There have been multiple articles written about remote monitoring, its advantages and advances, and how we can best utilize it to optimally manage our patients and their devices. When the Heart Rhythm Society published their Expert Consensus Statement on Remote Interrogation and Monitoring for Cardiovascular Implantable Electronic Devices (CIEDs) in 2015,1 it sent a message to the CIED community about the importance of this technology, and emphasized how management of these devices needs to have proper workflows and training in place.
Slotwiner2 recently commented that wireless remote monitoring (RM) has marked a fundamental change in how physicians and allied professionals manage patients with CIEDs. He pointed out that numerous clinical trials and registry datasets have demonstrated the superiority of strategies that incorporate RM, including a reduced number of routine scheduled in-office visits, early event detection, fewer shocks and increased battery longevity, accurate detection of paroxysmal atrial fibrillation, and an associated reduction in all-cause mortality. However, he noted that adoption of RM into practices in the U.S. so far has been variable. His review included recommendations on how to successfully incorporate RM into clinical practice, such as pairing the CIED in the hospital prior to discharge or soon thereafter to be most advantageous. This will be discussed later in this article.
Piccini3 observed this growth in remote monitoring, which was once considered a convenient alternative to office visits. Development and subsequent arrival of remote monitoring as a class I recommended treatment represented a significant evolution in clinical practice. Further change is expected in the future, including increased utilization of remote monitoring in clinical practice and research, development of streamlined information technology and software programs, and improved patient access and management of their remote monitoring data.
Overview of Remote Monitoring Technology
Remote monitoring systems are intended to serve as an Internet-based repository of patient device data. CIEDs with wireless capability allow for transmission of automatic daily measured lead parameters, battery status, real-time electrograms, stored electrograms, and details of delivered therapies. Alerts, which are set for device-based thresholds per select diagnostic data, will be transmitted if crossed. Once a day, typically at night, the home transmitter performs a handshake sequence with the device and accesses the alert status within the device. The home transmitter functions as a data transponder between the CIED and the server. Should there be an alert triggered in the device, a full download of the data will be performed and sent to the server for storage. The server may be reached via phone lines, cable connections, or cellular methods. Once received by the server, a notification is sent to the respective office and those designated to receive them. The office can select alert priority levels and how they wish to receive the notifications — either via text, email, or fax.
Point-of-care pairing refers to synchronizing the patient’s implanted device with their home transmitter on site and prior to hospital discharge. It is direct and in real time, not requiring an intermediary such as customer service to implement the pairing. When point-of-care pairing is performed prior to the patient being discharged, it allows the patient to be immediately monitored (without a time gap) once they arrive home. In addition, it expedites same-day discharging for low-risk patients without procedural complications. The technology platform that offers point-of-care pairing also allows for single transmissions for patients who present in an emergency room, as well as remote review of CIED performance.
In 2012, Choudhuri et al4 evaluated the feasibility of same-day discharge after implantable cardioverter-defibrillator (ICD) implantation in low-risk patients. They prospectively randomized low-risk primary prevention ICD candidates to next-day discharge with overnight observation or same-day discharge with remote monitoring for 24 hours after ICD implant. With no acute complications in the same-day discharge patients and only one instance of pneumothorax in the next-day discharge patients, they concluded that ICD implantation with same-day discharge and remote monitoring is reasonable in low-risk patients.
Lead Failures Versus Programming Versus True Arrhythmias
Lead performance monitoring algorithms have advanced tremendously during the last several years. What began as basic impedance measurements to monitor lead reliability during the course of an advisory, has now expanded to monitoring impedance of all lead vectors, far-field vs near-field dyssynchrony, lead noise, and others. These diagnostics, combined with programmed therapy zones and traditional discriminators, have become very valuable for acute remote assessments when alerts or clinical events occur. In addition, efforts to reduce and prevent inappropriate or unnecessary therapies have driven lead monitoring algorithms to become more robust and reliable, so that we as clinicians can confidently utilize the clinically relevant features of devices. Ironically, it is often advisories and device issues that lead to technical advancements and some of the best utilization of technology today, and remote monitoring of lead reliability is an excellent example of this.
