External Sensors for remoTe MoniToring of Heart Failure Patients With Implantable Defibrillators: the ESTIMATE-HF Study

Based on positive outcomes from numerous randomized, controlled trials, the current European Society of Cardiology (ESC) guidelines and current American guidelines for the management of chronic heart failure include the implantable defibrillators as a standard of care in selected chronic heart failure patients .

Heart failure patients with implantable defibrillators often visit the hospital for unscheduled examinations, placing a great burden on healthcare providers. Device manufacturers offer a technology for remote defibrillator monitoring with the purpose of allowing physicians to remotely access patients' data and reducing unnecessary routine and interim visits. The Evolution of Management Strategies of Heart Failure Patients With Implantable Defibrillators (EVOLVO) study was a multicenter randomized trial designed to assess whether remote management can reduce emergency healthcare use in heart failure patients implanted with defibrillators endowed with specific diagnostic features compared with standard management consisting of scheduled in-office visits and patient response to audible alerts. Over 16 months, the rate of emergency department or urgent in-office visits for heart failure, arrhythmias, or device-related events decreased by 35% and total healthcare visits were 21% less frequent with remote monitoring.

The study confirmed that remote management of heart failure patients implanted with defibrillators allows timely notification of potentially critical situations. Moreover, it has the effect of shifting healthcare visits from the emergency department to the clinic and increasing the appropriateness of in-office visits, thereby reducing costs and the burden on the healthcare system.

Nonetheless, in the EVOLVO study these findings were obtained with defibrillators equipped with specific diagnostic and alerting capabilities, and thus they cannot be fully extended to different technologies. In particular, defibrillators were equipped with these alert capability for the detection of possible fluid accumulation and decompensation, and these alerts accounted for the majority of endpoints recorded during the study.

That alert was shown to be associated with a relatively high rate of false positive detections , and the Diagnostic Outcome Trial in Heart Failure (DOT-HF) recently showed an increased number of hospital admissions among patients with the audible alert enabled.