Earlier this week, Thoratec Corporation sent a voluntary Urgent Medical Device Correction Letter to all hospitals with patients supported by the HeartMate II LVAS (left ventricular assist system) after two patients died trying to switch device controllers.
The patients were attempting to make the switch because they had gotten a warning alarm that the device’s backup battery was nearing its expiration date. The backup battery has a 36-month expiration date. As the battery nears expiration, this triggers an advisory alarm, indicated by a yellow wrench symbol. This alarm occurs at 12:00 a.m. on the first day of the month in which the backup battery expires, the Food and Drug Administration (FDA) explains. The letter reminded hospitals to monitor the expiration date of the backup battery contained in the HeartMate II “Pocket” System Controller.
A left ventricular assist device is a pump implanted to help circulate blood when the patient’s heart is too weak to circulate blood on its own. LVAS devices are implanted in patients with severe heart failure who are waiting for heart transplants.
Thoratec received reports from several hospitals about patients who experienced advisory alarms due to the expiration of the controller’s backup batteries. Some of these patients who experienced an advisory alarm attempted to switch from the primary to the backup controller. Three of them were unable to connect the pump to their backup controller soon enough. Two patients died and one suffered serious injury.
The FDA explains that a yellow wrench alarm does not affect normal HeartMate II LVAS function. Although HeartMate II LVAS instructions advise monitoring and changing the backup battery before it reaches the expiration date, Thoratec has recently received reports of patients experiencing advisory alarms for expired backup batteries.
The FDA said the Urgent Medical Device Correction Letter is intended to stave off preventable advisory alarms that may occur when patients attempt a System Controller exchange. Thoratec is working with hospitals to identify patients whose devices may be close to reaching the expiration date of the backup battery in order to facilitate priority replacement and to ensure routine monitoring of backup battery lifetime during clinic visits.
Patients with a HeartMate II LVAS System Controller whose serial number begins with the letters EPC are not affected by this recall and do not need to take any action. If the controller’s serial number begins with PC (Pocket Controller) and if the patient received the device more than two years ago, the patient should have the expiration date of the backup battery in their HeartMate II System Controllers (both primary and backup) checked and replaced if necessary. If the patient received the LVAS implant less than two years ago, the backup batteries should be checked during each clinical visit and should be replaced approximately six months before expiration, depending on appointment schedule.
The FDA stresses that patients with a HeartMate II LVAS with a Pocket System Controller who experience a backup battery alarm should not attempt to replace the controller unless instructed to do so by the hospital.
This recall has not yet been given an FDA recall classification but because of the risk of death or serious injury, the recall is likely to be designated Class 1—the most serious classification.