Biomarkers and heart–kidney interaction

© The Author(s) 2018. Chronic kidney disease (CKD) is becoming epidemic in the western world with 20 million Americans and a similar number of European citizens affected. Epidemiological studies confirm that CKD confers at least a two-fold increase in cardiovascular risk. Compared with age-matched persons in the general population, both coronary disease and left ventricular hypertrophy are more prevalent in those with CKD. Therefore, it is not unexpected that 33–56% of heart failure (HF) patients have impaired renal function. The interpretation of biomarkers in either symptomatic or asymptomatic patients with CKD has been a source of confusion and controversy since their introduction into clinical practice. However, numerous recent studies have shed considerable light on the interpretation of biomarker levels. In the current review, we focus on biomarkers of myocyte injury (cardiac troponins) and of HF, mainly natriuretic peptides but also soluble interleukin-1 receptor-like 1 (ST2) and galectin-3, and novel biomarkers of renal dysfunction (neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, cystatin-C, and N-acetyl-(D)-glycosa-minidase) in patients with renal disease. Clinicians must, in most instances, adjust biomarker cut-off values whenever evaluating patients with CKD. Among the options discussed here, ST2 is the least influenced by renal function, while galectin-3 appears to be significantly influenced by CKD. None of the novel renal biomarkers have met the bar for clinical use.