Medtronic, after having identified welding defects with some of the batteries used in its HeartWare HVAD pumps last year, is asking patients and physicians to return 12 more batteries so that the company can conduct further engineering analysis. 

The Food and Drug Administration posted the medical-device correction on Monday morning, one of several recalls for the heart pump since it was pulled from the market in 2021. The device, which consists of the pump, and an external battery and controller, was implanted in patients who are awaiting a heart transplant, or as a more permanent solution.

Medtronic first identified the welding problem with the batteries in May 2022, noting that if both batteries in the controller malfunctioned, it could result in the pump stopping due to loss of power. In June, Medtronic found a second battery issue, noting that the interaction between the battery software configuration and the battery circuit board can cause electrical faults in some batteries.

As of May 2022, the company reported two patient deaths and more than 1,000 complaints related to the battery problems. 

Medtronic is asking users to return 12 batteries with the potential welding defect, which the company will exchange. The company said some of the batteries that were distributed had an electrical signature that could indicate a welding problem.

“Although actions have been taken to improve control of the welding process, batteries manufactured prior to the improved weld detection methods may still be in use and it is not known if this new electrical data screen will identify all latent weld nonconformances,” the company stated in a Jan. 13 letter to healthcare providers.