Medtronic's HeartWare pump racks up another safety alert, this time for jammed driveline covers

Medtronic’s HeartWare Ventricular Assist Device (HVAD) may be off the market, but it’s still very much on the company’s mind.

The devicemaker discontinued new sales and implants of its HeartWare devices in June 2021, citing several years’ worth of serious recalls and other safety events. But in the months since, the complaints have continued to roll in from the approximately 4,000 patients who had already been implanted with the device before it was taken off the market.

Medtronic’s most recent safety notice for the pump came at the end of November, sparked by nearly three dozen patient complaints received between January 2017 and mid-September of this year. In a letter (PDF) sent to healthcare providers Nov. 29, the company noted that “no critical harms or deaths” have been linked to the device’s latest issue.

That notice revolves around the HVAD’s driveline cover, a small, flexible plastic tube that is threaded onto the cable that’s inserted through the skin to connect the HeartWare implant to its external controller. The cover is placed over the cable’s connection to the controller for protection.

In some cases, however, the cover has been found to cause more issues than it prevents. Medtronic said it has received 33 reports detailing how the component can become hardened or stuck, making it difficult to move or remove by hand—which must be done if a controller exchange is needed.

Though minimal or no patient harm was reported alongside the majority of those complaints, four of the hardened driveline covers were discovered when patients had been hospitalized for unrelated reasons, and their pumps had to be briefly turned off while the cover was serviced and removed. Another four of the instances were found during routine clinical visits or following controller alarms and required hospitalization to fix the cover.

Medtronic has identified “plasticizer loss” over time as the cause of the issue, referencing the material used to keep the cover soft and malleable. In the reported events, the hardening occurred “after multiple years of use,” the company said in its letter, and could potentially be exacerbated by environmental factors.

Neither patients nor their clinicians should attempt to unstick a jammed driveline cover themselves, according to Medtronic. Instead, they should contact a company representative to assess and service the damage if needed.

In the meantime, the devicemaker advised healthcare providers to keep an eye out for the issue: They should check for hardened covers during standard clinic visits and before a scheduled controller exchange. Those checks should be done gently by wiggling the cover back and forth, rather than yanking it back or attempting to twist it off.