Introduction: biomarkers in heart failure

Practitioners have long known that the clinical manifestations of cardiovascular disease, exemplified by signs and symptoms, may be nonspecific and confusing during the diagnostic process. Worse, these classical clinical indicators do not fully reflect the extent of the underlying pathophysiological process and may give an incomplete picture of prognosis. In addition, the treatment of cardiovascular disease has become increasingly complex, with polypharmacy, the rule and novel devices often of benefit, but standard clinical assessment often does not indicate what combination of therapy should be used or adequately reflect the response to treatment. Finally, signs and symptoms typically emerge late in the natural history of these disorders, delaying their identification until after preventative measures and early treatments could have reduced disease burden. These considerations point to the limitations of standard clinical assessment for the diagnosis, prognostic stratification, and monitoring of therapeutic response in cardiovascular disease and indicate more sophisticated characterization of the clinical phenotype is needed. Biomarkers are emerging as one powerful adjunct to standard clinical assessment in a variety of cardiovascular disorders including heart failure. Biomarkers function as physiological measurements that may be molecular in nature (specific hormone concentration, genotype, or protein expression) or reflect macroscopic organ function (estimated pulmonary artery pressure or ambulatory blood pressure) [1]. The ability of biomarkers to provide more accurate and sensitive detection and characterization of cardiovascular disease than clinical assessment alone is becoming more widely accepted [2]. Ongoing investigation suggest that these physiological measurements, which may be defined as biological parameters subject to quantitative determination, are of significant clinical value as they appear to accurately reflect the extent of disease physiology, prognosis, and likely response to therapy. In this special edition of Heart Failure Reviews, composed by an international group of experts, various aspects of the current clinical utility of biomarkers in heart failure are presented along with an in depth discussion of many novel aspects and emerging concepts related to biomarkers in this major cardiovascular syndrome. Molecular biomarkers that reflect critical systems in the pathophysiology of heart failure (fibrosis or inflammation) and important markers of disease activity in this syndrome (natriuretic peptides) are emphasized in the review. As expected, several papers focus on natriuretic peptides, which represent a highly successful application of biomarkers in heart failure, and whose role continues to be refined and expanded [3]. Chiong, Pu, and co-authors provide comprehensive and detailed reviews of how natriuretic peptides have enhanced diagnosis and prognostic stratification in both acute and chronic heart failure and how they vary in other clinical subsets of heart failure and other important disease states. As illustrated by the remainder of the papers, many new markers and strategies for the utilization of biomarkers as physiological probes and aids in management have been developed these approaches that build upon the solid foundation established by the natriuretic peptides. Rocchiccioli, McMurray, and Dominiczak begin the issue with a comprehensive review of biomarkers currently K. F. Adams (&) Departments of Medicine and Radiology, School of Medicine, UNC Heart Failure Program, University of North Carolina at Chapel Hill, 730 Martin Luther King Jr Blvd, Suite 207, Chapel Hill, NC 27514, USA e-mail: kfa@med.unc.edu