Renal biomarkers of kidney injury in cardiorenal syndrome.

The cardiorenal syndromes comprise a group of disorders in which impairment of either the heart or the kidney results in injury to the other. Although the pathophysiology is not yet well understood, the clinical consequences are increasingly recognized. In congestive heart failure, the development of worsening renal function is associated with increased hospitalizations and death. Urinary biomarkers offer a rapid and noninvasive method for detecting kidney injury. The role of urinary biomarkers such as neutrophil gelatinase-associated lipocalin, kidney injury molecule 1, N-acetyl-β-D-glucosaminidase, interleukin-18, and cystatin C are being investigated to provide diagnostic, prognostic, and, eventually, therapeutic information. This article reviews the utility of urinary biomarkers in congestive heart failure and explores directions for future research.