Why not, More recently, however, manufacturers have developed some pacemakers and defibrillators that can be scanned with an MRI. “We don't refer to them as 'MRI-safe' but instead as 'MRI-conditional'

Article Magnetic resonance imaging safety in pacemaker and implantab...

thanks Abdallah Hussien Fathy

Interesting question. New for me. Thanks for asking this question.

Good one!

Perhaps this helps also a little

April 26, 2018 N Engl J Med 2018; 378:1652-1653 DOI: 10.1056/NEJMc1802623 Metrics

Magnetic Resonance Imaging and Cardiac Devices

TO THE EDITOR

The study by Nazarian et al. (Dec. 28 issue)1 adds to the growing body of evidence that patients with a cardiac device that is not labeled as a “magnetic resonance imaging (MRI)–conditional” device (termed a “legacy” device) can undergo MRI safely. The Centers for Medicare and Medicaid Services (CMS) currently does not reimburse for MRI in such patients unless they are enrolled in a prospective clinical study.2 However, the study by Nazarian et al., along with other recent studies,3,4 seems to have led CMS to reconsider its position.2

A common misconception among physicians is that MRI-conditional devices are safe for MRI. MRI-conditional devices have fewer ferromagnetic elements than other devices. They also have filter circuitry to prevent internal damage and leads designed to limit current induction.5 However, these devices are not immune to the effects of MRI.6 MRI-conditional labeling refers to implanted cardiac devices that the Food and Drug Administration has identified as having no known hazards under specific device and MRI scanner conditions. Before and after MRI, these devices require reprogramming that is similar to that of legacy devices, and they are often treated in the same way as legacy devices. Given the substantial additional cost of such devices, the findings of this study argue against widespread adoption of MRI-conditional devices as the new standard of care, as some commentators have suggested.5

Mrinal Yadava, M.D. Charles A. Henrikson, M.D., M.P.H. Oregon Health and Science University, Portland, OR [email protected]

No potential conflict of interest relevant to this letter was reported.

6 References

1.Nazarian S, Hansford R, Rahsepar AA, et al. Safety of magnetic resonance imaging in patients with cardiac devices. N Engl J Med 2017;377:2555-2564. 2.Centers for Medicare and Medicaid Services. Proposed decision memo for magnetic resonance imaging (MRI) (CAG-00399R4). January 11, 2018. (https://www.cms.gov/medicare-coverage-database/details/nca-proposed-decision-memo.aspx?NCAId=289). 3.Russo RJ, Costa HS, Silva PD, et al. Assessing the risks associated with MRI in patients with a pacemaker or defibrillator. N Engl J Med 2017;376:755-764.Free Full Text

4.Yadava M, Nugent M, Krebsbach A, Minnier J, Jessel P, Henrikson CA. Magnetic resonance imaging in patients with cardiac implantable electronic devices: a single-center prospective study. J Interv Card Electrophysiol 2017;50:95-104. 5.Mavrogeni SI, Poulos G, Kolovou G, Theodorakis G. Magnetic resonance imaging-conditional devices: luxury or real clinical need? Hellenic J Cardiol 2017;58:256-260. 6.Krebsbach A, Dewland TA, Henrikson CA. Malfunction of an MRI-conditional pacemaker following an MRI. HeartRhythm Case Rep 2016;3:148-150.

RESPONSE

The authors reply: Yadava and Henrikson address the implications of our article on widespread adoption of MRI-conditional pacemaker and implantable cardioverter–defibrillator (ICD) systems. MRI-conditional systems have minimal ferromagnetic components and incorporate design elements to reduce heating, current induction, electromagnetic interference, and power-on reset (in which device settings are reset automatically to a backup mode, as if the power to the device had been shut off and then turned on again). Most important, however, all MRI-conditional systems have an MRI mode that is easy to enable. In our opinion, this feature improves safety by circumventing the necessary expertise to carefully review, recognize, and appropriately change all programmable system settings that mitigate susceptibility to electromagnetic interference within legacy systems. Any design elements or simple programming algorithms to mitigate safety issues and improve access to MRI are welcome.

We agree that the high cost of MRI-conditional systems poses challenges in the current health care environment and may not be justified in centers that have the programming and monitoring resources for scanning legacy devices. However, we suspect that within the next decade all new pacemaker and ICD systems will be MRI-conditional, without the premium costs attributed to MRI-related design elements.

Saman Nazarian, M.D., Ph.D. University of Pennsylvania Perelman School of Medicine, Philadelphia, PA [email protected]

Henry R. Halperin, M.D. Johns Hopkins University, Baltimore, MD

Since publication of his article, Dr. Nazarian reports receiving research funding from Siemens and Imricor as the principal investigator for investigator-initiated studies. No further potential conflict of interest relevant to this letter was reported.

Recommend Share