CFx Longevity Estimator Software Error
Subset of IPG, ICD, CRT-P, CRT-D, and Micra TPS devices
Original Date of Communication:
Affected Programmers & Remote Monitoring Software Apps
2090 CareLink™ Programmer
29901 Encore™ Programmer
CareLink Network Application Software 2491
CareLink SmartSync™ Device Manager
MyCareLink Heart™ Mobile Application
Subset of the following devices:
Claria MRI™/Amplia MRI™/Compia MRI™/Viva™/Brava™ CRT-Ds
Visia AF™/ Visia AF MRI™/Evera™/ Evera MRI™/Primo MRI™/Mirro MRI™ ICDs
Medtronic identified the potential for Medtronic programmer and remote monitoring software applications to display an inaccurate remaining longevity estimate for a subset of implanted cardiac device models. This issue does not impact device functionality. Furthermore, the Recommended Replacement Time (RRT) remains an accurate indicator for device replacement.
Through September 18, 2019 there have been three (3) reported complaints and there have been no (0) serious adverse events or deaths.
The inaccurate longevity estimation is limited to a well-defined subset of devices manufactured between October 2018 and April 2019, and only occurs in the middle (plateau) phase of the device life, as illustrated in the graph below. Approximately 53,100 devices worldwide, out of 1.23 million distributed or sold from the identified device families, are susceptible to displaying inaccurate longevity.
The cause of the inaccurate longevity estimate is a slightly lower-than-typical discharge voltage during the plateau phase of the battery depletion curve (dashed line), compared to a typical voltage plateau (solid line), as illustrated in the graph below. During this plateau period, the Carbon Monofluoride (CFx) in the battery cathode is powering the device. Note, longevity estimates early after implantation and later in the device life are unaffected, as shown below. The battery remains within operating specifications.
Software updates to programmers and remote monitoring systems are under development to correct for the inaccuracy in longevity estimates. Medtronic is targeting regulatory approval and release of the software updates to begin in mid-2020. Once available, Medtronic will inform you of the availability of the software and work with you to install the software onto clinic and hospital programmers. Software updates to individual patient devices will not be necessary to correct this issue, since longevity estimation resides on the programmers, mobile app and the CareLink Network
Internal analysis estimates approximately 11% of the 53,100 identified devices are projected to display an inaccurate longevity estimate before mid-2020.
Patient Management Recommendations
We realize that each patient requires unique clinical considerations. In consultation with our Independent Physician Quality Panel, Medtronic provides the following guidance:
Prophylactic device replacement is not recommended, as device functionality, true longevity and the RRT indicator are not impacted by the inaccurate longevity estimate.
Until the software update becomes available:
Continue normal patient follow-up in accordance with standard practice.
Per labeling, continue to use the RRT notification to identify when device replacement should be scheduled. Where available, utilize the low battery voltage RRT audible alert or wireless CareAlert™.
At any time, if a lower-than-expected remaining longevity estimate occurs, contact Medtronic Technical Services for assistance – additional analysis of stored device information will be required to assess if the decreased longevity estimate is due to this issue.
Note: For Azure IPG or Percepta/Serena/Solara CRT-P patients remotely monitored via the MyCareLink Heart mobile app, patients’ mobile app longevity estimates will not change until the software update has been released.
We sincerely regret any difficulties this may cause you and your patients. Medtronic remains dedicated to patient safety and will continue to monitor device performance to ensure we meet your needs and those of your patients.