Medtronic Safety Communication Regarding a Subset of ICDs and CRT-Ds

Publication Date: February 8, 2021

Medtronic has issued a follow-up to its Product Performance Note relating to battery performance for a subset of Implantable Cardioverter Defibrillators (ICDs) and Cardiac Resynchronization Defibrillators (CRT-Ds).  HRS is working together with Medtronic and the Food and Drug Administration on this communication to ensure our members have the latest information.

Medtronic had originally identified in November 2019 a subset of ICD and CRT-D devices that may exhibit rapid battery depletion resulting in an earlier-than-expected Recommended Replacement Time (RRT) followed by a shortened RRT to End of Service (EOS) interval. The battery depletion can occur over days to months and, in the affected devices, the median time from RRT to EOS has been 14 days rather than the expected 3 months.

The affected subset of devices include Claria MRITM/Amplia MRITM/Compia MRITM/VivaTM/BravaTM CRT-Ds Visia AFTM/Visia AF MRI™/EveraTM/Evera MRI™ ICDs.

The subset of ICDs and CRT-Ds affected by this issue were last implanted in February 2019 and manufactured with a specific battery design that is no longer distributed. Approximately 339,900 devices susceptible to this issue are still active worldwide. The observed rate of occurrence has increased from 0.04% in Nov. 2019 to 0.07% currently, and Medtronic projects approximately 0.22% of the affected device population may experience this issue.  Although most of the devices exhibiting this rapid battery drain either triggered an alert for RRT or exhibited an unexpected drop in battery voltage leading to a generator change prior to RRT, in about 10% of cases there was insufficient information to determine whether an RRT alert had triggered or whether the patient had ignored the audible alert.
Medtronic has not received any reports of permanent patient harm related to this issue.

Root Cause: Lithium plating is the depositing of lithium within a battery over the normal course of the battery life. If lithium builds up and "bridges" between the anode and cathode, an internal short will develop and the battery will deplete rapidly.

Devices with low current drain (i.e. ICDs with 0% pacing and no shocks delivered) have a higher probability of experiencing battery depletion due to Lithium plating whereas devices with higher current drain (i.e. CRT-Ds with higher programmed outputs and 100% BiV pacing and occasional shocks) have a lower probability.  Importantly, the probability of Lithium plating causing battery depletion appears to be constant after approximately 3 years from date of implant.

Medtronic recommends the following:

• Continue normal follow-up. 
• Medtronic recommends against Prophylactic device replacement.
• Where possible, utilize CareLink home monitoring and the wireless low battery voltage CareAlert.
• Monitor for unexpected decreases in the battery longevity estimate during follow up
• Ensure the low battery voltage audible alert is "On" with high-urgency tones and consider checking whether patients are able to hear the alert. Remind patients to contact their clinic if they hear an audible alert.
• Inform a Medtronic representative of any unexpected device behaviors.
• If unexpected RRT is observed, perform prompt device replacement (immediately if pacer-dependent and within 1 week for non-dependent patients)

HRS strongly encourages its members to read the Medtronic advisory communication. The serial number lookup page can be used to query potentially affected devices.

Adverse reactions or quality problems experienced with the use of this product should be reported to Medtronic and to the FDA MedWatch Safety Information and Adverse Event Reporting Program either online, by regular mail or by fax.

• Complete and submit a report online at www.fda.gov/medwatch/report.htm.
• Call 1-800-332-1088 to request a reporting form or download from www.fda.gov/MedWatch/getforms.htm. Forms may be mailed or faxed. Follow instructions on form.

For additional questions, contact your local Medtronic Representative or Medtronic Technical Services at 800-723-4636.