Is magnetic resonance safe in implanted cardiac devices patients?

Area of Science:

• Cardiovascular Imaging
• Medical Device Technology
• Electrophysiology

Background:

• Implanted cardiac devices like pacemakers (PM) and implantable cardioverter-defibrillators (ICD) can pose safety concerns during Magnetic Resonance Imaging (MRI).
• Previous studies have raised concerns about potential device malfunction and patient safety during MRI scans in patients with cardiac devices.

Purpose of the Study:

• To evaluate the safety and impact of a 1.5 T MRI protocol on patients with implanted cardiac devices (ICD and PM).
• To assess acute and long-term changes in device variables and identify potential risks associated with MRI in this patient population.

Main Methods:

• A prospective, non-randomized trial involving 438 participants with PM or ICD underwent 555 MRI examinations.
• Specific pacing modes were programmed, and ICDs were disabled in non-PM-dependent patients. Continuous monitoring included vital signs and symptoms.
• Device variables (sensing, impedance, capture threshold, battery voltage) were evaluated before, immediately after, and 3–6 months post-MRI.

Main Results:

• Only 0.7% of patients experienced acute power-on-reset events, with no long-term device dysfunction observed.
• Immediate post-MRI showed reduced right ventricular sensing and lead impedance. Long-term follow-up revealed decreased RV sensing, lead impedance, and battery voltage, with increased RV capture threshold in 61% of patients.
• Observed device variable changes did not necessitate device revision or reprogramming. Thoracic MRI sequences were more likely to cause artifacts.

Conclusions:

• The 1.5 T MRI protocol is safe for patients with implanted cardiac devices (PM and ICD).
• While minor, transient device variable changes can occur, they are generally not clinically significant and do not require intervention.
• Careful patient selection and adherence to specific MRI protocols are crucial for ensuring patient safety.