TF and heart failure: Furthermore, survival curve analysis for heart failure events revealed that patients with transferrin saturation levels ≥ 30% had a significantly better prognosis than those with transferrin saturation levels < 30%, with a crude HR of 0.42 (95% CI 0.23–0.79, P < 0.01), which was significant even with an adjusted HR of 0.26 (95% CI 0.13–0.53, P < 0.001) (shown in Supplemental Fig. 4).