Figure 6.

To demonstrate the sequence in which information becomes clinically available for risk stratification, the global Wald χ² are shown for separate Cox regression models predicting death (panel A) or death/VAD/cardiac transplant (panel B) whereby age, coronary disease (myocardial infarction or prior revascularization), left ventricular ejection fraction (EF), and finally the extracellular volume fraction (ECV) are each added in succession (p<0.01 for all global Wald χ² for each model). The incremental Wald χ² (type 3 tests) and p values attributable to the addition of the new variable are also shown in the shaded gray boxes to demonstrate the magnitude of incremental information introduced by each additional variables in the model accounting for the variables already present in the model. EF and ECV each add significant additional prognostic information beyond the variables that preceded them.