This week of activity for Medtronic (Minneapolis) has been the equivalent of taking two steps forward and then one giant step back. On Monday the med-tech powerhouse reported that it would be shelling out $1.025 billion to snag CoreValve (Irvine, California) and Ventor Technologies (Netanya, Israel) to expand its cardiovascular business.

A day after that news, a newly published report in the Heart Rhythm Society (Washington) journal HeartRhythm shows that there could be a higher rate of failure for the Sprint Fidelis Leads, than previous studies have revealed. The study shows that the incident of failure in patients is significantly higher than what is found in the company's ongoing analyses of the lead's performance.

The new study, which was written by Robert Hauser, MD, of the Minneapolis Heart Institute and David Hayes, MD, of the Mayo Clinic (Rochester, Minnesota), shows that the Fidelis lead continues to function in only 88% of patients studied three years after being implanted. However Medtronic's data, which also used a three year-measurement, had findings that the lead continued to work in 95% of the patients.

In an e-mailed response to Medical Device Daily, Medtronic briefly commented on the differences in the data.

"It is important to note that data collected from center to center would be expected to vary. The Hauser/Hayes analysis is based on a small study population of Fidelis leads (n=848). A recent larger study by Krahn, et al., involving nearly 6,000 leads, showed results much more similar to those found by Medtronic in our review of more than 20,000 leads," a company spokesman said.

According to the med-tech giant, the lead performance for System Longevity Study data is at 95.4% and at 97% for a CareLink Data study.

But the Hauser and Hayes study, which monitored the performance of all defibrillator leads implanted at their respective institutions from 2004 to 2008, shows that out of the 3,000 leads implanted during that timeframe, the Sprint Fidelis accounted for nearly 30% of the total or 848 leads. In that period, the failure rate of those leads was 3.75% compared with 0.6% for other leads.

The two authors also found that the failure rate is increasing and that in some patients, removal of the Fidelis lead might be appropriate if the benefits clearly outweighed the risks.

Medtronic says in its statement that the authors of studies other than Hauser and Hayes, "do not" recommend prophylactic removal of leads.

Larry Biegelsen, senior analyst for medical supplies and devices at Wachovia Capital Markets (Charlotte, North Carolina), said there isn't a clear distinction as to why there is a difference in the failure rates for Medtronic's studies and Hauser/Hayes' study.

"While it is unclear why the failure rate in the new study differs from Medtronic's results, we think the constant reminder of the Fidelis recall will result in Boston Scientific [Natick, Massachusetts] and St. Jude [St. Paul, Minnesota] gaining share from [Medtronic] as physicians diversify their ICD implants among the three major manufacturers," Bieglesen told Medical Device Daily. "A second issue is whether Medtronic's current recommendations regarding patient management are appropriate, namely to monitor Fidelis leads for signs of fracture and not replace it unless a defect is identified."

Biegelsen added that "we do not envision at this time a major disruption in the ICD market caused by a large number of Fidelis patients having their leads replaced prophylactically. Medtronic currently estimates that 150,000 patients in the U.S. have a Fidelis lead."

Hauser has been on record as being one of the first who raised concerns the Fidelis lead was fracturing and failing in patients prior to Medtronic recalling the device back in 2007 (MDD, Oct. 16, 2007).

Originally the FDA approved the Fidelis defibrillation leads in September 2004 (MDD, Sept. 3, 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.

Nearly three years after its approval, the Sprint Fidelis leads spurred numerous recalls and lawsuits. A saving boon came to the company when a Supreme Court decision in Reigal v. Medtronic (MDD, Feb. 21, 2008) found that federal law shielded developers of some medical devices from product liability lawsuits.

When called to comment on the possibility of lawmakers and legislators pushing to reverse the decision because of the new findings, the Advanced Medical Technology Association (AdvaMed; Washington), declined to talk specifics about the study but did offer comment on its position for the Supreme Court's ruling.

"Allowing state court lay juries to serve as secondary regulatory bodies would interfere with FDA's extensive oversight of medical devices, delay or deny patient access to life-saving treatments and increase the costs to the healthcare system," Christopher White, executive VP and general counsel for Advamed, said in a submitted statement.

Bieglesen said that there could indeed be some repercussions of the study results.

"We think it is worth monitoring legislation in Congress that would overturn preemption, which has thus far helped shield Medtronic from large product liability damages due to Fidelis," he said.

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