St. Jude Durata Leads May Be Immune From Riata Problems: Study

A new study indicates that the St. Jude Durata defibrillator lead should be relatively “immune” from suffering the same problems that led to a recall for St. Jude Riata leads, which were found to be prone to insulation failures that allowed the small wires to become exposed inside the body.  

Dr. Ernest W. Lau, a cardiologist who was one of the first to spot the St. Jude Riata problems that ultimately led to a recall and dozens of product liability lawsuits, says that there is little chance that the St. Jude Durata leads will experience the same problems. His findings were published earlier this month online in the medical journal Pacing and Clinical Electrophysiology.

A St. Jude Riata lead recall was issued in December 2011, after the manufacturer acknowledged a risk of problems with the insulation surrounding the wires used to connect implantable cardiac defibrillators to the heart. The St. Jude Riata insulation was found to have a higher-than-expected failure rate, which allowed the wires to become externalized. This could result in unnecessary shocks or cause the defibrillator to fail to deliver a life-saving jolt when needed.

The St. Jude Durata lead was introduced as a second generation defibrillator lead, and the manufacturer has maintained that the insulation is stronger. However, concerns have surfaced in the medical community that the St. Jude Durata leads may be prone to similar insulation problems.

According to Lau, the coating on the Durata leads is applied very differently than those on the Riata. It is a stronger insulation with a coating that compresses it onto a lead in a way that makes externalization unlikely, Lau found.

Concerns Over St. Jude Durata Leads

Last year, concerns about the risk of problems with the St. Jude Durata lead were raised after a case report in the medical journal Heart Rhythm outlined a patient who had one of the newer ICD leads. The St. Jude Durata lead was implanted in January 2008 and began showing signs of problems in July 2010, which were described as “inside-out insulation failure.” As a result of the St. Jude Durata ICD insulation failure, the patient required surgery to extract and replace the lead.

Concerns were further raised by a report submitted last year to the FDA’s MAUDE adverse event database, which described similar problems with a St. Jude Durata ICD lead. According to that single adverse event report, doctors discovered St. Jude Durata problems in April 2012, when non-invasive programmed stimulation of the ICD revealed undersensing. After the lead was extracted, it was confirmed that the lead wire had become externalized, or penetrated the insulating material.

St. Jude claimed that the MAUDE report involved problems different from those that led to the Riata lead, indicating that they believed the lead was damaged because it scraped against a hard, calcified heart valve inside the patient’s body or against another lead.

St. Jude Riata Debrillator Lead Failures

The manufacturer currently faces a growing number of St. Jude Riata lawsuits, which allege that the manufacturer knew or should have known about the risk of problems and continued to allow the product to be implanted.

Approximately 227,000 St. Jude Riata wires were sold worldwide before it was removed from the market, and estimates suggest that approximately 79,000 of the leads remain active in patients in the United States, as the process of attempting to remove the lead is very risky and doctors usually recommend keeping the recalled lead in place unless there is evidence that it has failed.

In August 2012, the FDA issued a safety communication in response to concerns among individuals who still have one of the recalled St. Jude Riata or Riata ST leads, recommending that individuals undergo x-ray or other imaging exams to monitor the condition of the leads.

The agency also indicated at that time that it was ordering St. Jude to conduct additional studies on the potential risk of insulation failures and problems with the debrillator leads, including the newer versions sold under the Riata ST Optim and Durata names.