Remote Patient Monitoring of Patients with a Cardiac Implantable Electronic Device: An Introduction

A variety of cardiac implantable electronic devices (CIEDs) are used routinely in clinical practice. These include implantable loop recorders (ILRs), permanent pacemakers (PPMs), implantable cardioverter-defibrillators (ICDs), cardiac resynchronization therapy (CRT)-PPMs, and CRT-ICDs. Following implantation, these devices require either in-office or remote follow-up. The Heart Rhythm Society (HRS) and the European Heart Rhythm Association (EHRA) have identified four distinct goals for CIED monitoring (Table 1).^1,2 The first goal is to improve the patient’s quality of life by optimizing device programming to ensure that they meet the patient’s clinical needs. The second goal is to ensure proper assessment of device function (e.g., battery longevity, lead integrity, etc.). The third goal is to manage the patient’s underlying disease through knowledge of underlying atrial and ventricular arrhythmias as well as indices that may portend an exacerbation of congestive heart failure. The fourth and final goal is to effectively communicate the retrieved information to the patient and all healthcare providers involved in the patient’s medical care. 

To meet these goals, information from CIEDs needs to be retrieved at regular intervals. Current recommendations advocate that all CIEDs be checked through direct patient contact within 72 hours of implant and again within 2-12 weeks post implant. Disappointingly, a prior review of Medicare beneficiaries showed that only 42.4% of eligible patients who underwent CIED implantation between 2005-2009 actually had an initial in-person evaluation within 2-12 weeks.³ Subsequent device evaluation has generally occurred quarterly, either in person or remotely.

Although in-office visits for device check serve an important purpose, technology has long been sought that can obviate this need for routine in-office visits. Prospective studies have shown that patient compliance with the desired in-office follow-up schedule is low and that most in-office visits do not result in the need for any significant reprogramming.^4,5 The first foray into remote follow-up was the use of transtelephonic monitoring (TTM) to monitor PPM function. Over time, CIEDs became capable of storing more diagnostic information. The availability to retrieve and adjudicate stored electrograms facilitated the ability of the physician to target therapy to the individual patient. Thus, remote follow-up systems were developed that could, with the exception of inhibiting pacing or performing manual threshold checks, replicate an in-office device interrogation. With time, devices become capable of transmitting the data wirelessly over a cellular network, thus eliminating the need for patient involvement (other than ensuring connectivity of the remote monitoring system in their home) in the data transmission process. This ushered in the process of remote monitoring, in which the patient and physician are tethered to each other on a 24/7/265 basis. Critical alerts are transmitted to physicians immediately, as opposed to the time of next patient-initiated transmission or retrieval at the next in-person evaluation.

There is a wealth of scientific data supporting the clinical value to remote monitoring in CIED patients. In addition to early management of important arrhythmias (e.g., atrial fibrillation, ventricular tachycardia/fibrillation), reductions in hospitalizations and strokes related to atrial arrhythmias, reductions in inappropriate and appropriate ICD shocks, an increase in battery longevity, and decreased mortality have all been demonstrated.⁵ As an “early notification” system, remote monitoring is well aligned with the ongoing healthcare reform in the United States. For example, the Affordable Care Act of 2010 required the U.S. Department of Health and Human Services to establish a Readmissions Reduction Program. Towards that end, remote patient monitoring may significantly reduce the likelihood of readmission by heading off small problems before they become critical. These problems may be related to the device, lead(s), arrhythmias, or a patient’s heart failure status.

Current guidelines recommend that (1) all patients with CIEDs should be offered remote monitoring as part of the standard follow-up management strategy, (2) it may be beneficial to initiate remote monitoring within two weeks of CIED implantation, and (3) a strategy of remote CIED monitoring and interrogation, combined with at least an annual in-person evaluation is recommended over a calendar-based schedule of in-person CIED evaluation alone.^6,7 These guidelines, along with their rationale, will be discussed in depth in the June 2016 issue of EP Lab Digest. Additionally, over the remainder of the year, each issue of EP Lab Digest will address an important aspect of CIED remote monitoring. 

