FDA requires St. Jude to conduct post-market studies on Riata, other leads

The FDA recommended Aug. 16 that patients who have implantable cardioverter-defibrillators (ICDs) with Riata and Riata ST leads, manufactured by St. Jude Medical, should have x-rays or other imaging alternatives to check for abnormalities in the insulation surrounding the lead. The agency also is requiring St. Jude to conduct three-year post-market surveillance studies on its Riata and Riata ST leads, as well as its QuickFlex LV CRT leads; QuickSite LV CRT leads; and Riata ST Optim and Durata ICD leads.

The manufacturer of the leads, St. Jude, recalled them in late 2011 after reports of premature erosion of the insulation around the electrical conductor wires, also called insulation failure. St. Jude had stopped selling the leads in late 2010. According to the St. Paul, Minn.-based company, as of 2011, about 79,000 Riata leads remained implanted in patients in the U.S.

Riata and Riata ST leads are used to connect an ICD or cardiac resynchronization therapy-defibrillator (CRT-D) to the heart in order to monitor its rhythms. ICDs and CRT-Ds can detect life-threatening abnormal heart rhythms and deliver an electrical shock to the heart to restore normal heart rhythms.

ICD and CRT-D leads typically have layers of insulation surrounding them that protect electrical conductor wires inside the lead. According to the FDA, insulation failure may cause some of the electrical conductors inside Riata leads to move within or move entirely outside the outer lead insulation. The lead may malfunction and lead to inappropriate or no shock therapy and potentially life-threatening abnormal heart rhythms, the agency noted.

The FDA said its recommendation is supported by several studies, such as one late-breaking clinical trial presented at the 2012 Heart Rhythm Society in Boston, that have demonstrated that routine imaging of the leads may detect previously unrecognized abnormalities with the insulation. X-rays or other imaging techniques will help healthcare providers develop individualized patient treatment plans. The FDA also is cautioning against routine removal of leads without careful evaluation of benefits and risks to the individual patient.

“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, MD, 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 healthcare professionals and patients get the data they need to better guide clinical management decisions.” 

The FDA also is requiring St. Jude to conduct three-year post-market surveillance studies (or section 522 studies), to collect clinical data related to the potential for premature insulation failure in Riata and Riata ST leads.

The 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; and
• Adverse events associated with treatment for failing or malfunctioning leads.

While the current recommendations apply only to the Riata and Riata ST ICD and CRT-D leads, the FDA also is requiring St. Jude to conduct post-market surveillance studies on its: QuickFlex LV CRT leads; QuickSite LV CRT leads; and Riata ST Optim and Durata ICD leads.

St. Jude voluntarily recalled and stopped selling its QuickSite LV CRT leads and QuickFlex LV CRT leads in April 2012. These devices were recalled due to insulation abrasion.