Safety and performance of MR-conditional pacing systems with automated MRI mode at 1.5 and 3 Tesla.

OBJECTIVES: To evaluate at 1.5 and 3 T MRI the safety and performance of trademarked ENO®, TEO®, or OTO® pacing systems with automated MRI Mode and the image quality of non-enhanced MR examinations. METHODS: A total of 267 implanted patients underwent MRI examination (brain, cardiac, shoulder, cervical spine) at 1.5 (n = 126) or 3 T (n = 141). MRI-related device complications, lead electrical performances stability at 1-month post-MRI, proper functioning of the automated MRI mode and image quality were evaluated. RESULTS: Freedom from MRI-related complications at 1 month post-MRI was 100% in both 1.5 and 3 T arms (both p < 0.0001). The stability of pacing capture threshold was respectively at 1.5 and 3 T (atrial:: 98.9% (p = 0.001) and 100% (p < 0.0001); ventricular: both 100% (p < 0001)). The stability of sensing was respectively at 1.5 and 3 T (atrial: 100% (p = 0.0001) and 96.9% (p = 0.01); ventricular: 100% (p < 0.0001) and 99.1% (p = 0.0001)). All devices switched automatically to the programmed asynchronous mode in the MRI environment and to initially programmed mode after the MRI exam. While all MR examinations were assessed as interpretable, artifacts deteriorated a subset of examinations including mostly cardiac and shoulder ones. CONCLUSION: This study demonstrates the safety and electrical stability of ENO®, TEO®, or OTO® pacing systems at 1 month post-MRI at 1.5 and 3 T. Even if artifacts were noticed in a subset of examinations, overall interpretability was preserved. CLINICAL RELEVANCE STATEMENT: ENO®, TEO®, and OTO® pacing systems switch to MR-mode when detecting magnetic field and switch back on conventional mode after MRI. Their safety and electrical stability at 1 month post MRI were shown at 1.5 and 3 T. Overall interpretability was preserved. KEY POINTS: • Patients implanted with an MRI conditional cardiac pacemaker can be safely scanned under 1.5 or 3 Tesla MRI with preserved interpretability. • Electrical parameters of the MRI conditional pacing system remain stable after a 1.5 or 3 Tesla MRI scan. • The automated MRI mode enabled the automatic switch to asynchronous mode in the MRI environment and to initial settings after the MRI scan in all patients.