Postoperative 20% Albumin and Cardiac Surgery Associated Kidney Injury, Statistical Analysis Plan and Updated Protocol

Background The incidence of cardiac surgery associated acute kidney injury (CS-AKI) remains high. Patients who develop AKI after cardiac surgery are at higher risk of persistent renal dysfunction and increased long-term mortality. The risk of CS-AKI is significantly increased in patients with chronic kidney disease and in patients having prolonged bypass for complex surgery. Previous trials of albumin did not show any benefit in prevention of CS-AKI. These trials, however, did not focus on high-risk patients and used albumin as a resuscitation strategy. The aim of ALBICS-AKI is to demonstrate the effect of concentrated albumin infusion on CS-AKI in high-risk patients undergoing cardiac surgery compared with standard care. Methods ALBICS-AKI is an investigator initiated, multicentre, randomised, open label trial. Seven centres in Australia and Italy will participate in the trial. We will randomise 620 adult patients who will undergo on-pump cardiac surgery with one of the following: an estimated glomerular filtration rate <60 ml/min/1.73m2, combined valve/s, coronary artery, or surgery involving thoracic aorta. Within 6 hours after surgery, a 20% albumin infusion will commence at 20ml/h for 15 hours. All patients will receive standard care as per institutional protocols. The primary outcome is the proportion of patients with AKI according to creatinine based KDIGO definition at hospital discharge or day 28, whichever comes first. Secondary outcomes include Major Adverse Kidney Events at day 28, AKI stage II and III, need for renal replacement therapy, and hospital mortality. Ethics and dissemination The trial was approved by Monash Health Lead Research Committee for Australian sites and by the Italian Medicine Agency for Italian sites. The estimated study completion date is Sep 2024. The results will be presented at major conferences and submitted for publication in peer-reviewed journals. Trial registration number Australian New Zealand Clinical Trials Registry ACTRN12619001355167