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 lead safety alert at HRS 2012May 10, 2012 14:13 EDT
The Heart Rhythm Society convened a special session on St Jude Medical's most troubled ICD lead. Attendance was off the charts. The conference room was packed, and nervous-looking folk gathered around crowded hallway monitors. It was a sight indeed.
Most of the major names in the story were there: Dr Estes, Dr Robert G Hauser, two doctors named Epstein, and my friend, Dr Chuck Love, among others.
I tapped out some enotes and have some brief comments.
Dr Larry Epstein gave a very nice presentation on "Risk vs Risk." Immediately, as a minimalist, that spoke to me. He focused on what to do with patients with Riata leads without manifest failures. (As for patients with failed leads, it's easy: they need an intervention.)
Starting with the worst of the worst, he said Riata was no Acufix lead. (These prehistoric leads are infamous for the tendency to erode through the atrium and tear into blood vessels.) In other words, Riata leads do not actively harm our patients. But at the end of his talk, he pointed to (potential) future concerns of externalized cables--namely, thrombosis, erosion, and fibrosis. All bad things, for sure. Along these lines, Dr Carrilo, from Miami, showed a slide of an externalized Riata cable with an attached clot. Scary.
Dr Epstein's talk emphasized the need to balance bad choices. He spoke of the risk of leaving the leads in place vs the risk of operating on them. He presented interesting cases that highlight the sudden and abrupt onset of high-voltage failures seen with Riata but then countered with the not-insignificant risk of extraction or even adding additional leads. Like many others have noted, Riata leads are not easy to extract. Dr Carrilo offered amazing pictures of a Riata extraction. This procedure is no heart cath.
Continuing on, Dr Epstein mused that he was most scared that we don't know the mechanism of Riata failure. Paraphrasing: "It's not Fidelis; the externalized cable issue with Riata amps the concern of abandoning [leaving in] the lead."
The other notable talk came from Dr Love. In his aptly named presentation, "Should we trust Durata?" he addressed the most pressing concern for heart-rhythm doctors. The question: "With all the other leads available, does Durata offer enough advantages to outweigh concerns that it too closely resembles Riata?"
Dr Love did not back away. He showed a number of technical slides to back up his contention that Durata is 85% different from Riata. He liked Durata's internal design, which brings internal cables closer together. He explained that this decreases shear force. Next, he talked about the positives of Optim insulation. St Jude's Optim insulation adds significantly to the improved Riata ST design changes, is what I took from his message. Comparing it with other "reliable" ICD leads, Dr Love said Durata looked competitive. He quoted Durata's excellent performance data and noted follow-up on Durata is now available through five years.
I was surprised. It was an overwhelmingly positive assessment of Durata. This is telling coming from Dr Love. He has an excellent reputation, and I trust him. When Chuck speaks, I listen.
That said, the naysayers on Durata worry that as of now, the numbers of patients past five-year follow-up with Durata are very small. And that is the issue: time. Has enough time passed that we can be comfortable?
In the Q&A following, Dr Epstein worried that we don't know whether Durata design will prevent internal abrasions or simply delay them. Dr Love responded that we are likely to see rare cases of internal failures with Durata—no lead is perfect—but so far its performance looked excellent. Also, he added that Optim insulation appears very biostable and the follow-up of Durata has been more robust than for Riata.
Here's a question that was brought up by an astute colleague after the talk: Why hasn't someone published the results of bench testing on the three leads? Take a Riata lead and put it on a machine that flexes it millions of time. Do it for Riata ST and then Durata. Then tell us how much better Durata performs. Where are those data? Knowing that Durata measured better on bench stress tests might allay at least some fear.
ICD lead durability is now front and center. This is good—for a lot of reasons. Not just that we know about specific devices. There's a bigger picture here.
For me, one of the grandest messages from Riata and Fidelis is how wrong we can be about stuff that sounds so good. Take lead diameter, for example. Years ago, low profile was what we needed. It was surely better than the clunky fat leads we were using. The Riata and Fidelis debacles smack this idea down. I've seen numerous posters here that all show small-diameter leads perform worse than their fatter brethren. There's even a nice clinical paper from an Iowa group that reports lead size did not predict vein occlusions. (They say size does not matter.)
So, yes, this story illustrates the need for staying skeptical, thinking critically, and emphasizing the importance of avoiding disease in the first place.