#3381 Predicting chronic kidney disease progression in elderly patients with acute kidney injury : a 10-year retrospective analysis

Abstract Background and Aims Acute kidney injury (AKI) is a common condition in elderly patients, characterized by a rapid decline in kidney function, particularly in this vulnerable population, where AKI frequently progresses to chronic kidney disease (CKD). This progression, reported in up to 58.6% of cases, [1] carries significant clinical and socioeconomic consequences, including increased morbidity, prolonged hospital stays, and reduced quality of life. Identifying predictive factors of CKD progression is crucial to improving outcomes. This study aims to analyze these factors in elderly AKI patients. Method A retrospective study including patients aged 65 years or older admitted to a nephrology department for AKI between 2012 and 2022. AKI was defined according to KDIGO 2012 criteria. Data on demographics, clinical and biological parameters, therapeutic interventions, and patient outcomes were collected. CKD progression was analyzed as a primary outcome. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of CKD evolution. Results Seventy-five patients were included, with a mean age of 72.9 ± 5.7 years and a male-to-female ratio of 0.59. The median baseline estimated glomerular filtration rate (eGFR) was 46.8 ± 21.7 mL/min/1.73 m2. Hypertension and diabetes were the most common comorbidities, present in 77% and 48% of cases, respectively. The most frequent causes of AKI were prerenal (45%), tubular (35%), and interstitial (27%), with 25% of cases being iatrogenic. Forty-four patients (59%) required intermittent hemodialysis, and 29 patients (39%) developed intra-hospital complications, most notably septic shock. At discharge, the mean eGFR was 28.4 ± 20.5 mL/min/1.73 m². After three, six, and twelve months, 56%, 44%, and 28% of patients had impaired renal function, respectively. The median follow-up was 13 months, with 36% of patients having persistent renal dysfunction and 32% recovering their baseline renal function. The overall mortality rate was 32%, with septic shock being the leading cause of death. Analysis of the factors influencing CKD progression revealed several significant predictors at different time points: At six months, elevated 24-hour proteinuria (P = 0.045) and high discharge creatinine levels (P < 0.001) were significantly associated with CKD progression. At one year, hypertension (P = 0.035) and elevated discharge creatinine (P < 0.001) remained significant predictors. At the latest follow-up, factors associated with CKD progression were: use of renin-angiotensin-aldosterone system blockers (P = 0.114), elevated 24-hour proteinuria (P = 0.041), the use of renal replacement therapy (RRT) (P = 0.019), the number of RRT sessions (P = 0.023), and high discharge creatinine levels (P < 0.001). Multivariate analysis identified elevated discharge creatinine as the strongest independent predictor (P = 0.035; Or = 31.7; 95% CI [6.6–28.7]). Conclusion Elevated serum creatinine at discharge emerged as the strongest independent predictor of CKD progression in elderly patients with AKI. Other factors, such as 24-hour proteinuria, RRT use, and hypertension, also contributed to CKD evolution. Early identification and management of at-risk patients could help mitigate CKD progression in this vulnerable population.