Safety and efficacy of a new magnetic resonance imaging– compatible pacing system: Early results of a prospective comparison with conventional dual-chamber implant outcomes Giovanni B. Forleo, MD, PhD, Luca Santini, MD, PhD, Domenico G. Della Rocca, MD, Valentina Romano, MD, Lida P. Papavasileiou, MD, Giulia Magliano, MD, Marianna Sgueglia, MD, Francesco Romeo, MD From the Department of Internal Medicine, Division of Cardiology, University of Rome “Tor Vergata,” Rome, Italy. BACKGROUND A new pacing system has been designed and tested preclinically for safe use in the magnetic resonance imaging (MRI) environment. Experience with this innovative system has not yet been reported. OBJECTIVE The purpose of this study was to verify the safety and effectiveness of this newly designed system compared to conven- tional DDD implant outcomes. METHODS Over an 11-month period, 107 consecutive patients (71 men and 36 women; age 72.6  8.5 years) were implanted with either the MRI system (n = 50; MRI group) or a dual- chamber, active-fixation lead (Medtronic 4076) non-MRI sys- tem (n = 57; DDD group). Data were collected at implant and during postoperative follow-up at 1, 3, 6, and 12 months. Procedural and fluoroscopic times at implant, as well as lead measurements, handling characteristics, and procedural-re- lated complications, were prospectively analyzed. RESULTS The implantation success rate in both groups was 100%. Cephalic access was 63% for MRI patients and 70% for DDD patients (P = NS). Follow-up was obtained for all patients (median 6.8 months, range 3–12 months). At implant and at the end of follow-up, stimulation thresholds, sensing, and impedance were acceptable. No cases of high pacing thresholds or inadequate sensing were noted. No complications occurred, and no patient experienced subsequent lead displacement. CONCLUSION This prospective, controlled study provides strong evidence that the feasibility and safety of this novel technology compare favorably with those of the conventional technique. KEYWORDS Cardiac pacing lead; Lead performance; Magnetic res- onance imaging; Pacemaker ABBREVIATIONS MRI = magnetic resonance imaging; RV = right ventricular (Heart Rhythm 2010;7:750 –754) © 2010 Heart Rhythm Society. All rights reserved. Introduction The presence of a cardiac pacemaker is an absolute contra- indication to magnetic resonance imaging (MRI); therefore, most patients with a pacemaker are excluded from under- going MRI. Recently, a new pacing system (Medtronic EnRhythm MRI SureScan and CapSureFix MRI leads, Medtronic, Inc., Minneapolis, MN, USA) has been designed and tested preclinically for safe use in the MRI environ- ment. In order to make the system “MR-conditional,” com- ponents have been redesigned, and new features, especially lead design and geometry, have been incorporated into the system. The increased diameter and stiffness of the leads are the main drawbacks of the MRI leads compared with con- ventional leads (Table 1). Whether these features result in a different handling and performance between leads has not yet been proven. Recently, both physicians and device manufacturers have raised concerns about how to better identify device mal- functions of new pacing systems. The Heart Rhythm Soci- ety has formed a task force on lead performance issues to study many of the important topics stimulated by the Sprint Fidelis lead problems. 1 Although new devices might be associated with an even greater risk of complications and failure, no experience with this innovative pacing system has yet been reported. The purpose of this study was to verify the safety and effectiveness of an MRI-compatible pulse generator and lead system compared to conventional DDD implant out- comes. Methods Study population This single-center, prospective, controlled, nonrandomized study was performed in a tertiary-care university hospital. We were familiar with the SureScan system as it was pre- viously used in five patients. In the current investigation, This manuscript was processed by a guest editor. Dr. Papavasileiou has received research support from Medtronic, Inc. Address reprint requests and correspondence: Dr. Giovanni B Forleo, Division of Cardiology, University Hospital of Tor Vergata, Viale Oxford, 81, 00133, Roma, Italy. E-mail address: forleo@me.com. (Received January 15, 2010; accepted February 10, 2010.) 1547-5271/$ -see front matter © 2010 Heart Rhythm Society. All rights reserved. doi:10.1016/j.hrthm.2010.02.020