Dr. Robert Hauser’s report in the Heart Rhythm Journal linking the deaths to the Riata leads, based on an analysis of the FDA’s medical device adverse event report database (Maude), was inaccurate and biased on several levels, the company claimed.
"St. Jude Medical was not consulted prior to the publication, nor asked to validate any of the data," the company said in a press release. "Since the manuscript was published, the company has spent more than 300 hours attempting to reach the same conclusions as Dr. Hauser, but can find no way of analyzing the MAUDE database that reproduces the same numbers reported in the manuscript."
St. Jude accused the study of "inaccurate facts and biased analysis," claiming that Hauser’s research miscounted the total number of deaths in the FDA’s MAUDE adverse event database "which therefore resulted in substantial errors."
"The company has identified duplicate reports, inconsistent categorizations and failures to include all available reports," according to the release.
Hauser’s manuscript reviewed data on the Riata line of defibrillator leads from the MAUDE database, culling 133 lead-related deaths. Of those, the study attributed 22 to failures in the Riata or Riata ST leads, compared to 5 for Medtronic’s (NYSE:MDT) Quattro Secure leads.
"Riata and Riata ST ICD leads appear to be prone to high-voltage failures that have resulted in multiple deaths," according to the study in the March 26 Heart Rhythm Journal. "These failures often occurred abruptly, without warning, and they appeared to be caused by insulation defects that caused short-circuiting between high-voltage components."
None of the Riata deaths were tied to "externalized conductors," a condition which occurs when the leads’ wires poke through their insulation and the prime reason for a Class I recall that began in December 2011.
St. Jude was quick to find fault with several of Hauser’s factual conclusions, especially the 22 deaths figure, in its initial response to the study.
"As the manuscript noted, the MAUDE database often contains incomplete reports that do not fully reflect the conclusions following testing and review of the reported device malfunction," St. Jude chief medical officer Dr. Mark Carlson wrote. "For this reason, it is often not possible to draw conclusions on the root cause of a failure mode based on a review of this source."
According to St. Jude’s initial analysis, 2 of the 22 deaths in the study were duplicates, 9 were the result of abrasions and another 9 can’t be assigned to specific failures because the failed leads were not returned to the company, leaving 2 that were definitively the result of electrical shorts.
The company later found 377 deaths related to Medtronic’s Quattro lead, compared with Hauser’s 62, and 74 deaths related to the Riata leads, compared to Hauser’s 71.
"Dr. Hauser’s manuscript is mistaken or misleading in a number of other respects as well," according to St. Jude. "It is important to note that Dr. Hauser has selectively chosen to include only 1 Quattro Secure lead model in his analysis, versus all of the Riata and Riata ST models for St. Jude Medical."
Ultimately, the St. Paul, Minn.-based med-tech titan questioned the entire premise of Hauser’s study comparing polyurethane-insulated Quattro leads with silicon-insulated Riata leads.
"It is acknowledged in the industry that silicone-insulated leads are more susceptible to abrasion than leads with newer insulation materials. A more appropriate comparison would have been to compare the Riata and Riata ST leads to other recalled leads," the company said.
Hauser, of the Minneapolis Heart Institute, was 1 of the physicians who helped uncover problems with Guidant Corp.’s pacemakers after a patient he was treating died,, a story he shared on a recent appearance on CBS news. He’s a vocal critic of the FDA’s policies regarding post-market surveillance and considers the high-profile Riata recall a defect that should have been caught sooner.
"Patients in the U.S. continue to be exposed to under-performing and potentially hazardous medical devices after they have been approved by the FDA, despite multiple recalls and some tragic adverse events," Hauser wrote in an article published in the New England Journal of Medicine earlier this month. "We are confronted once more with a critical clinical situation in which we have no scientifically valid information to guide us."