Acute kidney injury (AKI) occurs in 5% to 42% of patients undergoing cardiac surgery and represents a considerable burden in terms of health outcomes and hospital costs.1 In this population, severe or prolonged AKI has been independently associated with increased risk for mortality, as well as end-stage kidney disease and earlier stages of chronic kidney disease (CKD).1,2 AKI and its associated outcomes are often difficult to predict, even in specific settings such as cardiac surgery,3 hampering progress in clinical research.