Chronic Hyperglycemia as a Predictor of Acute Kidney Injury Requiring Continuous Renal Replacement Therapy (CRRT) in Patients Undergoing Coronary Artery Bypass Graft (CABG) Surgery

Abstract

Background: Chronic Hyperglycaemia with HBA1C is an indicator affecting postoperative care after CABG. AKI is one of the frequent postoperative complications after CABG, impacting short- and long-term outcomes. This research project will investigate the association between chronic hyperglycemia and post operative incidence of AKI requiring CRRT in CABG patients. Methods: A retrospective study was conducted from 1st January 2016 to 31st December 2019 who underwent isolated CABG in Institut Jantung Negara, Malaysia. Patients were divided into two groups; patients who have HbA1c ≤6 and patients who have HbA1c >6. Primary outcome measured were the incidence of AKI that leads to CRRT. Secondary outcome measured were, mortality, chest reopen, length of ICU stay and total hospital stay. Results: Total of 2019 patients were included. Baseline characteristic were measured. BMI, hypertension and high cholesterol were significantly higher in the HbA1c > 6. The rest of the baseline characteristic including age, smoking status and COPD status showed no significant differences in both groups. 17 patients (1.5% p<0.05) develop AKI which requires CRRT in the HbA1c>6 group, compare to 3 patient (0.3% p<0.05) in the HbA1c ≤6 group. There were no significant differences in mortality and chest reopen rates. However, ICU length of stay is longer in the HbA1c>6 group at 2.3 ±3.1 days p<0.05, compare to HbA1c ≤6 at 2.1±3 days p<0.05. Total length of post-op hospital stay was also higher in the HbA1c>6 group at 8.3 ± 6.6 days p<0.05, compare to HbA1c ≤6 at 7.6 ± 4.5 days p<0.05. Conclusion: This study suggests chronic hyperglycaemia defined on a single measurement of HbA1c >6 was associated with higher incidence of AKI requiring CRRT. Length of ICU and post-op hospital stay were higher in the HbA1c >6 group. This finding might implicate the importance of sugar control preoperatively, especially in diabetes patients.