Medtronic withdraws leads for heart devices

Shares of medical-device maker Medtronic mdt dropped 11% to $50 Monday after it halted sales of a best-selling component used in heart devices because of safety concerns.

The Sprint Fidelis leads — wires implanted in patients' hearts and connected to defibrillators that shock abnormal heartbeats back to normal — have suffered a higher-than-expected rate of fractures, which can cause unwanted heart shocks or none if needed.

Medtronic, the leading maker of implantable cardioverter defibrillators, or ICDs, asked doctors to stop implanting the Fidelis leads and return unused ones to Medtronic. It didn't call the action a "recall," but the Food and Drug Administration did.

Most Fidelis users, estimated at 235,000, won't need their leads replaced but should have their defibrillators reprogrammed so that they alert doctors to potential fractures, say Medtronic and the FDA. At estimated failure rates, about 4,000 to 5,000 patients may need replacements. Pacemaker patients are not affected.

The withdrawal of the Fidelis leads is the second major blow to the ICD industry since 2005 when Medtronic's major rival, Guidant, now owned by Boston Scientific, had a string of safety-related issues.

ICD sales have yet to fully recover. The Fidelis issue is "a hit to industry efforts to repair the U.S. ICD market," and may scare off future ICD users, said Morgan Stanley analyst Glenn Reicin in a note to investors.

He also says the "recall" will challenge Medtronic's claim to superior quality control, and may raise questions as to whether Medtronic acted fast enough.

The Fidelis leads were withdrawn after data showed a 2.3% failure rate after 30 months vs. a 0.9% failure rate for Medtronic's older lead, the Quattro. Medtronic said it expected the failure rate to become "statistically significant over time," which triggered the withdrawal.

Medtronic said Fidelis lead fractures may have contributed to five patients' deaths.

The company first alerted doctors in March that the Fidelis leads may be experiencing a higher fracture rate than expected. Medtronic said its investigation suggested that some doctors were struggling with implantation and were "contributing significantly to these fractures," the letter says. At the time, Medtronic had 24-month data that showed 98.9% of the Fidelis leads still viable — a rate consistent with other leads. That dropped with six more months of data, Medtronic spokesman Rob Clark says.

James Coman, an associate professor of medicine at the University of Oklahoma College of Medicine, says he stopped using Fidelis leads 10 months ago after a routine check on a patient revealed a fractured lead, which he says is highly unusual. Medtronic's March statement didn't convince him otherwise. Coman says he'll check Fidelis patients every month instead of every quarter via an in-home monitoring system.

Medtronic and doctors are not recommending patients have the leads automatically replaced because of the substantial risk associated with the surgery. Replacing a lead is riskier than replacing the defibrillator, in part because scar tissue forms around the wires in the heart.

Medtronic, with annual sales of about $12.3 billion, expects a loss of $150 million to $250 million in revenue in its second fiscal quarter. Fidelis leads accounted for 60% of Medtronic's U.S. sales of leads.