Safety Of Magnetic Resonance Imaging In Patients Research Articles

Joint Position Paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the French Society of Diagnostic and Interventional Cardiac and Vascular Imaging on magnetic resonance imaging in patients with cardiac electronic implantable devices

Magnetic resonance imaging (MRI) has become the reference imaging technique for the management of a large number of diseases. The number of MRI examinations increases every year, simultaneously with the number of patients receiving a cardiac electronic implantable device (CEID). The presence of a CEID was considered an absolute contraindication for MRI for many years. The progressive replacement of conventional pacemakers and defibrillators by "magnetic resonance (MR)-conditional" CEIDs and recent data on the safety of MRI in patients with "MR-non-conditional" CEIDs have gradually increased the demand for MRI in patients with a CEID. However, some risks are associated with MRI in CEID carriers, even with MR-conditional devices, because these devices are not "MR safe". Specific programming of the device in "MR mode" and monitoring patients during MRI remain mandatory for all patients with a CEID. A standardized patient workflow based on an institutional protocol should be established in each institution performing such examinations. This joint position paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the French Society of Diagnostic and Interventional Cardiac and Vascular Imaging describes the effect of and risks associated with MRI in CEID carriers. We propose recommendations for patient workflow and monitoring and CEID programming in MR-conditional, "MR-conditional non-guaranteed" and MR-non-conditional devices.

Magnetic resonance imaging in non-conditional pacemakers and implantable cardioverter-defibrillators: a systematic review and meta-analysis.

There is growing evidence that magnetic resonance imaging (MRI) scanning in patients with non-conditional cardiac implantable electronic devices (CIEDs) can be performed safely. Here, we aim to assess the safety of MRI in patients with non-conditional CIEDs. English scientific literature was searched using PubMed/Embase/CINAHL with keywords of 'magnetic resonance imaging', 'pacemaker', 'implantable defibrillator', and 'cardiac resynchronization therapy'. Studies assessing outcomes of adverse events or significant changes in CIED parameters after MRI scanning in patients with non-conditional CIEDs were included. References were excluded if the MRI conditionality of the CIEDs was undisclosed; number of patients enrolled was <10; or studies were case reports/series. About 35 cohort studies with a total of 5625 patients and 7196 MRI scans (0.5-3 T) in non-conditional CIEDs were included. The overall incidence of lead failure, electrical reset, arrhythmia, inappropriate pacing and symptoms related to pocket heating, or torque ranged between 0% and 1.43%. Increase in pacing lead threshold >0.5 V and impedance >50Ω was seen in 1.1% [95% confidence interval (CI) 0.7-1.8%] and 4.8% (95% CI 3.3-6.4%) respectively. The incidence of reduction in P- and R-wave sensing by >50% was 1.5% (95% CI 0.6-2.9%) and 0.4% (95% CI 0.06-1.1%), respectively. Battery voltage reduction of >0.04 V was reported in 2.2% (95% CI 0.2-6.1%). This meta-analysis affirms the safety of MR imaging in non-conditional CIEDs with no death or implantable cardioverter-defibrillator shocks and extremely low incidence of lead or device-related complications.

Safety of magnetic resonance imaging in patients with legacy pacemakers and defibrillators and abandoned leads

During magnetic resonance imaging (MRI), abandoned leads may act as antennae that result in tissue heating and arrhythmia induction. The purpose of this study was to assess the safety of MRI in patients with abandoned leads, with the addition of cardiac troponin T (cTnT) assessment to screen for myocardial damage. We reviewed our prospectively collected database of patients with cardiovascular implantable electronic devices (CIEDs) undergoing MRI between 2008 and 2017 at Mayo Clinic, Rochester, MN, and selected patients who had abandoned leads. We compared the adverse events in this population with an age, sex, and site of MRI-matched cohort of patients selected from this database. We evaluated paired (before/after) cTnT values using MRI in these patients. Of 952 patients, 80 (8.4%) underwent 97 MRI scans with CIEDs in situ with 90 abandoned leads in place during the scans. The median age was 66 years (interquartile range 22.3 years) 66.1 years (interquartile range, Q1,Q3: 53.6, 75.9) with 66.3% (53 patients) men. There was no clinical or electrical evidence of CIED dysfunction, arrhythmias, or pain. Paired samples for the measurement of cTnT values were available in 40 patients undergoing 44 MRI examinations. The mean difference between the pre- and postimaging values was -0.002 ± 0.006 ng/mL (interquartile range 0). There was no difference after adjustment for total number of leads per patient and total number of implantable cardioverter-defibrillator coils. There was no evidence of myocardial injury as measured by paired cTnT. The risk of MRI with abandoned leads appears low, suggesting a favorable risk-benefit profile in patients with CIEDs and abandoned leads who are considered for MRI.

Magnetic resonance imaging in patients with cardiac implantable electronic devices: a single-center prospective study.

