Healthcare Professionals

MRI Safety for Implantable Cardiac Devices

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MRI Safety for Implantable Cardiac Devices

MRI Overview

How many of your patients are excluded from the benefits of MRI because of their implantable cardiac device?

Most likely several since cardiac devices have not been considered safe in the MRI environment.

The Dilemma

As MRI use increases, so too does the number of patients benefiting from pacemakers and implantable cardioverter defibrillators (ICDs). This convergence results in an escalating number of patients who may be denied MR diagnostic imaging.

Convergence of Trends:
Many Patients Potentially Denied MR Scans

Total-Patients

Detail - Pacemaker and ICD Implants - Prevalence of Implantable Pulse Generators (IPGs) and Implantable Cardioverter Defibrillators (ICDs) implanted in the U.S. 1993-2004.*

 

Utilization

Detail - MRI Procedures - Total US MRI procedure volume, hospital and non-hospital sites, 1993-2003.†

The Impact

  • MRI scans are potentially unsafe and off-limits for more than 2 million Americans because they have an implanted cardiac device1
  • In 2004 alone, about 200,000 implantable cardiac device patients were denied the benefits of an MR scan2
  • 40% of Europeans and 50-75% of Americans with implantable devices will be indicated for MR scanning over the lifetime of their device2
  • Every 3 minutes in the US, and every 6 minutes in Europe, a patient is denied an MRI because of the presence of a pacemaker or defibrillator2-5

Recently, the FDA approved the Revo MRI SureScan Pacing System designed for use in the MRI environment under specified conditions.

The Revo MRI SureScan pacing system is MR Conditional designed to allow patients to undergo MRI under the specified conditions for use. A complete system, consisting of a Medtronic Revo MRI SureScan IPG implanted with two CapSureFix MRI™ SureScan leads is required for use in the MRI environment.

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OUR VIEWPOINT

Medtronic Viewpoint

Medtronic does not support the off-label use of its products and believes that the safe use of implantable cardiac devices in the MR environment cannot be guaranteed unless devices are designed to be safe from the ground up. And such devices must be backed by rigorous scientific testing as well as review from appropriate regulatory agencies.

Medtronic recognizes that under certain circumstances, physicians will determine that the medical benefit of conducting an MRI on a patient with an implanted cardiac device outweighs the associated risks. But Medtronic cautions the scientific community about drawing conclusions from limited studies that have reported no adverse events. MRI experts Kanal and Gimbel clearly state: …failing to identify an adverse event is not equivalent to demonstrating safety1… in small studies with products not intended for the MR environment.

This is especially true since the hazards associated with scanning devices have a low frequency of occurrence. Furthermore, research needs to account for numerous variables, including inconsistency among MRI manufacturers, lead type and length, anatomical position of implant, and scan parameters. All these variables can change with the introduction of new cardiac devices and leads, and the continuous evolution of MRI technology.

The Revo MRI™ SureScan® Pacing System is the first MR-conditional FDA approved pacing system.

The Revo MRI SureScan pacing system is MR Conditional designed to allow patients to undergo MRI under the specified conditions for use. A complete system, consisting of a Medtronic Revo SureScan IPG implanted with two CapSureFix MRI™ SureScan leads is required for use in the MRI environment.

  • A complete SureScan pacing system including a Revo MRI SureScan IPG and two CapSureFix MRI SureScan leads is required for use in the MRI environment
  • Any other pacing system combination may result in a hazard to the patient during an MRI scan

Medtronic has an ongoing commitment to design future device systems to be safe in MRI scanners. Physicians and their patients should accept nothing less than this commitment to safety and quality.

For other industry and government viewpoints, refer to the April 2005 issue of PACE.

Reference

1

Gimbel J and Kanal E. Can patients with implantable pacemakers safely undergo magnetic resonance imaging? J Am Coll Cardiol. 2004;43:1325-1327.

SOURCES/HAZARDS

CLINICAL CONTROVERSAY

*

Copyrighted information provided with permission from IMV Medical Information Division. 2004 MRI Benchmark Report.

†

Cumulative implants minus mortality. Medtronic data on file.

References

1

Modern implantable heart devices safe for use in the MRI scans. Cardiovascular Week. 2005; March 28:193.

2

Medtronic data on file.

3

Magnetic Resonance Imaging Equipment-Global Strategy Business Report, Global Industry Analysts, Inc. San Jose, CA. 2002.

4

2002/03 MRI Benchmark Report, IMV Medical Information Division. Des Plaines, IL. 2003.

5

GE Medical Systems. Waukesha, WI. Press Release, 2002.