Bioimpedance-based edema index as a promising indicator of hypervolemia in heart failure

초록

Background: Hospitalization for acute decompensation is associated with mortality in heart failure (HF) patients. If early detection and clinical intervention can take place at a subclinical stage of hypervolemia, it may lead to decreased hospitalization and mortality. Bioimpedance analysis (BIA), a noninvasive and inexpensive method of measuring body water compartments, may be a promising tool of remote patient monitoring. We aimed to assess the diagnostic value of edema index by BIA in heart failure patients. Methods: Patients with heart failure who received both N-terminal (NT)-pro hormone BNP (NT-proBNP) and body composition test at were enrolled in the Hospital from July 2018 to July 2019. BIA was measured using a tetra-polar eight-point tactile electrode system. For patients who had multiple tests, the initial results were included in analysis (N=87). We tested the correlation between edema index, calculated by the proportion of extracellular water (ECW) among total body water (TBW), and NT-proBNP levels. Results: Edema index by BIA was positively correlated with NT-proBNP levels with a strong relationship (r=0.604, P <0.001). After multiple sets of adjustment made for age, body mass index (BMI), gender and estimated glomerular filtration rate (eGFR), a consistently strong relationship was observed (Table). Conclusion: Edema index measured by BIA shows a strong positive correlation with NT-proBNP levels, promising to be a noninvasive and cost-effective index of volume overload.