Boston Scientific (NYSE: BSX) has issued a notice to customers related to a previous recall of its Accolade pacemakers.
In December 2024, the company warned of the potential need for the early replacement of certain pacemaker devices. Affected devices had an increased potential to initiate “Safety Mode” during telemetry or other normal, high-power operations. This occurs because of high battery impedance, underpowering the device system. This is attributed to a manufacturing issue.
The company reported two deaths in pacemaker-dependent patients implanted with devices from the subpopulation of devices that initiated Safety Mode in an ambulatory setting. The FDA later deemed the recall Class I, the most serious kind. At the time, the company said it planned to implement updated manufacturing work instructions for the process used to make cathodes for Accolade product batteries. It also planned to develop a software update to detect battery health in all Accolade pacemaker devices.
In a notice issued to customers published by the FDA today, Boston Scientific said its recently launched Model 3869 v2.04 software, released in the United States, Australia, and New Zealand, was designed to prevent potential initiation of Safety Mode due to a high battery impedance condition in Accolade pacemakers. First, the software enables the detection of an elevated battery impedance condition. Second, it disables ZIP telemetry when the battery reaches a high impedance state to prevent the initiation of Safety Mode in an ambulatory setting.
Since the rollout of the software last month, and subsequent firmware upgrades, Boston Scientific identified two unintended behaviors. Device sensing, therapy delivery and all programmed functions remained unaffected except for changes to wandless telemetry.
More about the behaviors identified in the Boston Scientific software update
Although the new software significantly mitigated the initiation of Safety Mode issue, it may not fully eliminate the risk.
First, the company identified the incomplete disablement of wandless automatic telemetry after detecting a high battery impedance condition. If an Accolade family device with an elevated battery impedance induced Code-1003 remains in service, the software’s new telemetry activated battery test is designed to continue assessing battery impedance and disable all wandless telemetry operation before high impedance is achieved and device resets can initiate Safety Mode.
Second, Boston Scientific found the potential for the software’s new daily battery test to misinterpret measurements in the presence of a magnet. This may initiate a false positive response that disables wandless telemetry sessions.
Despite the possible occurrence of the unintended behaviors, the benefits of the new software outweigh the risks of prophylactic replacement. As such, Boston Scientific strongly recommends the continued installation of the software for all devices in the Accolade family.
The company is actively developing a software update to address the unintended behaviors. The FDA said it intends to continue working with the company on the issue.
