Intravenous Amino Acids May Reduce Risk of Cardiac Surgery-Associated AKI: Study
USA: Researchers have found in a new study that intravenous amino acid (AA) administration was associated with a lower risk of cardiac surgery–associated acute kidney injury (CSA-AKI) across varying degrees of AKI severity. However, it was not associated with significant differences in other major clinical outcomes.
The meta-analysis, published in IJC Heart & Vasculature, evaluated randomized controlled trials investigating whether intravenous amino acid therapy could protect against kidney injury following cardiac surgery requiring cardiopulmonary bypass (CPB). The study was conducted by Alexandre N. Pantaleao of the School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil, and colleagues.
CSA-AKI is a frequent complication following cardiac surgery and can contribute to prolonged hospitalization and adverse outcomes. Although intravenous amino acids have been investigated as a potential strategy to reduce kidney injury, evidence regarding their effectiveness has remained uncertain.
For the meta-analysis, researchers searched three databases for randomized controlled trials comparing intravenous amino acids with placebo or standard care in patients undergoing cardiac surgery with CPB. The primary outcome was the occurrence of CSA-AKI, including its severity according to Kidney Disease: Improving Global Outcomes (KDIGO) stages. The investigators also assessed renal replacement therapy (RRT), 30-day mortality, and 90-day mortality.
Five randomized trials involving 4,499 patients were included, with 2,247 participants receiving intravenous amino acid infusion.
The analysis revealed:
- Intravenous amino acid administration was associated with a 19% lower relative risk of CSA-AKI compared with placebo or standard care (RR 0.81).
- The reduction was more pronounced for stage 2 or 3 AKI.
- No significant difference was observed in the requirement for RRT.
- Amino acid administration was not associated with differences in 30-day mortality or 90-day mortality.
The researchers noted that the overall finding was influenced substantially by the largest included trial, although smaller studies conducted at different centers produced broadly similar results. Differences between trials in the amino acid formulations, doses, treatment timing, and surgical procedures also introduce uncertainty. Four studies initiated treatment around the perioperative period, while one began infusion four hours after CPB was discontinued.
The study’s limitations include its study-level design, methodological differences among trials, variation in AKI definitions, and the lack of individual patient data for detailed subgroup analyses. The exclusion of conference abstracts and preprints may also have introduced publication bias. Differences in amino acid regimens and treatment duration further limit the robustness of the findings.
The researchers concluded that intravenous amino acid administration was associated with a reduced risk of CSA-AKI across different levels of severity, but did not demonstrate an association with RRT or short- and intermediate-term mortality. Further research is needed to establish the optimal amino acid formulation, dose, and timing of administration.
Reference:
Pantaleao, A. N., Mutarelli, A., Kang, J., Braga, M. A., Passos, F. S., Caldonazo, T., Kirov, H., Doenst, T., Bagchi, A., & Melnitchouk, S. (2026). Intravenous amino acids to prevent acute kidney injury in cardiac surgery with cardiopulmonary bypass: A meta-analysis of randomized controlled trials. IJC Heart & Vasculature, 66, 101986. https://doi.org/10.1016/j.ijcha.2026.101986
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