Importance: Magnetic resonance imaging (MRI) is the modality of choice for many conditions. Conditional devices and novel protocols for imaging patients with legacy cardiac implantable electronic devices (CIEDs) have increased access to MRI in patients with devices. However, the presence of abandoned leads remains an absolute contraindication.
Objective: To assess if the performance of an MRI in the presence of an abandoned CIED lead is safe and whether there are deleterious effects on concomitant active CIED leads.
Design, setting, and participants: This cohort study included consecutive CIED recipients undergoing 1.5-T MRI with at least 1 abandoned lead between January 2013 and June 2020. MRI scans were performed at the Hospital of the University of Pennsylvania. No patients were excluded.
Exposures: CIEDs were reprogrammed based on patient-specific pacing needs. Electrocardiography telemetry and pulse oximetry were monitored continuously, and live contact with the patient throughout the scan via visual and voice contact was performed if possible. After completion of the MRI, CIED evaluation was repeated and programming returned to baseline or to a clinically appropriate setting.
Main outcomes and measures: Variation in pre- and post-MRI capture threshold of 50% or more, ventricular sensing 40% or more, and lead impedance 30% or more, as well as clinical sequelae such as pain and sustained tachyarrhythmia were considered significant. Long-term follow-up lead-related data were analyzed if available.
Results: A total of 139 consecutive patients (110 men [79%]) with a mean (SD) age of 65.6 (13.4) years underwent 200 MRIs of various anatomic regions including the thorax. Repeat examinations were common with a maximum of 16 examinations for 1 patient. There was a total of 243 abandoned leads with a mean (SD) of 1.22 (0.45) per patient. The mean (SD) number of active leads was 2.04 (0.78) and 64 patients (46%) were pacemaker dependent. A transmit-receive radiofrequency coil was used in 41 patients (20.5%), all undergoing MRI of the brain. There were no abnormal vital signs or sustained tachyarrhythmias. No changes in battery voltage, power-on reset events, or changes of pacing rate were noted. CIED parameter changes including decreased right atrial sensing in 4 patients and decreased left ventricular R-wave amplitude in 1 patient were transiently noted. One patient with an abandoned subcutaneous array experienced sternal heating that subsided on premature cessation of the study.
Conclusions and relevance: The risk of MRI in patients with abandoned CIED leads was low in this large observational study, including patients who underwent examination of the thorax. The growing aggregate of data questions the absolute contraindication for MRI in patients with abandoned CIED leads.