Remote patient management using implantable devices

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1 DOI /s Remote patient management using implantable devices Colin Movsowitz & Suneet Mittal Received: 22 September 2010 / Accepted: 20 January 2011 # Springer Science+Business Media, LLC 2011 Abstract Remote patient management utilizing the Internet is a milestone in the management of patients with an implantable cardiac device. Pacemakers and implantable cardioverter defibrillators (ICDs) store diagnostic information about device and lead integrity, the occurrence of atrial and ventricular arrhythmias, and parameters that may reflect on a patient s heart failure status. Previously, these data could only be retrieved with a programmer at an inperson office visit. The introduction of remote follow-up and monitoring has changed the paradigm for the management of patients with implanted devices. Remote follow-up has been shown to be superior to traditional transtelephonic monitoring for the detection of clinically actionable events in pacemaker patients. Remote monitoring using ICDs with wireless technology has been demonstrated to result in detection of lead malfunction and atrial and ventricular arrhythmias while reducing the need for in-office evaluations without compromising patient safety. Studies are underway to evaluate the clinical utility of identification of atrial high-rate episodes and to identify patients at risk for exacerbation of heart failure. Remote monitoring technology has yet to be universally adopted by patients or physicians. Impediments to the implementation of remote monitoring including issues related to work flow and data management are explored. C. Movsowitz Cardiology Consultants of Philadelphia, Lankenau Hospital, Wynnewood, PA, USA S. Mittal (*) The Al-Sabah Arrhythmia Institute and Division of Cardiology, The St. Luke s and Roosevelt Hospitals, Columbia University College of Physicians and Surgeons, New York, NY 10025, USA smittal@chpnet.org Keywords Implantable cardiac device. Implantable cardioverter defibrillators. Transtelephonic monitoring. Pacemakers Remote patient management utilizing the Internet is a milestone in the management of patients with an implantable cardiac device. Both pacemakers and implantable cardioverter defibrillators (ICDs) now store diagnostic information about device and lead integrity, the occurrence of atrial and ventricular arrhythmias, and parameters that may reflect on a patient s heart failure status. Previously, these data could only be retrieved with a programmer at an in-person office visit. However, the introduction of remote follow-up and monitoring has changed the paradigm for the management of patients with implanted devices. The aims of this paper are to review the evolution of remote followup and monitoring of patients with implantable devices, the current data supporting the utilization of remote follow-up and monitoring in clinical practice, and to highlight the key barriers that need to be overcome to maximize the clinical utility of these systems. Remote device monitoring is not a new concept to the cardiology community. Since its introduction in 1971, transtelephonic monitoring (TTM) of pacemakers has been utilized to complement biannual or annual in-office evaluations [1 3]. TTM was developed to address battery longevity, which can be estimated by analyzing the magnet rate of the device. TTM also provides a brief presenting ECG tracing that allows for a limited analysis of the underlying rhythm. One can also glean information about the presence or absence of atrial and ventricular capture and sensing by analyzing both the presenting and magnet ECGs. Pacemakers have acquired increased capacity for storage of diagnostic information. For example, pacemakers now

2 store atrial and ventricular electrograms, which allow for the adjudication of arrhythmic events. Trended diagnostic information about battery status and lead integrity is also available. Remote monitoring systems offer an opportunity to access these data. Although Biotronik had launched their home monitoring technology in 2001, in the United States remote evaluation of devices was introduced by Medtronic in 2002 with the launch of their Carelink Network. The system was initially designed for the remote follow-up of patients with an ICD; subsequently, remote follow-up of pacemaker patients also became available. In our opinion, the clinical goals of remote follow-up were to obviate the need for ICD patients to come to the office, facilitate the follow-up of patients who lived in remote areas, and constitute a mechanism to improve the efficiency of device follow-up clinics. The first data to support the utility of remote follow-up were obtained in pacemaker patients [4]. The PREFER trial compared the identification of clinically