MRI Safety in Patients with Pacemakers, Other Implanted Devices
If you have a pacemaker, an implanted defibrillator, or other implanted device, is it safe for you to undergo magnetic resonance imaging (MRI)? A new survey by the National Council on Aging (NCOA) found that many older adults who have implanted devices are not aware that getting an MRI scan can be risky.
The NCOA survey was performed by the firm Penn Schoen Berland, which conducted 1,077 online interviews with 652 older adults, 273 caregivers, and 152 physicians from November 19-30, 2009. The survey revealed, among other things, that 40 percent of patients with an implantable device did not remember being warned before receiving their device that getting an MRI would be risky, 13 percent of seniors with pacemakers and their caregivers did not recall being told about the risks before they received an MRI, and about 20 percent of seniors with pacemakers or their caregivers said there was a problem with the device after they received an MRI scan.
In a news release from the NCOA, Stuart Spector, Senior Vice President of the NCOA, noted that the survey “clarifies that older adults with electronic implantable devices such as pacemakers need better information on the benefits and risks of medical imaging.” One possible risk is that MRI magnetic pulses can cause pacemakers to deliver a significantly altered pulse and stimulate the heart inappropriately, according to a recent study published in BioMedical Engineering Online.
In November 2007, the American Heart Association (AHA) published a scientific statement on the safety of MRIs in patients who had cardiovascular devices. The statement, which was also endorsed by the American College of Cardiology, the North American society for Cardiac Imaging, and the Society for Cardiovascular Magnetic Resonance, states that for most devices, if there is a good clinical indication for an MRI procedure, then the benefits likely outweigh the risks.
The AHA statement covers a wide range of devices, including coronary stents, peripheral stents, embolization coils, inferior vena cava filters, aortic stent grafts, prosthetic heart valves, annuloplasty rings, cardiac closure and occlude devices, and loop recorders, as well as pacemakers and implantable cardioverter-defibrillators (ICDs). For all but the last two devices, it is generally safe to perform an MRI on patients at any time, although physicians should check the recommendations for a specific device, especially those that may not yet have been tested for MRI safety.
Regarding pacemakers and ICDs, the statement recommends that MRIs be done only at very experienced centers that have expertise in MRI safety, physics, and electrophysiology, and only when there is a strong indication for the scan; that is, healthcare professionals have determined that an MRI is the best imaging technique to resolve a clinical question.
According to the NCOA survey, 90 percent of doctors said they know MRI is risky for patients who have an implanted device and very few of them order the imaging for these individuals. Yet 30 percent of patients surveyed said they had had an MRI despite having an implanted device. This indicates that communication about the safety of MRIs for patients who have implanted devices is not adequate, and that there needs to be more dialogue about MRI risks and benefits between patients, caregivers, and healthcare providers.
Given that an individual’s need for medical imaging doubles after age 65, and that from 50 to 75 percent of patients who have an electronic implantable device will probably need medical imaging, it is important that both patients and medical professionals are educated about MRI safety and implantable devices. To support that effort, the NCOA is sponsoring a series of free community events across the country called “A Look Within: What To Know, What To Do, What To Ask.” Information about the events can be found on the NCOA website.
Bassen H, Mendoza GG. BioMedical Engineering Online 2009 Dec. 15; 8:39
Levine GN et al. An American Heart Association Scientific statement. Circulation 2007 DOI: 10.1161/CIRCULATIONAHA.107.187256
National Council on Aging news release, Feb. 17, 2010