Medtronic letter reveals Micra pacemaker deployment troubles

Medtronic has been fielding complaints from physicians who have had trouble releasing the company’s Micra pacemaker from its delivery system inside patients’ bodies.

In a letter dated August 2019, the company noted that it had received 52 complaints worldwide involving a tangled tether that resulted in prolonged or additional procedures. Specifically, the company said it learned that flushing the delivery system after the tether has been cut may cause tether’s free end to enter the ventricular chamber and tangle.

“If this happens, the tangle could potentially prevent tether removal from the delivery system and potentially prevent release of the Micra pacemaker,” the company’s letter said.

No deaths have been reported, the company added. It was unclear whether any patients were injured.

The company’s letter provided physicians with updated instructions on releasing the pacemaker without tangling the tether.

“This update is specific to language about implant procedures in the Micra IFU (instructions for use) and Tip Card,” Medtronic said in an email to MassDevice. “The Micra device continues to perform as expected and this update does not affect the device, its battery, its ability to deliver therapy, or other functions. No action is needed for patients already implanted with a Micra device, as this update to instructions only applies to new implant procedures.”