Though it discontinued the recall-ridden HeartWare Ventricular Assist Device over a year ago, Medtronic is still grappling with the heart pump’s many issues as part of its pledge to continue providing support to the approximately 4,000 patients still implanted with the device.
In its latest effort to keep those pumps pumping, the medtech giant has made new, unapproved software available that could potentially remedy an issue in some HeartWare devices that has been on its radar since at least the end of 2020.
In a December 2020 letter (PDF) to healthcare providers, Medtronic described how some of the pumps were prone to experiencing a delay or failure to restart after they had been purposely stopped, such as during a pump exchange. The issue was linked to an internal pump component present in just over 500 of the HeartWare systems that were distributed around the world between 2017 and 2019.
As of December 2021, according to another letter (PDF) from the company, the issue had sparked 41 complaints linked to 36 devices, including reports of 10 patient deaths.
Though the restart issue is most prevalent in just two subsets of HeartWare pumps identified by Medtronic, the company is now making a possible fix available to all patients still implanted with the heart pump, it announced in an Oct. 13 letter (PDF) to healthcare providers.
Initially described in yet another missive (PDF) sent out in June—when it was limited only to those pumps that fell into either of the two identified subsets—the potential remedy centers around a new pump start algorithm for the HeartWare controller’s software that may help restart the pumps after they’re stopped.
“The software modification changes the way the controller sends power to the pump when it is starting and provides increased force to start the impeller in the pump,” the company wrote. “Based on the design of the software and the testing performed to date, the other software within and functionality of the controller are unchanged.”
That said, Medtronic noted, “The long-term durability and functionality of a controller with the unapproved software is not yet known.”
The algorithm has undergone only “very limited testing” so far, Medtronic said. Its internal bench testing has produced “mixed results,” prompting the company to admit that “the potential for this unapproved software to restart a pump may be low.”
In one of two attempted real-world uses reported in this month’s letter, the algorithm was able to restart a pump on the first try, after the standard controller had been unable to revive the pump in five failed attempts. In the other reported use case, however, the new algorithm was unsuccessful in restarting the pump, despite multiple attempts.
Because of the lack of testing and the fact that the FDA has yet to sign off on the algorithm’s safety and efficacy, Medtronic noted that it should be used only as a last-ditch “rescue” effort for patients whose HeartWare pumps won’t restart and who don’t have any other options.
With those risks in mind, healthcare providers who determine that the potential benefits are weighty enough can request a modified controller from Medtronic at no cost.