A new study conducted by a prominent cardiologist is raising concerns about St. Jude Medical’s line of Durata defibrillator lead wires. According to Dr. Robert Hauser, a new type of coating that is used on the Durata lead may not prevent the same types of insulation abrasion problems that prompted a recall of St. Jude’s Riata and Riata ST leads. Among other things, Hauser’s study revealed one patient death tied to the failure of a Riata ST Optim wire, which is made with the same new coating.
A lead is the wire that connects an internal cardiac defibrillator to a patient’s heart. As we’ve reported previously, St. Jude stopped selling the Riata and Riata St. defibrillator leads in late 2010, and warned doctors not to use them because they were poking through their insulation. In December 2011, the U.S. Food & Drug Administration (FDA) deemed St. Jude’s action a Class I medical device recall, its most serious type of recall. The Durata and Riata ST Optim leads replaced the recalled Riata-series. According to The Wall Street Journal, both wires are structurally similar, and St. Judge actually renamed the Riata ST Optim with the Durata label in 2008. Both are coated with new material called Optim, which St. Jude hoped would prevent abrasion issues seen with the recalled Riata line.
According to The Wall Street Journal, Hauser’s study, which was published online yesterday in the medical journal Europace, looked at Durata and Riata ST Optim lead failures reported by St. Jude to the FDA. The study found 52 instances of lead failures – 37 for the Durata and 15 for the Riata ST Optim. Hauser concluded that many of the abrasion problems were caused when the leads rubbed against other object. Four abrasions associated with the Riata ST Optim lead resulted in high-voltage failures and one death. Hauser also attributed three cases of Durata lead failure and one involving the Riata ST Optim to internal insulation problems that were similar to what occurred with the recalled Riata leads.
Hauser called his findings “unexpected.”
“There is no need to use this lead until we have more confidence in its performance,” Hauser told The New York Times in an interview.
“I think it is a red flag,” he added. “I think we need more data. But fundamentally, I’m afraid that this material is not going to perform as advertised.”
Limitations in the way Hauser conducted the study prevented him from calculating the actual incidence of lead failure. Pointing out that adverse event reports to the FDA are often missing or incomplete, Hauser wrote that the “Number of lead failures in this study likely underestimates the actual number that has occurred.” He is advising that physicians monitor their Durata defibrillator patients for signs of abrasion. Dr. Hauser said he and colleagues would complete an additional study by early next year to assess failure rates.
Last week, the FDA advised that the 128,000 patients who have defibrillators that inlcude the recalled Riata leads be monitored via x-rays and other imaging tests to check for abnormalities in the wire’s insulation. Such a defect can cause a defibrillator to emit unnecessary shocks to a patient’s heart, and even worse, fail to emit a life-saving electrical impulse to the heart when it’s needed.
The FDA also ordered St. Jude to conduct studies into the scope of Riata lead failures, as well as its Durata-series ICD leads and its QuickSite LV and QuickFlex LV CRT leads. St. Jude Medical voluntarily recalled and stopped selling its QuickSite LV CRT leads and QuickFlex LV CRT leads in April 2012 because of problems with insulation abrasion. Among other things, the agency asked St. Jude to routinely X-ray patients in one continuing Durata study to scan for signs that wires have broken through their insulation, The Wall Street Journal said.