Heart failure (HF) is the currently leading cause of hospitalization in people over 65 years in Europe. The standard evaluation of this disease does not reliably predict HF outcome. Volume overload due to neuro-hormonal activation is the primary factor leading to HF hospitalisation, and volume measurements by bioimpedance (BI) have preliminary shown to be useful for diagnosis and prognosis. However, the measures are performed punctually, or in a short period, but the dynamics of fluid overload in patients with acute HF during hospitalisation and after discharge have not been previously described. The aim of this study is evaluate the prognostic value of monitoring changes in body volumes by continuous BI measurement with a novel wearable device to predict early clinical outcome in patients with acute HF.