Abstract 125: Kidney-specific Biomarkers For Predicting Acute Kidney Injury Following Cardiac Arrest

Abstract

Introduction: Acute kidney injury (AKI) is a common complication following cardiac arrest (CA) and is associated with poor outcomes. Early detection of AKI is crucial; serum creatinine (sCR) is the most commonly used indicator of AKI, despite low sensitivity and specificity for early detection of AKI. Hypothesis: Kidney-specific serum biomarkers neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and cystatin-C could better predict post-CA AKI than sCR. Methods: Adult CA patients who had kidney-specific biomarkers of AKI collected shortly after return of spontaneous circulation (ROSC) as part of four randomized trials and one observational study were included. Patients with Kidney Disease Improving Global Outcome (KDIGO) stage III AKI or end-stage renal disease, or renal replacement therapy at the time of enrollment were excluded. The association between renal biomarker levels (sCR, NGAL, KIM-1, cystatin-C) shortly after ROSC and the development of KDIGO stage III AKI within 7 days of enrollment were assessed as well as their predictive value of future AKI development. Results: Of 155 patients, 46 (29.7%) developed stage III AKI within 7 days, and 98 (63.2%) died prior to hospital discharge. Patients who developed stage III AKI, compared to those who did not, had higher median levels of sCR (1.4 mg/dL [IQR: 1.2, 1.9] vs. 1.2 [IQR: 1.0, 1.5]; p=0.001), NGAL (868,208 pg/mL [IQR: 412,547.1, 1,341,597] vs. 298,928.3 [IQR: 170,786.6, 594,389.7], p<0.001). and cystatin-C (1,649,202 pg/mL [IQR: 1,184,788, 2,440,583] vs. 1,132,955 [IQR: 795,323.7, 1,580,415]; p<0.001). There was no difference in KIM-1 between groups (150.6 pg/mL [IQR: 150.8, 288.4] vs. 158.9 [IQR: 78.8, 284.7]; p=0.351). There was no significant difference between biomarkers in their ability to predict development of stage III AKI (NGAL AUC=0.75 [95%CI: 0.67-0.83], cystatin-C AUC=0.71 [95%CI: 0.62-0.79], KIM-1 AUC=0.55 [95%CI: 0.45-0.65], sCR AUC=0.67 [95%CI: 0.57-0.76], p>0.05 for all). Both NGAL and cystatin-C performed better than KIM-1 (p<0.01). Conclusion: In post-CA patients, sCR, NGAL, and cystatin-C (but not KIM-1) measured shortly after ROSC were higher in patients who subsequently developed AKI. No biomarker was statistically superior to sCR. Comparison was limited by the small number of patients who developed AKI.