Medical device manufacturer, St Jude Medical, has issued a medical device safety alert concerning its implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-Ds) manufactured before May 2015. The affected models are Fortify, Fortify Assura, Quadra Assura, Quadra Assura MP, Unify, Unify Assura and Unify Quadra.
According to the manufacturer, among 398,740 devices sold worldwide, 841 devices returned for analysis due to premature battery depletion have had evidence of lithium material in the form of "clusters" in the battery. Forty-six exhibited visible clusters bridging the cathode and anode causing shorting. Lithium cluster formation is a known phenomenon with this type of battery.
The manufacturer is contacting physicians to provide details regarding risk and patient management recommendations because premature battery depletion has been observed to occur within days. There have been two deaths that have been associated with the loss of defibrillation therapy as a result of premature battery depletion.
High voltage devices (ICDs and CRT-Ds) that utilize Lithium-based battery chemistries are subject to Lithium cluster formation during high voltage charging. Depending on their location, Lithium clusters may cause a short circuit that can lead to premature battery depletion. The manufacturer's investigation indicates that if a short circuit occurs, battery depletion can occur in these devices within a day to a few weeks, which may result in the inability to deliver therapy.
Premature battery depletion can be identified by physicians through home monitoring or in person visits showing Elective Replacement Indicator (ERI) or more advanced battery depletion. Patients may become aware when their device reaches ERI because they may feel a vibratory patient notifier alert. Patients who cannot feel the vibratory alert may not know their device has reached ERI. Therefore, the manufacturer has provided recommendations below that include confirming patients can feel and recognize vibratory alerts and reaffirming the availability and usage of home monitoring to avoid or minimize time without device therapy for bradycardia and tachycardia events.
The manufacturer provided physicians with the following patient management recommendations:
According to the local supplier, the affected products are distributed in Hong Kong.
If you are in possession of the affected products, please contact your supplier for further patient management recommendations and other necessary actions.
Posted on 11 October 2016