St Jude’s Chief Medical Officer Dr Mark Carlson is becoming a bit of a household name in cardiology world. He’s been the voice of the company in recent months as it seeks to protect its status in the pantheon of Cardiology Medtech elite. Now he’s been called into action again, this time in order to “clarify” the companies position in regard to a newly published item in the Heart Rhythm Journal, the abstract for which can be found here.
Only recent arrival from another planet could excuse the industry watcher for being unaware of the ongoing brouhaha concerning the so-called “externalisation” of Implantable Cardioverter/Defibrillator (ICD) leads. Most recently, while it’s not the only product family under the spotlight, all the noise has seemingly been generated around St Jude’s Riata and Riata ST leads. Indeed this week we’ve already reported on additional work being undertaken by the company to generate data to better inform decision making for patients and clinicians embroiled in the calamity.
Now, a group from Minneapolis Heart Institute Foundation, including another household name and activist in the deliberations, Dr Robert Hauser, has seen its work published in the Heart Rhythm Journal. The publication cites FDA’s Manufacturer and User Facility Device Experience (MAUDE) database, finding 133 deaths to be associated with Riata, Riata ST and Medtronic’s Quattro Secure Leads. It quotes; “Of these, 22 were caused by Riata or Riata ST lead failure, and 5 were caused by Quattro Secure failure. Riata and Riata ST deaths were typically caused by short-circuits between high voltage components. No death was due to externalized conductors.”
St Jude’s rapid response
Dr Carlson has used St Jude’s riatacommunication.com site on which to issue clarification. His retort can be found here. In it he first refutes the data, before reaffirming St Jude’s commitment to achieving “the highest levels of device performance and public transparency”.
First the data: According to St Jude’s analysis of the 22 deaths identified on MAUDE:
- 2 of the 22 reports are duplicates
- 7 are the result of lead-to-can abrasion, which is the most common cause of abrasion for all leads
- 2 are the result of lead-to-lead abrasions
- 2 are due to internal electrical “shorts”
- These “shorts” resulted from previously referenced and published abrasion of the silicone material
- There were no cases of internal “shorts” on the Riata ST leads
- The internal shorts were limited to Riata 8F leads in this MAUDE analysis, which supports our data that the flat-wire shock coil and silicone backfill design improvements introduced in the Riata ST 7F leads have significantly reduced an already low incidence of “shorts” under the shock coil
According to Dr Carlson, “The remaining nine leads in this analysis were not returned to the company and as a result we cannot assign a specific failure mechanism to these reports; however, it is likely that the failure rates would be similar to those that were returned to the company. Therefore, the majority of these remaining reports are likely related to lead-to-can abrasion. We continue to enroll patients in our 500 patient Riata Lead Evaluation study to further understand the electrical failures associated with these silicone-only insulated leads. We will share information resulting from that study as soon as it is available.”
“Given this understanding (the manuscript noted that the MAUDE database often contains incomplete reports that do not fully reflect the conclusions following testing and review of the reported device malfunction) of the lack of information and reliability of the MAUDE database, it is not surprising that the manuscript published this week is not entirely accurate.”
It would be easy to ignore the ongoing PR tennis going on here, but patients remain at the core of the situation, so we’re continuing to cover the unfolding story. What’s interesting to note in this paper is that so-called “externalisation”, the initial focus of everyone’s attention, appears not to be the causative factor, the authors citing high voltage failures caused by insulation defects resulting in internal short circuits.
It’s also interesting to note that much of Dr Hauser’s ire is directed toward the regulators, with his clearly and oft stated belief that this should and perhaps could have been caught earlier.
For now, St Jude can perhaps sleep just a little easier as it appears from analyst reports that cardiologists (as reported from ACC this week) have been expressing the view that the Durata lead, St Jude’s current offering, does not seemingly offer the same cause for concern as its ancestor.
Source: St Jude Medical, Heart Rhythm Journal