MRI using defined protocol is safe even in patients with older implanted cardiac devices

Is magnetic resonance imaging using a carefully defined protocol safe for patients with older implanted cardiac devices?

Adverse events from magnetic resonance imaging (MRI) using a carefully defined protocol are rare and do not result in clinical harms for patients with older implanted cardiac devices. Only 1 in 2103 scans resulted in the need to replace the device and there were no clinically significant arrhythmic events. (LOE = 2b)

Nazarian S, Hansford R, Rahsepar AA, et al. Safety of magnetic resonance imaging in patients with cardiac devices. N Engl J Med 2017;377(26):2555-2564.  [PMID:29281579]

Cohort (prospective)

Government

Inpatient (any location)

This study reports the outcomes in 1509 patients with a "legacy" (ie, non-MRI approved) pacemaker or implantable defibrillator who underwent 2103 MRI examinations at Johns Hopkins University. The radiologists used an MRI protocol they developed, as well as a clinical protocol administered by a nurse that involves reprogramming the device to asynchronous mode for patients with intrinsic bradycardia and to an inhibited mode for all other patients. The MRIs used a 1.5 Tesla magnet and took place over the period from 2003 to 2015. The median age of participants was 69 years, 36% were women, 58% had a pacemaker, and 42% had an implantable defibrillator. In 2103 examinations, there were only 9 adverse events in which the device experienced a power-on reset (making it temporarily inactive). However, no patient experienced any serious clinical adverse event, with the excpetion of a single patient who required replacement of his pacemaker. A limitation of this study is that they had long-term (6-month) follow-up for only approximately 80% of patients.