Cardiac implantable electronic devices (CIEDs) have traditionally been a contraindication for magnetic resonance imaging (MRI). Recent studies suggest that MRI can be conducted safely in select patients with pacemakers (PPMs) and implantable cardioverter defibrillators (ICDs). We sought to determine the safety of MRI in patients with CIEDs, using a protocol for patient selection and device programming. This is a prospective, single-center study. Patients with a PPM or ICD and a clinical indication for MRI were considered. Exclusion criteria included newly implanted devices (<4weeks), PPMs manufactured before 1996 and ICDs before 2000, epicardial and abandoned leads, and pacemaker-dependent ICD patients. Pacemaker-dependent PPM patients were programmed to asynchronous pacing. Tachycardia detection/therapies were disabled for ICDs. Devices were interrogated pre- and post-scan, and at follow-up 1-6weeks later. Defibrillation threshold (DFT) was not tested post-scan. Patients were followed to monitor device therapies. Two hundred twenty-seven patients underwent 293 scans. Devices included 170 (70.6%) PPMs and 71 (29.5%) ICDs. Thirteen (4.4%) scans were aborted mainly due to subjective complaints or artifact on scout cardiac imaging. Post-scan and follow-up interrogation demonstrated no changes in device parameters requiring reprogramming or revision. Over long-term follow-up (median, 354days [IQR 65-629]), nine ICD patients had appropriate shocks (median, 3 [IQR 1-8]). One had four inappropriate shocks for atrial fibrillation. All tachyarrhythmias meeting criteria for defibrillation were successfully terminated. MRI can be conducted safely in patients with CIEDs when done in a protocoled manner with appropriate supervision. DFT testing after MRI may not be necessary.

Magnetic Resonance Imaging in Nondependent Pacemaker Patients with Pacemakers and Defibrillators with a Nearly Depleted Battery.

Magnetic resonance imaging (MRI) in patients with non-MRI-conditional cardiac implantable electronic devices (CIEDs) has been shown to be safe when performed under closely monitored protocols. However, the safety of MRI in patients with devices with a nearly depleted battery has not been reported. Prospective data were collected between January 2008 and May 2015 in patients with non-MRI-conditional CIEDs undergoing clinically indicated MRI under institutional protocol. Patients who were pacemaker dependent were excluded. Patients whose devices were at elective replacement indicator (ERI) at the time of MRI or close to ERI (ERI or replacement for battery depletion within 3 months of scan) were identified through database review and analyzed for clinical events. MRI scans (n = 569) were performed in 442 patients. Of these, we identified 13 scans performed with a nearly depleted battery in nine patients. All scans with implantable cardioverter defibrillators (ICDs, n = 9) were uneventful. However, two scans with pacemakers close to ERI resulted in a power-on-reset (PoR) event. One scan with a pacemaker close to ERI that was programmed to DOO mode reached ERI during MRI and automatically changed to VVI mode. Additionally, one scan with a pacemaker at ERI did not allow programming. All pacemakers with events were implanted before 2005. Patients with pacemakers and ICDs with a nearly depleted battery can safely undergo MRI when patients are not pacemaker dependent. Attention should be paid because old devices can result in PoR or ERI during MRI, which may lead to oversensing and inhibition of pacing.

Multicenter study of the safety and effects of magnetic resonance imaging in patients with coronary sinus left ventricular pacing leads.

Magnetic resonance imaging (MRI) in patients with left ventricular (LV) leads may cause tissue or lead heating, dislodgment, venous damage, or lead dysfunction. The purpose of this study was to determine the safety of MRI in patients with LV pacing leads. Prospective data on patients with coronary sinus LV leads undergoing clinically indicated MRI at 3 institutions were collected. Patients were not pacemaker-dependent. Scans were performed under pacing nurse, technician, radiologist, and physicist supervision using continuous vital sign, pulse oximetry, and ECG monitoring and a 1.5-T scanner with specific absorption rate <1.5 W/kg. Devices were interrogated pre- and post-MRI, programmed to asynchronous or inhibition mode with tachyarrhythmia therapies off (if present), and reprogrammed to their original settings post-MRI. MRI scans (n = 42) were performed in 40 patients with non-MRI conditional LV leads between 2005 and 2013 (mean age 67 ± 9 years, n = 16 [40%] women, median lead implant duration 740 days with interquartile range 125-1173 days). MRIs were performed on the head/neck/spine (n = 35 [83%]), lower extremities (n = 4 [10%]), chest (n = 2 [5%]), and abdomen (n = 1 [2%]). There were no overall differences in pre- and post-MRI interrogation LV lead sensing (12.4 ± 6.2 mV vs 12.9 ± 6.7 mV, P = .38), impedance (724 ± 294 Ω vs 718 ± 312 Ω, P = .67), or threshold (1.4 ± 1.1 V vs 1.4 ± 1.0 V, P = .91). No individual LV lead changes required intervention. MRI scanning was performed safely in non-pacemaker-dependent patients with coronary sinus LV leads who were carefully monitored during imaging without clinically significant adverse effect on LV lead function.

