Fatalities and failures prompt defibrillator recalls

Two deaths and dozens of product failures have led to worldwide recalls in June 2005 of tens of thousands of cardiac defibrillators implanted in the chest of patients susceptible to dangerous arrhythmias, or abnormal heart rhythms.

The pager-size devices, made by the Guidant Corp. of Indianapolis, Ind., are programmed to deliver a potentially life-saving electrical shock when the heart rhythms go awry. Several problems have been detected in different models: The insulation around the wiring could wear off and cause a short circuit; an error in the computerized memory could prevent delivery of the shock; or a switch could get stuck, causing the device to malfunction and the battery to wear out prematurely.

The Food and Drug Administration, which regulates medical devices, is not advising patients to automatically have the defibrillators removed and replaced. Instead, the FDA recommends that patients weigh the pros and cons of the replacement operation with their doctor. Guidant corporate communications spokeswoman Annette Ruzicka says that in some cases the risks of surgery might be greater than the slight possibility of product failure, and a doctor might elect instead to monitor the patient more often.

Both deaths and most of the failures have been linked to the following devices:

• Ventak Prizm 2 DR, model 1861, made before April 17, 2002. An estimated 17,000 people worldwide, 13,900 in the U.S., are still using this defibrillator. It has been tied to 28 reported failures, including 1 death, according to Guidant and the FDA. No failures have been reported in devices made after April 2002, when Guidant redesigned the product.
  
  
• Contak Renewal, model H135, and Contak Renewal 2, model H155, both made before Aug. 27, 2004. About 11,900 are still in use worldwide, 6,700 in the U.S. There have been 15 reported failures, including 1 fatality. Like the Ventak Prizm, the models could short-circuit.

Also recalled were 21,000 Ventak Prizm AVT, Vitality AVT, Renewal 3 AVT, and Renewal 4 AVT models, including 18,000 in the U.S. Guidant has confirmed two failures, neither involving injury. The memory on these AVT (atrial ventricular therapy) defibrillators could malfunction, preventing detection and correction of an irregular heartbeat. The short-term fix, Ruzicka says, is for doctors to reprogram them using a handheld wand, which can be done during a routine office visit. However, the procedure reduces the amount of useful information that the devices can collect. By the end of 2005, Guidant expects to have a permanent solution involving new, noninvasive software.

The recall was announced on June 17. A week later, on June 24, Guidant issued a notice to physicians regarding 46,000 Contak Renewal 3 and 4, Renewal 3 and 4 AVT, and Renewal RF defibrillators because their magnetic switches could get stuck. Three patients have had to have the device surgically removed and a new one implanted. The Renewal AVT defibrillators involved in the switch malfunction had been included in the June 17 recall for potential memory error. Guidant is advising physicians to consider turning off the device’s "Enable Magnet Use" function, again using the wand. The company also is urging patients to call their doctor or go to an emergency room immediately if their unit emits an audible tone.


What to do

If you don’t know whether your defibrillator is one of the affected models and you haven’t been notified of the recall, you can find out in several ways. All patients should have received a wallet-sized card containing model information. If you can’t find the card, ask your doctor or call Guidant at 866-484-3268. If your defibrillator was recalled and your doctor advises replacing it, Guidant will provide a free replacement device and reimburse any documented out-of-pocket medical expenses up to $2,500. For more information, visit Guidant’s Web site at www.guidant.com.

Consumers and physicians can voluntarily report problems with these or other medical devices to the FDA's MedWatch program online at www.fda.gov/medwatch or by calling 800-332-1088.