St Jude halts pacemaker implants due to data, battery issues

Medical device maker St. Jude Medical Inc said it has notified doctors to stop implants of one of its cardiac pacemakers, citing reports of problems with electronic data reporting caused by a battery malfunction that could put patients at risk.

The affected device is the Nanostim leadless cardiac pacemaker (LCP). St. Jude, which is being acquired by Abbott Laboratories, said it had seven reports of lost telemetry and heart pacing output from the devices.

Of a total of 1,423 Nanostim devices implanted worldwide, 1,397 remain in service and represent a potential risk to patients, the company warned.

There have been no reports of patient injury associated with the malfunction, St. Jude said.

"We are currently working to ensure our physician partners worldwide have the information they need to effectively manage their patients," St. Jude Chief Medical Officer Mark Carlson said in a statement, adding that the company remains committed to developing leadless pacing technology.

In a letter to doctors, St. Jude said they should not implant any Nanostim pacemakers they might have in stock and instead return them to the company. It said device replacement is recommended, with priority given to patients with implants of the longest duration.

Pacemakers are used to keep a patient's heart beating at a normal healthy rate.

The seven reports of problems occurred between 29 and 37 months after implant, St. Jude said.

Two of the affected patients received replacement LCPs, three received more traditional pacemakers and two are awaiting replacement devices, it said. The company said it will analyze returned LCPs.

The LCP issue follows other recent problems with St. Jude heart devices. Earlier this month, the company announced a recall of some of its other implanted heart devices due to risk of premature battery depletion, which was linked to two deaths in Europe.

That recall involved ICDs and CRT-Ds that are used to shock a dangerously racing heart back to its normal rhythm, or to help maintain a normal heart rhythm. ICDs are implantable cardioverter defibrillators, while CRT-D stands for cardiac re-synchronization therapy defibrillator.

St. Jude shares were off 71 cents, or nearly 1 percent, at $78.30 on the New York Stock Exchange.