Risk factors for postoperative acute kidney injury after cardiac surgery

Abstract

Objectives. To describe the frequency of postoperative acute kidney injury (AKI) following cardiac surgery and to analyse risk factors for its development. Materials and Methods. We conducted an observational analytical cohort study using prospective data from adult patients who underwent cardiac surgery between 2003 and 2023 at a high-complexity centre in Argentina. AKI was defined according to KDIGO criteria. Risk factors were assessed using logistic regression. Results. A total of 13,215 patients were analysed, with a mean age of 64 years; most were men (75.7%). The frequency of AKI was 7.3%, with an in-hospital mortality of 4.7%. Independent risk factors included advanced age (OR: 1.05, p<0.001), urgent surgery (OR: 2.87, p<0.001), cardiopulmonary bypass (OR: 1.41, p<0.001), and comorbidities such as chronic obstructive pulmonary disease and preoperative anaemia. Asymptomatic status prior to surgery was identified as a protective factor. Conclusions. The frequency of postoperative AKI is comparable to international registries. The main predictors of risk were age, surgical urgency, and use of cardiopulmonary bypass. Identifying risk factors can improve perioperative prevention and management in cardiac surgery.