Introduction:
Coronary artery bypass grafting (CABG) is a lifesaving surgical intervention for severe coronary artery disease (CAD). However, postoperative complications such as acute kidney injury (AKI) and progression to chronic kidney disease (CKD) significantly impact patient outcomes and healthcare resources. This research aims to elucidate the incidence and risk factors associated with AKI and CKD following CABG surgery and identify the key prognostic factors contributing to short-term mortality post-CABG.
Methods:
This is a single-centre retrospective cohort study that included all patients with preserved kidney function, defined as eGFR ≥60 ml/min/1.73m² before CABG surgery between 2016 to 2020 at University Malaya Medical Centre. Patient data were retrieved from electronic medical record, including demographics, medical history, medications and laboratory results. Acute Kidney Injury and Chronic Kidney Disease were defined based on KDIGO criteria. These patients were followed up for 1 year post CABG to assess the incidence of new-onset CKD. Mortality data were collected from the date of surgery until 90 days post-CABG. Statistical analyses were performed using SPSS software version 26. Logistic regression models were used to identify risk factors for AKI and CKD while Cox regression models were applied to determine predictors of mortality. A p-value of <0.05 was considered statistically significant for all analyses.
Results:
684 patients were included, mean age was 60 years old and 83.8% were male. Notably, 26.3%(n=180) of patients developed AKI post CABG, of which 68.3%(n=123) were stage I, 21.7%(n=39) stage II, and 10%(n=18) were stage III AKI. Univariate analysis identified elevated preoperative serum urea, baseline serum creatinine and preoperative albumin as significant predictors for AKI. The use of diuretics and intraoperative factors like prolonged operation time and nephrotoxic agents further increased AKI risk. Postoperative predictors of AKI included peak serum creatinine. Subsequent multiple logistic regression identified baseline serum creatinine(OR=1.117 . 95% Cl [1.077-1.159], p<0.001) and peak serum creatinine(OR=0.846. 95%Cl[0.802-0.892], p<0.001) as significant predictors. Among the 224 patients that attended follow-up up to 1 year, 10 out of 53 (18.9%) who had AKI developed CKD. In contrast, 23 out of 171 patients (13.5%) who did not develop AKI postoperatively went on to develop CKD. Multiple logistic regression identified serum creatinine upon discharge (OR=1.103. 95% Cl [1.042-1.168], p<0.001) as the sole significant predictors of CKD. The mortality rate within 90 days was 8% and was primarily influenced by use of intra-aortic balloon pump use (OR=13.042. 95% CI[1.042-120.468], p=0.024).
Conclusions:
This study emphasized the critical relationship between AKI and subsequent CKD development. The risk factors identified can aid in preoperative risk stratification and guide perioperative management to mitigate the incidence of AKI, CKD and short-term mortality post CABG. These findings highlighted the importance of early nephrology consultation for patients at-risk which can potentially improve outcomes post-CABG surgery.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.