Pump delay or failure to restart

Medtronic issued notifications titled “urgent medical device communication” in December 2020, May 2021, December 2021, October 2022, August 2023, and April 2024 to advise that an identified subpopulation (defined as Subgroups 1, 2, and 3) of HVAD™ Systems may experience a delay or failure to restart at a higher rate than the overall population of HVAD™ Systems. Pumps that are outside of the subpopulation are referred to as the General Population.

A pump delay or failure to restart is linked to an interaction between the impeller and the top housing. Changes in the impeller or housing curvature may cause contact between the impeller and housing in a way that may make it more difficult for a pump to restart due to increased friction. It is important to note that this issue does not cause a running HVAD™ pump to stop; rather, the pump may fail to restart after a pump stop event, such as a controller exchange.

Table 1 below presents the cumulative probabilities of experiencing a pump stop resulting in either a delay or failure to restart, or a delay or failure to restart leading to a device exchange, decommission, or death by three years. Tables 2 and 3 summarize pump populations, observed events of delay or failure to restart, and adverse events in Subgroups 1, 2, and 3.

Tables 1, 2, and 3 reflect updated failure or delay to restart data as of July 2025; however, patients on support data was last collected in April 2025.

Table 1: Cumulative probabilities for each Subgroup and the General Population by three years

Group Patients on support globally Cumulative probability of experiencing a pump stop resulting in delay or failure to restart (by three years) Cumulative probability of experiencing a device exchange, decommission, or death due to a delay or failure to restart (by three years)
Subgroup 1  17 3.1% 1.3%
Subgroup 2 8 31.3% 27.0%
Subgroup 3
 ~153 3.8% 2.2%
General Population excluding subgroups ~1,142 0.4% 0.1%

 

Table 2: Cumulative event data by pump population

Group Number of pumps distributed Cumulative event total Related death events
Subgroup 1  316 13 4
Subgroup 2 174 48 15
Subgroup 3
 1,026 57 17
General Population 21,511 170 37
Totals 23,027 288 73

 

Table 3: Total number of events categorized for Subgroups 1, 2, and 3

Category Number of events
Death 36

Reoperation with VAD exchange

18

Reoperation with heart transplant

3

VAD thrombus

2

Neurological

2

Cardiac arrest

1

Hospitalization

18

Intraoperative pump exchange

4

Outflow graft occlusion

1

Worsening heart failure

1

Hypoperfusion

1

Asymptomatic VAD stop event

30

No patient harm

1

Total number of events

118

Pump weld

In April 2022 and July 2022, Medtronic issued notifications titled “Urgent Medical Device Correction” about a pump weld non-conformance with the HVAD™ system. The pump weld non-conformance causes the impeller to rotate non-concentrically and contact the center post of the pump, consistent with corrosion of the center post magnet. Patients with affected devices may present with signs and symptoms that resemble pump thrombus.

The table below provides a summary of the seven confirmed complaints provided to Medtronic as of August 2025. In all seven instances, suspected thrombus, high watt alarms, and/or grinding sounds were consistently reported.

Complaint ID Manufacturing date Implant duration Reported signs and symptoms
1 December 2017 25 months
  • Suspected thrombus
  • High watt alarms
  • Grinding sounds
  • Vibration
  • Reported patient symptoms: fatigue, light-headedness and dizziness, shortness of breath
2 January 2018 28 months
  • Suspected thrombus
  • Grinding sounds
  • High watt alarms
  • Elevated LDH level
  • Reported patient symptoms: dark urine
3 May 2018 26 months
  • Suspected thrombus
  • Grinding sounds
  • High watt alarms
  • Elevated LDH level
  • Patient symptoms not reported
4 April 2019 30 months
  • Suspected thrombus
  • Grinding sounds
  • High watt alarms
  • Low flow alarms
  • Elevated LDH level
  • Patient symptoms not reported
5 April 2018 37 months
  • Suspected thrombus
  • Grinding sounds
  • High watt alarms
  • Vibration
  • Patient symptoms not reported
6 May 2018 Not reported
  • Suspected thrombus
  • Grinding sounds
  • High watt alarms
  • Patient symptoms not reported
7 January 2018 72 months
  • Low flow alarms
  • Grinding sounds
  • High watt alarms
  • Patient did not have any abnormal symptoms or complications