Introduction: The prognostic value of the ratio of haemoglobin to red cell distribution width (HRR) in different types of heart failure (HF) is not well known. Method and Results: We analysed the long-term prognostic value of HRR in patients with HF using the Cox proportional risk model and Kaplan-Meier method. We reviewed consecutive 972 HF patients. The overall mortality rate was 45.68%. Mortality was 52.22% in the HFrEF group and 40.99% in the HFpEF + HFmrEF group. Cox regression showed that when HRR increased by 1 unit, the risk of all-cause death in all HF patients decreased by 22.8% (HR: 0.772, 95% CI: 0.724, 0.823, p < 0.001), in the HFpEF + HFmrEF group it decreased by 15.5% (HR: 0.845, 95% CI: 0.774, 0.923, p < 0.001), and in the HFrEF group it decreased by 36.1% (HR: 0.639, 95% CI: 0.576, 0.709, p < 0.0001). Subgroup analysis showed that there were interactions between the EF and HRR groups. The group in which HRR best predicted all-cause death from HF was group 1 (EF <40%, HRR <9.45), followed by group 2 (EF <40%, HRR >= 9.45), and group 3 (EF >= 40%, HRR <9.45). HRR had no predictive value in group 4 (EF >= 40%, HRR >= 9.45). Conclusion: HRR is an important predictor of all-cause mortality in patients with HF, especially HFrEF. There is an interaction between HRR group and LVEF group.<br /> (c) 2024 The Author(s).Published by S. Karger AG, Basel