St. Jude Medical wants the Heart Rhythm Journal to retract a study published last month that linked its Riata line of internal defibrillator leads to more 20 deaths. In a statement issued by St. Jude on Friday, the company asserted the Riata lead study was biased and based on inaccurate facts.
A defibrillator lead is a thin wire attached to the heart wall that delivers an electrical impulse via an implantable defibrillator. Late last year, St. Jude recalled its Riata and Riata ST. defibrillator leads after finding the wires could potentially penetrate their insulation, compromising the device’s integrity. Exposed wires could cause an internal defibrillator to inappropriately shock some patients, and at other times fail to deliver life-saving therapy when needed. At the time, St. Jude said two deaths had been linked to exposed Riata wires.
Last month’s Heart Rhythm study discussed another alleged problem with the Riata defibrillator leads. Cardiologist Robert Hauser wrote in the article that “high-voltage failures” of the Riata leads had caused 22 deaths. The high voltage failures were not the result of protruding wires, Hauser said, but rather cases where the silicone coating of the Riata defibrillator lead wore away. Hauser also asserted that deaths caused by the alleged Riata malfunctions were about nine times greater than those associated with the Quattro Secure, a rival lead made by Medtronic Inc. Hauser’s assessment was based on a search of the U.S. Food and Drug Administration (FDA) Manufacturers and User Facility Device Experience (MAUDE) database. None of the deaths seen in the study were attributed to the protruding wire issue that prompted last year’s Riata recall.
According to a report in The New York Times, St. Jude is not disputing Hauser’s finding that at least 20 Riata lead patients have died in such episodes. Rather, the company insists that Riata is not alone in being associated with this type of problem. The company further claims that Hauser undercounted the number of deaths associated with Medtronic’s Quatro Secure lead. According to the St. Jude statement, its own analysis of the FDA database found 377 reports of deaths involving Quattro Secure wires, while Hauser reported 62. The company’s analysis of Riata lead events in the database found 74 deaths, while Hauser reported 71. St. Jude said it used the same criteria as Hauser had in performing its analysis.
The company also contends that Hauser’s analysis was biased “against manufacturers that more transparently report on device malfunctions” The statement claimed that Medtronic reports the least amount of detail compared with other companies in the industry, and further points out that “the detail and rate of reporting has increased since Medtronic’s Cardiac Rhythm Management business received a warning letter from the Food and Drug Administration in 2009, meaning events prior to this date in the analysis may have been under-detected.”
In an email issued Friday to several medial outlets, Hauser disputed St. Jude’s assertions. “We stand by the conclusions of our study, namely ‘Riata and Riata ST (defibrillator) leads appear prone to high-voltage failures that have resulted in multiple deaths,” he wrote.
The Heart Rhythm Journal has yet to comment.