U.K. regulators issued new updates to physicians handling patients implanted with St. Jude Medical‘s (NYSE:STJ) recalled Riata defibrillator wires, urging continued monitoring for failures that may prompt replacement.
The country’s Medicines & Healthcare products Regulatory Agency asked clinics to check on patients every 3 months to look for varying signs of failure and conduct lead integrity testing.
The agency warned against replacing intact devices, which involves an invasive and potentially dangerous surgery, except in "exceptional clinical circumstances."
The new alert, issued last week, follows previous notifications in which the agency categorized warning risks associated with the Riata and Riata ST silicone-coated defibrillator wires based on model numbers. New findings suggest that the risk of cable externalization, which occurs when the wires poke out of their insulated coating, are similar among different models, the agency noted.
Health and regulatory agencies have been keeping a close eye on St. Jude and its Riata leads since late last year when the medical device company yanked the Riata leads off the market, a move the FDA slapped with Class I recall status.
Reports later emerged that the devices may be prone to internal short circuits that were more rare than the incidence of exposed wires but potentially more dangerous.
A few months into the Riata recall, St. Jude also pulled its QuickSite and QuickFlex left-ventricular leads after finding 39 confirmed cases of exposed wires.
St. Jude has been busy ever since calming fears about its next-generation Durata leads. The company hosted several events at the Heart Rhythm Society meeting in Boston in May, distancing Durata from its troubled forebears.
In a HRS conference presentation entitled "Should we trust Durata?" Dr. Chuck Love told listeners that "Durata is 85% different from Riata," noting that the Durata device has a more robust coating in place of the Riata’s silicone insulation.
Months later the company’s shares took a 6% hit after investors got wind of a single incident of wire externalization in a Durata defibrillator lead.
The U.K.’s latest alert calls for physicians to keep close tabs on Riata patients, conduct regular testing to determine the integrity of the leads and consult with patients about whether or not to replace defective wires or take a proactive approach against intact leads, perhaps during a defibrillator box replacement procedure.
The MHRA urged physicians to make sure that, should a patient decide to keep Riata or Riata ST leads at the time of box replacement, that any future devices contain remote/advanced monitoring capabilities.
Last month the FDA ordered St. Jude to launch the 3-year post-market review of its recalled Riata defibrillator leads, plus 3 other leads that are still on the market. The order prompted a 4% dip in the company’s shares.
The watchdog agency ordered St. Jude to collect data on the number of patients with insulation failure and whether the failures were detectable with X-ray imaging, as well how soon after implantation the leads failed, the time between implantation and failure and adverse events associated with treatment for failing leads.
St. Jude had already launched its own post-market study and in July published early results from Phase I of the investigation.
"The clinical significance of externalized cables will not, however, be evident until phase II of the study is completed; this is unlikely to be before the end of 2013," according to the MHRA alert. "For this reason this Medical Device Alert is focusing on detection of early signs of functional lead failure, as these lead models continue to fail at a higher rate."