Federal health regulators are warning that patients with implantable cardiac defibrillators (ICD) and cardiac resynchronization therapy (CRT) devices that are connected to their hearts via St. Jude Medical’s Riata or Riata ST lead wires need to undergo x-rays or other imaging tests. According to the U.S. Food & Drug Administration (FDA), the screening is needed to check for abnormalities in the insulation surrounding the St. Jude Riata lead wire.
As we’ve reported previously, St. Jude stopped selling the Riata line of defibrillator leads in late 2010, and warned doctors not to use them because they were poking through their 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. In December 2011, the FDA deemed St. Jude’s action a Class I medical device recall, its most serious type of recall. About 128,000 patients worldwide still use the Riata lead, according to the company.
The FDA has also asked 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. According to a report from The Wall Street Journal, the potentially life-threatening failures associated with the Riata leads haven’t been reported in relation to the Durata devices. But the FDA is concerned because the wires are similar. 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.
In a notice posted on the FDA’s website, the agency said St. Jude’s studies must address:
- The number of patients with evidence of insulation failure and whether the failure was detectable with X-ray imaging.
- How soon after implantation the lead insulation fails.
- The time between lead implantation and lead malfunction.
- Adverse events associated with treatment for failing or malfunctioning leads.
Despite recommending x-rays for patients with the affected St. Jude Riata defibrillator leads, the FDA is not recommending that patients automatically have the wires removed if their imaging tests indicate problems. Such procedures are risky, and the FDA says each patient should be evaluated individually to determine if the benefits of lead removal outweigh its risks.
“The majority of Riata and Riata ST leads, including those that show signs of electrical conductor migration or externalization, continue to function normally and provide life-saving support for patients,” said Jeffrey Shuren, M.D., director of FDA’s Center for Devices and Radiological Health. “However, the agency does not have enough information to determine the frequency and timing of insulation failure in these leads; therefore, the postmarket surveillance studies will ensure that health care professionals and patients get the data they need to better guide clinical management decisions.”
A recent study conducted by St. Jude found the problems occurred in about 19% of more than 700 patients with Riata leads, according to The Wall Street Journal.