Updated event rates for pump issues

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 (3) 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 include data as of December 2023 as communicated in the April 2024 FCA letter.

Table 1. Cumulative probabilities for each subgroup and the general population by 3 years

Table 2: Cumulative event data by pump population

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

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 six confirmed complaints provided to Medtronic as of March 2024. In all six instances, suspected thrombus, high watt alarms, and grinding noises were consistently reported