Minneapolis, MN - Medtronic has voluntarily suspended worldwide distribution of the Sprint Fidelis family of defibrillation leads because of the potential for lead fractures [1]. Such fractures might have played a part in five patient deaths, the company told heartwire.

Medtronic spokesperson Rob Clark said the company estimates that around 2.3% of patients with the Fidelis lead will experience a lead fracture within 30 months of implantation. The majority of the 235 000 patients with active implants are in the US, he noted. Sprint Fidelis leads are used in implantable cardioverter defibrillators (ICDs) and cardiac resynchronizationn therapy defibrillators (CRT-Ds), but not in Medtronic pacemakers.

The company is sending a letter directly to all patients with a Sprint Fidelis lead "within a matter of days," and physicians will be notified of the issues today by letter and will be receiving a visit from a Medtronic rep in the field. Information has also been posted on the company website, and patients can call a toll-free number for more details, he added [2,3].

Although the most typical manifestation of a lead fracture is an inappropriate shock, it is possible that a fracture could result in the defibrillator failing to provide a life-saving shock, Clark said.

Although inappropriate shocks are "painful, they are not life-threatening," he noted. Patients who experience such episodes should discuss what to do with their doctors, he added. The company will cover the cost of a replacement lead for those that have fractured and up to $800 in medical expenses that are not covered by insurance.

However, the company, its independent physician quality panel, and president of the Heart Rhythm Society, Dr Bruce Lindsay, are warning against patients seeking removal of the Sprint Fidelis leads as a precaution, stressing that the risks of removal or insertion of another lead exceed the small risk of a lead fracture. Clark says there is another option to removal of the lead—capping the old one and stringing in a new lead—but the exact complication rate for this procedure is not known.

The company will not pay for procedures to replace functioning leads simply as a precaution against future problems.

Clark said that concerns about the Sprint Fidelis lead arose earlier this year when the company started to get reports from certain facilities about higher-than-expected lead fracture rates with the Sprint Fidelis. "This prompted us to look into it, and we sent out a letter to physicians," he noted.

But just to confuse matters, there are three possible contributing factors to lead fracture, he said: a problem with the design; the implant procedure used—hence the "Dear Doctor" letter that reminded physicians of the correct implant technique; and the patient's level of activity. "Some activities can result in lead fracture," Clark said.

Following the concerns earlier this year, the company initiated an analysis of 25 000 patients in its CareLink system for remotely monitoring implants. This generated the 2.3% figure for lead fractures, which was validated by another study—the multicenter prospective System Longevity Study of 650 patients at 17 hospitals. Clark added that the company also used returned-product-analysis data, but that this is notoriously unreliable and in fact showed 99.2% effectiveness of the lead at 30 months.

Statistically speaking, the rate for lead fractures with the Fidelis lead is not significantly different at the current time from the company's older lead, the Sprint Quattro, he said, "but this figure may become significant over time."

The main difference between the Sprint Quattro and the Sprint Fidelis is in the diameter of the lead; the Fidelis has a much smaller diameter, which physicians prefer. Medtronic is advising physicians who need to replace the Sprint Fidelis lead to use the Quattro, but Clark acknowledged that doctors could also use a competitor's small-diameter lead.

"We will make some design changes to the current Fidelis and improve it for the future, and we hope to bring back a smaller-diameter lead to the marketplace," he noted.