Association of anaemia and all-cause mortality in patients with ischaemic heart failure varies by renal function status

Aims The aims of the current study were to evaluate the association between anaemia and all-cause mortality according to chronic kidney disease (CKD) status and to explore at what level of haemoglobin concentration would the all-cause mortality risk increase prominently among CKD and non-CKD patients, respectively. Methods and results This is a prospective cohort study, and 1559 patients with ischaemic heart failure (IHF) were included (mean age of 63.5 +/- 11.0 years, 85.8% men) from December 2015 to June 2019. Patients were divided into the CKD (n = ) and non-CKD (n = 1078) groups based on the estimated glomerular filtration rate of 60 mL/min/1.73 m(2). In the CKD group, the incidence rate of all-cause mortality in anaemic and non-anaemic patients was 15.4 per 100 person-years and 10.8 per 100 person-years, respectively, with an incidence rate ratio of 1.42 (95% confidence interval: 1.00-2.02; P-value = 0.05). In the non-CKD group, the incidence rate of all-cause mortality in anaemic and non-anaemic patients was 9.8 per 100 person-years and 5.5 per 100 person-years, respectively, with an incidence rate ratio of 1.78 (95% confidence interval: 1.20-2.59; P-value = 0.005). After a median follow-up of 2.1 years, the cumulative incidence rate of all-cause mortality in anaemic and non-anaemic patients was 41.5% and 44.1% (P-value = 0.05) in the CKD group, and 30.9% and 18.1% (P-value < 0.0001) in the non-CKD group. In the CKD group, cumulative incidence rate of all-cause mortality increased prominently when haemoglobin concentration was below 100 g/L, which was not observed in the non-CKD group. Conclusions Results of the current study indicated that among IHF patients, the association between anaemia and all-cause mortality differed by the renal function status. These findings underline the importance to assess mortality risk and manage anaemia among IHF patients according to the renal function status.