P5407Body-composition analysis of patients with acute heart failure - preliminary results from the SCALE HF trial
Authors: De Ieso F , Mutke M , Du Fay De Lavallaz J , Raichle C , Brasier N , Keller B , Sucker C , Abdelhamid K , Bloch T , Reissenberger P , Mueller C , Eckstein J 
Published: October 2019

Abstract

Background
Guidance for intensified diuretic therapy in acute heart failure (AHF) is mainly based on body weight measurement, frequently leading to a short episode of dehydration with kidney failure after recompensation. In addition, patients often present immobilized due to severe health issues making weight measurement stressful.

Purpose
Bioelectrical impedance analysis (BIA) may be a more direct approach to guide intensified diuretic therapy analysing patient's body composition. We hypothesized that patient's weight loss during therapy correlates with loss of body water measured by BIA. Therefore, we tested if this method could be an alternative to daily weight measurement.

Methods
We conducted an observational, single-centre study to evaluate and monitor body composition of patients hospitalised with AHF, adjudicated according to current ESC/HFA guidelines by a cardiologist. We used an eight-electrode, segmental, multi-frequency body composition analyser, previously validated against air displacement plethysmography, whole body MRI, deuterium and sodium bromide dilution. We investigated patients until hospital discharge or latest one day after ending intensified diuretic therapy. Disease specific properties, BIA and weight measurement were assessed daily. Furthermore, we investigated BIA raw data.

Results
390 BIA were applied on 76 patients (47 men; 29 women; mean age 76±11 years; mean weight 75.6±15.7 kg). 34 patients presented with global, 27 with left-heart, 8 with right-heart and 7 with not specified AHF. 44 patients presented with pleural effusion. Pearson correlations showed that total body water (r=0.737, p≤0.001) and extracellular water (r=0.69, p≤0.001) correlated each with total body weight. Changes in total body water accurately (within a range of ± 1kg) reflected changes in total body weight in 40.28% of the patients and changes in extracellular water showed a similarly accurate reflection of total body weight change in 68.06% of the patients. BIA raw-data analysis showed significant changes using Wilcoxon test between measurements at the beginning of intensified diuretic therapy and at its end. We found a significant increase of resistance (mean from 334.6±67.5 to 362.8±69.5 Ohm/m; p=0.021) and reactance (mean from 21.3±7.1 to 24.1±6.2 Ohm/m; p=0.009) standardized to patients height and a non-significant increase of phase angle (mean from 3.6±0.9 to 3.8±0.8 °; p=0.149) during hospitalisation.

Conclusion
BIA is able to estimate changes in total body weight by analysing changes in extracellular body water in patients under intensified diuretic therapy and raw data analysis seems even more accurate and promising. This data derive from a heterogeneous AHF patient group, needing further investigation. Once validated, wearable BIA connected to an automated device monitoring system would enable an easy to use diuretic therapy monitoring for impaired patients or outpatients and could help reducing care efforts.