Data through March 2026

References to the “algorithm B controller” refer to the modified 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 algorithm B controller has not been approved as being safe or effective for use by the U.S. 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 algorithm B controller with unapproved software is not available in all geographies. The algorithm B 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 March 31, 2026, there have been 49 instances where an algorithm B controller with the modified software has been used in an attempt to restart an HVAD™ pump. The pump restarted in 39 of the 49 instances. Of the 39 restarts, two were Subgroup 1 patients, two were Subgroup 2 patients, 13 were Subgroup 3 patients, and 22 were General Population patients. No adverse events have been reported or evidence provided that use of the algorithm B controller has adversely impacted the patient and/or their pump within the 39 successful use cases.

Use cases

For the ten unsuccessful use cases, one involved a Subgroup 2 patient, three involved Subgroup 3 patients, and six involved General Population patients. The clinical information is as follows:

  • The first instance in which the algorithm B controller was unsuccessful in restarting the pump was for a patient who required a controller exchange in July 2022. This patient’s pump was in the General Population. The patient’s pump had been off for over 18 hours. After five failed restart attempts using a backup standard (commercially available) HVAD™ controller, the clinician exchanged to the HVAD™ algorithm B controller. The pump did not restart after multiple attempts using the algorithm B controller. The patient was not a candidate for pump exchange and was placed under hospice care.
  • The second instance in which the algorithm B controller was unsuccessful in restarting the pump 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 (commercially available) HVAD™ controller, which failed to restart the pump. The patient was transferred to the hospital where the algorithm B controller 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 algorithm B controller 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 Stopped] 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. The patient was admitted to the hospital, and the hospital care team performed a controller exchange using the patient’s backup standard (commercially available) HVAD™ 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 an algorithm B controller. The HVAD™ pump did not restart, 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 algorithm B controller 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 Stopped] alarm while admitted to an inpatient 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. The patient performed a controller exchange using the patient’s backup standard (commercially available) HVAD™ controller; however, the HVAD™ pump did not restart. The patient was transferred to a main hospital, and the hospital performed a controller exchange using an algorithm B controller, but the algorithm B controller was not successful in restarting the pump. The hospital staff performed another controller exchange using a different algorithm B controller, but that controller did not restart the pump either. Following this second controller exchange, the HVAD™ pump failed to 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 algorithm B controller was unsuccessful in restarting the pump involved a patient with a pump in the General Population. The patient experienced a high priority [VAD Stopped] 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) HVAD™ controller, a controller exchange was performed using the patient’s backup standard (commercially available) HVAD™ 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 algorithm B controller, 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 algorithm B controller was unsuccessful in restarting the pump involved a patient with a pump in the General Population. The patient experienced a high priority [VAD Stopped] 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) HVAD™ controller. When the pump did not restart, the patient performed a controller exchange using the patient’s backup standard (commercially available) HVAD™ 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 an algorithm B controller, but the algorithm B controller 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 inoperable. The healthcare team reported that they plan to discontinue HVAD™ therapy for this patient.
  • The seventh instance in which the algorithm B controller was unsuccessful in restarting the pump involved a patient with a pump from Subgroup 2 (a subgroup that experiences a higher rate of failure or delay to restart). The patient felt 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 Stopped] alarm was triggered. The controller was exchanged for a backup standard (commercially available) HVAD™ controller, but the pump did not restart. The patient was transported to the clinic where another controller exchange was performed using the algorithm B controller, but that controller was unsuccessful in restarting the pump. The patient subsequently expired.
  • The eighth instance in which the algorithm B controller was unsuccessful in restarting the pump involved a patient with a pump in the General Population. The patient was admitted to the hospital with an active [VAD Stopped] alarm. The VAD stop was suspected to be due to a thrombus inside the pump. The healthcare team treated the patient with anticoagulants, thrombolytic therapy, heparin, Lasix™*, sodium nitroprusside, dobutamine, and adrenaline. After approximately eight hours of pump-off time, the patient’s healthcare team attempted to restart the patient’s pump using an algorithm B controller. The HVAD™ pump did not restart, and it was last reported that the patient discontinued HVAD™ therapy and was stable.
  • The ninth instance in which the algorithm B controller was unsuccessful in restarting the pump involved a patient with a pump in the General Population. The patient experienced a power loss event due to a disconnect of both power sources, and the HVAD™ pump did not start once power was restored. Both the patient’s primary and backup controllers were algorithm B controllers. The patient was transported to the emergency department where several controller exchanges were performed, including the use of algorithm B controllers. None of the controllers were successful in restarting the pump. The patient subsequently expired.
  • The tenth instance in which the algorithm B controller 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). It was reported that a VAD and controller exhibited a motor start event outside of the typical range and multiple controller fault alarms respectively. The VAD and controller remained in use and the controller was silenced. It was further reported, less than a week after the initial event, that the controller continued to emit alarms. The decision was made to exchange the controller. The controller was exchanged to the backup standard (commercially available) HVAD™ controller which failed to restart the VAD. Another controller exchange was attempted using an algorithm B controller, but was unsuccessful in restarting the VAD. The patient underwent a pump exchange to another commercially available device and was reported as alive following the event.

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