Problems With Implantable Heart Devices Need More Public Airing

Experts say companies that make them should work closely with government, doctors

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By Amanda Gardner
HealthDay Reporter

MONDAY. May 15, 2006 (HealthDay News) -- Although implantable cardiac devices are largely reliable, the companies that make them need to communicate better with the government, patients and physicians to make sure life-threatening malfunctions do not go unnoticed.

Those are the views expressed in a perspective article appearing in the June 1 issue of the New England Journal of Medicine, which is being released early to coincide with this week's annual meeting of the Heart Rhythm Society, which represents the physicians who implant these devices.

Reliability is an important issue for the hundreds of thousands of Americans walking around with either a pacemaker -- designed to keep the heart beating regularly -- or a defibrillator -- a device that delivers a shock to restart a malfunctioning heart.

And there has been an explosion in the use of the devices. "Increasingly, these devices have been used not only in survivors of sudden cardiac arrest but also in people who may be at risk," explained Dr. Bruce Lindsay, co-author of the paper and director of clinical cardiac electrophysiology at Washington University School of Medicine in St. Louis.

"The devices, overall, have been pretty reliable," he said.

But what does a corporation do when one of the inevitable, albeit rare, problems crop up?

Indeed, that question cropped up last year, when Guidant Corp. reported that about 28,000 pacemakers had defects that could cause them to malfunction. The company created even more of a furor when it later revealed that it had decided not to issue alerts about life-threatening defects in some of its implanted defibrillators.

"The company identified a very low frequency failure mode and, based on the best judgments of engineers, decided that the risks of replacing the device were not warranted," Lindsay said. "They really didn't get medical input. They made their own decision, oddly enough, without any real input from people higher in the corporation," he added.

After these events came to light, the corporation established an independent panel, which included Lindsay, to analyze what had happened.

That critique and its recommendations are essentially summarized in the New England Journal report.

The devices save thousands of lives each year with a small number of failures, the panel concluded. "If you have a device, there's maybe a one in 1,000 chance it will fail, but, if you don't have it in, there's a 100 percent chance it will fail," Lindsay said.

Nevertheless, when things do go wrong, engineers need to communicate with people who have medical expertise. Ideally, the company should also get advice from an independent panel, either one put together by the corporation or one embedded within the U.S. Food and Drug Administration.

The panel also recommended more post-marketing surveillance by the FDA. "Basically, all this information was given to the FDA by Guidant," Lindsay said. "They didn't hide it. It's just that the FDA is overwhelmed with things." And the FDA seems to have responded, announcing recently its plans to address post-marketing surveillance more actively.

Until recently, industry tended to lump all malfunctions together, not disclosing specific malfunctions as long as the overall rate fell within overall performance predictions.

This made sense for routine problems, such as a battery dying, but not for more serious malfunctions.

"In the big picture, these devices are remarkably reliable," Lindsay said. "It doesn't necessarily make sense to take out all these devices, but it might be with individual patients who are at such high risk that you would want to make that decision. That's where the physician taking care of the patient has to be informed, so that he or she can make that decision," he said.

The Heart Rhythm Society, of which Lindsay is president-elect, has also made recommendations that are expected to be released at the annual meeting, which starts Wednesday in Boston.

More information

Visit the Heart Rhythm Society for more on implantable devices.

SOURCES: Bruce D. Lindsay, M.D., associate professor, medicine, and director, clinical cardiac electrophysiology, Washington University School of Medicine, St. Louis; June 1, 2006, New England Journal of Medicine

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