The Effect of Preoperative and Postoperative Glycemic Control on Acute Kidney Injury After Off-Pump Coronary Artery Bypass Grafting: A Case-Control Study.

BACKGROUND

Acute kidney injury (AKI) is a common complication after cardiac surgery. It is closely related to poor perioperative glycemic control. We aimed to explore the relationship between preoperative hemoglobin A1c (HbA1c) levels and cumulative postoperative insulin usage and AKI after off-pump coronary artery bypass grafting (OPCABG).

METHOD

The included a total of 284 patients undergoing isolated OPCABG from 2018 to 2020. According to KDIGO's diagnostic criteria, patients were divided into the AKI group and the non-AKI group. Methods included ① increase in SCr by ≥0.3 mg/dl (≥26.5 µmol/l) within 48 hours; ② increase in SCr to ≥1.5 times baseline, which is known or presumed to have occurred within the prior 7 days; ③ urine volume <0.5 ml/kg/hour for 6 hours.

RESULTS

Fifty-one patients (17.9%) had postoperative AKI. HbA1c levels (non-AKI group 6.1 (5.8, 7.1) vs. the AKI group 7.1 (5.9, 8.6) (P = 0.014, cut-off=7.2, AUC=0.61, sensitivity 49%, specificity 76.4%) and postoperative insulin usage (non-AKI group 16.0 (4.0, 36.0) vs. the AKI group 56.0 (11.0, 132.0), P < 0.001, cut-off=39.5, AUC=0.673, sensitivity 60.8%, specificity 76.8%) were different between the two groups. Multivariate logistic regression analysis showed that HbA1c > 7.2% (OR=2.869, P = 0.04) and postoperative insulin usage > 39.5 U (OR=7.548, P < 0.001) were independently associated with AKI.

CONCLUSIONS

HbA1c levels and cumulative postoperative insulin usage could be used as independent predictors for AKI after OPCABG. Postoperative insulin usage is more predictive than preoperative HbA1c levels.