Researchers behind a Canadian study of the recalled Riata defibrillator leads made by St. Jude Medical (NYSE:STJ) today recommended that physicians make a case-by-case determination on revising or explanting the leads.
The 2,707-patient study covered 59.7% of all patients in Canada implanted with recalled versions of the Riata leads. The study reported a 5.8% failure rate and a 7.8% rate of cable externalization, with a 6.3%rate of major complications. Cable externalization occurs when the silicone coating on the leads wears away, leaving parts of the lead exposed.
Primary investigator Dr. Ratika Parkash of Nova Scotia’s Dalhousie University said today at the annual Heart Rhythm Society conference in Boston that isolated lead revision or extraction is not warranted.
"Personally, if the patient has had a prior shock I would be prompted to revise. In terms of extraction, it’s difficult to say. These leads have been implanted for more than 10 years in some cases, and the risk of extraction in these patients is very different than in other lead advisories where the leads were not implanted for very long. I think we have to take into account the patient’s comorbidity versus the possibility of cable externalization interacting with another lead we put in," Parkash said.
Three deaths were recorded during the study: 2 were due to sepsis occurring in patients who did not undergo lead extraction and the other was due to a failed defibrillation due to lead malfunction, she said.
Previous issues with Riata leads often focused on lead shorts leading to device malfunction, something Parkash said they had only seen once in the Canadian study.
"Certainly, it’s not as great of a problem than we potentially previously thought it was," she said. "We have seen data that has reported on that, but we have not observed the same thing in Canada, so far, but more is yet to come on that."
The study will continue to follow patients with Riata leads for 2 more years, Parkash added.