Acute Kidney Injury After Cardiac Surgery in Patients Without Chronic Kidney Disease: Incidence, Predictors, and Outcomes

Abstract

Acute kidney injury (AKI) is a frequent and serious complication following cardiac surgery, even in patients without preexisting chronic kidney disease (CKD). This prospective cohort study included 950 adult patients undergoing elective cardiac surgery at Assiut University Hospital between 2021 and 2024. Using KDIGO criteria, the incidence of cardiac surgery–associated AKI (CSA-AKI) was 42%, with 18.6% classified as severe (stage 3). AKI patients were significantly older, more often female, and had higher rates of hypertension, diabetes, and valvular surgery. They also experienced longer cardiopulmonary bypass and cross-clamp times, more postoperative hypotension and sepsis, and a greater need for renal replacement therapy. Mortality was 22.3% compared with 6.5% in patients without AKI. Multivariate analysis identified hypertension, diabetes, and prolonged ICU and hospital stays as independent predictors. CSA-AKI remains common and strongly associated with adverse outcomes, highlighting the need for preventive perioperative management strategies.