Objective: To estimate the safety of cardiac magnetic resonance imaging in patients with implantable cardioverter-defibrillators (ICCD) compatible and non-compatible with MRI.
Patients and methods: 92 patients with ICD, aged 60.7 +/- 10.6 years (90% with coronary artery disease) underwent CMR examination. ICD was implanted for primary prevention in 64 patients, and in 28 patients for secondary prevention. The MRI-compatible and non-compatible devices were implanted in 50 and 42 patients, respectively.
CMR was performed on 1.5 T scanner (Magnetom Avanto, Siemens). ICD was re-programmed for the duration of MRI examination according to the 2013 ESC guidelines. The baseline settings were restored after CMR. ICD parameters were checked three times: before, immediately after and 30 days after CMR. Patients’ safety was monitored by pacing impedance, defibrillation impedance, pacing threshold and sensitivity of the detection of R wave (sensing amplitude).
Results: No device-related adverse events were documented during CMR. There were no significant differences for both MRI-compatible and MRI-non-compatible devices in terms of parameters measured before, immediately after and 30 days after CMR. The pacing impedance measured at all three timepoints showed no significant differences for both MRI-compatible (521.02? ± 113.02? vs 524.52? ± 112.06? vs 521.02? ± 111.89?; p=ns) and MRI-non-compatible devices (445.45? ± 106.95? vs 438.00? ± 104.56? vs 454.05? ± 106.18?; p =ns). Similarly, no differences in defibrillation impedance were observed for both types of devices, MRI-compatible (79.52? ± 8.35? vs 80.52? ± 8.11? vs 80.58? ± 8.07?; p=ns) and MRI-non-compatible ones ( 65.70? ± 6.62? vs 67.60? ± 6.83? vs 65.93? ± 6.77?; p = ns). Pacing threshold and sensitivity of R wave detection (sensing amplitude) were also within normal limits.
Conclusions: With appropriate precautions, CMR may be performed safely in patients with either compatible or non-compatible devices. All device parameters measured after the CMR scan for both, MRI-compatible and MRI-non-compatible devices, confirmed normal device performance.