Amino acids infusion after cardiac surgery may prevent AKI: NEJM

The study found that infusion of amino acids reduced the occurrence of acute kidney injury (AKI) in adult patients undergoing cardiac surgery.

Acute kidney injury is a severe and common complication of cardiac surgery, for which reduced kidney perfusion is a key contributing factor. IV amino acids increase kidney perfusion and recruit renal functional reserve. However, the efficacy of amino acids in reducing AKI occurrence after cardiac surgery is uncertain.

Against the above background, Giovanni Landoni, Department of Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Via Olgettina, Milan, Italy, and colleagues performed the PROTECTION trial, a multinational, double-blind, randomized, placebo-controlled trial comprising adult patients scheduled to undergo cardiac surgery with cardiopulmonary bypass, to test the hypothesis that IV amino acid therapy would lead to a lower occurrence of postoperative AKI than placebo.

Adult patients scheduled to undergo cardiac surgery with cardiopulmonary bypass were randomly assigned to receive an IV infusion of either a balanced mixture of amino acids at a dose of 2 g per kilogram of ideal body weight per day or a placebo (Ringer’s solution) for up to 3 days.

The primary outcome was AKI occurrence, defined according to the Kidney Disease: Improving Global Outcomes creatinine criteria. Secondary outcomes were the use and duration of kidney-replacement therapy, the severity of AKI, and all-cause 30-day mortality.

3511 patients were recruited at 22 centers in three countries, and 1759 patients were assigned to the amino acid group and 1752 to the placebo group.

The researchers reported the following findings:

• AKI occurred in 26.9% of patients in the amino acid group and 31.7% of patients in the placebo group (relative risk, 0.85).
• Stage 3 AKI occurred in 1.6% and 3.0% of patients, respectively (relative risk, 0.56).
• Kidney replacement therapy was used in 1.4% of patients in the amino acid group and 1.9% in the placebo group.
• There were no substantial differences between the two groups in other secondary outcomes or adverse events.

"In this trial involving adult patients scheduled to undergo elective cardiac surgery with cardiopulmonary bypass, the infusion of amino acids significantly decreased the overall occurrence of acute kidney injury," the researchers concluded.

Reference:

Landoni G, Monaco F, Ti LK, Baiardo Redaelli M, Bradic N, Comis M, Kotani Y, Brambillasca C, Garofalo E, Scandroglio AM, Viscido C, Paternoster G, Franco A, Porta S, Ferrod F, Calabrò MG, Pisano A, Vendramin I, Barucco G, Federici F, Severi L, Belletti A, Cortegiani A, Bruni A, Galbiati C, Covino A, Baryshnikova E, Giardina G, Venditto M, Kroeller D, Nakhnoukh C, Mantovani L, Silvetti S, Licheri M, Guarracino F, Lobreglio R, Di Prima AL, Fresilli S, Labanca R, Mucchetti M, Lembo R, Losiggio R, Bove T, Ranucci M, Fominskiy E, Longhini F, Zangrillo A, Bellomo R; PROTECTION Study Group. A Randomized Trial of Intravenous Amino Acids for Kidney Protection. N Engl J Med. 2024 Jun 12. doi: 10.1056/NEJMoa2403769. Epub ahead of print. PMID: 38865168.