Real World Use of AKI Biomarkers: A Quality Improvement Project Using Urinary Tissue Inhibitor Metallo-protease-2 and Insulin-like Growth Factor Binding Protein 7 ([TIMP-2]*[IGFBP7])

Introduction. Novel urinary biomarkers, including Tissue Inhibitor Metallo-protease-2 and Insulin-like Growth Factor Binding Protein 7 ([TIMP-2]*[IGFBP7]), have been developed to identify patients at risk for acute kidney injury (AKI). We investigated the real world clinical utility of [TIMP-2]*[IGFBP7] in preventing AKI.Methods. We performed a prospective single-center quality improvement study of intensive care unit (ICU) patients at risk for severe (KDIGO stage 2 or 3) AKI. In the prospective cohort, ICU providers were allowed to order [TIMP-2]*[IGFBP7] for patients at their discretion, then offered AKI practice recommendations based on the result. Outcomes were compared to a historical cohort in which biomarker values were not reported to clinical teams.Results. There was no difference in 7-day progression to severe AKI between the prospective (n=116) and historical cohorts (n=63) when [TIMP-2]*[IGFBP7] & GE;0.3 (24(28%) vs 8(21%), p=0.38) despite more stage 1 AKI at time of biomarker measurement in the prospective cohort (58(67%) vs 9(23%), p<0.001). In the prospective cohort, patients with higher [TIMP-2]*[IGFBP7] values were more likely to receive a nephrology consult. Early consultation (within 24 hours of biomarker measurement, n=20) had a nonsignificant trends towards net negative volume balance (-1787mL(6716mL) vs +4974mL(15540mL)) and more diuretic use (19(95%) vs 8(80%)), and was associated with less severe AKI (9(45%) vs 10(100%), p=0.004) and inpatient dialysis (2(10%) vs 7(70%), p=0.002) compared to delayed consultation (n=10).Discussion/Conclusions. Despite the prospective cohort having more preexisting stage 1 AKI, there were equal rates of progression to severe AKI in the prospective and historical cohorts. In the setting of [TIMP-2]*[IGFBP7] reporting, there were more nephrology consults in response to elevated biomarker levels. Early nephrology consultation resulted in improved volume balance and favorable outcomes compared to delayed consultation.

Automated summary

This study investigated the clinical utility of novel urinary biomarkers [TIMP-2]*[IGFBP7] in preventing acute kidney injury (AKI). The results showed that patients with higher [TIMP-2]*[IGFBP7] values were more likely to receive nephrology consults, and early consultation resulted in improved volume balance and favorable outcomes.