Acute kidney injury following coronary artery bypass graft surgery in a tertiary public hospital in Malaysia: an analysis of 1228 consecutive cases

ABSTRACT

Background: Acute kidney injury (AKI) following cardiac surgery is well established but the reported incidence is variable due to varying definitions and criteria. Furthermore there is a paucity of such data from Southeast Asia. Objectives: To determine the incidence of AKI, the associated risk factors, and its impact on early mortality and intensive care unit/hospital stay. Method: This is a single centre retrospective observational study to evaluate outcomes on 1260 consecutive patients from a multi-ethnic Southeast Asian population who underwent a primary isolated coronary artery bypass graft (CABG) operation. Data was collected from the hospital’s electronic database and analysed using basic descriptive statistics and logistic regression. Results: Overall incidence was 36.2% including 5.5% of patients who required renal replacement therapy (RRT). Multivariate analysis identified age, insulin-dependent diabetes mellitus (IDDM), baseline serum creatinine level (SCr), recent myocardial infarction (MI), cardiopulmonary bypass (CPB) time and intra-aortic balloon pump (IABP) use as independent risk factors for AKI. For patients who required RRT, the SCr and IDDM remained independent predictors. Early 30-day mortality (11.5% vs 0.9%) was significantly higher in patients who developed AKI following CABG. Similarly, AKI was associated with a slight but statistically significant increase in intensive care unit (ICU) and hospital stay. Conclusion: Better prognostication and preventative strategies are required to better risk stratify patients undergoing CABG and optimise utilisation of limited healthcare resources.