Canadian Heart Rhythm Society and Canadian Association of Radiologists Consensus Statement on Magnetic Resonance Imaging with Cardiac Implantable Electronic Devices

Abstract

Magnetic resonance imaging (MRI) has historically been considered contraindicated for individuals with cardiac implantable electronic devices (CIEDs) such as pacemakers and implantable defibrillators. Magnetic resonance scanners produce magnetic fields that can interact negatively with the metallic components of CIEDs. However, as CIED technology has advanced, newer MRI conditional devices have been developed that are now in clinical use and these systems have had demonstrated safety in the MRI environment. Despite the supportive data of such CIED systems, physicians remain reluctant to perform MRI scanning of conditional devices. This joint statement by the Canadian Heart Rhythm Society and the Canadian Association of Radiologists describes a collaborative process by which CIED specialists and clinics can work with radiology departments and specialists to safely perform MRI in patients with MRI conditional CIED systems. The steps required for patient and scanning preparation and the roles and responsibilities of the CIED and radiology departments are outlined. We also briefly outline the risks and a process by which patients with nonconditional CIEDs might also receive MRI in highly specialized centres. This document supports MRI in patients with MRI conditional CIEDs and offers recommendations on how this can be implemented safely and effectively.

Magnetic Resonance Imaging for Patients with Cardiac Implantable Electronic Devices: Reduced Concerns Regarding Safety, but Scrutiny Remains Critical

“…Since their first introduction to the European Union in 2008, MR-conditional CIEDs have become the standard care for patients indicated for cardiac device implantation. The current recommendation is that MRI can be performed in patients with MR-conditional CIEDs if the magnetic field is under 1.5 T. This represents a moderate (class IIa) recommendation (evidence/opinion in favor of usefulness/efficacy rather than risk) based on level C evidence (consensus of expert opinion and/or small prospective, retrospective, or registry studies) according to the European Society of Cardiology (ESC) guidelines published in 2013,4) and a strong recommendation based on moderate-quality evidence according to the Canadian Heart Rhythm Society and Canadian Association of Radiology consensus statement published in 2014 5)…”

“…Therefore, the approach of the Canadian group does not constitute standard practice. However, in a clinical scenario where MRI might provide crucial information in the management of the patient's care, such a non-standard investigation may be allowed, with the understanding that it carries a risk of serious and potentially life-threatening complications 5). Such allowance necessarily involves cooperation among the referring physician, cardiologist with expertise in CIED management, and MR radiologist.…”

“…While CIED manufacturer have recently released devices that are MR conditional in 3-T fields,1) little information exists regarding the behavior of either MR-conditional of non-MRconditional CIEDs during MRI performed at 3-T. Currently, 3-T MRI is not recommended 5). However, because the use of 3-T MRI is increasing, it is expected that the experience of performing 3-T MRI in patients with non-MR-conditional or MR-conditional CIEDs will grow as well 9)10)…”

“…Along with the above consideration, there is an absolute contraindication for MRI in patients with pacing leads implanted <6 weeks before the MRI investigation, and in patients with abandoned or epicardial leads 4)5). Non-MR-conditional CIEDs have ferromagnetic components, which cause movement and vibration of the cardiac device in the strong static and gradient magnetic fields of the MR system.…”

“…A period of at least 6 weeks after implantation is required to ensure that the CIED is securely embedded into the tissue 8). Some CIED manufacturers recommend that MRI should not be performed sooner than 6 weeks after implantation even for MR-conditional devices 5). Nevertheless, the risk for lead and generator movement is extremely low,13) and imaging may be performed earlier on a case-by-case basis if there is a clinical necessity.…”