Remote Monitoring for Implanted Devices and its Effect on Heart Failure Patients

Heart failure (HF) affects over 5 million Americans each year. Of all the heart failure symptoms that these patients face, fluid retention is one major area that needs to be continually monitored. Some HF patients may develop sub-clinical congestions days or even weeks before any signs or symptoms show. The ability for implanted devices to monitor cardiac trends has provided clinicians with early warning on impending fluid overload. By monitoring physiological changes, clinicians can improve and even change the clinical outcomes for these patients. In this article, we will take a look at some of the remote monitoring technology available to HF patients. The latest concept in remote monitoring systems for patients with implanted devices such as ICDs and CRT-Ds has been a hit with electrophysiologists throughout the country. Not only are these systems able to remotely interrogate the implanted device (e.g., check battery status, detect arrhythmias, provide lead data, and confirm delivered therapy), but some can also check on fluid retention using several different methods. One such system that allows for fluid retention checks is Boston Scientific’s LATITUDE® Patient Management system. LATITUDE enables physicians to interrogate and monitor a patient’s ICD or CRT-D device for any shift in fluids by using a weight scale that is tied in directly to the remote system. The data is then sent via telephone to the physician, making treatment for these critical patients significantly faster. Another system available is Medtronic’s CareLink® network. This has the ability to continuously monitor cardiac trends and intrathoracic fluid, allowing the clinician to have early warning of changes in cardiac status (including impending fluid overload) by using OptiVol® Fluid Status Monitoring. OptiVol detects pulmonary congestion/heart failure decompensation, lead dislodgement, and the onset of atrial fibrillation or pneumonia. St. Jude Medical offers the Merlin.net™ Patient Care Network and Housecall Plus™ Remote Patient Monitoring system for patients with implanted cardiac devices. Merlin.net provides access to patient device information anywhere an Internet connection is available to help streamline patient management and convenience. The Housecall Plus™ allows for live communication with a specially trained medical professional to immediately analyze device transmissions. The Housecall Plus system can monitor parameters and settings on the ICD, clear diagnostics and evaluate real-time electrograms, surface ECGs, delivered therapies and stored electrograms. Here at the Cleveland Clinic Florida, we have been using remote follow-up for a little over two years and have enrolled over 300 patients. We implant approximately 4–8 cardiac devices (ICDs, CRT-Ds or pacemakers) each week. These patients then get enrolled the same week for the remote monitoring system. Our process here at the hospital is very efficient. First, the device representative sends the implanted information, along with the type of device the patient received, to the electrophysiology nurse. The nurse then enrolls the patient in the corresponding remote monitoring system and sends the patient information about the remote system. Once the patient receives the remote monitoring unit, they should follow its instructions and send their first interrogation from home. When the nurse receives the transmissions, he or she determines whether or not it should be checked by the physician. For example, if there are any signs of malfunction or changes in the device trends, the printed interrogation would then be given to the electrophysiologist to view. At that time, the electrophysiologist would determine if the patient required a change in medication or if they needed to come in for a device optimization (or, in a worst case scenario, to the emergency room). Because of this remote monitoring technology, we have been able to provide faster care to several patients who otherwise would have been getting treatment only after they had decompensated. Some patients have even been saved a trip to the emergency room since they were able to check their device from home. Below are two clinical case studies of patients who have benefited from such technology. Case #1: This case involves an 88-year-old male with a history of congestive heart failure, ICM with EF of less than 20%, chronic kidney disease, and atrial fibrillation and ventricular arrhythmias. He had a Medtronic ICD implanted in November 2007. The patient called, advising the nurse he was not feeling well. He complained of labored breathing, fatigue, and an irregular heart rate. The nurse advised to send an interrogation of the device using CareLink. Figures 4 and 5 show the device trends. The nurse was able to determine that since mid October, the patient had been retaining fluid. By looking at the patient’s activity levels, they were able to see that the levels had started to decline in August, then shortly after, the activity levels picked up again — this was when the patient was placed on a higher dose of diuretics. By the beginning of November, his fluid index had dropped significantly. Case #2: This case involves an 81-year-old male with a history of congestive heart failure, atrial fibrillation, diabetes, and ICM with EF under 40%; he was implanted with a Boston Scientific CRT-D device. The patient called the on-call physician complaining of an irregular heart rate, swelling of the lower extremities, and fatigue. The physician advised the patient to follow up with his doctor in the morning unless his symptoms changed. Figures 6-8 show his transmitted reports. The patient’s weight had increased by 11 lbs. in a period of only 5 days, and the arrhythmia trends from the transmission showed him to be in atrial fibrillation for some time. If this patient would not have had this monitor at home, he would have ended up being admitted to the hospital after he would have decompensated or had ended up in the emergency room. Instead, the patient was placed on diuretics right away and given instructions for a low sodium diet. Benefits Patients should have no trouble setting up their remote monitoring system; they are easy to use, and anyone with a landline can use these systems. Most pacemaker companies also have a customer support staff that can help both patients and physicians in setting up the systems. These systems can also benefit the patient by allowing fewer office visits, thereby lessening travel expenses and traveling inconveniences, and by allowing for greater flexibility and convenience in sending transmissions anytime and from anywhere. Since the systems are interactive, physicians benefit because they can easily change their patient and device information as well as schedule times for remote interrogation. The systems also allow for integration with most electronic medical record programs. Providers can bill globally for each system’s remote follow-ups, if they are providing both the technical and professional components of the service. About the Systems There are several different manufacturers of implantable heart devices. Each manufacturer uses its own proprietary technology. When doctors implant a device, they consider the manufacturer and model of the device that will be the best match for each patient's particular condition. Each manufacturer's devices and monitoring systems must also meet very stringent requirements and earn the approval of the U.S. Food and Drug Administration (FDA). In addition, while each manufacturer's monitoring systems are similar, differences do exist. A manufacturer's monitoring system is designed to work only with their devices. Conclusion Overall, these remote monitoring systems are a great asset to both physicians and patients. It’s great to know that as time passes and technology develops new ways of making quality of life better for our patients, we still have tools like these to better access and provide better care for the sick.