Diagnostics & Imaging Week

Medtronic (Minneapolis) said Monday it has stopped selling its Sprint Fidelis defibrillation leads — the wire connecting the device to the heart — because they may break inside the body.

Of the roughly 268,000 implanted leads, Medtronic said it has identified five patient deaths in which a Fidelis lead fracture may have been a contributing factor.

A lead fracture can cause the device to stop working, emit a beeping sound, or inappropriately shock patients.

“I think this is going to be one more kick in the shins to the ICD market,” said Kenneth Ellenbogen, MD, an electrophysiologist in Virginia, noting that ICD fractures have generated a lot of bad publicity in recent years. He made the comments during a conference call hosted by Bear Sterns.

Ellenbogen, vice chairman of cardiology at Virginia Commonwealth University (VCU; Richmond) and director of clinical cardiac electrophysiology and pacing at VCU, told listeners that he began decreasing the use of Medtronic leads about six months ago after noticing that the Fidelis lead was not performing as well as others on the market.

The FDA has termed Medtronic’s action a product recall. However, both the company and the agency are recommending against surgical removal of the leads, saying that the risk of replacing the device exceeds the risk of a lead fracture.

Instead, they are recommending closer monitoring of the devices.

The Fidelis leads are used to deliver therapy in defibrillators only, including implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy — defibrillators (CRT-Ds). The recall does not affect Medtronic pacemaker patients, the company said.

ICDs and CRT-Ds are used to treat abnormal heart rhythms that can cause the heart to stop suddenly. The devices are designed to shock the heart back into normal rhythms by sending a pulse of energy through an electronic wire — the lead — that is connected to the heart.

The Fidelis is one of two key ICD leads made by Medtronic; it makes up 60% of the company’s lead sales in the U.S., according to Rick Wise, Bear Stearns med-tech analyst. Medtronic will now sell only its earlier-generation Sprint Quattro lead, approved by the FDA in 2001.

“There is nothing more important to Medtronic than the safety and well-being of patients,” Bill Hawkins, president/CEO of Medtronic, told reporters yesterday during the company’s conference call about the recall action.

The FDA approved the Fidelis defibrillation leads in September 2004. At 6.6 Fr in size, the leads were the world’s smallest right ventricular defibrillation leads, allowing for compatibility with 7 Fr introducers, according to Medtronic. The small size of the leads was intended to help improve passage into a patient’s venous system for an easier implant, and minimize venous obstruction.

Now, the company is saying that, based on performance data, Fidelis lead viability is trending lower than its Quattro lead at 30 months (97.7% Fidelis vs. 99.1% Quattro).

Medtronic’s competitors in the ICD market are St. Jude (St. Paul, Minnesota) and Boston Scientific (Natick, Massachusetts). Ellenbogen estimates that Medtronic has about 55% of the market share, Boston Scientific has about 25%, leaving St. Jude with about 20%.

Ellenbogen said the recall is going to hurt other companies with ICD leads on the market as well as Medtronic because more physicians will decide to hold off on implanting patients with ICDs.

“The biggest bad thing that’s going to come out of this is [leaving] a bad taste in people’s mouths about ICDs,” Ellenbogen said.

His office has already received a number of calls from patients, and he said he plans to follow Medtronic’s recommendations by reprogramming affected patients’ devices to more effectively monitor for potential problems and provide an audible alert in the event of lead fractures.

“I don’t want a bunch of people coming in after they’ve gotten 25 [inappropriate] shocks,” he said.

During Medtronic’s conference call, Bruce Lindsay, MD, a professor of medicine and director of cardiac electrophysiology at Washington University School of Medicine (St. Louis) and president of the Heart Rhythm Society (HRS; Washington), told listeners that as a physician he always advises patients of the risk of potential fracture before implanting them with the device.

“We deal with these kinds of issues all the time, even with leads that are not recalled,” Lindsay said, adding that most of the time lead fractures are detected before it causes a problem. “This is a manageable situation.”

While doctors are aware that leads are sometimes associated with deaths, Lindsay said the benefits of the ICD outweigh their failures.

“If you don’t put these devices in, thousands of patients die. We know that drugs don’t work in these situations — the best treatment we have is these devices.”

Kevin Hackett, MD, of Columbus Cardiology Consultants and a member of Medtronic’s Independent Physician Quality Panel, said he also advises patients of the risks before implanting them with an ICD. He said the panel believes that the potential risk to patients already implanted with a Fidelis lead is “very low.”

According to Wise, the recall could have a significant near-term financial impact on Medtronic. In a research note, he said the company estimates $150 million to $200 million sales impact from revenue reversals and a potential loss of European tender offers for F2Q08. The company also expects to take a $20 million inventory write-off charge with another $10 million to $20 million in direct costs, he wrote.

According to the FDA, Medtronic first notified physicians in March about the fracture rate and the proper method for implantation. It said that the recall was prompted by the accumulation of additional data on adverse events since then.

Daniel Schultz, MD, director of the Center for Devices and Radiological Health of the FDA, attempted to calm any possible panic among patients by issuing a statement saying that defibrillators “are life-saving products for patients with a heart rhythm abnormality. We know it can be frightening for a patient to learn that a product they rely on so much might have a serious defect. However, patients can be assured that the likelihood of fracture is very low, and FDA is committed to ensuring that the risk to patients is minimized.”