MRI Safety for Patients Implanted With the MRI Ready ICD System: MRI Ready Study Results

A prospective, multicenter study was performed to assess the safety and efficacy of the Durata and Optisure HV leads and the Ellipse VR implantable cardioverter-defibrillator (ICD) (St. Jude Medical, Sylmar, California) in a 1.5-T magnetic resonance imaging (MRI) environment. The primary safety objective was >90% freedom from MRI scan-related complications. The primary efficacy objectives were absence of change in capture threshold and absence of decrease of sensing amplitude from pre-MRI examination to 1 month after MRI.

MRI scanning of patients has been shown to be safe in patients with magnetic resonance-conditional implantable cardioverter-defibrillators (ICD) systems.

Patients with a previously implanted magnetic resonance-conditional system underwent a nondiagnostic MRI scan. After the scan, a questionnaire was given to investigators and patients who returned for 1-month follow-up examination. A subset of patients underwent ventricular tachyarrhythmia or ventricular fibrillation (VT/VF) induction testing after the MRI to evaluate defibrillation function.

There were 220 patients (81% male; 62.1 ± 11.2 years of age) enrolled who received an MRI scans from 29 centers. All primary safety and efficacy endpoints were met (p < 0.0001). No significant detection delays were found in 34 patients who had VT/VF episodes after the MRI scan was performed. Most physicians reported easy and acceptable programming and ease of MRI scheduling.

The MRI Ready MRI-conditional ICD system is safe, and electrical performance was not affected in patients receiving a 1.5-T whole-body MRI scan. Investigators reported favorable collaboration between cardiologists and radiologists in the MRI Ready IDE clinical trial. (A Clinical Evaluation of the Durata or Optisure High Voltage Leads and Ellipse VR ICD Undergoing MRI, an IDE Study [MRI Ready IDE]; NCT02787291).