Dr John Mandrola practices cardiac electrophysiology in Louisville, KY. He finished training at Indiana University in 1996. His practice encompasses catheter ablation, including an eight-year experience with AF ablation, device implantation, and consultative EP. Outside of the EP lab, Dr Mandrola's two hobbies include competitive cycling and writing. He has maintained a medical, fitness, and cycling blog, Dr John M, for the past two years.
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Riata and Fidelis: Shining a light on ICD riskFeb 22, 2012 08:45 EST
There is an important debate going on in electrophysiology.
The issue of the moment involves the imperfect durability of human-made implantable cardiac devices. Yes, ICDs have again taken center stage.
Just off the heels of the recent Sprint Fidelis debacle comes the St Jude Riata defibrillator lead recall. Although fewer Riata leads (78 000 Riata vs 268 000 Fidelis) have been implanted, medical decision making concerning Riata may pose greater challenges than those of Fidelis. That's saying a lot, as dealing with Fidelis leads has been stressful.
Here's my quick summary of the Riata situation:
Riata (and Riata ST) defibrillator leads have a serious design problem. In a not-insignificant (and debatable) percentage of cases, these leads can exhibit a unique mechanism of failure involving internal wires wearing through their insulation. These abrasions can lead to the exposure of bare metal in the heart—called externalization. In addition to dramatic and frightening visuals, externalized wires cause two other significant issues: higher electrical failure rates, which might mean a patient receives painful inappropriate shocks or the opposite—the lead might not work to pace or defibrillate when needed; breach of insulation allows "body material" to infiltrate the lead's central core, which makes these leads very difficult to extract. Reports of disastrous Riata lead extractions have emerged, and all have agreed that Riata extraction is more difficult than Fidelis.
This is terrible news.
Dr Robert Hauser has weighed in with this New England Journal of Medicine Perspective article. He bemoans St Jude's delayed response; questions the design differences between the recalled Riata and currently approved Durata leads; and emphasizes the need for more robust postapproval monitoring of ICD hardware.
First, Dr Carlson contends that St Jude did indeed initiate an ongoing forward-looking trial of patients with Riata leads. Second, he states St Jude's position on Durata: that its sufficiently different design makes Durata less apt to show externalized cables. He emphasizes Durata's many patient-years of follow-up and that no similar externalizations have been reported with the newer lead design. Third, Dr Carlson believes St Jude has well addressed postmarket surveillance:
"We have regularly communicated that St Jude Medical began prospective, actively monitored registries assessing the performance of our Optim/Durata leads more than five years ago. Collectively, those studies now include 10 836 leads implanted at 292 sites by 571 physicians and represent the largest postmarket surveillance program in the history of implantable stimulation devices.”
My friend and fellow electrophysiologist, Dr Jay Schloss, adds much-needed clarity to this complex situation with this easy-to-read guest post published on the blog Cardiobrief. As a non–foundation-supported EP trying to take the best care of his patients and make a difference in his spare time, Dr Schloss's take is worth a look.
As an implanting electrophysiologist who was spanked hard by the Fidelis debacle, I am following this situation closely.
Questions that buzz around in my head include:
- Is Durata sufficiently different from Riata? Three recent case reports to the MAUDE database describe Durata abrasions. Each has been "corrected" by further data (provided by St Jude) that explain away the abrasions. Should these three cases make us think, where there's smoke . . . ?
- Has the duration of Durata follow-up been long enough to warrant comfort with the lead? Many of the Riata failures manifested late (three to four years) after implant. Mean follow-up for Durata has not yet reached this time frame.
- How should Riata patients be followed? Some have suggested using serial fluoroscopy to look for externalizations. But why look if no agreed-upon therapy exists? Miraculously, not all externalized leads exhibit electrical failure. What's more, extracting these leads exposes the patient to great risk. Unlike the Fidelis story, the only deaths from Riata leads have occurred during extraction procedures.
- What are the best means to protect patients from device hardware failures? Common sense tells us that prospectively detecting all potential flaws before approval would be both impossible and futile. And worse, acting on the ill-conceived idea that premarket testing could eliminate all future defects would surely stifle innovation and limit patients' access to life-saving devices. Who would disagree with enhancing postapproval surveillance? But when would a "recall" be called? How many case reports would trigger an alert? Sorting out noise from real problems will require nuance—a prickly concept in today's world of black-and-white quality measures.
- Does Durata offer our patients any advantage? Why not use more tried-and-true leads from other companies? I wonder a lot about that one. But if this were your philosophy, when would you ever try new stuff? Balancing how best to incorporate new technology represents one of the greatest challenges for cardiologists.
And then the big picture:
- How much do current recalls like Fidelis and Riata add to the already-complex decision of implanting an ICD in the first place?
Clearly there are ICD proponents, antagonists, and agnostics. But regardless of one's opinion of ICDs, recent lead recalls shine a bright light on the real risk of living with permanent cardiac devices. Doctors and patients alike tend to focus on the benefits of an intervention. Optimism is indeed heart-healthy. Making good medical decisions, however, means considering the risk of treatment with that of no treatment. Failures of ICD hardware, sometimes seen years after implant, along with the need for more surgery (extraction, lead revision, and generator changes) only serve to increase the inherent risks of living with an ICD.
And in parting, the least-zoomed view . . .
This kind of sobering news only strengthens my resolve to emphasize the best way to treat heart disease—preventing it!