actionable events (Table 1) with inductive remote patient transmission at 3, 6, and 9 months following single- or dual-chamber pacemaker implantation with standard six monthly in-office visits interspersed with TTM every 2 months [4]. An inductive transmission requires that the patient apply a wand over their device during the data transfer; patients are provided with a modem that can upload the data to a central Web server for physician review. In the control group, patients with a dual-chamber pacemaker were seen in the office at 6 months; all patients in the study were seen in the office at 12 months. Clinically actionable events were detected on average 2 months earlier in the remote monitoring arm. Of note, only three (2%) of the 190 clinically actionable events in the TTM arm were detected during a TTM transmission; the majority of events were detected only during an inoffice evaluation. In contrast, 446 (66%) of the 676 clinically actionable events in the remote monitoring arm were detected during a remote transmission. However, the most frequently detected clinically actionable event was an episode of non-sustained ventricular tachycardia, a finding whose clinical significance in a pacing population remains undefined. The next advance in remote patient monitoring came with the release of wireless devices. These devices automatically (without the requirement for the patient to apply a wand over the device to initiate or maintain the data transfer) transmit data to a bedside communicator, which forwards the data to a central server. Transmitted data include: (1) programmable alerts related to device and lead function as well as atrial and ventricular arrhythmias (Table 1) that are transmitted on a daily or weekly basis, (2) a real-time intracardiac electrogram that is transmitted on a monthly or quarterly basis, and (3) a complete device data download that can either be initiated by a patient in response to symptoms (including an ICD discharge) or is scheduled to occur on a quarterly basis. This constitutes remote monitoring of an implantable device. The clinical value of remote monitoring using wireless ICDs was evaluated recently in a randomized control trial [5]. The TRUST trial was a prospective (non-inferiority) trial, which compared the safety and efficacy of the Biotronik remote home monitoring with quarterly in-office evaluation in a cohort of 1,450 non-pacemaker-dependent patients following single- or dual-chamber ICD implantation. Patients in the home monitoring arm were seen in the office 3 months post-enrollment and then a year later. In the interim, physicians were notified for the following alert Table 1 Remote alerts Device related ERI or EOL Tachy therapy OFF Device reset Lead related Atrial or ventricular pacing impedance (<200 or >2,000 Ω) P and R amplitude <50% of threshold (threshold programmable) Pacing thresholds (devices with auto-threshold) Percentage of right ventricular pacing (programmable) Percentage of left ventricular pacing (programmable) Arrhythmia related Duration of atrial high-rate episodes (longest episode, min) Burden of atrial high-rate episodes (percentage of overall rhythm, min) Ventricular rates during ongoing atrial tachycardia or fibrillation (bpm) Sustained ventricular tachycardia and fibrillation, including information about anti-tachycardia pacing and delivery of ICD shocks ERI elective replacement indicator, EOL end of life

3 conditions: out of range impedance, elective replacement indicator, ventricular tachycardia/fibrillation (VT/VF) detection turned off, episodes of supraventricular tachycardia or VT/VF, delivery of an ineffective 30-J ICD shock, mode switch duration >10% over 24 h, and device transmission failure for >3 days. The primary end point of the study was the number of total in-office device evaluations in the two groups. The mean number of (scheduled and unscheduled) visits was reduced by 45% in the remote home monitoring arm; there was no difference in the likelihood of observing an adverse event. Additionally, home monitoring reduced the median time from the onset of an arrhythmic event (atrial fibrillation, ventricular tachycardia, and fibrillation) to physician evaluation to a median of 1 day, as compared with 35.5 days in the conventional arm. Eighty-nine percent of the alert notifications could be managed remotely. The remaining 11% alert notifications necessitated an in-office visit; 52% of these visits resulted in a clinical intervention (device reprogramming, drug initiation, or adjustment in drug dosing). Importantly, remote monitoring increased patient compliance with their scheduled in-office visits. A unique feature of the Biotronik home monitoring system is that a wireless transmitter housed within the pulse generator communicates the stored data to a communicator that can be carried by the