The reality is that a significant number of patients are never enrolled in remote monitoring despite undergoing implantation of a CIED fully capable of such monitoring. Data from the Medtronic CareLink system show that in 2010, only 66% of eligible patients were enrolled into remote monitoring; by 2013, the enrollment rate had actually fallen to 55% (Figures 1 and 2, left).^5,8 Thus, there seems to be a disparity between the scientific data supporting the clinical value of remote monitoring and the ability/willingness of healthcare providers to actually implement this for their patients. Furthermore, even when patients are enrolled into a remote monitoring system, only a trivial number of patients are actually undergoing quarterly remote monitoring (Figures 1 and 2, right). Similar data were recently reported from the Merlin.net registry of nearly 270,000 patients.⁹ Over half the patients were never enrolled into remote monitoring; once enrolled, only half the patients exhibited a high adherence to remote monitoring. The most important barriers appear related to the fear of new technology and limited patient/physician understanding of the value of remote monitoring. The July and August 2016 issues of EP Lab Digest will explore these as well as additional barriers to the incorporation of remote monitoring into clinical practice from the perspective of the allied health professional and physician, respectively. Understanding these barriers is critical to ensure that all patients are enrolled into a remote monitoring program following CIED implantation and remain adherent to monitoring over long-term follow-up. 

Currently available guidelines are silent on an important issue, namely the relationship between CIED type and efficacy of remote monitoring. For example, do patients with a PPM derive the same benefit from remote monitoring as patients with an ICD or CRT device? Furthermore, do patients with a single-chamber device derive similar benefit as patients with a dual-chamber device? The answers to these questions may provide important insight into the mechanism through which use of remote monitoring translates into improved patient outcomes. This topic will be the subject of review in the September 2016 issue of EP Lab Digest. 

One area that has greatly impacted remote monitoring has been the development of miniaturized ILRs, which provide daily wireless data downloads.¹⁰ These devices are typically implanted in patients with unexplained syncope as well as suspected (e.g., cryptogenic stroke) or known atrial fibrillation (to understand duration and burden of atrial fibrillation).^11-13 In our practice, these devices already constitute the greatest burden on remote monitoring (Figures 3 and 4). An emerging area that is developing is the role of data device downloads to guide decisions regarding the need for long-term anticoagulation in individual patients.^14,15 This topic will be explored in depth in the October 2016 issue of EP Lab Digest. 

In addition, data accumulate through interaction of CIED patients with healthcare personnel in settings such as the emergency room, operating room, radiology suite, and inpatient hospital floors. These patients frequently need to have their CIEDs interrogated to examine the stored data, which may shed light on their clinical presentation. All device vendors have developed or are actively developing proprietary “universal” and “agnostic” interrogators (with respect to devices manufactured by a given vendor) capable of performing inductive downloads of device data to the company’s web proprietary portal. Two systems have recently been tested in clinical practice; both showed that device interrogations performed through the use of a remote interrogation system facilitated rapid download and interpretation of device data. Additionally, in 90% of patients, no immediate intervention was necessary; this facilitates a more efficient use of time and resources.^16,17 The future of remote patient monitoring will be discussed in depth in the November 2016 issue of EP Lab Digest. 

Ultimately, a robust infrastructure is necessary to handle the large volume of incoming data emanating from wireless CIEDs. The data have to be reviewed to ensure that all device/lead advisories are accounted for, pacing algorithms have been optimized to minimize the degree of right ventricular pacing and maximize the degree of biventricular pacing, atrial high-rate episodes are appropriately adjudicated and a plan for management (e.g., anticoagulation) defined, devices programmed to minimize inappropriate and appropriate ICD shocks, and signs of impending heart failure identified. Additionally, data have to be accounted for on a 24/7/365 basis to ensure that information is not missed that could adversely affect a patient’s clinical outcome. This is a major barrier to overcome and contributes to a concern about the legal liability inherent to managing these data. The December 2016 issue of EP Lab Digest will address specifically the challenges inherent to building an infrastructure to handle the incoming data effectively and efficiently. 

A paradigm shift in the follow-up of CIEDs is underway. Remote monitoring of wireless devices and alert-driven office visits are being asked to replace scheduled in-office visits. This shift in care has been driven by trials demonstrating the clinical superiority of remote monitoring and by financial constraints in the healthcare system. Over the next year, a series of articles in EP Lab Digest will review where we are with respect to remote monitoring, what are our existing challenges, and discuss what the future seems to hold in this area.

Disclosures: Dr. Mittal is a consultant for Boston Scientific, Medtronic, Philips Healthcare, Sorin, and St. Jude Medical. 

References

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