Remote Monitoring in Heart Failure: the Current State.

The treatment of congestive heart failure is an expensive undertaking with much of this cost occurring as a result of hospitalization. It is not surprising that many remote monitoring strategies have been developed to help patients maintain clinical stability by avoiding congestion. Most of these have failed.

Stratifying patients at the risk of heart failure hospitalization using existing device diagnostic thresholds.

Background: Heart failure hospitalizations (HFHs) cost the US health care system ∼$20 billion annually. Identifying patients at risk of HFH to enable timely intervention and prevent expensive hospitalization remains a challenge. Implantable cardioverter defibrillators (ICDs) and cardiac resynchronization devices with defibrillation capability (CRT-Ds) collect a host of diagnostic parameters that change with HF status and collectively have the potential to signal an increasing risk of HFH.

Implantable device diagnostics on day of discharge identify heart failure patients at increased risk for early readmission for heart failure.

Aims: We hypothesized that diagnostic data in implantable devices evaluated on the day of discharge from a heart failure hospitalization (HFH) can identify patients at risk for HF readmission (HFR) within 30 days.

Methods And Results: In this retrospective analysis of four studies enrolling patients with CRT devices, we identified patients with a HFH, device data on the day of discharge, and 30-day post-discharge clinical follow-up. Four diagnostic criteria were evaluated on the discharge day: (i) intrathoracic impedance>8 Ω below reference impedance; (ii) AF burden>6 h; (iii) CRT pacing<90%; and (iv) night heart rate>80 b.

Development of a method to risk stratify patients with heart failure for 30-day readmission using implantable device diagnostics.

The aim of the present study was to evaluate whether diagnostic data collected after a heart failure (HF) hospitalization can identify patients with HF at risk of early readmission. The diagnostic data from cardiac resynchronization therapy defibrillator (CRT-D) devices can identify outpatient HF patients at risk of future HF events. In the present retrospective analysis of 4 studies, we identified patients with CRT-D devices, with a HF admission, and 30-day postdischarge follow-up data.

Threshold crossing of device-based intrathoracic impedance trends identifies relatively increased mortality risk.

Aims: Threshold crossings of impedance trends detected by implanted devices have been associated with clinically relevant heart failure events, but long-term prognosis of such events has not been demonstrated. The aim of this study is to examine the relationship between alterations in intrathoracic impedance and mortality risk in patients with implantable devices.

Methods And Results: We reviewed remote monitoring data in the de-identified Medtronic CareLink(®) Discovery Link that captured intrathoracic impedance trends for >6 months.

Uncovering interim clinical events at the time of clinical encounter by reviewing intrathoracic impedance threshold crossings.

Background: Acute decreases in intrathoracic impedance monitored by implanted devices have been shown to precede heart failure exacerbations, although there is still debate regarding its clinical utility in predicting and preventing future events. However, the usefulness of such information to direct patient encounter and enhance patient recall of relevant preceding clinical events at the point of care has not been carefully examined.

Methods And Results: In this multicenter study, we interviewed 326 patients with heart failure who received an implanted device with intrathoracic impedance-monitoring capabilities both before and after device information was reviewed.

A critical link between heart failure self-care and intrathoracic impedance.

Background: Effective self-care is regarded as essential to the management of heart failure (HF). The influence of self-care on HF decompensation, however, is not well understood. Accordingly, we examined the relationship between self-care and fluid accumulation accompanying worsening HF as indexed by decreasing intrathoracic impedance (Z).

Changes in intrathoracic impedance are associated with subsequent risk of hospitalizations for acute decompensated heart failure: clinical utility of implanted device monitoring without a patient alert.

Background: Acute decreases in intrathoracic impedance monitoring have been shown to precede heart failure hospitalization in a limited population of heart failure patients. We evaluated the relationship between changes in intrathoracic impedance with hospitalizations associated with acute decompensated heart failure (ADHF) in patients with cardiac resynchronization therapy plus defibrillator (CRT-D) devices.

Methods And Results: The study enrolled 326 heart failure patients who had received CRT-D with impedance-monitoring capabilities (InSync Sentry, Medtronic).

Integrating device-based monitoring into clinical practice: insights from a large heart failure clinic.

Heart failure is a difficult and costly disease to manage in part because the symptoms may be protean, the physical findings obscure, and the laboratory assessments unreliable. New implanted physiologic monitors may simplify the care of patients with heart failure, if they can be incorporated into routine clinical practice. Cardiac resynchronization therapy/defibrillators and implantable cardioverter defibrillators with continuous intrathoracic impedance monitoring capabilities (OptiVol fluid status monitoring; Medtronic, Inc.