Preoperative Hypoalbuminemia as an Independent Predictor of Postoperative Acute Kidney Dysfunction After Cardiac Surgery.

BACKGROUND: Postoperative acute renal failure associated with mortality after cardiac surgery. Whereas many variables result in postoperative renal failure, current literature lacks commentary on preoperative serum albumin optimization. METHODS: We performed a retrospective review of a single adult cardiac surgery center database between 2021 and 2024. Patients were divided into 2 cohorts: preoperative hypoalbuminemia (<3.5 g/dL) and normal albuminemia (3.5-5.4 g/dL). Demographic and clinical characteristics were compared. The primary outcome was kidney injury or kidney failure, defined by the RIFLE (risk, injury, failure, loss of kidney function, end-stage kidney disease) criteria. Multivariable logistic regression evaluated the association of preoperative albumin level and postoperative kidney dysfunction. RESULTS: There were 1673 patients who underwent cardiac surgery during 4 years, 444 (27%) with hypoalbuminemia and 1229 (63%) with normal albuminemia. The hypoalbuminemia group was younger (63 vs 65 years; P < .01) and less likely to be male (66% vs 71%; P = .04), with lower body mass index (28 kg/m2 vs 30 kg/m2; P < .01). Preoperative creatinine concentration (1.0 vs 1.0; P = .85) was comparable between groups. Postoperative kidney dysfunction was significantly greater in the hypoalbuminemia group (12% vs 5%; P < .01). Multivariable logistic regression found hypoalbuminemia to be an independent risk factor for acute kidney dysfunction after cardiac surgery (odds ratio, 1.8 [1.1-3.1]; P < .05). CONCLUSIONS: Hypoalbuminemia is significantly associated with postoperative acute kidney dysfunction in cardiac surgery patients. Preoperative optimization may decrease the risk of renal complications.