Correlation Between Plasma B-Type Natriuretic Peptide Levels and Remote Dielectric Sensing in Patients with Heart Failure

Plasma B-type natriuretic peptide (BNP) is a practical tool with which to estimate hemodynamic status in-cluding intra-cardiac pressure in patients with heart failure (HF). However, plasma BNP levels cannot be measured immediately in an outpatient private clinic. We investigated the value of remote dielectric sensing (ReDS), a novel non-invasive electromagnetic energy-based tool to quantify lung fluid amount immediately, to predict plasma BNP levels. Successive measurements of ReDS values and plasma BNP levels were performed in patients hospitalized to treat HF in a prospective manner. Correlations between ReDS values and plasma BNP levels were assessed. A total of 117 datasets for HF patients were obtained in this prospective study. The median ReDS value was 28% (interquartile range: 25%, 34%) and the median plasma BNP level was 205 (86, 469) pg/mL, both of which had a slight correlation (r = 0.234, P = 0.011). Their correlation improved when those with a body mass index less than 18.5 (n = 23) were excluded (r = 0.278, P = 0.007). ReDS might be a practical tool for estimating plasma BNP levels, particularly in outpatient private clinics where the immediate measurement of plasma BNP levels is not available.