Urinary Syndecan-1 and acute kidney injury after pediatric cardiac surgery.

INTRODUCTION: Acute kidney injury (AKI) is a common occurrence after pediatric cardiac surgery. Plasma syndecan-1 is a biomarker of endothelial glycocalyx damage and it is associated with AKI. Syndecan-1 is also expressed in renal tubular cells but there is no study evaluating urinary syndecan-1 in predicting AKI. METHODS: Prospective cohort study with 86 patients ≤18 years submitted to cardiac surgery at one reference institution. Postoperative urinary syndecan-1 was collected within the first 2 h after cardiac surgery. Severe AKI - defined according to KDIGO as stage 2 or 3 - doubling of serum creatinine from the preoperative value or need for dialysis during hospitalization was the main outcome. Analyses were adjusted for clinical cofounders. RESULTS: Postoperative urinary syndecan-1 levels were higher in patients with severe AKI and even after adjustment for several clinical variables; the fourth quartile was significantly associated with severe AKI. The AUC-ROC for postoperative urinary syndecan-1 showed good discriminatory capacity (AUC-ROC = 0.793). The addition of urinary syndecan-1 improved the discrimination capacity of a clinical model (0.78 to 0.84). It also improved risk prediction, as measured by net reclassification improvement (NRI). CONCLUSION: Urinary syndecan-1 predicts severe AKI after pediatric cardiac surgery. Moreover, it appears to add capacity to predict severe AKI into a clinical model.

Syndecan-1 improves severe acute kidney injury prediction after pediatric cardiac surgery.

OBJECTIVE: Acute kidney injury is a common occurrence after pediatric cardiac surgery and is associated with adverse patient outcomes. Syndecan-1 is a biomarker of endothelial glycocalyx damage, and its early increment after surgery can be associated with acute kidney injury. METHODS: We performed a prospective cohort study with 289 patients aged less than 18 years who underwent cardiac surgery at 1 reference institution. Postoperative plasma syndecan-1 was collected within the first 2 hours after cardiac surgery. Severe acute kidney injury, defined according to Kidney Disease: Improving Global Outcomes stage 2 or 3, doubling of serum creatinine from the preoperative value, or need for dialysis during hospitalization, was the main outcome. Analyses were adjusted for clinical variables and "renal angina index" components (early decrease in estimated creatinine clearance from baseline and increase in percent of intensive care unit fluid overload on the first postoperative day). RESULTS: Plasma syndecan-1 levels measured early in the postoperative period were independently associated with severe acute kidney injury. The accuracy of postoperative syndecan-1 for the diagnosis of severe acute kidney injury was moderate (area under the curve receiver operating characteristic, 0.77; 95% confidence interval, 0.68-0.85). The addition of syndecan-1 improved the discrimination capacity of a clinical model from 0.80 to 0.86 (P = .004) and improved risk prediction, as measured by net reclassification improvement and integrated discrimination improvement. Postoperative sundecan-1 levels also were independently associated with longer length of intensive care unit and hospital stay. CONCLUSIONS: Postoperative plasma syndecan-1 is associated with subsequent severe acute kidney injury and poor outcomes among children undergoing cardiac surgery. It may be useful to identify patients who are at increased risk for acute kidney injury after cardiac surgery.