September 16, 2015 — Thoratec Corp. issued a voluntary Urgent Medical Device Correction Letter to all hospitals who have patients supported with the HeartMate II LVAS (Left Ventricular Assist System) reminding them to monitor the expiration date of the backup battery contained within the HeartMate II "Pocket" System Controller, as specified in the product Instructions for Use. This backup battery has a 36-month expiration date. If 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.
It is important to note that exceeding the backup battery expiration and any associated advisory (or "yellow wrench") alarms do not affect normal HeartMate II LVAS function. While the HeartMate II LVAS Instructions for Use provides information on monitoring and changing the backup battery before it reaches the 36-month expiration date, Thoratec has recently received reports of patients experiencing advisory alarms for expired System Controller backup batteries.
On Sept. 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 received the advisory alarm attempted to switch from their primary to backup System Controller, and of those, three were unable to connect their pump to their backup System Controller in a timely manner, resulting in two patient deaths and one serious injury.
The Urgent Medical Device Correction Letter is intended to prevent the occurrence of certain preventable advisory alarms that may result in patients deciding to attempt a System Controller exchange. Thoratec is working with hospital staff to identify patients that may be close to reaching the 36-month 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 for Use.
If you are a HeartMate II LVAS patient and the serial number on your System Controller starts with the letters "EPC," you are not affected by this action and there is nothing you need to do. If you are a HeartMate II LVAS patient and the serial number on your System Controller starts with the letters "PC" (i.e. "Pocket Controller") and you received your device more than two years ago, please contact your doctor immediately to have the expiration date of the backup battery within your HeartMate II System Controllers (both primary and backup) checked and, if necessary, replaced. If you received your HeartMate II LVAS implant less than two years ago, please ask your doctor to check both your primary and backup HeartMate II System Controller backup batteries during each clinical visit. As a reminder the backup battery should be replaced approximately six months before expiration, dependent upon your clinic schedule.
For more information: www.thoratec.com
January 27, 2026 
