Emerging Applications for Remote Monitoring

Mark Mitchell, MD
Director, Cardiac Electrophysiology Laboratory
Forsyth Medical Center
Winston-Salem, North Carolina

Mark Mitchell, MD
Director, Cardiac Electrophysiology Laboratory
Forsyth Medical Center
Winston-Salem, North Carolina

The demand to assess patients with implantable pacemakers and defibrillators increases yearly. Proper assessment of these patients currently requires: 1) access to the appropriate manufacturer’s programmer, 2) the presence of appropriately trained personnel to operate the programmer, and 3) access to trained specialists (electrophysiologists, cardiologists, device clinic nurses or physician’s assistants) who can interpret the data and make programming changes when appropriate. Because access to the physical programmers and trained personnel is limited, delays in device assessment are common, leading to inefficiencies in patient care. The current article describes our experiences piloting Medtronic’s new CareLink Express remote monitoring technology, created to improve the efficiency of assessing patients with implantable pacemakers and defibrillators. Various applications of this technology are reviewed, and speculation on future directions is provided.

Current Challenges

There is currently a shortage of personnel required to meet the demand to assess implantable cardiac pacemakers and defibrillators in a prompt manner. Many factors contribute to this mismatch. The aging of the “baby boomers” and the increased number of indications for device implantation has resulted in proportionately more patients with these devices in the general population. The increase in demand for non-cardiac medical services by patients has resulted in more requests for peri-procedural device assessment by anesthesiologists and surgeons. Growing numbers of emergency department visits have also resulted in frequent requests to assess implantable cardiac devices in that setting. Increasing healthcare costs in a declining economy have led to increased scrutiny of the device assessment process by physicians, patients, device manufacturers, and health care organizations (hospitals, insurers, and governments).

The assessment of patients with implantable pacemakers and defibrillators is inherently inefficient. The average time from request for a device assessment to the time the device interrogation data is on the chart is 84 minutes, with a range of 30 minutes to four hours (according to unpublished data from the CareLink Express pilot study). This assessment process has multiple steps which contribute to the inefficiency. These steps include: 1) identification of a patient with an implanted device, 2) determination of the manufacturer of the device, 3) identification of the appropriate device specialist (which can be a physician, device nurse or physician’s assistant, or device company representative) and establishment of communication with that specialist, 4) delay time from request to arrival of the specialist (frequently due to travel issues or the specialist being involved in the care of another patient), 5) interrogation of the device and printing of the data on paper, 6) communication of the data with the patient’s cardiologist, 7) programming of changes in the patient’s device if indicated, and 8) placement of data in the patient’s medical record.

About CareLink Express

Medtronic’s CareLink Network was established 10 years ago and is used throughout the world. The network enables patients to electronically interrogate their cardiac devices at home and transmit the data to a central server, which can be viewed by the patient’s physician and Medtronic personnel. For safety and security reasons, the current CareLink transmitters are paired in a “lock and key” fashion with a patient’s implanted device so that one patient’s transmitter cannot evaluate another patient’s device. There are over 700,000 patients on the CareLink Network, and over 1.2 million CareLink data transmissions were completed in 2011. The network’s utility in the care of patients with implantable pacemakers and defibrillators is well established. The network has helped cardiac device clinics keep up with the burden of increasing demands for device assessment. At the same time, the CareLink Network has improved patient safety (by earlier diagnosis of arrhythmias and device abnormalities) and convenience (the number of trips to physician’s offices has been reduced).

CareLink Express was developed on the CareLink Network platform. The CareLink Express transmitter is a universal device that can interrogate most (99%) Medtronic devices (Figure 1). Interrogation can be done by almost any medical personnel, and the data can be easily transmitted to a central server via a standard telephone line. The data can be reviewed remotely by physicians, device clinic personnel, and Medtronic personnel. All transmissions are currently reviewed by a Medtronic technical service representative at a 24/7 call center. Call center representatives will make an interpretation indicating whether a device, lead, or rhythm issue is identified and will fax this interpretation back to the requesting healthcare provider (Figure 2).

Pilot Study

A non-randomized, non-blinded pilot study was conducted using CareLink Express in various clinical settings. The purpose of the pilot program was to determine if CareLink Express would make the device assessment process more efficient. Five regions in the United States were selected for study: Portland, Houston, Minneapolis, central Massachusetts, and Charlotte. Baseline data on device assessment patterns was collected prior to the introduction of CareLink Express. CareLink Express was then introduced to the device specialists. Physicians were encouraged to use the device at their discretion. Data on device assessment patterns was again collected.