patient; thus, events can be detected and transmitted (either via a landline or cellular telephone connection) to a global service center for automatic processing and online review. Since the patient can carry the communicator, there is no requirement for the patient to be at home in order for data transmission to occur. As a result, as was observed in the TRUST trial, it is feasible to reduce significantly the interval between arrhythmia detection and physician notification. Currently, all manufacturers offer an ICD that permits remote monitoring. In addition, two manufacturers offer similar capability in their pacemakers. However, these alternative systems utilize a bedside communicator; data from the device is transmitted only when the patient is in the vicinity of the communicator. Remote monitoring offers three distinct promises. The first is the detection of lead malfunction and device-related issues (Figs. 1, 2, 3). The latter include elective replacement indicator status of the device, inadvertent programming of the device that results in ventricular arrhythmia detections being turned off, and an electrical reset condition within the device. In the TRUST trial, remote home monitoring significantly reduced the time to detection of device and lead malfunction. Device and lead malfunction may not be associated with patient symptoms and thus not be otherwise amenable to early detection [6]. Similarly, the Carelink A tip- V tip- Fig. 1 Fracture of a Medtronic Sprint Fidelis ICD lead fracture. (Top) The device triggered a wireless alert because characteristics suggestive of a lead fracture were identified. Specifically, there was a high number of short RR intervals, a significant variation in the right ventricular (RV) pacing lead impedance in the preceding 60 days and an absolute RV pacing impedance of >1,000 Ω. (Bottom) Intracardiac electrograms from the atrial and ventricular lead confirm the presence of sinus rhythm. However, the device detects an episode of ventricular tachycardia (TF) and fibrillation (FS) due to oversensing of noise

4 Fig. 2 Fracture of a Guidant left ventricular pacing lead. Our patient had a non-ischemic cardiomyopathy, severe left ventricular dysfunction. New York Heart Association class III chronic systolic congestive heart failure and left bundle branch block. A cardiac resynchronization therapy defibrillator was implanted in April 2005, following which the patient s ventricular function normalized and the patient became asymptomatic with respect to heart failure. On November 15, 2007, our office received a fax with the following yellow alert: High left ventricular pacing lead impedance detected on 13 Nov 2007, 00:00. Schedule in-office follow-up to evaluate LV pacing lead. (Top) Initial screen observed after logging into the Web server and retrieving this patient s remote monitoring data. The yellow alert is highlighted for the health care provider. (Bottom) At the last weekly check on November 8, 2007, the left ventricular pacing impedance had been normal, and in line with the values observed over the previous 3 months. On November 13, 2007, there was an abrupt increase in the left ventricular pacing threshold to >2,000 Ω, consistent with a fracture of the lead. The remote monitoring system notified us on November 15, 2007 at a time when the patient was still asymptomatic despite the loss of biventricular pacing. The fractured lead was extracted and a new left ventricular pacing lead was implanted, all before there was an opportunity for clinical deterioration

5 remote monitoring system is being used to provide longterm performance data on the Medtronic Sprint Fidelis ICD lead (Fig. 1) [7]. The second is the detection of asymptomatic atrial and ventricular arrhythmias. Of these, substantial interest surrounds the clinical utility of the detection of atrial high-rate episodes (Fig. 4), given the association of atrial fibrillation with congestive heart failure and stroke. Atrial high-rate episodes are the most common arrhythmia recorded by wireless devices [8, 9]. It has previously been shown that atrial high-rate episodes lasting 5 min double the risk of stroke or death in patients with sinus node dysfunction who undergo dual-chamber pacemaker implantation [10]. However, there are certain undetermined considerations. The first is the precise relationship between the burden of atrial high-rate episodes and risk of stroke. The TRENDS study evaluated the risk of thromboembolism (ischemic stroke, transient ischemic attack, systemic embolism) in a cohort of pacemaker, ICD, and cardiac resynchronization therapy defibrillator (CRT-D) patients with a CHADS2 score 1. Patients with at least one atrial high-rate episode lasting more than 5.5 h in a 30-day period had double the thromboembolic risk as compared to patients with no atrial high-rate