MRI Safety in Patients with Coronary Artery Stents

Introduction to MRI Compatibility

• Metal in the chest from sternal wires or coronary stents may preclude visualization of coronary arteries near the metal during MRI, and the coronary lumen is generally not well observed in the region of a coronary stent during imaging studies, according to the American Heart Association guidelines 1
• Patients with implanted electronic devices such as internal defibrillators are generally excluded from receiving MR imaging, and claustrophobia occurs in 1-5% of patients who undergo MR imaging and may require anxiolytics, as recommended by the American College of Cardiology 1

Imaging Alternatives

• If visualization of the interior of the stent is needed, CT or invasive angiography may be preferred, as suggested by the American College of Radiology 2

Patient Preparation

• Patients should remain on their prescribed dual antiplatelet therapy (DAPT) when undergoing MRI, with the duration of DAPT depending on the type of stent, and the American College of Cardiology recommends at least 12 months of DAPT for drug-eluting stents, although the strength of evidence for this recommendation is moderate 3, 4, 5, 6
• For patients with bare-metal stents, aspirin should be continued indefinitely, and a thienopyridine (such as a generic substitute for clopidogrel) is typically needed for at least 4 weeks, according to the American Heart Association 4
• MRI can be safely performed immediately after coronary stent placement, with no need to delay imaging, as recommended by the American College of Cardiology 3, 4, 5
• Modern coronary stents are made of non-ferromagnetic materials that are not significantly affected by MRI magnetic fields, and are MRI-compatible, though the effect of MRI on heating of drug coatings in drug-eluting stents is not fully characterized, as stated by the American Heart Association and the American College of Cardiology 3, 7