FDA test guidelines under fire

A prominent Minneapolis cardiologist, writing in this week's edition of the New England Journal of Medicine, is questioning whether a next-generation heart defibrillator in development by several Minnesota companies will be sufficiently tested for safety before its U.S. launch.

Dr. Robert Hauser of the Minneapolis Heart Institute Foundation said in the Dec. 11 edition of the medical journal that the novel technology could expose patients to potentially lethal risks if it is not rigorously tested in humans before being approved by federal regulators.

"The consequences for the patient could be catastrophic," Hauser said in an article he wrote with the Heart Institute's Dr. Adrian Almquist.

Three cardiac device companies that have local ties -- Medtronic Inc., Boston Scientific Corp. and St. Jude Medical Inc. -- are developing the new defibrillator system.

AdvaMed, the med-tech industry association, responded to Hauser's article by saying that each manufacturer will subject the new defibrillator system to rigorous tests.

All the products are still in development.

Hauser is a well-known gadfly in the medical technology community. In 2005, he and a colleague, Dr. Barry Maron, went public with safety concerns about a defibrillator made by Guidant Corp. (now part of Boston Scientific) after the death of one of their patients who had been implanted with the device.

Their disclosure led to Guidant recalling thousands of defibrillators and pacemakers, and triggered a hard examination into the way medical device malfunctions are tracked and monitored by the Food and Drug Administration (FDA).

Part of a $5 billion market, implantable cardioverter defibrillators (ICDs) are stopwatch-size devices that ward off sudden cardiac arrest by shocking an errantly beating heart back into rhythm. More than 160,000 are implanted annually in the United States.

Typically, a sophisticated implantable medical device such as a defibrillator must be studied in human patients before gaining FDA approval. But such clinical trials are expensive and time-consuming for medical device companies, and sometimes a device can win approval with little review by piggybacking onto an application of an existing device.

A defibrillator's pulse generator contains a battery that is connected to the heart with an insulated wire called a lead. In his article, Hauser cites the 2007 recall of the Sprint Fidelis lead made by Medtronic as an example of a device that was not properly vetted by the FDA for safety and effectiveness before being launched in the United States.

As it turned out, the widely used Fidelis lead is prone to fracture, and five people have died as a result.

The device that Hauser takes issue with in the Journal article is a new breed of defibrillator, which features four leads, as opposed to two or three, that thread into a single connector that is plugged into the pulse generator.

Hauser argues that this design is substantially different from existing defibrillator technology, and therefore needs extensive clinical studies before being approved.

Industry executives, he adds, "are not only concerned about the costs of a clinical trial but also eager to introduce an attractive product into the troubled ICD market, which has not been growing."

In a letter to the editor in the same issue of the Journal, the head of the FDA's device division said that the agency "has made no absolute decision" concerning the matter. But Dr. Daniel Schultz wrote, "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."