episodes and those in whom episodes lasted <5.5 h [11]. The second is whether detection of atrial high-rate episodes can affect the management of patients. The currently ongoing IMPACT study is seeking to clarify this issue [12]. The study will enroll 2,718 patients with a CHADS2 score 1 who undergo ICD or CRT-D implantation. Patients are randomized to remote home monitoring or conventional in-office follow-up. In this study, the decision to initiate as well as discontinue anticoagulation is based on the duration of an atrial high-rate episode and the patient s underlying CHADS2 score. The hypothesis of the study is that home monitoring facilitated detection of an atrial high-rate episode will result in the earlier initiation of systemic anticoagulation, which will translate into a reduced risk of thromboembolism. The answer is increasingly important with the recent release of a new anticoagulant with rapid offset and offset of action [13]. The third allure of these devices is for the identification of patients with an impending exacerbation of congestive heart failure. Since the vast majority of ICD recipients have some degree of left ventricular systolic dysfunction, these patients are at risk for heart failure hospitalizations, which impose an economic burden on the health care system. There are several methods currently available to diagnose high-risk patients (Table 2). The RAPID-RF study sought to evaluate how remote collected heart failure (including weight and blood pressure) and arrhythmic surveillance data alter the management of heart failure patients with a CRT-D device [14]. The data have not been published to date. Nonetheless, patient weight is currently the only surrogate of heart failure status that can be obtained remotely as an alert condition. Intrathoracic impedance, which can be measured by implantable cardiac devices, appears to be inversely correlated with pulmonary capillary wedge pressure and fluid balance (Fig. 5). Preliminary studies suggest that the intrathoracic impedance decreases before the onset of patient symptoms and thus may serve as an early notification system to reduce hospital admission for management of a heart failure exacerbation [15]. However, intrathoracic impedance measurements are not Fig. 3 A red alert in a patient with a Guidant ICD. Our practice was informed of this red alert by fax as well as a direct telephone call from a Guidant representative. In addition, the alert was posted on our Latitude Web portal. The condition resulted from an inadvertent exposure of the ICD generator to radiotherapy in our patient being treated for a malignancy

6 available as a remote device alert in the Unites States. Currently, an implantable system capable of recording left atrial pressure directly is undergoing clinical investigation [16]. More data are needed to determine whether any of these indicators has adequate sensitivity and specificity to serve as a singular monitoring tool. In 2009, the Centers for Medicare and Medicaid Services afforded reimbursement for remote device follow-up (Table 3). These coverage guidelines permit reimbursement on a quarterly basis for remote follow-up of pacemakers and defibrillators. In addition, reimbursement is available to physicians for monthly remote follow-up of an implanted loop recorder and implantable cardiovascular monitor system ; the latter, which can be either a stand-alone device or incorporated into a pacemaker or ICD system, provides physiologic cardiovascular data elements from internal Fig. 4 Alert and corresponding stored electrogram of an atrial high-rate episode. This 61-year-old female has hypertension and paroxysmal atrial fibrillation. A dual-chamber pacemaker capable of wireless remote monitoring had been implanted for management of symptomatic sinus bradycardia. Subsequently, the patient underwent pulmonary vein isolation to manage highly symptomatic, drug-refractory, paroxysmal atrial fibrillation. Data remotely available from her pacemaker are being used to guide the need for long-term anticoagulation in this patient with a CHADS2 score of 1. The device is programmed to alert us if she has any individual atrial high-rate episode lasting >1 h or if she has an aggregate atrial high rate burden of >1 h in any 24-h period. A text message was sent to my cell phone to alert me that both conditions had been met. (Top) Initial screen observed after logging into the Web server and retrieving this patient s remote monitoring data. (Bottom) On December 20, 2010, the patient had a single atrial high-rate episode lasting nearly 2 h and 17 min; her total atrial high rate burden on this day was nearly 3 h and 40 min

