Recalled Cardiac Leads Need Close Monitoring to Prevent Problems

A new study published online in Heart Rhythm, the journal of the Heart Rhythm Society (http://www.heartrhythmjournal.com/), recommends large-scale monitoring of patients with Riata and Riata ST cardiac leads. The recalled leads are manufactured by St. Jude Medical based in St. Paul, Minnesota.

The endocardial defibrillation leads are commonly used in implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization devices. The Riata and Riata ST ICD leads contain silicone insulation over the lead cables, which may be at risk for damage due to abrasion. This can cause the conductor cables to be exposed, or externalized, and the ICD to malfunction.

Last year, a medical device advisory warning of the increased failure rates of Riata and Riata ST high voltage leads was issued by St. Jude Medical. St. Jude released its own data confirming failed lead insulation stating that it was aware of 671 cases worldwide in which the insulation of the lead was worn through. Further review led the Federal Drug Administration (FDA) (www.fda.gov) to issue a Class I recall in December of 2011. The FDA recall centered on the failures of the lead insulation.

CardiacThe Heart Rhythm study was conducted by Edmund Keung, MD, of the University of California San Francisco. Keung and his colleagues, using a retrospective analysis, compared the five-year survival rate of patients implanted with Riata and Riata ST leads with leads from other manufacturers. Over 24,000 patients who were being remotely monitored from 2002 to 2012 were reviewed. The report finds, “There is decreased survival probability of Riata/ST versus other contemporary high voltage leads.”

Another earlier study conducted by Raed Abdelhadi, MD, of the Minneapolis Heart Institute, also concluded that the St. Jude Riata leads were more likely than other leads to fail. This multicenter study classified failure as occurring when the lead performance standards were not met or when the lead did not perform correctly. In addition, a normally functioning lead was considered a failure if it had been externalized.

Signs of Trouble

Physicians and their patients should be aware of the signs of lead failure which include:

  • Electrical noise
  • Elevated thresholds requiring lead replacement
  • Abnormal pacing impedance
  • Abnormal high-voltage impedance
  • A decline in R-wave requiring lead replacement
  • Failed defibrillation threshold testing resulting in lead replacement

The authors of the Heart Rhythm study recommend long-term follow-up and monitoring in order to prevent the device from failing or providing inappropriate shocks to patients.

Lead failure can bring about additional surgeries for revision, lead extraction or the implantation of new leads. Patients with ICDs should follow up with their doctors to determine if they are at risk.

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