Remote Management of Atrial Fibrillation
Once a patient is home with a reliable monitoring system and being properly monitored for device and lead performance, physicians and their staff can focus more proactively on the safe and efficient management of clinical arrhythmias. Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. It has been estimated that 2.2 million Americans have paroxysmal or persistent AF, and 10 million Americans are anticipated to develop the disease by 2050.5 The treatment strategy for AF has been focused on three cornerstones of AF management: rate control, rhythm control, and prevention of thromboembolism. The AFFIRM,6 RACE,7 and PIAF8 trials have shown no mortality benefit to a rhythm control strategy compared to a rate control strategy. Therefore, a rate control strategy, without attempt at restoration or maintenance of normal sinus rhythm (NSR), is reasonable in some patients with AF, especially those who are elderly and asymptomatic. In younger patients as well as those older patients in whom rate control offers inadequate symptomatic relief, restoration of NSR may become a long-term goal. Remote monitoring by patient cohort to modify treatment regimen is vital to our practice. When it comes to antithrombotic therapy for patients with AF, it is recommended based on their associated clinical risk factors which include congestive heart failure, hypertension, diabetes mellitus, age, and prior stroke or TIA.9 Additionally, multiple studies have demonstrated that paroxysmal and permanent AF are associated with an equivalent risk of stroke.10-12 It is widely accepted that in patients with AF, the risk of stroke generally develops with AF duration of greater than 48 consecutive hours. A difficulty with correlating AF duration with the risk of stroke results from the frequency of asymptomatic AF, even in patients with documented symptomatic AF.13-17 This may, in fact, be one of the most important factors in justifying remote monitoring.
Passman and Tomson18 recently questioned whether the use of continuous remote monitoring has presented more questions about AF than it has answered. Ongoing clinical studies are evaluating treatment of device-detected “subclinical” episodes of AF and its responsiveness to anticoagulation. Could anticoagulation guided by remote monitoring reduce bleeding, decrease costs, and improve quality of life in millions of patients with AF? If this personalized approach is demonstrated to be safe and effective, it could expand the indications for rhythm control beyond symptom relief to include reducing exposure to long-term anticoagulation. Passman challenged his readers to question whether current approaches make sense and to look into how advances in remote monitoring within EP can be leveraged to better care for our patients.
Remote Heart Failure Management
There is also a growing need for remote monitoring of patients with heart failure (HF) to enhance their management and reduce hospital admissions. Current evidence indicates that remote surveillance of implanted devices in high-risk HF patients may be associated with a reduction in hospitalization (29-43%) compared with conventional follow-up. An accelerated heart rate in patients with HF was identified as a potential predictor of morbidity and mortality.19,20 Various other electrophysiological and hemodynamic parameters such as ventricular and atrial tachyarrhythmia burden, new onset of AF, evolution of fluid overload, and loss of cardiac resynchronization therapy (CRT) can be retrieved by remote interrogation.
As was demonstrated by the PARTNERS HF Study21, diagnostic parameters have greater clinical value when used in combination. Data was analyzed from 694 CRT defibrillator patients that were followed for 11.7 ± 2 months after enrollment. In 954 evaluations with ≥2 criteria triggered, a high fluid index, low activity, and low heart rate variability were the most common criteria met. This was followed by long AF duration, low CRT pacing, high night heart rate, rapid ventricular rate during AF, and ICD shocks. Patients who had positive combined HF device diagnostics had a 5.5-fold increased risk for HF hospitalization with pulmonary signs or symptoms within 30 days.
Once again, use of the full features of remote monitoring, including appropriate alert settings for all diagnostic parameters, further advances our ability as clinicians to provide quality and value in the continuum of care for our patients.
This review of literature and of recent advancements in technology had our private cardiology practice questioning whether or not we are as intentional with remote monitoring as we need to be. Are remote monitoring alerts truly valuable, or are they a nuisance? Are the alerts translating into appropriate interventions for our patients? Is our practice in position for future advancements?
In Fall 2013, we began to seriously adopt the use of remote monitoring within our practice. We began to give informed consents to patients in conjunction with the guidelines. At the time, 40 patients from five separate locations within our practice were being remotely monitored. We are currently using remote monitoring platforms from 3 different manufacturers. For the purpose of this article, we took a prospective look into one of our practice’s clinics using the Merlin.net™ Patient Care Network (St. Jude Medical, now Abbott). Today, over 500 patients are being actively monitored in the Merlin.net™ PCN system with >97% compliance.
