Medtronic’s HeartWare HVAD Recalled for Pump Weld Defect

Pump thrombosis may develop in patients who are implanted with Medtronic’s HeartWare Ventricular Assist Device (HVAD) system due to a weld defect that has been found in some of the pumps, the US Food and Drug Administration said yesterday in a letter to healthcare providers.

Medtronic stopped the sale and distribution of the troubled HVAD in June 2021 due to increased risk of neurological adverse events and mortality, as well as a risk that the internal pump could stop working. The latest update from the FDA affects patients who are still being supported by the device as a bridge to heart transplantation.

Prior to the FDA’s letter, Medtronic issued an urgent medical device correction saying it has received three complaints of patients with suspicion of pump thrombosis, with device malfunctions found in all three. “Wear marks indicated that the impeller was rotating non-concentrically and contacting the center post of the pump,” the company notes. “The ongoing investigation suggests this was caused by a weld defect that allowed moisture into the center post and corroded the magnets that keep the impeller rotating concentrically.”

All three affected patients underwent pump exchanges. Of those, one received a heart transplantation two months after the pump exchange, and the other two patients died. The company says signs and symptoms of pump thrombosis include:

• Abnormal pump sounds such as grinding or excess vibration
• Transient power spikes on the log files and high-watt alarms
• Elevated lactate dehydrogenase
• Low motor speed resulting in low perfusion
• Dizziness/lightheadedness

For patients with a diagnosis of pump thrombosis, the FDA says a pump exchange, heart transplant, or pump explant for recovery should only be considered if the symptoms do not resolve.

The FDA maintains the same position that it took at the time the device was recalled, saying the HVAD should not be electively explanted in patients for whom it is functioning properly. Instead, the agency urges healthcare providers to make any decisions about removal or exchange on “a case-by-case basis, considering the patient’s clinical status and surgical risks.”