Nurse led assessment of congestion in outpatient heart failure patients: remote dielectric sensing versus lung ultrasound comparison

Abstract Introduction Congestion stands as a primary driver behind exacerbating heart failure (HF), leading to hospitalizations and increased mortality rates. Despite the evident significance of congestion as a prognostic indicator, there exists a pressing need for a straightforward, trustworthy assessment method that caters to various healthcare providers' needs. Aims To assess the feasibility and compare the accuracy of nurse-led congestion assessment using radar based dielectric sensing (ReDS) to a "gold-standard" point of care assessment using lung ultrasound (LUS). Methods A retrospective analysis of consecutive patient visits at the ambulatory advanced HF clinic was used in which both exams (ReDS and LUS) were conducted. Study population included heart failure patients (Stage C, NYHA II-IV). ReDS, an objective non-invasive, transcutaneous measurement of lung fluid status, was assessed by HF nurse and LUS, evaluated using 6 measurement zones, was performed by HF cardiologist. Results During 17-month period and 174 clinic visits (103 patients), ReDS and LUS were recorded simultaneously. Mean ReDS reading was 33%±6% vs. mean LUS of 2.3±3.2 B-lines. Pearson correlation coefficient between the readings was moderate r= 0.41 (p<0.05). For LUS cutoff of 3 B-lines, ReDS sensitivity was 55.5% and specificity was 70% (p<0.01). ReDS negative predictive value (NPV) was 88% with positive predictive value (PPV) of 27%. ReDS overall accuracy was 68%. Conclusion Despite its low sensitivity, nurse-led ReDS assessment is feasible and possess a relatively high NPV allowing to rule out congestion at point-of-care. The simplicity of use empowers more health providers to assess congestion.