Cardiac Biomarkers and Acute Kidney Injury After Cardiac Surgery

Abstract

OBJECTIVES: To examine the relationship of cardiac biomarkers with postoperative acute kidney injury (AKI) among pediatric patients undergoing cardiac surgery.METHODS: Data from TRIBE-AKI, a prospective study of children undergoing cardiac surgery, were used to examine the association of cardiac biomarkers (N-type pro-B-type natriuretic peptide, creatine kinase-MB [CK-MB], heart-type fatty acid binding protein [h-FABP], and troponins I and T) with the development of postoperative AKI. Cardiac biomarkers were collected before and 0 to 6 hours after surgery. AKI was defined as a $50% or 0.3 mg/dL increase in serum creatinine, within 7 days of surgery. RESULTS:Of the 106 patients included in this study, 55 (52%) developed AKI after cardiac surgery. Patients who developed AKI had higher median levels of pre-and postoperative cardiac biomarkers compared with patients without AKI (all P , .01). Preoperatively, higher levels of CK-MB and h-FABP were associated with increased odds of developing AKI (CK-MB: adjusted odds ratio 4.58, 95% confidence interval [CI] 1.56-13.41; h-FABP: adjusted odds ratio 2.76, 95% CI 1.27-6.03). When combined with clinical models, both preoperative CK-MB and h-FABP provided good discrimination (area under the curve 0.77, 95% CI 0.68-0.87, and 0.78, 95% CI 0.68-0.87, respectively) and improved reclassification indices. Cardiac biomarkers collected postoperatively did not significantly improve the prediction of AKI beyond clinical models.CONCLUSIONS: Preoperative CK-MB and h-FABP are associated with increased risk of postoperative AKI and provide good discrimination of patients who develop AKI. These biomarkers may be useful for risk stratifying patients undergoing cardiac surgery.WHAT'S KNOWN ON THIS SUBJECT: Acute kidney injury (AKI) occurs in up to 50% of children after cardiopulmonary bypass and is associated with adverse outcomes. Renal biomarkers have been shown to predict postoperative AKI, but few studies have examined cardiac biomarkers for risk classification.WHAT THIS STUDY ADDS: Preoperative levels of creatine kinase-MB and heart-type fatty acid binding protein are strongly associated with the development of postoperative AKI after pediatric cardiac surgery and can be used to improve preoperative clinical risk prediction.