Renoprotective Effect of Intravenous Amino Acid Infusion in Adult Patients Undergoing Cardiac Surgery: Systematic Review and Meta-Analysis

Background: Acute kidney injury (AKI) complicates 5–42% of cardiac surgeries, with severe cases requiring renal replacement therapy (RRT) (1–5%) linked to mortality rates up to 63%. Despite extensive research, no pharmacologic intervention has proven definitively effective for prevention. This study evaluates whether amino acid infusion reduces AKI incidence, RRT requirement, and 30-day mortality post-cardiac surgery. Methods: A systematic search (PubMed/MEDLINE, CENTRAL, Embase, Web of Science) up to April 1, 2025, identified randomized controlled trials (RCTs) comparing perioperative amino acid infusion with standard care in adults undergoing cardiac surgery. Outcomes included AKI incidence, RRT initiation, and 30-day mortality. Fixed-effects meta-analyses (Review Manager 5.4) calculated pooled odds ratios (OR) with 95% confidence intervals (CI). Results: Three studies (3646 participants) were included. There was no significant heterogeneity among the studies. Amino acid infusion had decreased incidence of AKI (overall) by 22% (OR 0.78, 95% CI: 0.68, 0.90; P = 0.0008) and reduced the number of patients needed to be initiated on RRT by 45% (OR 0.55, 95% CI: 0.33, 0.93; P = 0.02) post-cardiac surgery. Our analysis did not show a significant effect on 30-Day mortality. However, there was a trend towards benefit favoring the amino acid group. Conclusion: Perioperative amino acid infusion significantly lowers AKI risk and RRT need in cardiac surgery patients, supporting its potential as a preventive strategy. While mortality effects remain inconclusive, these findings highlight its clinical relevance for mitigating postoperative kidney injury in high-risk populations.Figure. The pooled estimate showed that amino acid infusion had reduced the incidence of AKI (overall) by 22% (OR 0.78, 95% CI: 0.68, 0.90; P = 0.0008; I2 = 0%). Characteristics of Included Studies - Author Number of Patients Age (SD) Control Intervention AKI Definition Follow-up of AKI Type of Surgery Jadad Composite Scale Pu(2019) 69 C: 70.8 (9.0)I: 72.3 (9.5) Standard of Care L-amino acids 2 gm/kg of IBW (max of 100 g/day) for 3 days ( Synthamin 17 Electrolyte Free) KDIGO 7 days Cardiopulmonary Bypass 5/5 Kazawa(2024) 66 C: 71 (56, 75)I: 72 (52, 77) Standard of Care L-amino acids ( Amiparen ) 60 g/day for 3 days KDIGO 7 days Cardiopulmonary Bypass 5/5 Landoni(2024) 3511 C: 67 (58, 73)I: 66 (57, 73) Standard of Care L-amino acids 2 gm/kg of IBW (max of 100 g/day) KDIGO 7 days Cardiopulmonary Bypass 5/5 The study designs in the analysis were all double-blinded, randomized controlled trials which were published between 2019 and 2024.