Renal implications of off-pump coronary artery bypass grafting: A retrospective cohort study analyzing postoperative creatinine levels

Abstract

Background/Aim: Coronary artery disease is a significant health concern worldwide. While coronary artery bypass grafting is a gold standard of treatment, acute kidney injury (AKI) is a possible postoperative complication of concern. Off-pump coronary artery bypass grafting (OPCABG) aims to curtail perioperative complications; however, its impact on postoperative AKI is debated. This retrospective study aims to inform patient care by identifying potential effects of OPCABG on AKI utilizing postoperative creatinine alterations. Methods: This retrospective study was conducted at Koç University Hospital in Istanbul, Turkey. We reviewed the records of patients who underwent OPCABG between June 2018 and June 2019. Patients with incomplete records or individuals who had undergone renal replacement therapy prior to surgery were excluded. The primary metric was serum creatinine levels, which were assessed preoperatively and up to 7 days postoperatively. Preoperative creatinine levels were compared with postoperative levels using the Wilcoxon signed-rank test. Acute kidney injury was defined using Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Results: Seventy-two patients satisfied the inclusionary criteria. A significant increase in creatinine was observed on postoperative Day 1 (P<0.001); creatinine levels fell below baseline by postoperative Day 4 and 5. We note that the incidence of AKI was low; there were no instances of Stage 2 or higher AKI during the observation period. Conclusion: Our data suggest that OPCABG may result in a transient increase in creatinine post-surgery. Creatinine levels normalize over time, implicating the renal safety of OPCABG. Despite these promising findings, additional comprehensive studies are essential to validate these observations and assess long-term renal outcomes after OPCABG.