Background

The incidence and risk factors of cardiac surgery–associated acute kidney injury (CS-AKI) are variable. We describe the incidence of severe postoperative CS-AKI (i.e., stage 2 or 3 AKI) and operative mortality in total neonates and in neonates with single ventricle (SV) physiology at a high-volume heart center. Additionally, we determine risk factors associated with severe CS-AKI and operative mortality.

Methods

A single-center, retrospective cohort study of neonates who underwent STAT (The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery) category 3, 4, and 5 surgeries between June 2015 and June 2022 was conducted. AKI was defined using the neonatal Kidney Disease Improved Global Outcome criteria. The cohort was compared based on SV physiology vs. biventricular physiology, development of stage 2 or 3 AKI vs. no AKI or stage 1 AKI, and operative mortality. Associations of risk factors were determined using univariate and multivariate analyses.

Results

Our study included 501 neonates, 223 (45%) of which had SV physiology. About 50% developed stage 2 or 3 AKI in both neonatal and SV cohorts. The operative mortality rate was 8% for total neonates and 14% for SV neonates. Following multivariate analyses, longer cardiopulmonary bypass time and delayed sternal closure were associated with severe AKI stages and operative morality. A lower preoperative creatinine was independently associated with severe postoperative AKI.

Conclusions

There is a high prevalence of CS-AKI and operative mortality in both of our neonatal cohorts, with multiple risk factors associated with both outcomes. Future prospective, multi-center, randomized studies and development of an AKI prediction tool are necessary to further investigate these findings.