Guidant Says Defibrillator Fix May Make Things WorseJul 23, 2005 | Star Tribune Guidant Corp. issued an urgent warning to doctors today saying a recommendation it issued just last month to fix a problem in three of its implantable defibrillators may actually make matters worse.
The notice affects a subset of patients with implanted defibrillators sold under the names Ventak Prizm AVT, Vitality AVT and Contak Renewal AVT.
On June 17, Guidant issued a warning letter saying that some of the devices were subject to locking up. At that time, 20,950 of the devices had been implanted, and two failures had been investigated by the company.
One of the company's recommendations to fix the problem included a programming change.
But on July 11, a third device reportedly locked up in a U.S. patient. The device had been reprogrammed according to Guidant's earlier recommendations. The patient was not injured but the defibrillator had to be replaced.
The company said it is investigating additional "events," including a possible injury.
The latest warning may be considered a recall by the Food and Drug Administration, Guidant said. The company determined that one of its original programming recommendations can actually increase the risk of failure in some of the defibrillators.
When these devices enter what's called a "latched state," they won't detect arrhythmias. Communication with the devices won't work properly. And they may continue delivering therapy "independent of patient need," according to the corrective action letter Guidant issued to doctors. If latching has occurred, the device should be replaced, the company said.
Doctors were advised to schedule a follow-up visit as soon as possible for patients whose defibrillators were reprogrammed according to the company's June recommendations, as well as certain other patients with specific device settings. The company has issued new programming recommendations.
Guidant is working on a software fix for the Vitality AVT and all Renewal AVT devices. It expects the fixes to be available early in the fourth quarter, pending FDA approval. No software update is pending for the Prizm AVT, as the company estimates that few will be in service by the time one would be developed and approved.
Additional information is available at 1-866-484-3268, and www.guidant.com/physician_communications/AVT_2.pdf.