Abstract
Background Children with Down syndrome (DS) often have hypoplastic kidneys and urinary tract malformations that increase their renal dysfunction risk. They also have a higher congenital heart disease (CHD) rate, requiring cardiac surgery during infancy. Renal dysfunction in such patients may be associated with the development of cardiac surgery-associated acute kidney injury (CS-AKI), but this remains unclear. In this study, we compared the incidence, severity, and prognosis of CS-AKI between infants with and without DS complicated by CHD. Methods We retrospectively analyzed 144 consecutive infants with (n=59) and without (n=85) DS who underwent cardiac surgery for CHD between January 2013 and October 2018. The primary endpoint was CS-AKI incidence, and the secondary endpoints were CS-AKI severity and perioperative prognosis. We assessed the severity of CS-AKI using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Results The DS group had significantly smaller kidney size when measured by ultrasound at birth than the non-DS group (P<0.001). Preoperative renal function assessment revealed significantly higher serum creatinine (Cr, 0.29 vs. 0.20 mg/dL, P<0.001) and lower Cr-estimated glomerular filtration rates (82.0 vs. 101.4 mL/min/1.73 m(2), P<0.001) in the DS group than in the non-DS group. CS-AKI incidence and severity did not differ between the groups. Risk factors for CS-AKI incidence included being younger at the time of cardiac surgery and a prolonged cardiopulmonary bypass in the overall cohort and DS group. Conclusions The incidence and severity of CS-AKI did not differ between the DS and non-DS groups. Understanding potential renal dysfunction and managing patients with DS and CHD may assist in preventing perioperative acute kidney injury after cardiac surgery.