When Cardiac Failure, Kidney Dysfunction, and Kidney Injury Intersect in Acute Conditions

OBJECTIVE: To review and describe diagnostic and prognostic value of biomarkers of renal function and renal injury in the cardiorenal syndrome complicating acutely decompensated heart failure. DATA SOURCES: PubMed search and review of relevant medical literature. STUDY SELECTION: Two reviewers screened and selected studies in English with diagnostic or prognostic assessment of biomarkers of renal injury. DATA EXTRACTION: Narrative review of the medical literature. DATA SYNTHESIS: Cardiorenal syndrome has a complex pathophysiology and has a generally poor prognosis in patients with acutely decompensated heart failure. Among the methods to recognize risk for cardiorenal syndrome may be the use of circulating or urinary biomarkers, which may allow for more accurate early diagnosis and risk stratification; use of biomarkers may provide important pathophysiologic understanding beyond risk prediction. However, different phenotypes of patients with acute renal dysfunction may be present, which has ramifications with respect to response to treatment strategies. Addition of biomarkers of renal injury may provide additional prognostic value to biomarkers of renal or cardiac function, but more data are needed. CONCLUSIONS: Biomarkers reflecting renal function and injury are likely to better phenotype subgroups of patients with cardiorenal syndrome and to provide unique prognostic information. Future studies are needed relative to strategies using such biomarkers to guide care of affected patients.