MOnitoring REsynchronization deviCes and cARdiac patiEnts

Major cardiovascular adverse events in patients with heart failure treated with cardiac resynchronization therapy (CRT-D) represent a big concern to the medical community, as they require hospitalizations and may lead to death.

Subjects with a history of heart failure are counseled regarding the importance of contacting their clinicians promptly if they experience any changes or worsening of their condition.

Acute heart failure episodes with hospitalizations represent one of the most relevant causes of health status deterioration for these patients. Moreover, atrial arrhythmias occurrence is a big issue, as it increases the risk of heart failure itself, stroke and inappropriate shocks. In addition to affecting patient health, hospital admission resulting from these complications will impact healthcare costs.

Latest generations of Medtronic CRT-D devices are equipped with a system that triggers an alarm if possible fluid accumulation is detected (OptiVol). This may initiate patient-clinician contact before evident cardiac decompensation. Moreover, advanced diagnostic capabilities for detecting atrial arrhythmias occurrence and total burden are available on such devices.

Importantly, all these devices are now able to inform physician of these events by remote monitoring with CareLink Network parameters, and have the potential of playing a key role in patient monitoring.

Over the last years, interest has been increasing in remote monitoring models for delivering care to HF patients, either as telemonitoring (transfer of physiological data through telephone or digital cable from home to healthcare provider) or as regular structured telephone contacts between patients and healthcare providers, which may or may not include data transfer.

Several studies with relatively large numbers of patients have been published (see table).

A recent meta-analysis found that remote monitoring programs for patients with chronic HF living in the community reduced admissions to hospital and all cause mortality by nearly one fifth while improving health related quality of life, but had no significant effect on all cause admission to hospital.

However, none of the published studies considered remote monitoring systems able to provide device-detected information on fluid accumulation, AT/AF total burden, arrhythmias occurrence and device-related issues in patients treated with CRT-D devices.

Early intervention may then be a key element in avoiding major cardiovascular events to occur and possible deterioration of the disease progression. The Carelink Network remote monitoring system, through Care Alerts, may initiate subject-clinician contact before typical signs and symptoms are exhibited, since it provides the physician with an automatic alert for atrial arrhythmias occurrence, fluid accumulation, and system integrity issues. However, clinical evidence must be provided of the superiority of this patient management strategy with respect to standard clinical practice, based on routine in-office visits.

Very recent findings showed that the use of CareLink in European clinical practice is technically feasible and that remote follow-up is an efficient method of surveillance of implanted patients. Moreover, the early detection and review of device and clinical events suggest the potential impact of remote monitoring on overall patient care.

There are a number of possible limitations with remote monitoring. The CareLink Network system requires that the patient establishes an initial contact between the device and the remote monitor unit, and that the unit is properly hooked up to the phone line. Not all patients may be able to perform the setup properly. There may be a delay by the physician in consulting patient data (for example over weekends), with a risk of adverse events occurring during that interval. There may be difficulties in contacting patients (e.g. if they are traveling). These possible limitations need to be properly assessed, especially for monitoring atrial arrhythmias, where the time factor is of importance for avoiding complications.

Remote patients' disease management has the potential for avoiding hospitalization. Clear demonstration that remote monitoring of AT/AF/HF plus strict treatment guidelines leads to a reduction in hospitalization rates has not been proven, and it could be a major argument for using this technology in routine clinical practice.

The MORE-CARE Study is aimed at comparing two different strategies of disease management in heart failure patients treated with CRT-D devices:

1. Remote disease management via Carelink Network system
2. Standard disease management by means of scheduled routine in-patient follow-ups. The main objective of the study is to demonstrate that the remote management strategy is superior to the standard strategy, both in terms of clinical effectiveness and total healthcare system utilization.