Cardiac Surgery Associated Acute Kidney Injury - Incidence, Risk Factors, Outcomes, and Risk Score Validation from a Single Centre in Bahrain

Abstract

Background: Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common complication in patients undergoing cardiac surgery. Early prediction of acute kidney injury (AKI) is crucial to estimate and communicate the prognosis and outcome of surgery. This research is particularly significant as it addresses the need for validation of risk scores in non-Caucasian populations with a higher incidence of risk factors, potentially leading to improved patient care and outcomes. Objective: This prospective study aimed to investigate the association between socio-demographic and clinical variables in patients undergoing cardiac surgery in a single center in Bahrain and their correlation with a predictive risk score. Methods: This comprehensive study included 100 patients who underwent cardiac surgery. The distribution of study subjects was meticulously assessed based on the kidney disease: Improving Global Outcomes (KDIGO) classification for AKI. The association of AKI with socio-demographic and clinical variables was rigorously analyzed using chi-square tests and logistic regression analysis and compared to the predicted incidence from the Acute Kidney Injury after Cardiac Surgery (AKICS) score, ensuring the reliability and accuracy of our findings. Results: Among the study subjects, 65% were not affected by acute kidney injury (AKI). In contrast, 19% were classified as having Stage 1 AKI, 8% as Stage 2, and 8% as Stage 3. Additionally, 2% of the patients required dialysis. The findings of our study underscore the significant impact of AKI on hospital stay and the need for dialysis. Female gender, previous myocardial infarction, UF heparin use, and elevated preoperative creatinine levels were significantly associated with AKI. The AKICS score was found to predict AKI in our patients, with a sensitivity of 91% and a specificity of 46.9%. Conclusion: Female gender, previous myocardial infarction, UF heparin use, and elevated preoperative creatinine levels were found to be independent predictors of AKI. We found that patients with AKI had a significantly longer hospital stay duration. The AKICS score has been validated in our local cohort of Middle Eastern patients with high sensitivity. Keywords: Acute kidney injury; Cardiac surgery; Risk factors; Socio-demographic factors; Clinical variables