Medtronic is warning European healthcare providers of a potential safety issue found within many of its implanted heart devices that may make them less effective.
As described in a June notice made public this week by Germany’s Federal Institute for Drugs and Medical Devices, the recall concerns several models of Medtronic’s Cobalt, Cobalt XT and Crome devices. These include implantable cardioverter defibrillators, or ICDs, and cardiac resynchronization therapy defibrillators (CRT-D).
ICDs constantly monitor the heart’s rhythm and periodically issue electrical shocks to reset the heartbeat and correct any abnormalities, while CRT-D devices operate similarly to a standard pacemaker and direct their electrical pulses to the right and left ventricles to help coordinate contractions. A CRT-D implant can also send a shock to the heart to interrupt a dangerously fast heart rhythm.
Medtronic said in its notice to healthcare providers that it has discovered a flaw in some of the devices that may cause them to emit electrical pulses below the programmed strength while providing high-voltage therapy. Specifically, that strength drops down to around 79% of the programmed energy, leading to a possible 1% drop in the defibrillators’ efficacy.
If that occurs, the devices will automatically issue a short circuit protection alert. That alert could be misinterpreted by clinicians, Medtronic noted, possibly leading to unnecessary and risky replacement of the device or its accompanying components.
As of early June, the company said it had received reports of 27 devices—making up just 0.03% of the approximately 80,000 implants distributed around the world—that have emitted these “reduced-energy shocks.” None of those instances have been linked to reports of permanent harm or death.
However, Medtronic estimated that the number of affected devices could ultimately reach up to 0.18% of those currently in use, since the likelihood that a patient will require high-voltage therapy and that the energy reduction will occur both increase over time.
The devicemaker is not recommending that the implants be replaced. It cited data showing that the risk of death stemming from complications associated with device replacement clocks in between 0.032% and 0.043%, a relatively low risk that still far outweighs the 0.002% chance of death Medtronic has estimated for the technical issue.
Instead, the company is recommending that healthcare providers continue to perform remote monitoring and regular in-clinic checkups of the devices, reprogramming them to the highest possible voltage if necessary—so that an unplanned reduction will still provide a substantial shock. Medtronic said it has also submitted for regulatory approval a software update to address the issue. It’s expecting to make the update available for download to implanted devices beginning in the third or fourth quarter of this year.
Meanwhile, healthcare providers that have unused ICDs and CRT-D devices matching certain serial numbers listed in the notice are asked to quarantine and return the implants so Medtronic can inspect them to ensure they meet necessary manufacturing specifications.