FDA Sees Higher Infection Rate In Study Of New Type Of Heart Defibrillator
First Published Monday, 23rd April 2012 09:54 pm - © 2012 Dow Jones
By Jennifer Corbett Dooren
Of Dow Jones NEWSWIRES
WASHINGTON -(Dow Jones)- The Food and Drug Administration Monday said patients receiving a new type of heart defibrillator being developed by Cameron Health Inc. had higher rates of infection compared to rates seen with traditional implantable defibrillators and sometimes delivered "inappropriate" shocks to the heart.
The agency also raised concerns about the device's battery life that could hold up approval of the device. Boston Scientific Corp. (BSX) is in the process of buying Cameron Health as part of a deal that is expected to close later this year.
Cameron's defibrillator is the first implantable defibrillator designed to be implanted under the skin and doesn't require the placement of a lead wire in the heart, which FDA deemed the "primary benefit" of the product.
The device faces a review Thursday by the FDA's Circulatory System Devices Panel, which is made up of non-FDA medical experts. The panel is being asked to make a recommendation to the agency about whether the device should be approved. The FDA released a review of the defibrillator, referred to as the S-ICD system, on Monday.
An implantable defibrillator is a device that delivers electric shocks to a patient's heart whenever a life-threatening cardiac rhythm is detected in order to correct the heartbeat. Current implantable defibrillators require thin, insulated wires to pass through blood vessels and into the heart, while Cameron's system sits underneath the skin and doesn't touch the heart.
"Defibrillator therapy has saved millions of lives," said Kevin Hykes, Cameron Health's chief executive. "We believe we have a solution to the Achilles' heel of this therapy" by eliminating the placement of lead wires in or on the heart.
The leads in conventional defibrillators are susceptible to damage because the heart's regular pounding can stress a lead over time and, in rare instances, cause it to fail. The problem got fresh attention last month when the cardiac-medical journal Heart Rhythm reported that St. Jude Medical Inc.'s Riata and Riata ST heart wires, which are still implanted in 79,000 U.S. patients, had been linked to 20 deaths. The company stopped selling the Riata devices in December 2010.
St. Jude has said it believes Riata and Riata ST's performance is comparable to that of other defibrillator leads that were on the market in the past decade. In 2007, Medtronic Inc. pulled from the market a brand of wire that sometimes fractured and has been linked to at least 13 deaths out of more than 200,000 implanted.
The FDA said a clinical study looking at Cameron Health's defibrillator, which involved more than 300 patients, exceeded agency effectiveness and safety goals. But the agency said the safety goal didn't include all device complications such as 18 infections, four of which required the device to be removed.
The agency also said about 31% of shocks delivered by the device were considered inappropriate, meaning the system delivered a shock when it wasn't supposed to. However, FDA said the agency's review of the medical literature "suggests that approximately one-third of all shocks are inappropriate" among similar patients with traditional defibrillators.
Last year, Cameron Health discovered a problem with the batteries in some of devices after a battery was depleted less than six months after the device was implanted. The battery and device are meant to last for at least five years. The FDA said there's been three additional reports of premature battery depletion.
"FDA will not consider...approval of the device until this issue is resolved," the agency said. However, FDA said it expects the issue to be resolved, and the company said, in documents posted to FDA's website, that the battery depletion issue has been addressed.
-By Jennifer Corbett Dooren; Dow Jones Newswires, 202-862-9294; firstname.lastname@example.org
--Thomas M. Burton contributed to this article.