NEJM: Riata reveals FDAs postmarket shortcomings
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On Nov. 28, 2011, St. Jude Medical issued a letter to physicians saying the company planned to conduct a prospective study to evaluate the long-term performance of leads with externalized conductors. The medical device advisory was released after reports of all-cause insulation failure on silicone endocardial defibrillation leads in Riata and Riata ST implantable cardioverter-defibrillators (ICDs). In December, the company announced that the FDA classified the recall as Class I.
In his perspective, Robert G. Hauser, MD, of the Minneapolis Heart Institute Foundation, summarized St. Jude’s findings on the externalized conductors, noting that the lead may remain electrically intact and functional, and may be detected with radiography, fluoroscopy or after an adverse event.
“St. Jude Medical recommends that physicians continue to monitor these leads every three to six months, rather than replace them prophylactically,” Hauser wrote. “This recommendation is based on no meaningful data, because in a system notorious for under-reporting, no such data exist. Meanwhile, physicians and their patients are in a quandary: Will the lead work when lifesaving therapy is needed?”
Adding to clinician concerns, he described the design of St. Jude’s Durata leads—now on the market—as similar to Riata ST leads, although Durata has some differences as well. While there have been no indications of failures with Durata leads, Hauser stated adding there also is no surveillance mechanism to adequately detect low-frequency failures or adverse clinical events. (St. Jude challenged this claim about Durata surveillance on its website.) Physicians are left wondering how best to assess patient risk or manage patients who are found to have electrically intact externalized conductors.
Hauser queried, “Why are we guessing? Why are we placing patients at risk when the tools and technology are available to monitor vital medical devices such as ICDs, heart valves and coronary stents?”
Clinical registries and automated surveillance systems offer a means for prospectively monitoring device databases, according to Hauser. “The goal is a postmarketing surveillance system that not only detects device problems early but also accumulates the data needed to guide patient care,” he wrote. Until such a system exists, though, manufacturers of lifesaving devices should take the lead and conduct postmarketing studies.
He offered the Sentinel Initiative passed by Congress in 2007 as an “active” complement to the current reporting system that will have real-time capability for detecting safety and efficacy problems early on using electronic health data on 100 million people. But the initiative still faces significant challenges, he said.
“Meanwhile, more than 150,000 patients in the U.S. alone rely on lifesaving medical devices,” Hauser concluded. “Professional societies, the medical device industry and the FDA should mobilize available resources now to improve postmarketing surveillance for these patients. Otherwise, we will no doubt be back here again.”