Figure 1

ROC curves for all model building steps. Step 0 contains only the intercept; step 1 selects peak -dφ_hat/dV_hat at early diastole in the model; step 2 adds torsion hysteresis area into the model; step 3 adds E/A ratio into the model while step 4 adds mean E/e' into the model. The Wald chi-square statistics determines to remove mean E/e'. The final model therefore contains parameters peak -dφ_hat/dV_hat at early diastole, torsion hysteresis area and E/A.