introductionThe long-term renal outcomes of survivors of pediatric acute kidney injury (AKI) are varied within the current literature, and we aim to establish long-term renal outcomes for pediatric patients after cardiac surgery. We studied long-term renal outcomes and markers of kidney injury in pediatric patients after congenital cardiac surgery.

methodsIn a prospective case-control observational study (the Renal Outcomes in Children with acute Kidney injury post cardiac Surgery [ROCKS] trial) we reviewed all children who underwent cardiac surgery on cardiopulmonary bypass (December 2010-2017).

resultsDuring the study period, 2035 patients underwent cardiac surgery, of whom 9.8% developed AKI postoperatively. Forty-four patients who had postoperative AKI had a long-term follow-up, met our inclusion criteria, and were compared with 49 control subjects. We conducted a univariate analysis of reported parameters. At a median follow-up of 41 months, the cases had significantly higher urine levels of neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), and kidney injury molecule-1 (KIM-1). The biomarkers remained higher after adjusting for the urine creatinine, and the ratio of urine KIM-1/urine creatinine was significantly higher among cases. None of the patients had proteinuria or hypertension on follow-up. The presence of AKI, AKI stage, and younger age were not associated with the occurrence of low glomerular filtration rate (GFR) at follow-up.

conclusionsUrinary biomarker abnormalities persist years after a congenital cardiac surgery in children, who may have a low GFR on follow-up. The presence of AKI, AKI stage, and younger age at surgery are not associated with the occurrence of low GFR at follow-up. Children with a higher surgical complexity score have lower GFR on follow-up.