................................................................................................................................. .............................................................. RESEARCH Original article Q Assessment of a remote monitoring system for implantable cardioverter defibrillators Cristina Masella* , Paolo Zanaboni*, Francesca Di Stasi † , Serena Gilardi † , Patrizia Ponzi † and Sergio Valsecchi † *Department of Management, Economics and Industrial Engineering, Politecnico di Milano, Milan; † Medtronic, Italy Summary We conducted a multicentre study in five Italian hospitals to assess the feasibility of a remote monitoring service for the follow-up of implanted cardiac devices. The system was designed to monitor device performance as well as physiological aspects of the patient’s condition. Sixty-seven patients (mean age 64 years) affected by chronic heart failure and with a biventricular implantable cardioverter defibrillator for cardiac re-synchronization therapy (CRT-D) were enrolled for a three- month observation period. A total of 267 device recordings were transmitted through the ordinary telephone network, with a success rate of 99%. The telemonitoring service was more efficient than conventional face-to-face follow-up in terms of the time savings: both for physicians (4.7 minutes versus 15 minutes for remote and conventional monitoring) and for patients (6.6 minutes versus 116.3 minutes). In addition, a total of 23 clinical events occurred during the study, but only two cases required a clinic visit, thus reducing inappropriate hospital admissions. Finally, the service was well accepted by all the users. Introduction An implantable cardioverter defibrillator (ICD) is a battery-powered, fully implantable device, which can monitor the heart rhythm and deliver an electric shock to restore normal sinus rhythm when a potentially life-threatening arrhythmia is detected. 1 All devices have four functions: arrhythmia detection, arrhythmia treatment, bradycardia pacing and episode-data storage. 2 ICD, associated with cardiac re-synchronization therapy (CRT), has been shown to be effective for primary or secondary prevention of sudden cardiac death in patients with chronic heart failure. 3–6 Thus there has been a rise in new implantations 4 and a consequent increase in the number of follow-up visits in hospitals. 7 Follow-up visits are usually scheduled at three-month or six-month intervals. 8 The main disadvantage of intermittent follow-up is that any device problem which occurs will not be identified quickly. 9 Additional unscheduled visits are often required to investigate symptoms that may or may not be related to the cardiac disease or device. 10 Remote monitoring of cardioverter defibrillators is an alternative to frequent visits. The physician can decide whether the patient needs a visit to the outpatient clinic for device re-programming, 11,12 an emergency admission, a change in therapy or nothing. This reduces the need for follow-up and enables the individualization of correct routine follow-up intervals 13 avoiding unnecessary visits. In addition, remote monitoring allows the early detection of changes in the rhythm state of the patient 14 and the review of information from the device such as battery voltage and lead impedance. Remote monitoring service The Medtronic CareLink Network is an Internet-based remote monitoring service designed to assist physicians in the management of chronic cardiovascular diseases treated with an implantable device (ICD or pacemaker). There are two main components: (1) a small device, the Medtronic CareLink Monitor, with an attached aerial for wireless data transfer. The monitor is powered by batteries and can be plugged into a standard telephone connection; (2) a website, where clinicians can monitor the condition of patients who use the device. The service allows patients to interrogate their implanted device by pushing a button to turn on the Monitor and placing the aerial over the device. Then the Monitor automatically transmits device-related and physiological data to the Medtronic CareLink Network via the telephone Accepted 6 May 2008 Correspondence: Paolo Zanaboni, Department of Management, Economics and Industrial Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy (Fax: þ39 02 2399 4083; Email: paolo.zanaboni@polimi.it) Journal of Telemedicine and Telecare 2008; 14: 290–294 DOI: 10.1258/jtt.2008.080202