7 Table 2 Device parameters used to track the heart failure patient Vital signs Weight and blood pressure (daily) Symptoms Quality of life questions (weekly) Assessment of patient activity Lead related Significant change in atrial or ventricular pacing impedance (<200 or >2,000 Ω) Significant increase in pacing thresholds, especially the left ventricular lead Significant increase in the percentage of right ventricular pacing Significant decrease in the percentage of left ventricular pacing Arrhythmia related Atrial tachyarrhythmias Ventricular tachyarrhythmias Miscellaneous Transthoracic impedance Heart rate variability Respiratory rate Fig. 5 Cardiac Compass report in a patient with a Medtronic ICD. An episode of persistent atrial fibrillation (horizontal black arrow) developed in mid September Approximately a month later, a rise in the OptiVol Fluid Index was observed, suggesting a rise in pulmonary capillary wedge pressure. Following electrical cardioversion in late February 2009 (vertical solid black arrow), the patient returned to sinus rhythm and the OptiVol Fluid Index decreased to baseline. In August 2009, a rise in the OptiVol fluid again was again observed; this was approximately a month before atrial fibrillation recurred (vertical open black arrow). In some patients, atrial high-rate episodes and alterations in the OptiVol Fluid Index coincide [17]

8 Table 3 Practice and physician reimbursement of remote monitoring of patients with a cardiac rhythm monitoring device Technical reimbursement (US $36): Interrogation device evaluation(s) remote, up to 90 days; single, dual, or multiple lead pacemaker system or implantable cardioverter defibrillator system, remote data acquisition(s), receipt of transmissions and technician review, technical support, and distribution of results Professional reimbursement (US $37; once per 90 days): Interrogation device evaluation(s) (remote), up to 90 days; single, dual, or multiple lead pacemaker system with interim physician analysis, review(s), and reports(s) (US $66; once per 90 days): Interrogation device evaluation(s) (remote), up to 90 days; single, dual, or multiple lead implantable cardioverter defibrillator system with interim physician analysis, review(s), and reports(s) (US $26; once per 30 days): Interrogation device evaluation(s) (remote), up to 30 days; implantable cardiovascular monitor system, including analysis of 1 or more recorded physiologic cardiovascular data elements from all internal or external sensors, physician analysis, review(s), and reports(s) (US $30; once per 30 days): Interrogation device evaluation(s) (remote), up to 30 days; implantable loop recorder system, including analysis of recorded heart rhythm data, physician analysis review(s), and reports(s) 5-digit CPT code (base CPT reimbursement) CPT current procedural terminology (transthoracic impedance, heart rate variability, respiratory rate, intracardiac pressures) and external (weight and blood pressure) sensors. Remote patient monitoring has yet to become standard of care in the management of patients with implantable devices. For example, data obtained from Medtronic show that only 66% of patients with a wireless Medtronic ICD have even been enrolled into the Carelink remote monitoring system (Fig. 6). In our opinion, a number of concerns may be impeding the universal implementation of remote monitoring technology. There are administrative challenges to the implementation of remote monitoring into an office based practice. Conventionally, patients interact with the front staff, see the physician or physician extender (who documents the findings into the patient s medical record) and are billed and rescheduled at the conclusion of their visit. The now virtual patient poses a paradigm shift. Physician practices have the responsibility for responding to these new sources of patient data, creating appropriate documentation for reimbursement and scheduling future device downloads. Some physicians have expressed to us concerns about the legal implications of being responsible for information on a 24/7 basis. The development of practice guidelines on the appropriate role of remote follow-up and monitoring in the care of patients with an implanted device would help address many of these issues. In our opinion, remote follow-up and monitoring of implantable devices will not become the standard of care until clinical trials conclusively demonstrate that patient outcome is favorably affected. One cannot assume that detection of clinically actionable events will automatically translate into improved patient outcomes. In addition, methods will need to be developed to overcome the challenges inherent to managing the flow of information from virtual patients. The latter will require modifications to existing workflow patterns; we propose a model that may maximize the clinical utility of remote monitoring (Fig. 7). In our model, the first step is patient education. The physician initiates the process at the initial consultation; an