Tissue inhibitor of metalloproteinase-2 in patients aged 1 month to 1 year with and without cardiac surgery-associated acute kidney injury in congenital heart disease surgery with cardiopulmonary bypass: a single-center retrospective study

Introduction: Acute kidney injury is a common complication of cardiac surgery after management of congenital heart defects. Cardiac surgery-associated acute kidney injury (CS-AKI) results in longer stays of patients in the intensive care unit and hospital. However, using an increase in postoperative creatinine as a means of detecting AKI has some limitations, since significant changes occur after the loss of more than 50% of renal function. In children, the creatinine level is influenced by various factors such as muscle mass, cardiac output, etc. These factors vary significantly among young children and complicate the early diagnosis of AKI. Recent studies have explored biomarkers as potential predictors for the early detection of CS-AKI after cardiac surgery for management of congenital heart disease in children.Objective: To evaluate the urinary tissue inhibitor of metalloproteinase-2 (TIMP2) as a predictor of CS-AKI following management of congenital heart defects in children aged 1 month to 1 year who underwent cardiopulmonary bypass.Methods: A single-center retrospective study included patients aged 1 month to 1 year who underwent cardiopulmonary bypass for the correction of congenital heart defects. The groups were formed based on the presence of CS-AKI. The study group comprised of patients who had CS-AKI (group 1, n = 52), while those without CC-AKI constituted the control group (group 2, n = 98). To ensure minimal systematic errors and comparability between two groups, propensity score matching analysis was performed (52 patients in groups 1 and 2). Preoperative, intraoperative, and postoperative parameters and characteristics were compared.Results: The results showed no differences in baseline or demographic characteristics between the patients. In the study group, 34.6% of patients were diagnosed with CS-AKI. Among them, 67.4% (n = 35) were stage 1, 28.8% (n = 15) were stage 2, and 3.8% (n = 2) were stage 3. The results of the regression analysis show a decrease by 24% and an increase by 9 and 16% in CS-AKI respectively, with an increase in creatinine levels by 1 µmol/l, at baseline and on days 3 and 4. Additionally, male patients have a 76% lower likelihood to develop CS-AKI. It was observed that there was no significant difference in the tissue inhibitor of metalloprotease-2 levels between the groups with and without CS-AKI.Conclusion: Urinary TIMP2 levels were found to be unable to predict the early onset of CS-AKI in congenital heart defect patients ages 1 month to 1 year who underwent cardiopulmonary bypass surgery. Received 24 April 2023. Revised 27 November 2023. Accepted 28 November 2023. Funding: The study did not have sponsorship. Conflict of interest: The authors declare no conflict of interest. Contribution of the authors: The authors contributed equally to this article.