Residual Congestion on Discharge for Heart Failure Assessed by Impedance Technique Predicts 30-Day and One-Year Heart Failure Death. Results of IMPEDANCE-HF Extended Trial

Abstract

Introduction The aim of secondary analyses of the IMPEDANCE-HF extended trial was to find out if residual congestion on discharge for HF could predict 30-day and one-year Heart Failure death. Methods The IMPEDANCE-HF extended trial was a randomized controlled single-blinded trial of HF with LVEF ≤ 45% and NYHA class II-IV patients (ClinicalTrials.gov NCT01315223). Half of the patients (N=145) were assigned to the active Lung Impedance (LI)-guided treatment arm where clinicians were based therapy on LI level. The other half was assigned to the control arm where LI values were recorded but not conveyed to the clinical treatment team. A non-invasive impedance device (“CardioSet”, Tel Aviv) was used to assess the lung fluid content. Unlike the existing impedance devices, the present device can differentiate a true signal from the lungs from the noise signal of surrounding chest wall and enables to measure a small change in lung fluid content. A method to determine individual “dry” baseline LI (BLI) for each HF patient has been reported. BLI for each patient was used to calculate a new parameter, the ∆LIR= [(current LI/BLI)-1] × 100%, which determinate the degree of pulmonary congestion in time of measurement. Method. Degree of pulmonary congestion at discharge for HF hospitalization was divided into 5 categories. (1) ∆LIR= 0 to - 18% - minimal interstitial edema (IE), (2) ∆LIR= - 18.1 to -28% - mild IE, (3) ∆LIR= -28.1 to - 38 - moderate IE, (4) ∆LIR= -38.1 to -48% - severe IE to mild alveolar edema (AE) and (5) ∆LIR Results LI-guided patients were followed for 61.9.4±39.6 months and control patients for 46.7±33.3 months (p Conclusions The degree of pre-discharge pulmonary congestion as assessed by LI is a very robust and reliable predictor for 30-day and one-year HF death. Discharge of patients with pulmonary congestion corresponding to categories 4 and 5 is unacceptable and associated with 30-day and one-year mortality more than 80%.