Kidney Status and Events Preceding Death in Heart Failure: A Real-world Nationwide Study

Background Chronic kidney disease (CKD) is a frequent comorbidity in heart failure (HF) patients, affecting prognosis and mortality. This study investigates the relationship between kidney function and adverse kidney events preceding death in HF patients. Methods We analyzed registry data of HF patients who died between 2014 and 2021, with at least one year of HF diagnosis. Adverse kidney events, including acute kidney injury (AKI) and end- stage kidney disease (ESKD), were assessed. Patients were grouped by estimated glomerular filtration rate (eGFR) one year before death: eGFR≥60, eGFR 30-59, and eGFR<30. Results Among 36,435 HF patients who died, 37% had eGFR≥60, 46% had eGFR 30-59, and 17% had eGFR<30 one year before death. Median age was 81 years, and 61.2% were men. Adverse kidney events occurred in 13.1% of patients. AKI was inversely related to kidney function, affecting 6.5% (95% confidence interval 6.1-6.9) of those with eGFR≥60, 7.0% (6.6.-7.4) with eGFR 30-59, and 21.9% (20.9-22.9) with eGFR<30. ESKD occurred in 0.7%(0.6-0.9), 2.6% (2.4-2.8), and 35.5% (34.3-36.7) of patients in the respective eGFR categories. In the last three months before death, kidney function notably declined, with increased chronic kidney replacement therapy. Factors associated with higher adverse kidney events included younger age, male sex, in-hospital death, and greater frailty. Conclusions In HF patients, AKI and ESKD are common in the last year of life, particularly in those with lower baseline eGFR, with kidney decline accelerating in the final months.