Disclosure(s): No relevant financial relationship(s) to disclose.
Introduction: Acute kidney injury (AKI) is a frequent and serious complication following cardiac surgery. Experimental and clinical evidence suggests that amino acid (AA) infusion may improve renal perfusion and offer protective effects. This systematic review and meta-analysis aimed to evaluate the impact of perioperative AA infusion on AKI incidence in adult cardiac surgery patients.
Methods: We systematically searched PubMed, Embase, and the Cochrane from inception to June 2025 for randomized controlled trials (RCTs) assessing AA infusion for renal protection in cardiac surgery. Eligible studies reported AKI outcomes stratified by KDIGO stages. A random-effects meta-analysis was conducted to calculate pooled risk ratios (RRs) with 95% confidence intervals (CIs). Certainty of evidence (CoE) was evaluated using GRADE methodology. Artificial Intelligence assist tools were used for improving fluidity, grammar and structure of the writing, not included in data curation, analysis and interpretation.
Results: Seven RCTs comprising a total of 4,872 patients were included. AA infusion was associated with a significant reduction in severe AKI (Stage 3) (RR: 0.69; 95% CI: 0.41–0.89; p = 0.005). No statistically significant effect was observed for Stage 1 AKI (RR: 0.56; 95% CI: 0.77–0.96; p = 0.21) or Stage 2 AKI (RR: 1.24; 95% CI: 0.60–2.55; p = 0.568). Preliminary findings from studies evaluating single AA interventions indicated that glutamic acid may reduce overall AKI incidence, while glutamine improved surrogate biomarkers of renal injury; however, the certainty of evidence for these findings was rated as very low.
Conclusions: Perioperative amino acid infusion may reduce the risk of severe AKI (Stage 3) after cardiac surgery, although its effects on milder forms of AKI remain inconclusive. Single amino acid interventions, such as glutamic acid and glutamine, show potential renal protective effects that warrant further investigation. Larger, high-quality RCTs are needed to confirm these findings and improve treatment strategy.
