Emanuel Kanal MD, Presenter: Consultant, Bayer AG Consultant, Bracco Group Consultant, Covidien AG Consultant, General Electric Company Consultant, Guerbet SA Consultant, Medtronic, Inc Research support, Bayer AG Research support, Bracco Group Speakers Bureau, Bracco Group Speakers Bureau, General Electric Company

Torsten Sommer MD, Abstract Co-Author: Nothing to Disclose

Roger Luechinger PhD, Abstract Co-Author: Research Consultant, Medtronic, Inc

Milos Taborsky MD, PhD, Abstract Co-Author: Nothing to Disclose

Josef Vymazal MD, PhD, Abstract Co-Author: Consultant, EPIX Pharmaceuticals, Inc, Boston, MA Consultant, NovoCure Ltd, Haifa, Israel

Firat Duru, Abstract Co-Author: Nothing to Disclose

Bruce Larry Wilkoff MD, Abstract Co-Author: Consultant, Medtronic, Inc

David Bello, Abstract Co-Author: Consultant, Medtronic, Inc

Bernhard Kuepper, Abstract Co-Author: Nothing to Disclose

Peter Hunold MD, Abstract Co-Author: Speaker, Bayer AG Speaker, General Electric Company Speaker, Siemens AG Speaker, AstraZeneca PLC Speaker, Novartis AG

Inge Jenniskens MSC, Abstract Co-Author: Employee, Medtronic, Inc

et al, Abstract Co-Author: Nothing to Disclose

Approximately 60 million MR scans are performed annually worldwide and it is estimated that 50 to 75% of pacemaker patients (pts) will be indicated for an MR during the life-time of their pacemaker; however, pacemaker pts are contraindicated and thus restricted from receiving the diagnostic capabilities MR may offer. We report the first results of a randomized, worldwide clinical trial to evaluate safety and efficacy of a new pacemaker system in the MR environment. This system was designed and tested to minimize risks from MR.  

Pts needing a pacemaker and eligible to undergo an MR scan were enrolled. After implant, pts were randomized 1:1 to either undergo an MR scan (MR group) after 9-12 weeks or to not undergo an MR scan (No-MR group). Follow-ups occurred at 1 week and 1 month post MR/No-MR. Essential pacemaker checks (capture threshold, sensing and impedance) were performed at all follow-ups, including immediately before and after MR/No-MR. The 14 required clinically relevant head (e.g. Sagital spin echo T1, T2 Flair, Perfusion) and lumbar spine (e.g. Sagital T1 and T2, Axial T1 and T2) sequences were performed at 1.5T, while maximizing the gradient slew rate and/or radiofrequency power up to a Specific Absorption Rate (SAR) of 2 W/kg.

In Europe and Canada, 249 pts were enrolled. A total of 245 implanted pts, with a mean follow up of 6.3 months, were randomized. Of these, 90 underwent an elective MR scan and the 101 control pts waited 1 hour between pre- and post threshold measurements. No MR related complications were reported. No significant threshold changes were seen after the MR between the two groups and there was no significant difference in sensing after the MR between the two groups.

The results of this ongoing clinical trial indicate that this pacing system meets its performance requirements, when used in accordance with the system’s labeling. These results corroborate the results observed in preclinical bench, phantom and animal testing.

New pacemaker designed for use in MR environment met performance requirements in clinical study, when used in accordance with the labeling instructions.

Kanal, E, Sommer, T, Luechinger, R, Taborsky, M, Vymazal, J, Duru, F, Wilkoff, B, Bello, D, Kuepper, B, Hunold, P, Jenniskens, I, et al, , First Results of the Performance of a New Pacemaker System Designed for Use in the MR Environment.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6007234.html