St. Jude Medical has asked doctors to stop implanting its Nanostim leadless cardiac pacemaker (LCP) due to problems with electronic data reporting caused by a battery malfunction. Though no injuries have been tied to the Nanostim problem, the company is recommending that the devices be replaced.
The issue with the Nanostim devices comes just weeks after St. Jude announced an ICD and CRT-D recall for another group of implantable cardiac devices due to the potential for premature battery depletion. That problem has been linked to two patient deaths and dozens of adverse event reports.
Nanostim pacemakers are used to keep a patient’s heart beating at a normal healthy rate. In a letter issued to doctors last week, St. Jude said that it had received seven reports of lost telemetry and heart pacing output in Nanostim patients, all of which occurred between 29 and 37 months after implantation. While none involved patient injuries, all of the affected patients required replacement of their pacemakers. Two received new LCPs, while three received traditional pacemakers. Two other patients are awaiting replacement.
According to St. Jude’s letter, 1,423 Nanostim devices have been implanted worldwide, and 1,397 remain in service. The company said that priority for pacemaker replacement would be given to patients who have had the implants the longest. Doctors have been asked to return any unused stock.
This is just the most recent issue to involve implantable cardiac devices marketed by St. Jude Medical. On October 11th, the company recalled certain Fortify, Unify, and Assura ICDs and CRT–Ds, including 251,346 implants that had been sold in the U.S., due to reports of premature battery depletion. So far, two deaths (1 in the U.S.) have been linked to this problem. Ten patients, (9 in the U.S.) reportedly fainted, and 37 (30 in the U.S.) reported dizziness. Of the implants sold worldwide, 841 have been returned to St. Jude for analysis due to premature battery depletion.
The U.S. Food & Drug Administration (FDA) has designated St. Jude’s ICD and CRT-D recall a Class I recall, its most serious type. Among other things, the agency has advised that affected patients register for St. Jude Medical’s Merlin@home remote transmitter system in order to monitor their devices for premature battery failure. The recommendation was made in spite of an active FDA investigation into allegations that certain St. Jude cardiac devices, including the Merlin@home system, are vulnerable to hacking.