allied professional and/or device representative then reinforces the concept perioperatively and at the first postimplant office visit. The patient is then enrolled online into a remote monitoring program. The next step is to ensure that the patient receives the remote monitoring hardware, connects the hardware, and initiates the initial hand check Fig. 6 Penetration and use of remote monitoring in recipients of a Medtronic wireless ICD or CRT-ICD device. As of August 20, 2010, of the 265,024 patients implanted with a wireless device, only 174,531 (65.85%) had been enrolled in the Carelink system. Enrolled patients were eligible to transmit data on a quarterly basis. However, 25% had never made a transmission, 18.7% transmitted only once, 30.5% transmitted twice, 20.6% transmitted thrice, and only 5.2% of patients transmitted on a quarterly basis (Medtronic data on file, 20 August 2010)

9 transmission. Ideally, the device vendor would take the responsibility of ensuring that this process occurs. However, this support has not materialized, and patients often do not open the box that is delivered to them with the remote monitoring hardware. As the data from Medtronic demonstrate, a quarter of patients who have been enrolled in remote monitoring never transmit their data. Following the hand check transmission, the patient enters the virtual universe of remote monitoring. Physicians are notified along the way of actionable alerts (programmable for individual patients and clinics) that may require immediate intervention. Examples of possible interventions include asking a patient to perform a manual download for additional data review, ascertaining the clinical status of the patient over the telephone or recommending an in-office or emergency room visit. At the end of each 90-day period, the clinic has to obtain a full remote download, review and interpret the acquired patient data, share these data with the patient and referring physician(s), submit a bill for the process, and schedule the next download. There is a national health care initiative to incorporate an Electronic Medical Record (EMR) into clinical care. Today, any attempt to integrate remote follow-up and monitoring data into an EMR necessitates that a specific interface be written between each vendor website and the particular EMR system. Most practices have neither the expertise nor financial resources to accomplish this task. To make the EMR process feasible, the device industry will need to resolve at least three key challenges. These include (1) the ability of programmers to export data (including electrograms) directly into the EMR, (2) the export of all device data from the website in an industry standard HL7 format, and (3) the development of bidirectional communication between device websites and EMRs allowing for review, dismissal, and scheduling of patients without the need to open individual websites. In our opinion, it will be difficult for many practices to absorb the administrative and personnel costs inherent to the operation of a large virtual clinic in parallel to standard inoffice sessions. It also appears unlikely that the device industry will be able to interface with every commercially available EMR system in the near future. For these reasons, there is a need for the development of third party neutral service providers to address these unmet needs. These providers could funnel information from all websites to a single platform, communicate with patients (enrollment, transmissions, address questions related to billing, and results), ensure timely downloads, monitor all websites for alerts, provide the necessary documentation for physician oversight and billing, and interface with an EMR. Ideally, these data would be accessible to physicians from anywhere in the world over a secured Web portal. In summary, the paradigm for the follow-up of patients with an implanted device is evolving. The advent of wireless devices which can store and remotely transmit desired device and patient data have changed the way we manage these patients. In addition, the continued development of internal and external sensors capable of predicting impending exacerbations of heart failure will likely affect the way we manage our patients in the future. Physicians practices need to continue to think about how remote device follow-up and monitoring will be incorporated within their clinical practice; device vendors need to think collectively as an industry on Fig. 7 Current and possible future work flow for remote patient monitoring and follow-up Education Physician Allied Professional Industry Representative Physician Enrollment Scheduling Website Monitoring Communication Dismiss Download Rescheduling EMR Integration Preliminary Review Allied Professionals Arrhythmia Center Third-Party Device and Patient Management Vendor Billing Communication Physician Final Review Current Workflow Physician Future Workflow

