RCT: Intravenous Amino Acids Reduce AKI Incidence in Cardiac Surgery Patients – N Engl J Med

Study Design and Population: In this multinational, double-blind, randomized clinical trial, 3511 adult patients scheduled for cardiac surgery with cardiopulmonary bypass were recruited from 22 centers across three countries. Patients were randomly assigned to receive an intravenous infusion of either a balanced mixture of amino acids (2 g/kg/day) or a placebo (Ringer’s solution) for up to three days.

Main Findings: The primary outcome, occurrence of acute kidney injury (AKI), was significantly lower in the amino acid group (26.9%) compared to the placebo group (31.7%) with a relative risk of 0.85 (95% CI, 0.77 to 0.94; P=0.002). The incidence of severe AKI (stage 3) was also reduced in the amino acid group (1.6% vs. 3.0%; relative risk, 0.56; 95% CI, 0.35 to 0.87). There were no substantial differences between the groups regarding secondary outcomes such as the use and duration of kidney-replacement therapy or all-cause 30-day mortality.

Implications for Practice: The infusion of amino acids in adult patients undergoing cardiac surgery appears to reduce the incidence of AKI, indicating a potential protective renal effect. However, this intervention did not significantly impact other secondary outcomes, including mortality and the use of kidney-replacement therapy. These findings suggest that amino acids could be considered as a strategy to mitigate AKI risk in this patient population, although further research is needed to explore long-term benefits and other clinical outcomes.

Reference: Landoni G, Monaco F, Ti LK, Baiardo Redaelli M, Bradic N, Comis M, Kotani Y, for the PROTECTION Study Group. (2024). A randomized trial of intravenous amino acids for kidney protection. New England Journal of Medicine, 390(24), 1765-1774. DOI: 10.1056/NEJMoa2403769.