The emerging role of biomarkers and bio-impedance in evaluating hydration status in patients with acute heart failure

The quantitative and qualitative estimation of total body fluid content has proven to be crucial for both diagnosis and prognosis assessment in patients with heart failure. The aim of this review is to summarize the current techniques for assessing body hydration status as well as the principal biomarkers associated with acute heart failure (AHF). Although clinical history, physical examination and classical imaging techniques (e.g., standard radiography and echocardiography) still represent the cornerstones, novel and promising tools, such as biomarkers and bio-electrical impedance are achieving an emerging role in clinical practice for the assessment of total body fluid content. In the acute setting, the leading advantages of these innovative methods over device are represented by the much lower invasiveness and the reasonable costs, coupled with an easier and faster application. This article is mainly focused on AHF patients, not only because the overall prevalence of this disease is dramatically increasing worldwide, but also because it is well-known that their fluid overload has a remarkable diagnostic and prognostic significance. It is thereby conceivable that the bio-electrical vector analysis (BIVA) coupled with laboratory biomarkers might achieve much success in AHF patient management in the future, especially for assisting diagnosis, risk stratification, and therapeutic decision-making.