Immediate and 12 months follow up of function and lead integrity after cranial MRI in 356 patients with conventional cardiac pacemakers

Abstract

BackgroundConventional cardiac pacemakers are still often regarded as a contraindication to magnetic resonance imaging (MRI). We conducted this study to support the hypothesis that it is safe to scan patients with cardiac pacemakers in a 1.5 Tesla MRI, if close supervision and monitoring as well as adequate pre- and postscan programming is provided.MethodsWe followed up 356 patients (age 61.3 ± 9.1 yrs., 229 men) with single (n = 132) or dual chamber (n = 224) cardiac pacemakers and urgent indication for a cranial MRI for 12 months. The scans were performed at 1.5T. During the scan patients were monitored with a 3-lead ECG and pulse oximetry. Prior to the scan pacemakers were programmed according to our own protocol.ResultsAll 356 scans were completed without complications. No arrhythmias were induced, programmed parameters remained unchanged. No pacemaker dysfunction was identified. Follow-up examinations were performed immediately, 2 weeks, 2, 6, and 12 months after the scan. There was no significant change of pacing capture threshold (ventricular 0.9 ± 0.4 V@0.4 ms, atrial 0.9 ± 0.3 V@0.4 ms) immediately (ventricular 1.0 ± 0.3 V@0.4 ms, atrial 0.9 ± 0.4 V@0.4 ms) or at 12 months follow-up examinations (ventricular 0.9 ± 0.2 V@0.4 ms, atrial 0.9 ± 0.3 V@0.4 ms). There was no significant change in sensing threshold (8.0 ± 4.0 mV vs. 8.1 ± 4.2 mV ventricular lead, 2.0 ± 0.9 mV vs. 2.1 ± 1.0 mV atrial lead) or lead impedance (ventricular 584 ± 179 Ω vs. 578 ± 188 Ω, atrial 534 ± 176 Ω vs. 532 ± 169 Ω) after 12 months.ConclusionsThis supports the evidence that patients with conventional pacemakers can safely undergo cranial MRI in a 1.5T system with suitable preparation, supervision and precautions. Long term follow-up did not reveal significant changes in pacing capture nor sensing threshold.

Clinical Performance of Magnetic Resonance Imaging Conditional and Nonconditional Cardiac Implantable Electronic Devices

“…Lead sensing and long‐term follow‐up were not assessed in this study. It is possible that more significant changes in lead parameters would become apparent with time, though others have performed such follow‐up, and no changes were identified up to 12 months post‐MRI . As with any study of rarely occurring events, it is possible that the number of scanned patients precludes identification of meaningful trends.…”

“…It is possible that more significant changes in lead parameters would become apparent with time, though others have performed such follow-up, and no changes were identified up to 12 months post-MRI. 28 As with any study of rarely occurring events, it is possible that the number of scanned patients precludes identification of meaningful trends. The MagnaSafe registry is an ongoing multicenter study with an anticipated enrollment of 1,500 patients and should clarify this concern.…”

Magnetresonanztomographie und aktive kardiale Implantate

“…Gemessen an der Gesamtzahl der untersuchten Patienten beschränkt sich das Auftreten eines elektrischen Resets auf eine geringe Anzahl von Fällen. In der Studie von Muehling et al waren bei 37 Aggregaten (10,4 %) der Fall elektrischer Resets dokumentiert worden, in den postprozeduralen Abfragen konnte aber eine regelrechte Funktion wiederhergestellt werden [8]. In der MagnaSafe-Registry-Studie traten 6 Fälle auf, die ohne weitere Konsequenzen blieben [12].…”

Review of Journal of Cardiovascular Magnetic Resonance 2015

“…The increasing number of patients with MR-conditional devices in situ continues to be accompanied by greater CMR experience and more routine scanning of such patients, [188, 189] although stress perfusion has lagged somewhat behind due to feasibility and safety concerns, notably with regard to competitive pacing. Despite much research, accurately predicting who will respond to implantation of cardiac resynchronisation therapy (CRT) has remained problematic.…”