Abstract
BACKGROUND: There are six widely used equations to calculate the estimated glomerular filtration rate (eGFR) of patients. We aimed to assess the predictive power of preoperative eGFR calculated by these equations for the occurrence of postoperative acute kidney injury (AKI). METHODS: Patients who underwent isolated coronary surgery from January 2016 to January 2021 were continuously enrolled. Serum creatinine and cystatin C used to calculate eGFR were both measured within 1 week before surgery. The eGFR was calculated using six equations: Cockcroft Gault (CG) equation, Chinese abbreviated modification of diet in renal disease (MDRD) equation, chronic kidney disease-epidemiology (CKD-EPI) equation, and full age spectrum (FAS) equation. Postoperative AKI was diagnosed by Kidney Disease Improving Global Outcomes criteria (KDIGO) (① urine volume < 0.5 mL/kg/h for 6 h; ② an increase in serum creatinine by ≥ 26.5 µmol/L within 48 h; ③ an increase in serum creatinine to ≥ 1.5 times baseline levels, which is known or presumed to have occurred within the prior 7 days), and the occurrence of AKI within 7 days after surgery was followed. RESULTS: A total of 1428 patients were included, of which 319 patients (25.5%) developed postoperative AKI. After adjustment, all eGFRs (CG OR = 0.983, MDRD OR = 0.983, CKD-EPIcrea OR = 0.97, CKD-EPIcys OR = 0.955, FAScrea OR = 0.978, FAScys OR = 0. 941, all p < 0.001) were significantly associated with AKI. The area under the receiver operating characteristic curve (AUC) was 0.621 for CG, 0.614 for MDRD, 0.643 for CKD-EPIcrea , 0.739 for CKD-EPIcys , 0.643 for FAScrea , 0.744 for FAScys , respectively. There was no difference in predictive power between FAScys and CKD-EPIcys (p = 0.33, DeLong's test). CONCLUSIONS: Preoperative eGFR calculated by FAScys and CKD-EPIcys equations have better performance in predicting AKI after off-pump coronary artery bypass grafting than other equations.