MULTICENTER STUDY OF THE SAFETY AND EFFECTS OF MAGNETIC RESONANCE IMAGING IN PATIENTS WITH CORONARY SINUS LEFT VENTRICULAR PACING LEADS

Magnetic resonance imaging (MRI) in patients with left ventricular (LV) leads may cause tissue or lead heating, dislodgement, venous damage, or lead dysfunction. MRI conditional LV leads are not available. We therefore investigated the safety of MRI in patients with LV pacing leads. Prospective

Safety of MRIs in Patients with Pacemakers and Defibrillators

With a burgeoning population, increases in life expectancy, and expanding indications, the number of patients with cardiac devices such as pacemakers and implantable cardioverter defibrillators continues to increase each year. A majority of these patients will develop an indication for magnetic resonance imaging (MRI) in their lifetime. MRIs have established themselves as one of the most powerful imaging tools for a variety of conditions. However, given the historic safety concerns, many physicians are reluctant to use MRIs in this patient population. In this paper, we discuss the potential adverse effects of MRIs in patients with cardiac devices, review key studies that have addressed strategies to limit adverse effects, and provide our cardiovascular MRI laboratory's protocol for imaging patients with implanted cardiac devices.

New Device Technologies for the Future of Heart Failure Treatment

Due to multiple risks associated with magnetic resonance imaging (MRI) in patients with pacemakers, the American Heart Association published a consensus statement in 2007 indicating that MRI should only be used in patients with pacemakers if no other diagnostic techniques are available and if the benefits clearly outweigh the risks [Levine GN et al. Circulation 2007]. Risks include heating at the lead tips, image distortion, reed switch malfunction, asynchronous pacing, and death [Santini L et al. Pacing Clin Electrophysiol 2013]. This article discusses the safety of MRI in patients with pacemakers, the subcutaneous implantable cardiac defibrillator system, cardiac contractility modulators for patients with symptomatic heart failure, and the use of implanted devices for monitoring patient status, among other things.

Safety of magnetic resonance imaging in patients with permanent pacemakers: a collaborative clinical approach

This study aimed to characterize the interactions of pacemakers with magnetic resonance imaging (MRI) and to identify device characteristics that could predict adverse interactions. The safety of MRI in patients with indwelling pacemaker systems remains uncertain. Previous studies demonstrated safety in most patients, but unpredictable, potentially concerning changes in pacemaker behavior have occurred. We prospectively studied patients with pacemaker devices in situ who were not pacemaker dependent and in whom MRI was essential for adequate diagnosis and treatment. All patients were monitored by electrocardiography and pulse oximetry during scanning; devices were interrogated and cardiac enzymes were measured before and after scanning. Of 32 patients studied (46 MRI examinations), 28 patients had a dual-chamber system and one had a biventricular device. Regions scanned were the head and spine. Devices were reprogrammed to asynchronous pacing or sense-only mode in all except six patients before MRI. During six scanning episodes (five patients), "power-on" resetting of the device was noted. Magnet-mode pacing was noted during four episodes (three patients). Occasional premature ventricular contractions were noted in one patient. No significant changes in battery voltage, sensed P wave and R wave, pacing thresholds, lead impedance, or cardiac enzymes were noted immediately after MRI or at 1-month follow-up. Overall, no significant changes were seen in pacemaker device function, and no adverse clinical events were observed. A minority of patients with older devices had unpredictable changes in device behavior, which stresses the need for close monitoring during and careful device interrogation after scanning.

Is magnetic resonance imaging safe for patients with retained metal fragments from combat and terrorist attacks?

Increasing numbers of military confrontations and terrorist attacks have led to increasing reports of retained metal fragments among patients referred for magnetic resonance imaging (MRI). The potential hazard of retained metal fragments for patients undergoing MRI has been studied among patients with retained metal fragments from domestic violence but not from combat and terrorist attacks. To retrospectively evaluate the safety of MRI in patients with subcutaneous warfare-metal fragments. 10,322 consecutive metal screening forms of patients scheduled for 1.5 Tesla (T) MR examination were retrospectively reviewed. All patients reported to have retained metal fragments were contacted by telephone and asked to describe the event in which they were exposed to the fragments and for any adverse sequelae or sensations during and after MRI. Their radiographs were evaluated for the number and size of the fragments. The data were analyzed for correlations between these factors. Seven of the 24 patients who reported retained metal fragments were excluded, since there was no validating evidence of their presence. Fragments in the remaining 17 patients (18 MRI examinations) were inflicted by military or terrorist attacks that occurred 2-39 years prior to the MRI. The fragment size ranged between 1 and 10 mm. One patient reported a superficial migration of a 10-mm fragment after MRI. No other adverse reactions were reported. Conducting 1.5T MRI examinations is safe in patients with retained metal fragments from combat and terrorist attacks not in the vicinity of vital organs. However, caution is advised.