Medical Device Daily National Editor

Dr. Robert Hauser is at it again.

Hauser, of the Minneapolis Heart Institute Foundation, is one of the cardiologists – just referred to by a Minneapolis/St. Paul-area newspaper as a medical "gadfly" – who blew a very large whistle on Guidant. In 2005, he and another cardiologist made public their concerns about the safety of one of that company's defibrillators.

That publicity set in motion a mounting cascade of events: a wide recall of the company's defibrillators, and a plunge in the company's value, greatly complicating its acquisition by Boston Scientific (Natick Massachusetts) and subsequently having the halo effect of holding up additional product approvals by the FDA.

This time Hauser is questioning the development and oversight of a new defibrillator technology being developed by Boston Scientific and the other two of the cardiovascular "big three," Medtronic (Minneapolis) and St. Jude Medical (St. Paul, Minnesota) charging that if the technology is approved without sufficient testing and clinical data in humans, the results "could be catastrophic" for patients.

His concerns are addressed in the Dec. 11 issue of the New England Journal of Medicine, in an article written in collaboration with Dr. Adrian Almquist, also with the Minneapolis Heart Institute.

The new defibrillator system under development is distinguished from previous generations by having four leads, rather than the traditional two or three. The leads are thinner, in order to make them easier to implant.

In the article, "Learning from Our Mistakes? Testing New ICD Technology," Hauser and Almquist charge that this is a significant difference potentially making the leads prone to short-circuiting. "If high-voltage isolation is lost," the article says, ^"and a short circuit develops during therapeutic shock delivery, otherwise potentially lifesaving defibrillation may be ineffective."

And therefore likely lethal.

The cardiologists link this to recent concerns about ICD leads.

They cite last year's recall of the Sprint Fidelis lead made by Medtronic, charging that this product did not receive sufficient FDA review before approved for commercialization.

Five people implanted with the Fidelis ICD leads died because of fracturing, a problem found to be much more frequent than the expected risk parameters. The leads were subsequently pulled from the market, with class actions filed against the company (Medical Device Daily, Oct. 16, 2007).

Based on these concerns, Hauser and Almquest say they are raising issues about how extensive and adequate the testing of the new leads will be and highlighting the complex changes in technology described in lengthy documentation materials.

And the two cardiologists also suggest that the manufacturers may be attempting to push a new product into a $5 billion-plus market that has been stagnating a bit recently, but "reluctant to subject these innovations to premarket clinical testing because such trials are costly and may delay the introduction of new products."

Thus, he is warning that the new leads should not suffer the same fate, and unhappy consequences, of the Fidelis.

The concerns raised by the two cardiologists is countered in the same issue of the NEJM by Daniel Schultz, MD, head of the FDA Center for Devices and Radiological Health, in a letter to the editor.

He says that the agency "has made no absolute decision" concerning the matter. But he adds: "The agency decides what information is needed to support an approval on the basis of its review of an individual application. This is a scientifically sound approach to protecting public health."

The information that could best test the reliability of the leads, he said, could be non-human studies, such as bench testing.

Medtronic released a statement agreeing with that position, saying that lab testing "provides the opportunity to test a large number of devices and to stress them beyond what they will see in clinical application."

It said that existing leads were approved on the basis of laboratory and animal testing, rather than testing in humans.

However, in their NEJM article, the cardiologists specifically say that while these types of testing are "useful," they cannot identify all of the "hostile circumstances" that such devices experience as a result of the "wear and tear" in humans.

Issuing a resoundingly neutral statement on the debate, the Advanced Medical Technology Association (AdvaMed; Washington), simply underlined the fact that the leads are still under development and have not yet been submitted to the FDA for approval.

An organization obviously concerned with this issue, and likely to serve as a watchdog on the regulatory process for the new technology, is the Heart Rhythm Society (HRS; Washington).

In their article, the two cardiologists note that the FDA at this year's HRS meeting stated that the leads would be assessed only in animals and laboratory tests. And in commenting on the NEJM article, the society released a statement noting that in 2006 it issued recommendations concerning the surveillance and performance reporting of pacemakers and ICDs, with the purpose of creating "greater transparency" concerning the reliability of such devices.

It said that this year it created a task force that includes its members, "collaborating with regulatory agencies, industry and patients" to develop recommendations concerning lead performance.

Dr. N.A. Mark Estes, president of the society, told Medical Device Daily that the society will address the task force report dealing with the issue of the appropriate type of testing for leads, but he did not want to say what its conclusions are likely to be. And he declined to give a personal opinion on the controversy until the task force report is issued.

He said that a draft report of the task force's work will be presented to the board of the society during 1Q09 and that the final recommendations are to be released at the society's annual scientific sessions in Boston next May.

In a statement released by the society, Estes said, "We have been at the forefront of establishing policies and guidelines to ensure the safety of life-saving devices such as internal cardiac defibrillators and pacemakers. The society will continue to develop standards as technology continues to evolve."