Removing Medtronic heart wire might carry less risk

The difficult surgery to remove a Medtronic Inc. heart defibrillator wire that was recalled because of safety concerns may be a lot safer than previously thought, according to a study published in a medical journal late Wednesday.

Defibrillators are stopwatch-sized devices implanted in the chest that shock the heart when an abnormal rhythm is detected. A wire, or lead, connects the device to the heart.

The Fridley-based medical technology company pulled its popular Sprint Fidelis defibrillator lead off the market in 2007 because a small number of them could fracture, which could cause the device to stop working, or deliver painful and unnecessary shocks to patients. Thirteen deaths have been linked to the recalled lead.

Patients with the Sprint Fidelis leads were advised by the company to keep them intact once disconnected from the device -- claiming surgery to remove them from the body posed a higher risk of complication than simply leaving them in place. Two years after being implanted, roughly 2.3 percent of the leads fail, according to the study.

Since complication rates for lead extraction surgery range from 1.4 percent to 7.3 percent, most doctors have followed Medtronic's advice.

But in a 348-patient study published in the online edition of the Journal of the American College of Cardiology, doctors at five hospitals that perform a lot of lead extractions cited no major complications or deaths resulting from the surgeries. They concluded the guidelines for treating patients who still have Sprint Fidelis leads should be reconsidered, although they stopped short of recommending that all Sprint Fidelis leads be removed.

Still, the findings could have some implications on how the remaining 175,000 Sprint Fidelis leads still implanted in patients worldwide are handled, because doctors read medical journals for guidance in how they treat their patients.

"My concern is that many patients with Sprint Fidelis leads are cared for in centers that don't have a lot of experience" removing the leads, said Hauser, who has done several studies of his own regarding defibrillator and lead safety, including Sprint Fidelis.

Often scar tissue forms around the wire inside the chest, making it difficult for a surgeon to take them out.

The retrospective data cited in the study indicated that 49 percent of the leads removed from patients between May 2005 and August 2009 were fractured.

In an editorial accompanying the study, Dr. William Maisel from the Medical Device Safety Institute in Boston said the study "stands in contrast to other large studies of lead extraction."

Removing all of the remaining Sprint Fidelis leads from patients would "needlessly expose numerous patients to potentially unnecessary procedures" and complications, Maisel wrote. Still, he acknowledged, managing Sprint Fidelis patients "remains a challenge."