transplant center of the University of Turin. Patients were followed prospectively for 997 +/- 32 days, with outcome events defined as death prior to transplant or inotrope-dependent transplant.
Results: The discriminative abilities of peak VO2 and the HFSS and their respective risk strata were compared. At univariate Cox regression models, peak VO2 did not successfully predict outcomes, neither when evaluated continuously (p = 0.25) nor when dichotomized at 14 ml/kg/min (p = 0.18). Both the HFSS (p = 0.011) and the HFSS strata (p = 0.008) successfully predicted outcome events.
Conclusions: The HFSS was more accurate than peak VO2 for the prediction of event-free survival, both when evaluated continuously and as risk strata. The HFSS is a valid and widely applicable tool for the identification of patients who, in the absence of contraindications, would benefit from transplantation.