The recalled St. Jude Medical Inc. Riata wires, originally used to connect life-saving defibrillators to the heart, were found to short circuit on occasion, a defect that may have led to 22 deaths, according to researchers.
An analysis of the FDA’s safety database found 133 deaths linked to St. Jude’s Riata or Medtronic’s Quattro Secure leads, according to a report from Robert Hauser, a cardiologist at the Minneapolis Heart Institute. Hauser found that the 22 deaths that resulted from failures of the wires used to connect Riata and Riata ST to the heart were typically caused by short circuits between high-voltage components.
St. Jude, stopped selling the wires, or leads, in December 2010 and recalled them a year later after public reports that they could break through the insulation coating and fail to work properly. The wires remain in about 79,000 patients.
“Abrasion-related issues with defibrillator wires like Riata that are insulated with silicone are known to cause failure and patient harm,” Amy Jo Meyer, a St. Jude spokeswoman, told business Week. “The risk is documented in medical literature and is tied to a failure rate ranging from 3 percent to 10 percent.”
The information was included in a December 2010 letter the company sent to physicians. That risk is why St. Jude stopped selling silicone-only defibrillator leads, according to Meyer. The company instead started using a insulation known as Optim, which uses a polyurethane insulation.