Data through December 2024

References to the “modified controller” refer to the alternate pump start algorithm within the controller software that may be able to restart a pump if the standard controller is unsuccessful in restarting a stopped pump (the availability of this alternate pump start algorithm was communicated via an urgent medical device communication in June 2022). The software in the modified controller has not been approved as being safe or effective for use by the US Food and Drug Administration or any other regulatory authorities, which means it has not been tested to the same level as software in an approved medical device and comes with risk. As such, the modified controller with unapproved software is not available in all geographies. The modified controller should only be used if the pump has stopped, and the standard, commercially available controller is unsuccessful at restarting the pump.

Outcomes

As of December 31, 2024, there has been 30 instances where a controller with the modified algorithm has been used in an attempt to restart an HVAD™ pump. The pump restarted in 23 of the 30 instances. Of the 23 restarts, two (2) were subgroup 2 patients, six (6) were subgroup 3 patients, and fifteen (15) were general population patients (not in one of the subgroups). No adverse events have been reported or evidence provided that use of the controller with the modified algorithm has impacted the patient and/or their pump within the 23 successful use cases.

Use cases

For the seven (7) unsuccessful use cases, one (1) involved a subgroup 2 patient, two (2) involved subgroup 3 patients, and four (4) involved general population patients. The clinical information is as follows:

  • The first instance in which the controller with the modified algorithm was unsuccessful was for a patient who required a controller exchange in July 2022. This patient’s pump was in the general population, and the patient was not a candidate for a pump exchange. The patient’s pump had been off for over 18 hours. After five failed restart attempts using a standard backup HVAD™ controller, the clinician exchanged to the HVAD™ controller with the modified algorithm. The pump did not restart after multiple attempts using the controller with modified algorithm. The patient was placed under hospice care.
  • The second instance in which the controller with the modified algorithm was unsuccessful was for a patient with a pump in the general population. The patient experienced an unexpected pump stop and [VAD Stopped] alarm at home. The patient exchanged their controller to their backup standard controller, which failed to restart the pump. The patient was transferred to the hospital where the controller with the modified algorithm was used but it was unsuccessful at restarting the pump. The pump remained off for an unknown amount of time and the next day the patient’s pump was exchanged to another commercially available device.
  • The third instance in which the controller with the modified algorithm was unsuccessful in restarting the pump involved a patient with a pump from subgroup 3 (a subgroup that experiences a higher rate of failure or delay to restart). The patient experienced a high priority VAD stop alarm at home caused by an unexpected loss of power to the controller. The cause of the unexpected loss of power to the controller has not yet been determined at this time. The patient was admitted to the hospital, and the hospital care team performed a controller exchange using the patient’s backup standard (commercially available) controller. Following the controller exchange, the patient continued to experience unexpected losses of power and the HVAD pump failed to restart. The hospital staff performed another controller exchange using a controller with the unapproved algorithm. The HVAD pump was unable to be restarted, and it was last reported that the patient has discontinued HVAD therapy. The status of the patient was not reported.
  • The fourth instance in which the controller with the modified algorithm was unsuccessful involved a patient with a pump from subgroup 3 (a subgroup that experiences a higher rate of failure or delay to restart). The patient experienced a high priority VAD stop alarm while admitted to an in-patient facility. The VAD stop was due to an unexpected loss of power to the controller. The cause of the unexpected loss of power to the controller has not yet been determined at this time. The patient performed a controller exchanging using the patient’s backup standard (commercially available) controller; however, the HVAD pump did not restart. The patient was transferred to the main hospital, and the hospital performed a controller exchange using a controller with the unapproved algorithm, but the controller with the unapproved algorithm was not successful in restarting the pump. The hospital performed another controller exchange using a different controller with the unapproved algorithm, but that controller was not successful in restarting the pump either. Following this second controller exchange, the HVAD pump did not restart. The patient was neither a candidate for a VAD exchange nor a candidate for a heart transplant. It was further reported that the patient subsequently expired.
  • The fifth instance in which the controller with the modified algorithm was unsuccessful involved a patient with a pump in the general population. The patient experienced a high priority VAD stop alarm while admitted to a long-term acute care facility. The VAD stop was due to a loss of power to the controller. It was reported that the loss of power was caused by the patient inadvertently disconnecting all power sources while performing a routine power source exchange. After the HVAD pump failed to restart with the patient’s primary standard (commercially available) controller, a controller exchange was performed using the patient’s backup standard (commercially available) controller. The backup controller was not successful in restarting the HVAD pump, and the patient was transferred to the emergency room at the hospital. The emergency room team performed an additional controller exchange using the controller with the unapproved algorithm but that controller was not successful in restarting the HVAD pump. It was reported that the patient subsequently expired three days following the event.
  • The sixth instance in which the controller with the modified algorithm was unsuccessful involved a patient with a pump that was in the general population. The patient experienced a high priority VAD stop alarm at home caused by a loss of power to the controller. It was reported that the loss of power was caused by the patient inadvertently disconnecting all power sources. The patient attempted to restart their HVAD pump after the loss of power event using the primary standard (commercially available) controller. When the pump did not restart, the patient performed a controller exchange using the patient’s backup standard (commercially available) controller. The patient’s pump did not restart, and the patient was taken to the emergency room. The emergency room team performed an additional controller exchange using a controller with the unapproved algorithm but the controller with the unapproved algorithm was not successful in restarting the HVAD pump. The emergency room team made the decision to perform no further restart attempts. Based on initially reported information, the patient was reported to be stable with their HVAD pump still implanted, but off as their HVAD was unable to be restarted. The healthcare team reported that they plan to discontinue HVAD therapy for this patient.
  • The seventh instance in which the controller with the modified algorithm was unsuccessful involved a patient with a pump from subgroup 2 (a subgroup that experiences a higher rate of failing or delaying to restart). That patient was feeling unwell and lost consciousness at home. It was reported that the patient's wife started cardiopulmonary resuscitation and emergency medical services continued cardiopulmonary resuscitation upon their arrival. During the cardiopulmonary resuscitation efforts, it was noted that a VAD stop alarm was triggered. The controller was exchanged for a standard (commercially available) backup controller, but the pump did not restart. The patient was taken to the clinic where another controller exchange was performed using the controller with the unapproved algorithm, but that controller was unsuccessful in restarting the pump. The patient subsequently expired. 


It is not known if any of these results will be typical or representative.