On Monday, Thoratec Corporation sent an Urgent Medical Device Correction Letter to all hospitals with patients supported by the HeartMate II LVAS (left ventricular assist system). Two patients died when they were unable to switch from the devices’ primary controller to the backup controller in a timely fashion.
The letter reminded the hospitals to monitor the expiration date of the backup battery in the HeartMate II “Pocket” System Controller. The backup battery has a 36-month expiration date. If the battery is allowed to expire, an advisory alarm, indicated by a yellow wrench symbol, is triggered. 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.
An LVAS device is an implantable pump that helps circulate blood when the patient’s heart is too weak to circulate blood on its own. These devices are implanted in patients with severe heart failure who are waiting for heart transplants.
On September 1, 2015, Thoratec received reports from several hospitals about a number of patients who encountered an advisory alarm due to the expiration of their System Controller 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 in a timely manner, resulting in two deaths and one serious injury.
Exceeding the backup battery expiration and receiving associated advisory (“yellow wrench”) alarms does not affect normal HeartMate II LVAS function. Although the HeartMate II LVAS use instructions have information on monitoring and changing the backup battery before it reaches the expiration date, Thoratec has recently received reports of patients experiencing advisory alarms for expired System Controller backup batteries.
The Urgent Medical Device Correction Letter is intended to prevent the occurrence of preventable advisory alarms that may occur when patients attempt a System Controller exchange. Thoratec is working with hospital staff to identify patients who may be close to reaching the expiration date of their System Controller backup battery in order to facilitate priority replacement and to ensure routine monitoring of backup battery lifetime during clinic visits, as specified in the product instructions.
The FDA advises HeartMate II LVAS patients whose System Controller serial number begins with the letters EPC are not affected by this action and there is nothing they need to do. HeartMate II LVAS patients who have a system controller with a serial number beginning with the letters PC (i.e. Pocket Controller) and who received the device more than two years ago, should contact their doctor immediately to have the expiration date of the backup battery within their HeartMate II System Controllers (both primary and backup) checked and, if necessary, replaced. For patients who received the HeartMate II LVAS implant less than two years ago, the system controller backup batteries should be checked during each clinical visit. The backup battery should be replaced approximately six months before expiration, depending on clinic schedule.
The FDA stresses that patients with a HeartMate II LVAS with a Pocket System Controller who experience a backup battery alarm should follow the instructions for this alarm in the Patient Handbook and should contact their hospital for further instructions. Patients should not attempt to replace the controller unless instructed to do so by the hospital.
The FDA has not yet given this recall a designation of seriousness, but it is likely to be Class 1 recall—the most serious classification—because of the risk of death or serious injury.