In an issue that continues to haunt the company after months, St. Jude Medical has been fighting to maintain its reputation as a provider of reliable and safe medical devices in the face of the failure of its Riata implantable cardioverter defibrillator (ICD) lead wires. The lead wires were found to be the cause of 20 deaths by externalizing from their insulation. The wires were taken off the market in December 2010.

Recently, a question arose about the company’s Durata leads, which were accused of fraying. An unidentified doctor reported a case to the U.S. Food and Drug Administration (FDA) in May, but reportedly did not inform St. Jude he or she was doing so. Because the report was anonymous yet quite detailed, Goldman Sacks Analyst David Roman questioned its authenticity at the time.

St. Jude has, nonetheless, managed to assuage fears for now that this will be a repeat of the Riata saga. The company has announced that the frayed wires were caused by external abrasion rather than an internal wiring problem. According to the company, the Durata leads were damaged by the patient’s calcified heart valve. This condition commonly occurs in patients with heart disease. The Durata leads are insulated by polyurethane—which St. Jude has pointed out several times in the last several months—while the Riata leads were insulated by a silicone that tended to break down.

St. Jude announced in a statement that the FDA allowed the company to travel to the Florida hospital where the Durata lead was explanted in order to examine the cause. According to the company, one of its “senior engineers” travelled to the hospital to investigate:

“Through our investigation, we have identified that the patient had an additional defibrillation lead that had been capped (and was no longer being used). In the fluoroscopic images, the two leads cross in the region mentioned in the filed MAUDE [Manufacturer and User Facility Device Experience Database] report. Based upon physical examination, our analysis indicates the damage to the Durata lead is consistent with external abrasion from contact with a calcified, or hardened, heart valve or possibly from lead-to-lead contact. External abrasion is a known cause of failure across all cardiac leads in the industry, which is different from the inside-out abrasion seen with externalized conductors observed in some Riata leads.”

MAUDE is an FDA database where adverse events related to medical devices are aggregated. It was used in the March study on Riata leads published by Heart Rhythm Journal (HRJ). Conducted by Robert G. Hauser, M.D., St. Jude has asked for its retraction, but HRJ has refused.

News from our sister sites