De Ieso F, Mutke MR, Brasier NK, et al. - In heart failure patients receiving intensified diuretic therapy, body composition analysis (BCA) derived from bioelectrical impedance vector analysis (BIVA) with a focus on extracellular water (ECW) affords a promising tool to identify alterations in hydration status. Effective monitoring of hydration status can be achieved by defining personalized BIVA reference values using bioelectrical impedance devices.

• This is an observational, single-center study of hospitalized patients with acute heart failure; a total of 867 BCA and BIVA assessments were performed in 142 patients.

• A novel, validated eight-electrode segmental body composition analyzer was used to conduct BCA derived from BIVA with an alternating current of 100 μA at frequencies of 5, 7.5, 50, and 75 kHz.

• In 62.2% and 89.1% of all measurements, daily alterations in total body water (TBW) and ECW were significantly related to alterations in body weight, respectively.

• The mean weight loss was −2.5 kg between the first and last assessments, vs the −2.6 L mean TBW loss and −1.7 L mean ECW loss.

• BIVA unveiled an increment in mean Resistance R and mean Reactance X _c across all frequencies, with subsequent decrease in body fluid (including corresponding body weight) between the first and last evaluations.