10 how to interface the device (and resulting data) between patients, implanting and following physicians, and a growing array of EMR systems. Ultimately, the time may be ripe for the creation of entirely new vendors whose sole job is to liaison between patients, physician practices (including their EMRs), and the various device vendors. Disclosures Colin Movsowitz, MD is a consultant for Ambucor, a consultant and speaker for Biotronik and Boston Scientific, and a speaker for Medtronic and St. Jude Medical. Suneet Mittal, MD is a consultant for and EP fellowship training grant recipient from Biotronik, Boston Scientific, Medtronic and St. Jude Medical, and a speaker for Boston Scientific and Medtronic. Both authors had full control of all primary data; we agree to allow the journal to review all data upon request. References 1. Furman, S., Parker, B., & Escher, D. J. (1971). Trans-telephone pacemaker clinic. The Journal of Thoracic and Cardiovascular Surgery, 61, Federico, A. J., Giori, F., Bhayana, J. N., Chardack, W. M., & Michalek, S. (1979). Instrumentation for the follow-up of pacemaker patients: Telephone transmission of the electrocardiogram and self-check by the patient on pacemaker function and capture. Pacing and Clinical Electrophysiology, 2, Dreifus, L. S., Zinberg, A., Hurzeler, P., Puziak, A. D., Pennock, R., Feldman, M., et al. (1986). Transtelephonic monitoring of 25,919 implanted pacemakers. Pacing and Clinical Electrophysiology, 9, Crossley, G. H., Chen, J., Choucair, W., Cohen, T. J., Gohn, D. C., Johnson, W. B., et al. (2009). Clinical benefits of remote versus transtelephonic monitoring of implanted pacemakers. Journal of the American College of Cardiology, 54, Varma, N., Epstein, A. E., Irimpen, A., Schweikert, R., Love, C., & For the TRUST investigators. (2010). Efficavy and safety of automatic remote monitoring for implantable cardioverterdefibrillator follow-up: The Lumos-T safely reduces routine office device follow-up (TRUST) trial. Circulation, 122, Varma, N., Michalski, J., Epstein, A. E., & Schweikert, E. (2010). Automatic remote monitoring of implantable cardioconverterdefibrillator lead and generator performance: The Lumos-T Safely RedUceS RouTine Office Device Follow-Up (TRUST) trial. Circulation, Arrhythmia and Electrophysiology, 3(5), Medtronic physician/sprint-fidelis/6949-lead-performance. Accessed 15 Jan Crossley, G., Boyle, A., Vitense, H., Sherfesee, L., & Mead, R. H. (2008). Trial design of the clinical evaluation of remote notification to reduce time to clinical decision: The clinical evaluation of remote notification to reduce time to clinical decision (CONNECT) study. American Heart Journal, 156, Crossley, G.H. (2010) The clinical evaluation of remote notification to reduce time to clinical decision (CONNECT) trial: The value of remote monitoring. Journal of the American College of Cardiology, (in press) 10. Glotzer, T. V., Hellkamp, A. S., Zimmerman, J., Sweeney, M. O., Yee, R., Marinchak, R., et al. (2003). Circulation, 107, Glotzer, T. V., Daoud, E. G., Wyse, D. G., Singer, D. E., Ezekowitz, M. D., Hilker, C., et al. (2009). The relationship between daily atrial tachyarrhythmia burden from implantable device diagnostics and stroke risk: The TRENDS study. Circulation, Arrhythmia and Electrophysiology, 2, Ip, J., Waldo, A. L., Lip, G. Y., Rothwell, P. M., Martin, D. T., Bersohn, M. M., et al. (2009). Multicenter randomized study of anticoagulation guided by remote rhythm monitoring in patients with implantable cardioverter-defibrillator and CRT-D devices: Rationale, design, and clinical characteristics of the initially enrolled cohort (The IMPACT study). American Heart Journal, 158, Connolly, S. J., Ezekowitz, M. D., Yusuf, S., Eikelboom, J., Oldgren, J., Parekh, A., et al. (2009). Dabigatran versus warfarin in patients with atrial fibrillation. The New England Journal of Medicine, 361, Saxon, L. A., Boehmer, J. P., Neuman, S., & Mullin, C. M. (2007). Remote active monitoring in patients with heart failure (RAPID-HF): Design and rationale. Journal of Cardiac Failure, 12, Yu, C. M., Wang, L., Chau, E., Chan, R. H. W., Kong, S. L., Tang, M. O., et al. (2005). Intrathoracic impedance monitoring in patients with heart failure: Correlation with fluid status and feasibility of early warning preceding hospitalization. Circulation, 112, Ritzema, J., Melton, I. C., Richards, A. M., Crozier, I. G., Frampton, C., Doughtly, R. N., et al. (2007). Circulation, 116, Jhanjee, R., Templeton, G. A., Sattiraju, S., Nguyen, J., Sakaguchi, S., Lu, F., et al. (2009). Relationship of paroxysmal atrial tachyarrhythmias to volume overload: Assessment by implanted transpulmonary impedance monitoring. Circulation, Arrhythmia and Electrophysiology, 2,