Study: Extra ICD scrutiny not beneficial

-Star Tribune, MN

03/06/2008 - Stepped-up monitoring intended to detect failures in recalled heart defibrillator leads made by Medtronic Inc. did little to warn patients of potential trouble with their devices, according to a study by the Minneapolis Heart Institute Foundation.

The study was posted late last month on a website for a doctors group called the Heart Rhythm Society and will be formally published in June.

Patients in the study were treated using an implantable cardioverter defibrillator (ICD) system that had a wire lead called the Sprint Fidelis, which Medtronic recalled in October.

A defibrillator is implanted beneath the collarbone and connected to the heart with the lead, delivering an electric shock when it detects an irregular heartbeat. Patients say the shocks feel like a kick in the chest.

Medtronic said the Sprint Fidelis leads may fracture in a small number of cases, causing the devices to stop working, inappropriately shock some patients or emit a beeping sound if a problem is detected.

About 268,000 people worldwide have been implanted with Sprint Fidelis leads; five deaths may be linked to malfunctions.

When the Fridley-based medical technology company pulled the leads from the market last year, doctors were instructed to reprogram patients' ICDs in a way that would detect fractures. Patients would know something was wrong if their ICD's alarm went off -- like a car's "Check Engine" light.

Medtronic said that reprogramming ICDs would give 51 percent of patients who had Sprint Fidelis leads at least a day's notice of potential fractures.

Doctors could also track how patients' hearts were working, through Medtronic's remote monitoring system, CareLink -- an Internet-based system that links 96,500 Sprint Fidelis patients with their doctors.

"What the report states is that the monitoring technique for determining when a Sprint Fidelis lead is going to fail is relatively ineffective in preventing adverse clinical events," like inappropriate shocking, said Dr. Robert Hauser, a cardiologist at the foundation who is known nationwide for tracking safety information concerning heart devices.

Of the 514 Sprint Fidelis leads implanted at the Heart Institute, 17 failed 11 to 35 months after insertion, according to the study. Twelve patients received inappropriate shocks, and two did not hear the warning alarms.

Overall, enhanced monitoring of the leads did not prevent shocks in two-thirds of the Heart Institute's patients that had Sprint Fidelis, the study says.

In a prepared statement Thursday, Medtronic said the foundation's study "provides no new information that would alter our patient-management recommendations." The company said that it will release a new feature this summer that will improve its ICDs' alarm feature and increase the percentage of patients who will get the warnings of a potential lead problem.

In addition, a group of independent physicians will review the data that was used to develop programming recommendations from the October recall, as well as future changes scheduled for summer. The physicians will publish their findings in peer-reviewed publications and present them at medical gatherings, Medtronic said.

Ennis & Ennis, P.A. is representing individuals that have been harmed by defective medical devices such as the Medtronic defibrillator and pacemaker. If you or a loved one have suffered as a result of a defective Medtronic pacemaker or defibrillator or if you need more information about the Medtronic recall or class action lawsuit click here for a free, confidential case evaluation.