Can monitoring of intrathoracic impedance reduce morbidity and mortality in patients with chronic heart failure? Rationale and design of the Diagnostic Outcome Trial in Heart Failure (DOT-HF)

Background: Chronic heart failure is associated with frequent hospitalisations which are often due to volume-overload decompensation. Monitoring of intrathoracic impedance, measured from an implanted device, can detect increases in pulmonary fluid retention early and facilitate timely treatment interventions. Objective: The DOT-HF trial is designed to investigate if ambulatory monitoring of intrathoracic impedance together with other device-based diagnostic information can reduce morbidity and mortality in patients with chronic heart failure who are treated with cardiac resynchronization therapy (CRT) and/or an implantable defibrillator (ICD). Methods: Approximately 2400 patients will be randomised in a 1: 1 fashion to a management strategy with access to the diagnostic information from the implantable device ("access arm"), or a "control arm", where this information is not made available. Study subjects fulfil standard indications for CRT and/or ICD as outlined in current guidelines. In the access arm, a fluid alert algorithm is used to give early warning of decreasing intrathoracic impedance indicating a high risk of an impending volume-overload decompensation. The primary endpoint of DOT-HF is the composite of all-cause mortality or heart failure hospitalisation. Secondary and exploratory endpoints include all-cause mortality, the impact on total health care utilization, quality of life and cost effectiveness. The study is expected to close recruitment during 20 10 and to report in 2012. (C) 2008 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.