- FDA on Tuesday alerted physicians and patients of three adverse event reports in which the batteries in Medtronic pacemakers became fully depleted sooner than expected and without warning. One pacemaker-dependent patient died as a result.
- Prophylactic removal of the affected device models is not recommended, but FDA advised physicians to consider whether elective device replacement is warranted for any pacemaker-dependent or high-risk patients.
- Affected models include the Azure and Astra pacemakers and Percepta, Serena and Solara cardiac resynchronization therapy pacemakers (CRT-Ps), with various model numbers. As of April 10, 131,889 of the devices had been sold in the United States.
The problem stems from a device component called a capacitor that stores electrical energy. FDA said the battery in each of the three device reports had fully drained because of a crack in the capacitor. Such a crack can create an electrical short that can cause the battery to drain faster than expected.
The devices are designed to last 7.5 to 15 years and 6 to 10 years, depending on the model and the amount of pacing, before the battery needs replacing. But the batteries in the three device reports depleted on average within seven months of implantation in patients.
Remote monitoring systems such as Medtronic's MyCareLink can help healthcare providers track battery status and general functioning of an implanted pacemaker or CRT-P. An elective replacement indicator notification (ERI) is sent to the patient and healthcare provider when the battery level has dropped below a limit.
The pacemaker or CRT-P should be replaced immediately if an ERI alert appears, FDA said, because a device affected by the battery depletion issue is unlikely to have the standard three months of life remaining. Pacemaker-dependent patients with a device that has received a notification should be treated as a medical emergency, the agency said.
In addition to the reported patient death, a second patient had a device replaced after experiencing dizziness, and the healthcare provider was unable to communicate with the device. In the third case, the healthcare provider determined that a connection with the device could not be established, and the product was never implanted.
Pacemakers and CRT-Ps are placed in the chest and connected to the heart with lead wires, to provide pacing for slow heart rhythms and heart failure.
In a statement, Medtronic said the company received three complaints out of about 266,700 devices distributed worldwide since February 2017. The projected rate of occurrence for the battery depletion issue is 0.0028 percent, with the most susceptible period being the first 12 months after a device is implanted.
"Based on the low predicted rate of failure and the recent implementation of process and component enhancements, we expect few, if any, additional events to occur," the company said. Medtronic said after consulting with an independent physician quality panel, it does not recommend device replacement. The company advises physicians to continue normal patient follow-up and to use remote monitoring where possible.
To reduce the risk of rapid battery depletion, FDA said it recently approved a change in Medtronic's manufacturing process to better detect capacitor failures and for a different capacitor component for newly manufactured pacemakers.
"While the number of adverse event reports associated with today's safety communication is small and we expect very low rates of early battery depletion with this device, it's important that patients and health care professionals who rely on these devices know to pay close attention to device performance given the pacemaker's important, life-saving functions and discuss appropriate steps to reduce any potential safety risks to an individual patient," said William Maisel, director of product evaluation and quality and chief medical officer in FDA's Center for Devices and Radiological Health.
Last week, Medtronic received FDA approval for a product that allows healthcare professionals to wireless connect to implanted heart devices via an Apple iPad. The CareLink SmartSync Device Manager allows programming and data management. Medtronic anticipates a full U.S. launch of the system in August.
In March, the Department of Homeland Security flagged a cybersecurity weakness in the system Medtronic uses to transmit data from certain cardiac implants, including two MyCareLink models.