Intravenous amino acids to prevent acute kidney injury in cardiac surgery with cardiopulmonary bypass: a meta-analysis of randomized controlled trials

Background The efficacy of intravenous amino acids (AA) in preventing cardiac surgery-associated acute kidney injury (CSA-AKI) remains uncertain. Methods Three libraries were searched for randomized controlled trials (RCTs) comparing intravenous AA versus placebo or standard care to reduce the risk of CSA-AKI after cardiac surgery with cardiopulmonary bypass (CPB). The primary endpoint was the incidence of CSA-AKI, overall and stratified by KDIGO stage. Secondary endpoints were need for renal replacement therapy (RRT), 30-day mortality, and 90-day mortality. Risk ratios (RRs) with 95% confidence intervals (CIs) were pooled using a random-effects model. Results Five studies were included, comprising 4499 patients, of whom 2247 (50%) were randomized to intravenous AA infusion. Compared with placebo or standard care, intravenous AA administration significantly reduced the risk of CSA-AKI (RR 0.81, 95% CI 0.70–0.94; p = 0.005), predominantly driven by one trial. The relative risk reduction was more important for stage 2 or 3 AKI (RR 0.69, 95% CI 0.48–0.99; p = 0.046). No significant differences were observed in the need for RRT ( p = 0.223), 30-day mortality ( p = 0.893), or 90-day mortality ( p = 0.581). Conclusion Intravenous AA administration is associated with a reduced risk of CSA-AKI across the spectrum of AKI severity, without showing an association with other major clinical outcomes.