Overcoming the resistance to impedance monitoring in heart failure patients.

This editorial refers to ‘Device-based impedance measurement is a useful and accurate tool for direct assessment of intrathoracic fluid accumulation in heart failure’ by J. Becher et al ., doi:10.1093/europace/eup413 and ‘Intrathoracic impedance and pulmonary wedge pressure for the detection of heart failure deterioration' by M. Maines et al ., doi:10.1093/europace/eup419 Patients with moderate to severe heart failure who meet the criteria for implantation of a cardiac resynchronization therapy (CRT) device and/or an implantable defibrillator (ICD) carry a startling risk of suffering from adverse clinical events, in particular heart failure-related hospitalizations and death. Though CRT and ICDs improve survival and CRT also decreases morbidity, the event risk in device carriers remains high: while ICD treatment per se does not impact heart failure severity—from the perspective of the devil's advocate, it may contribute to prolonged suffering from recurring heart failure exacerbation—even many CRT recipients continue to suffer from frequent heart failure-related events, especially in the unfortunate group of non-responders. Therefore, increasing attention has recently been paid to the use of heart failure devices not only for therapeutic but also for diagnostic purposes. Device-based sensors and algorithms for continuous surveillance of various physiological parameters such as the heart rate, heart rate variability, physical activity, or arrhythmia incidence, may add valuable information to patient assessment and, thus, help to improve patient management in heart failure. In particular, diagnostic features of monitoring of cardiac filling pressures and pulmonary fluid retention have raised interest due to their potential to reveal changes in heart failure status timely and early enough to initiate appropriate therapeutic interventions and prevent further progression to overt cardiac decompensation. Both methods showed promising results in pilot studies,1,2 encouraging the design of large-scale clinical trials3, … *Corresponding author. Tel: +46 8 517 71629; fax: +46 8 31 1044, Email: frieder.braunschweig{at}karolinska.se