The role of serum cystatin C level in detection of early onset kidney injury after coronary artery bypass surgery

Aim: Acute kidney injury (AKI) is an important condition after coronary artery bypass graft (CABG) surgery. Precautions can be taken to prevent AKI by recognizing the risky patients in the preoperative period. In this study, we investigated the relationship between the serum cystatin C (CyC) levels and AKI after CABG surgery. Methods: A total of 42 patients (mean age 59.33 (6.66) and 69% male) who underwent isolated on-pump CABG between June 2018 and January 2019 were included in this prospective cohort study. Creatinine and CyC levels were evaluated at the preoperative period, postoperative 2nd and 24th hours. Patients were assessed for the development of AKI according to the Acute Kidney Injury Network criteria and divided into two groups as those with and without AKI in the postoperative period. Results: Based on the creatinine level at the postoperative 24th hour, 9 (21.4%) patients developed AKI. Compared to patients who did not develop AKI, it was found that CyC level was significantly higher at the postoperative 2nd hour in patients who developed AKI (1.06 (0.26) vs 0.87 (0.19), P=0.023). In patients who developed AKI, the duration of cross-clamp was significantly longer (P=0.038), and erythrocyte suspension (P<0.001) and the number of fresh frozen plasma infusions (P<0.001) were significantly higher. Conclusion: Increased CyC levels were associated with the development of AKI in the early postoperative period. CyC measurements performed in the initial period after CABG can be used in the diagnosis of cardiac surgery related AKI.