Kidney status and events preceding death in heart failure: A real world data study on 18,456 patients with heart failure

Abstract Background Despite advancements in heart failure (HF) management, kidney dysfunction remains a significant clinical challenge, and is associated with higher mortality rates and other adverse outcomes. However, there are few studies of kidney events preceding death in patients with HF in the real world. Methods Using registry-based data, the prevalence of kidney events preceding death in patients with HF over the period 2014-2018 in Denmark. All deaths in patients with a diagnosis of HF within the previous 10 years were included. Kidney events occurring during within 1 year of death compromised of: acute kidney injury, chronic renal replacement therapy, sustained eGFR<15 mL/min/1.73 m2, or renal transplantation. The prevalence of kidney events preceding death was calculated and different subgroups were compared. Results Among the 18,586 HF patients who died, a total of 3107 (16.7%) experienced kidney events during within 1 year of death. The prevalence of HF patients with kidney events before death was 15.5% for acute kidney injury, 5.8% for chronic renal replacement therapy, 7.4% for an eGFR<15 mL/min/1.73 m2, and 0.18% for renal transplantation (see Figure 1). Acute kidney injury episodes were frequently observed in the last month before death (7.5%) (Figure 2). Age-specific analysis revealed a higher proportion of deaths associated with kidney dysfunction in patients under the age of 65 years compared to those aged 80 years and above (24.3% vs 13.4%). Furthermore, male sex, death in-hospital, reduced pre-existing kidney function, a higher degree of frailty, and lower educational status were associated with higher frequency of death associated with kidney dysfunction. Conclusion In this real-world study, a significant proportion of deaths among HF patients were associated with kidney dysfunction, particularly with acute kidney injury. Further research and awareness of renal complications are necessary to improve outcomes in this population.