MAUDE Adverse Event Report: THORATEC CORPORATION THORATEC® HEARTMATE II®, SYSTEM CONTROLLER, US, EP; VENTRICULAR (ASSIST) BYPASS

Model Number	103696
Medical Device Problem Codes	Electrical /Electronic Property Problem (1198); Complete Loss of Power (4015)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	10/01/2025
Type of Reportable Event	Malfunction
Event or Problem Description
It was reported that on (b)(6) 2025 at approximately 4:30 am a system controller "battery module" alarm occurred, and the nurse replaced the controller.After the controller exchange a temporary red heart alarm occurred around 11:50 am on the same day.Upon checking the system monitor history a 'replace system controller' message was recorded, and the controller was replaced again.Log files from both controller were submitted for review.Log files from the first controller exchanged captured controller cell battery low events prior to changing the controller.The log files from the second controller captured the controller connected to power briefly and then it looked like the controller lost power as the timestamp reset back to zeros.The power was restored to the controller, and the pump was operating about 7 hours and then a pump stop occurred while using wall power and another pump stop occurred around 40 minutes later, still on wall power.It appeared that the controller was changed about an hour after the pump stop.No 'replace system controller' events were noted in the log.
Additional Manufacturer Narrative
No further information was provided.A supplemental report will be submitted once the manufacturer¿s investigation is complete.
Event or Problem Description
It was additionally reported that a pump shutdown without the typical increase in pump power was also recorded, making driveline damage a low suspicion but not completely ruled out.
Additional Manufacturer Narrative
No further information was provided.A supplemental report will be submitted once the manufacturer¿s investigation is complete.
Additional Manufacturer Narrative
Manufacturer's investigation conclusion: the reported event of a replace system controller alarm was confirmed via the submitted log file; however, it was not reproduced.A review of the submitted log file (b)(6) spanned approximately 8 hours (day 0 hour 0 minute 0 ¿ day 0 hour 8 minute 37 per time stamp).When the driveline was connected, the replace controller alarm was active due to the backup mcu being active.The backup mcu continued to be in use throughout the remainder of the log file until the driveline was disconnected.Low speeds and pump stops were captured between day 0, hour 7, minute 13 and day 0, hour 8, minute 37 while the system was connected to a grounded power source (power module).These events resulted in low speed and low flow hazard alarms alongside low speed operation and execution signature faults.On day 0, hour 8, minute 37, the driveline was disconnected, causing the pump to stop.This disconnection is consistent with the second reported system controller exchange.Based on previous complaint history, the events appear to be consistent with potential driveline wire compromise.There were no other notable alarms active in the log file.The returned system controller, serial (b)(6), was functionally tested and found to operate as intended during analysis.No atypical alarms were reproduced during testing.The controller was able to support pump function for an extended period of time.The provided information stated that a temporary red heart alarm occurred following the exchange to this controller.The system controller was replaced once again after the system monitor displayed a ¿replace system controller¿ message.The account later communicated that the cause of the pump stop was unknown.A root cause for the reported event was not conclusively determined through this analysis.Device history records were reviewed and showed no deviations from manufacturing or qa specifications.The patient handbook cautions the users to call their hospital contacts if they think, for any reason, any portion of their equipment is not functioning as usual, is broken, or they are uncomfortable with the operation of the equipment.All system controller maintenance and the proper actions to maintain the integrity of the controller are described in patient handbook.All system controller warning lights and sounds and the proper actions associated with them are described in patient handbook.No further information was provided.The manufacturer is closing the file on this event.
Additional Manufacturer Narrative
Manufacturer's investigation conclusion: the reported event of a replace system controller alarm was confirmed via the submitted log file; however, it was not reproduced during evaluation of the returned product.A review of the submitted log file (2a011746) spanned approximately 8.5 hours (timestamps 0:00:00 to 0:08:37 in a days:hours:minutes format).The recorded data suggested that the controller activated backup mode before the driveline was connected.The driveline was briefly connected, then disconnected, then reconnected again.Following reconnection, the system initiated operation at the desired set speed of 9200 revolutions per minute (rpm) and operated in backup mode for approximately 7 hours and 13 minutes.Speed interruptions to values as low as 0 rpm were then recorded between the timestamps of 0:07:13 and 0:07:18.Normal operation was recorded from the timestamp of 0:07:21 until 0:07:53, when another brief speed reduction to 0 rpm was recorded.Normal operation at 9200 rpm in backup mode was then observed from 0:08:00 until 0:08:37 hours, when the driveline appeared to be disconnected for the system controller exchange.The returned system controller, serial (b)(6), was functionally tested and found to operate as intended during analysis.No atypical alarms were reproduced during testing.The controller was able to support pump function for an extended period of time.The provided information stated that a temporary red heart alarm occurred following the exchange to this controller.The system controller was replaced once again after the system monitor displayed a ¿replace system controller¿ message.The account later communicated that the cause of the pump stop was unknown.A root cause for the reported event was not conclusively determined through this analysis.Device history records were reviewed and showed no deviations from manufacturing or qa specifications.The patient handbook cautions the users to call their hospital contacts if they think, for any reason, any portion of their equipment is not functioning as usual, is broken, or they are uncomfortable with the operation of the equipment.All system controller maintenance and the proper actions to maintain the integrity of the controller are described in patient handbook.All system controller warning lights and sounds and the proper actions associated with them are described in patient handbook.No further information was provided.The manufacturer is closing the file on this event.

• Brand Name: THORATEC® HEARTMATE II®, SYSTEM CONTROLLER, US, EP
• Common Device Name: VENTRICULAR (ASSIST) BYPASS
• Manufacturer (Section D): THORATEC CORPORATION; 6035 stoneridge drive; pleasanton CA 94588
• Manufacturer (Section G): THORATEC CORPORATION; 6035 stoneridge drive; pleasanton CA 94588
• Manufacturer Contact: lindsey sallese ; 6035 stoneridge drive; pleasanton, CA 94588 ; 7818528207
• MDR Report Key: 23262158
• Report Number: 2916596-2025-06570
• Device Sequence Number: 18331075
• Product Code: DSQ
• UDI-Device Identifier: 00813024010630
• UDI-Public: (01)00813024010630(17)200222
• Combination Product (Y/N): N
• Initial Reporter Country: JA
• PMA/510(K) Number: P060040
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Other,Foreign,Company Representative
• Initial Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial,Followup,Followup,Followup
• Report Date (Section B): 12/18/2025

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Lay User/Patient
• Device Expiration Date: 02/22/2020
• Device Model Number: 103696
• Device Catalogue Number: 103696
• Device Lot Number: 5931460
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Was the Report Sent to FDA?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 10/01/2025
• Supplement Date Received by Manufacturer: 10/09/2025; 11/19/2025; 12/16/2025
• Initial Report FDA Received Date: 10/09/2025
• Supplement Report FDA Received Date: 10/21/2025; 12/12/2025; 12/18/2025
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 02/22/2017
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Patient Age: 59 YR
• Patient Sex: Male
• Patient Weight: 65 KG