Body composition analysis in patients with acute heart failure: the Scale Heart Failure trial

Abstract

Aims: In this study, we aimed to investigate whether body composition analysis (BCA) derived from bioelectrical impedance vector analysis (BIVA) could be used to monitor the hydration status of patients with acute heart failure (AHF) during intensified diuretic therapy.

Methods and results: This observational, single-centre study involved a novel, validated eight-electrode segmental body composition analyser to perform BCA derived from BIVA with an alternating current of 100 μA at frequencies of 5, 7.5, 50, and 75 kHz. The BCA-derived and BIVA-derived parameters were estimated and compared with daily body weight measurements in hospitalized patients with AHF. A total of 867 BCA and BIVA assessments were conducted in 142 patients (56.3% men; age 76.8 ± 10.7 years). Daily changes in total body water (TBW) and extracellular water (ECW) were significantly associated with changes in body weight in 62.2% and 89.1% of all measurements, respectively (range, ±1 kg). Repeated measures correlation coefficients between weight loss and TBW loss resulted with rho 0.43, P < 0.01, confidence interval (CI) [0.36, 0.50] and rho 0.71, P > 0.01, CI [0.67, 0.75] for ECW loss. Between the first and last assessments, the mean weight loss was -2.5 kg, compared with the -2.6 L mean TBW loss and -1.7 L mean ECW loss. BIVA revealed an increase in mean Resistance R and mean Reactance X_c across all frequencies, with the subsequent reduction in body fluid (including corresponding body weight) between the first and last assessments.

Conclusions: Body composition analysis derived from BIVA with a focus on ECW is a promising approach to detect changes in hydration status in patients undergoing intensified diuretic therapy. Defining personalized BIVA reference values using bioelectrical impedance devices is a promising approach to monitor hydration status.

Keywords: Acute heart failure; Bioelectrical impedance vector analysis; Body composition analysis; Diuretic therapy; Impedance; eHealth.

Figure 1

Body composition analyser and electrode positions. (A) Body Composition Analyser seca® mBCA 515, Hamburg, Germany. (B) Electrode positions.

Figure 2

Flow of participants in the Scale Heart Failure trial. AHF, acute heart failure; PM, pacemaker; VRE, vancomycin‐resistant enterococci.

Figure 3

(A) Left: Association between weight loss (in kilograms) and extracellular water loss (in litres). (A) Right: Association between weight loss (in kilograms) and total body water loss (in litres). Red points are measurements that exceed the clinical relevant difference of 1 L (10.9% for extracellular water and 37.8% for total body water). (B) Change of different parameters between the first and last assessments.

Figure 4

(A–H) Diuretic drugs, weight, and bioelectrical impedance vector analysis [with standardized Resistance Z (R) and Reactance Z (X_c)] during hospitalization in the six patients with the most measurements, ranging from 8 to 26 body composition analysis for each patient. The upper third describes the prescribed diuretic medication during hospitalization, whereas the middle third shows the bioelectrical impedance vector analysis graphs compared with the weight loss in the lower third. furo, furosemide IV; IV, intravenous; met, metolazone PO; PO, per os; Spir, spironolactone PO; tora, torasemide PO.