Pre-CareLink Express baseline data was collected on 742 device checks (Figure 3). The majority of checks were on inpatients (69%), with the emergency departments (20%) and surgical pre- and post-areas (11%) comprising the rest. After implementing CareLink Express, data was collected on 432 device checks. The majority of CareLink Express checks were in the emergency departments (52%), with the inpatient wards (38%) and peri-operative areas (10%) comprising the remainder. Prior to CareLink Express, 23% of patients required reprogramming, and after CareLink Express, 5% of patients required reprogramming. The average time from device assessment request has dropped from 84 minutes before CareLink Express, to 15 minutes with CareLink Express.

The pilot study results support the conclusion that CareLink Express can be successfully implemented in the hospital setting by minimally trained medical staff. Emergency departments experienced a notable increase in utilization when the device was implemented. Response time for device interrogation was faster after CareLink Express was available. Our experiences with CareLink Express suggest that this technology can reduce the turnaround time for device assessment to 15 minutes for most hospitalized patients. The technology was readily implemented and non-device medical staff was able to use the system to obtain data more quickly. The emergency department was the primary target for implementation, but the inpatient wards and the peri-operative areas also adopted the technology readily. Although most patients who were checked with CareLink Express did not require reprogramming (95%), input from device specialists and Medtronic technical service representatives was available when needed to interpret data or to assist in device reprogramming.

On several occasions, unnecessary admissions to the hospital were aborted due to the application of CareLink Express in the emergency room setting. After device assessment, remote review by the patients’ cardiologist enabled early discharge from the emergency room. Furthermore, more prompt diagnosis of device malfunctions and cardiac arrhythmias were demonstrated. One patient was diagnosed with sustained ventricular tachycardia (which was thought to be atrial flutter by the emergency room personnel).

The application of CareLink Express is reducing the time patients spend in high-cost areas. The post-anesthesia unit in our hospital is using CareLink Express to shorten the time device patients spend in the PACU after surgical procedures. The emergency departments have reduced the waiting time for patients who need device interrogations. These improvements in efficiency may lead to improved quality of care for patients and reductions in healthcare costs for our medical system.

Future Directions

While the feasibility of CareLink Express remote monitoring is evident from our pilot experiences, the potential of this technology is vast and yet to be fully realized. From a technologic perspective, future generations of CareLink Express should include more options for connectivity (land line, WiFi, and cellular). Furthermore, because the data obtained with CareLink Express only includes the most recent automatic sensing and pacing threshold data, in some clinical situations, assessment with a programmer is required. For example, if a pacemaker patient presents at 10:00 pm with syncope, the sensing and pacing threshold data that the device reports is dated from the prior evening (and is, in this example, 20 hours old). Therefore, assessment with a programmer to obtain current threshold data would be indicated. Efforts to address this “information gap” should include having the CareLink Express interrogation result in an automatic threshold test at the time of interrogation.

As this technology evolves, I envision the development of remote reprogramming capabilities. Remote reprogramming will address more of the inefficiencies in delivery of care to patients with implantable cardiac devices, but concerns about safety issues will arise. The potential for programming errors resulting in ineffective therapy (like loss of capture in pacemaker-dependent patients) and the potential threat of computer “hackers” creating malware specific to these devices will need to be addressed.

From a clinical application perspective, there are many potential uses for CareLink Express. In addition to applying this technology “intra-hospital,” it should also be considered for “inter-hospital” use. We are currently constructing a network of these devices at the hospitals and emergency rooms that typically send patients to our facility. Once this is established, our electrophysiologists will be able to speak to outside emergency room staff and view the device interrogations remotely. In the current environment, many of these patients are transported to our facility because the outside physicians do not feel comfortable assessing these patients. Our pilot data suggests that 95% of these patients will have normal device function and therefore will not require transfer. Of course, a reduction in unnecessary transfers should result in a reduction in healthcare costs. Billing codes for remote assessment, interpretation, and remote consultation have not yet been established.

Another application for CareLink Express is in the device clinic. We are currently piloting this technology in our device clinic to determine whether it can reduce clinic visit time for our office patients. Follow-up visits for devices can be very inefficient when multiple patients are waiting in rooms to have their devices checked. We hope to identify a population of patients that may be better and more efficiently served by CareLink Express checks rather than standard programmer checks.


In summary, in its current version, CareLink Express is capable of reducing the time it takes to interrogate an implantable pacemaker or defibrillator. We have observed improved efficiency and patient flow with this technology. Improved input from device specialists, even when the patients are remotely located, has been observed. We have observed examples of improved clinical decision making because of the prompt input from specialists. Future developments may include inter-hospital use and device clinic use. Due to financial and demographic pressures, remote monitoring will likely become standard care for many, if not most, device patients.

Disclosures: Dr. Mitchell has worked as a speaker or consultant for the following: Medtronic, Boehringer Ingelheim, BIOTRONIK, and Sorin.