Abstract Body (Do not enter title and authors here): Background: Physicians have to find a balance between decongestion therapy and the risk of dehydration so non-invasive methods assessing congestion are of great importance.
Purpose: The study aimed to compare the clinical assessment of congestion to bioimpedance and microwave spectroscopy.
Methods: 27 hospitalized HF patients with congestion (40% females) (Congestion Group) and 59 HF patients without fluid overload (66% females) (NON-Congestion Group) were included. Clinical examination, chest x-ray, laboratory results, echocardiography, non-invasive body mass analysis (Tanita Pro), NT-poBNP, and selected modern biomarkers concentrations [GDF-15, galectin-3, FABP, copeptin, VEGF were performed. Additionally, we assessed pulmonary congestion using a proprietary sensor with a microwave spectroscopy method based on analyzing the dielectric properties of an object (patent applications P.442466).
Results: There were no differences in body mass index, blood pressure values, left ventricular ejection fraction (LVEF), and echocardiographic parameters of diastolic left ventricular function between groups. In the Congestion Group, we observed significantly more patients in NYHA Class 3 and 4 (p<0.001), lower values of fT3 (median 2.4 vs 2.7; p=0.02), higher a FIB-4 index (p=0.04), lower GFR MDRD (median 52.7 vs 66.7;p=0.04), higher concentrations of: NT-proBNP (pg/ml) (median 545 vs 101; p<0.001), galectin-3 (ng/ml) (median 15.01 vs 11.35; p=0.01), GDF-15 (pg/ml) (median 2069.27 vs 734.64; p=0.01), FABP (pg/ml) (median 293.6 vs 101; p=0.008) compared to NON-Congestion Group, and a larger number of detected congestion in chest x-ray (p<0.01) and more patients with limb edema (p= 0.0037). The patients with congestion also needed longer hospitalizations (p=0.008). Patients with congestion had lower total body water content in kg and intracellular water (ICW) (kg) (p=0.02 and p=0.01, respectively), and the higher extracellular water/total body water index (ECW/TBW) (p=0.001) assessed in bioimpedance and significantly higher Absorption Loss evaluated with the use of microwave spectroscopy (p=0.02). In a multiple logistic regression model, the factor that was independently associated with clinically diagnosed congestion was NT-proBNP >1095 pg/ml (OR 111.6, 95% CI: 2.6-50.6; p=0.001) (Figure 1).
Conclusions: Absorption Loss and ECW/TBW are valuable new diagnostic tools in diagnosing lung congestion in patients with heart failure.