1 / 36

Jennifer Cohen, MD, Heather Costa, PhD, Robert Russo, MD, PhD, Division of Cardiovascular Diseases, Scripps Clinic, La

The MagnaSafe Registry: Pacemaker and Implantable Cardioverter Defibrillator Safety for Patients Undergoing Magnetic Resonance Imaging. Jennifer Cohen, MD, Heather Costa, PhD, Robert Russo, MD, PhD, Division of Cardiovascular Diseases, Scripps Clinic, La Jolla, CA.

ravi
Download Presentation

Jennifer Cohen, MD, Heather Costa, PhD, Robert Russo, MD, PhD, Division of Cardiovascular Diseases, Scripps Clinic, La

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The MagnaSafe Registry: Pacemaker and Implantable Cardioverter Defibrillator Safety for Patients Undergoing Magnetic Resonance Imaging Jennifer Cohen, MD, Heather Costa, PhD, Robert Russo, MD, PhD, Division of Cardiovascular Diseases, Scripps Clinic, La Jolla, CA

  2. Presenter Disclosure Information • None of the authors have any disclosures.

  3. Background • The number of patients with permanent pacemakers or implantable cardioverter-defibrillators (ICD) in the U.S. is increasing dramatically. • Between 1990 and 2005, an estimated 2.8 million pacemakers and 690,000 ICDs were implanted*. National estimates of cardiac device implantation *Zhan, et al, 2008 J Gen Int Med 23 Supp 1:13

  4. Background • MRI is the diagnostic modality of choice without acceptable alternative for many disease states. • At Scripps Green Hospital: 8,000 MRI’s performed per year. • In the Scripps Health System: 18,000 MRI’s performed in 2007. • There is a 50-75% estimated probability that a patient with a PM or ICD will need an MRI.

  5. MRI Safety Studies • Small number of published studies at 1.5T with a total of approximately 350 patients. • Varying effects including impedance changes, battery depletion and an increase in pacing thresholds. • No serious adverse events have been reported. • No comparison to a control group.

  6. The MagnaSafe Registry A retrospective, single site experience • Data used to design the prospective, multi-center MagnaSafe Registry. • Establish expected event rates. • Sample size calculations. • Design the interrogation protocol.

  7. The MagnaSafe Registry • Prospective, multi-center registry to begin enrollment in April 2009. • Expected enrollment: • 1000 patients with permanent pacemakers • 500 patients with ICDs • Clinically-indicated, non-research, non-thoracic MRI deemed medically necessary by the ordering physician. • Performed under a conditional IDE with the guidance of the FDA .

  8. The MagnaSafe Registry • Prospectively document the incidence of adverse events or changes in device parameters associated with undergoing an MRI. • Will provide physicians the risk-assessment data needed to discuss the use of MRI with their patients as a diagnostic tool when no alternative test is available. • Ultimately, the goal is to amend the guidelines for performing MRI in patients with implanted cardiac devices.

  9. Hypothesis • Magnetic resonance imaging at 1.5T can be performed safely in selected patients with permanent pacemakers and implantable cardioverter-defibrillators using an optimized device programming protocol and screening process.

  10. Methods • Patients presented for a MRI that was deemed medically necessary by the ordering physician without acceptable alternative examination. • Clinical informed consent was obtained by a cardiologist who was present during the scan. • No scans were excluded. • No SAR limits placed. • Technicians were permitted to deviate from normal operating mode. • Performance of a diagnostic exam was a priority.

  11. Methods • Device interrogation was performed before and immediately following the scan. • Non-invasive monitoring performed. • IRB approval was obtained for retrospective analysis of data previously obtained during clinically-indicated (non-research) MRI.

  12. Methods Device Interrogation • Pacemaker-dependent patients were reprogrammed to asynchronous mode (VOO or DOO). Magnet response was disabled. • Non-dependent patients were programmed to no pacing. • For ICDs, tachycardia-therapy was turned off. • Pre and post-MRI interrogations were identical: • Measurement of intrinsic P/R waves, all lead impedances, shock lead impedances, all lead thresholds measured at a fixed pulse width.

  13. Methods Control Group • A control group was studied to determine the variability of device parameters without MRI. • 34 patients with pacemakers and ICDs underwent 2 device interrogations 1 hour apart to determine variation (without MRI). • Recruitment for the Control Group is ongoing.

  14. Methods Primary Outcomes • Decrease in battery voltage ≥ 0.04 V • Change in lead impedance: • Change in pacing lead impedance by ≥ 50 Ω • Change in shock lead impedance by ≥ 3 Ω • Change in lead threshold • Increase in lead threshold ≥ 0.50 V at 0.4 ms • Change in P/R wave amplitude • Decrease in P wave amplitude ≥ 50% • Decrease in R wave amplitude ≥ 25% • Loss of capture during scan, induced arrhythmia, device failure requiring generator or lead replacement

  15. Results Clinical Experience • 125 generators and 255 leads. • 157 clinically-indicated 1.5T MRI scans between Jan 2006 and March 2009. • Length of MRI scan 48.9±20.67 minutes. • One patient had a pacemaker and an ICD in place.

  16. Results Baseline Characteristics

  17. Results

  18. Results

  19. Results • No arrhythmias: atrial or ventricular • No loss of capture • No electrical reset-to-on • No generator or lead replacements • No syncope • No deaths • All scans were performed except for one due to severe claustrophobia

  20. Results Device Parameter Changes

  21. Results Device Parameter Changes

  22. Results Dependency p=0.43 4.7% p=1.0 5.2% 3.0% 3.6% 3.4% 0%

  23. Results ICD versus Pacemaker p=0.3 p=1.0 4.7% 4.5% 5.0% 3.9% 3.0% 2.6%

  24. Results Brain Scans p=1.0 4.7% 4.7% 4.7%

  25. Results Length of Scans 6.1% 3.8% 5.0% 4.7% 4.7% 3.0%

  26. Results Multiple Scans p=0.33 4.7% 5.4% 3.2%

  27. Results Time Since Implant 4.7% 5.4% 4.8% 3.0% 3.1% 1.1% 0% 0%

  28. Results Lead Threshold Changes Leads = 33 Leads = 19 Average Lead Threshold Change 0.02 ± 0.18 V

  29. Results Lead Threshold Changes Leads = 8 Leads = 8 Average Lead Threshold Change 0 ± 0.16 V

  30. Results Battery Voltage Changes Generators = 19 Generators = 6 Average Battery Voltage Change -0.004 ± 0.016 V

  31. Results Battery Voltage Changes Generators = 5 Generators = 3 Average Battery Voltage Change 0.00 ± 0.01 V

  32. Results Lead Impedance Changes Leads = 129 Leads = 54 Average Lead Impedance Change -5.9 ± 25.1 Ω

  33. Results Lead Impedance Changes Leads = 34 Leads = 19 Average Lead Impedance Change 6.2 ± 22.5 Ω

  34. Conclusions • A very low incidence of device parameter change was noted after MRI at 1.5T. • No patient experienced device failure or a permanent change in lead threshold. • Based on these findings, we anticipate <5% rate of device failure, <5% rate of permanent reprogramming, <10% rate of temporary reprogramming for the prospective MagnaSafe Registry.

  35. Patient with cardiac device and MRI clinically indicated Clinical care Research Subjects enrolls in study Device parameters recorded Magnetic resonance imaging Clinical Care Device parameters recorded Restore or Adjust settings Parameter Change? No Yes Follow-up interrogation within 7 days Research Follow-up interrogation at 3-6 months when clinically indicated Follow-up Interrogation at 3 months Follow-up Interrogation at 6 months MagnaSafe

More Related