August 21, 2012 — Dr. Robert Hauser, a researcher and cardiologist from Abbot Northwestern Hospital in Minneapolis, Minnesota, is the author of a new study that investigates dozens of cases of abrasion linked to St. Jude Medical’s defibrillator leads.
Dr. Hauser is recommending that cardiologists should not use St. Jude defibrillator leads with the new Optim coating (which includes the Durata and Riata ST leads) until more research is conducted regarding the long-term performance of the devices.
Dr. Hauser’s new study found 15 reports of abrasion with the Riata ST Optim defibrillator leads, and 37 reports with the Durata leads. The leads abraded within four years of the patient receiving the implant. He cautioned that patients due not need to be “unduly concerned,” but they should certainly continue regular check-ups with their doctor. He said, “I think it’s a red flag. I think we need more data. But fundamentally, I’m afraid that this material is not going to perform as advertised.”
This is not the first time Dr. Hauser has published research critical of the St. Jude defibrillator leads. He also published a study that identified three instances where the Optim coating abraded. He called the problem “inside-out” abrasion, which was the same problem in the Riata defibrillator leads. St. Jude asked the journal to retract the study, but the journal refused. However, St. Jude successfully convinced the journal to change Dr. Hauser’s description of the defect.
St. Jude has aggressively defended the safety of the Optim-coated defibrillator leads, amid growing concerns that the Optim defibrillator leads may have a similar defect as an older type of St. Jude defibrillator leads. The Riata defibrillator leads were prone to “inside-out” erosion — in which the internal conductor wires pushed against the insulation coating until they externalized. Recent studies have found that as many as 24% of large-diameter Riata leads may become prematurely externalized.
The externalized wires can malfunction, deliver an unnecessary shock, or fail during an emergency, which could be life-threatening. It is very difficult to determine whether the lead is functional until an adverse event occurs. However, surgery to remove the lead also has a significant risk of injury and death. St. Jude stopped selling the Riata in 2010, and initiated a recall in November 2011.
St. Jude developed the Optim coating and used it on a new line of defibrillator leads — including the Durata and Riata ST Optim. The company’s studies suggest that the new coating prevents abrasion in 99.9% of cases. According to a company spokeswoman, “the overall performance and high reliability of the Durata lead is comparable to other defibrillator leads.”
Even so, researchers and the U.S. Food and Drug Administration (FDA) are calling on St. Jude to conduct more safety studies. Last week, the FDA published a Safety Communication recommending routine chest X-rays for patients with the Riata leads. Routine X-rays can help a physician monitor how quickly the conductors are being externalized. The FDA also asked St. Jude to conduct additional safety studies regarding several defibrillator leads, including the Durata and Riata ST Optim.
The additional studies may help answer lingering questions about the safety of the St. Jude defibrillator leads. Approximately 129,000 people have been implanted with the Riata defibrillator lead, and another 278,000 with the Optim leads.
The lead is a component in a defibrillator. The device consists of a battery-powered device which monitors heart rhythm and delivers a high-voltage shock in the event of a severe irregular heart beat. The lead is a long, thin wire that connects the monitor directly to the heart tissue. It is responsible for transmitting data from the heart to the monitor. It also carries a high-voltage shock to the heart in an emergency.