St Jude Medical disputes study’s findings on Riata and Riata ST leads

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The medical device manufacturer St Jude Medical has called for the Heart Rhythm Journal to retract an online study in which the company’s recalled Riata and Riata ST implantable cardioverter defibrillator (ICD) leads were associated with 71 deaths and Medtronic’s Quattro Secure lead was associated with 62 deaths.

According to a press statement from St Jude Medical, the data presented in “Deaths caused by the failure of the Riata and Riata ST implantable cardioverter defibrillator leads” study (by Robert Hauser, Minneapolis Heart Institute Foundation, Minneapolis, USA, and colleagues) has “substantial factual errors”. The company claimed that Hauser et al “substantially undercounted” the number of total deaths associated with the Quattro Secure lead (“associated” referring to the number of deaths reported in patients with the Quattro Secure lead rather than implying a direct causal link between the lead and death). It added, by analysing the same set of data that Hauser et al used, it found 377 deaths were reported with Quattro Secure lead and 74 deaths were reported with the Riata and Riata ST leads rather than the 62 and 71 deaths, respectively, that Hauser et al found. St Jude Medical concluded its press statement by saying: “We are requesting that the manuscript immediately be retracted by the authors and removed from online publication by the official journal of the Heart Rhythm Society.” To support its argument, St Jude Medical has published information, from the FDA’s Manufacturers and User Facility Device Experience (MAUDE) database, on the 377 deaths it says it found with the Quattro Secure lead on its Riata communications website.


Hauser
et al reviewed the MAUDE database to assess the number of deaths that may have been caused by Riata and Riata ST lead failure. To “provide context”, they also evaluated MAUDE reports for deaths in people with the Medtronic Quattro Secure model 6947 ICD lead. They wrote: “Of 71 deaths involving Riata and Riata ST leads, 31% (22/71) were lead-related, while five of 62 (8%) were lead-related (p=0.0022). Four of the 18 Riata (22%) and three of the four Riata ST (75%) deaths were associated with can abrasions; these seven insulation defects resulted in short-circuits and failure to deliver therapy. None of the 62 leads in this study had can abrasions or a death caused by a documented insulation defect.”


In its press statement, St Jude Medical did not comment on the number of lead-related deaths with the Riata and Riata ST leads or the number of lead-related Quattro Secure deaths, and it does not seem to dispute that seven of lead-related deaths with Riata and Riata ST were associated with can abrasions while none of the Quattro Secure lead-related deaths were.


Also, St Jude Medical did not attempt to contradict Hauser et al‘s finding that “abnormal high voltage impedances were the hallmark of catastrophic Riata and Riata ST lead failure, often resulting in failure defibrillate.”


However, St Jude Medical did argue that the premise of comparing the Riata and Riata ST leads with the Quattro Secure lead was “flawed.” It explained that it is “acknowledged in the industry” that silicone-only insulated leads (ie, Riata and Riata ST) are more “susceptible to abrasion than leads with newer insulation materials.” It added: “A more appropriate comparison would have been to compare the Riata and Riata ST to other recalled leads. For example, there are approximately 1,200 MAUDE death reports associated with the recalled Medtronic Sprinit Fidelis lead.” Alternatively, St Jude Medical stated, Hauser et al could have compared with this Quattro Secure lead to St Jude Medical’s Durata lead, which “the company is confident would have resulted in a favourable comparison.”


Heart Rhythm
‘s response


In response to St Jude Medical, both Robert Hauser, lead author of the study, and Douglas Zipes, editor-in-chief of Heart Rhythm, have said they did not plan to retract Hauser et al‘s study. Hauser told Cardiac Rhythm News: “We stand behind the results and the conclusions.”

Zipes discussed the Heart Rhythm’s response to St Jude Medical’s call for a retraction in an editorial. He explained that he rarely wrote editorials because, as editor-in-chief, he needed to be “as impartial as possible” but said the events following the publication of Hauser
et al‘s study “compelled me to speak out”. Zipes said that the peer-review process was a “time-honoured, well-choreographed procedure that has served the intellectual world for several hundred years.” He added that, similar to disputing a court judgement, there was a “well-defined approach” to disputing data published in a study (ie, rather than calling for a retraction), which he said: “can begin with a letter to the editor or submission of one’s own data for peer review to counter the conclusions in the article.”


In a later statement, St Jude Medical said that it was “interested only” in ensuring that patients and physicians “have all of the correct facts”. It added: “Our intent in correcting the manuscript and in calling for a retraction is simply that our research indicates that the data in the published manuscript is in error. We will continue to work through the proper channels with the Heart Rhythm and the Heart Rhythm Society to ensure there is an appropriate presentation of validated, accurate information.”

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