Data from 78 patients enrolled in Merlin.net™ PCN at one of our offices were reviewed within a 7-month window from January 2016 to July 2016. All CIEDs in our St. Jude Medical/Abbott sample had wireless transmission capability, were point-of-care paired prior to discharge, and had daily communication with their Merlin@home™ Transmitter, which in turn connected to the server via cell or internet. The Merlin.net™ PCN clinic settings, which allow for global alert levels and customizable settings for all patients, were utilized.
Our practice operates with red alerts being an actionable alert, and yellow alerts being an awareness alert where action may or may not be necessary. We have device-trained ancillary staff that are responsible for daily checking the Merlin.net™ PCN alerts. Each red alert is reviewed to determine if it requires immediate attention from the physician. The staff member will add comments to the system for each alert.
Notification is made via our internal EMR system, and the appropriate action is taken. The system allows for the ancillary staff to view if the action has been completed or if there are instructions from the physician for the designee to follow up on. We work closely with the company to make sure the remote monitoring system is properly set up immediately after implantation.
Table 1 shows that of the 78 patients reviewed, 37% had alerts (29). A total of 33% of patients with pacemakers had alerts, and 44% of patients with ICDs had alerts. There was a total of 475 alerts, but unexpectedly, 3 patients each had over 100 alerts. Among 9 patients (11.5% of all patients, 31% of those with alerts), 40.6% of the alerts were AF related. Among 23 patients (29.5% of all patients, 79% of those with alerts), 27.6% of the alerts were ventricular rate related. Among 2 patients, 23% were lead-related alerts; however, these were false positives. Therapy was delivered in 2 patients, and 8% of the alerts were related to percent pacing. Five of 13 newly implanted devices had an alert within 3 months of implant. Four alerts were related to AF, and one was an SVT. (Figures 1-6)
Of the 3 patients with over 100 alerts, two had AF that was properly managed, yet the alert settings were never adjusted. One patient required an AF ablation. The third patient’s alerts were due to oversensed paced T waves. This issue required an office visit for reprogramming to avoid oversensing. The predominant alerts were for AF and high ventricular rates, which in many cases were dual alerts resulting from rapid ventricular response to the AF.
During this process, we found a number of alerts that were repetitive and created a burden on the staff. It was determined that alerts that were well documented, such as in patients with persistent AF, did not need the AF alert on. Those patients were notified at their next office visit to have the alert turned off. By programming these repetitive alerts off, we reduced the number of alerts in this patient sample by approximately 65%. Once the arrhythmia was discovered and being managed, the alerts were adjusted accordingly.
I cannot emphasize enough what this “pause and assess” meant to our practice. We came to realize that we had become immune and ignored alerts that had already been addressed. We accepted them as the status quo and tolerated them. This, in turn, had an unanticipated effect of devaluing the importance of remote monitoring and developed negative perspectives towards the technology. This assessment has revived our passion towards remote monitoring, and reminded us of the importance of programming properly and having a good process in place.
As we watch cell phone/mobile device advances occur exponentially, coinciding with the development of low-power WiFi and Bluetooth circuitry, it is only a natural progression to presume these technologies are in the development pipelines for next-generation devices. It is not a stretch by any means to expect the next-generation devices to be fully interactive with the mobile devices available today. Therefore, as we now have a greater appreciation for the value of remote monitoring as a result of this assessment, my practice is better off for it and we are ready for the next wave of technological advancements.
Disclosures: The authors have no conflicts of interest to report regarding the content herein.
- Slotwiner D, Varma N, Akar JG, et al. HRS Expert Consensus Statement on remote interrogation and monitoring for cardiovascular implantable electronic devices. Heart Rhythm. 2015;12(7):e69-100.
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- Botto GL, Padeletti L, Santini M, et al. Presence and duration of atrial fibrillation detected by continuous monitoring: crucial implications for the risk of thromboembolic events. J Cardiovasc Electrophysiol. 2009;20(3):241-248.
- Capucci A, Santini M, Padeletti L, et al. Monitored atrial fibrillation duration predicts arterial embolic events in patients suffering from bradycardia and atrial fibrillation implanted with antitachycardia pacemakers. J Am Coll Cardiol. 2005;46(10):1913-1920.
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- Whellan DJ, Ousdigian KT, Al-Khatib SM, et al. Combined heart failure device diagnostics identify patients at higher risk of subsequent heart failure hospitalizations: results from PARTNERS HF (Program to Access and Review Trending Information and Evaluate Correlation to Symptoms in Patients With Heart Failure) study. J Am Coll Cardiol. 2010;55(17):1803-1810.