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More doubt cast on St. Jude's Durata heart device wire

  • Article by: BARRY MEIER
  • New York Times
  • November 21, 2012 - 7:41 PM

An insulating material chemically similar to the one used by St. Jude Medical Inc. of Little Canada in a controversial heart device component was recently rejected for use by another producer because a study showed it degraded too quickly.

The decision by Fridley-based Medtronic Inc., the nation's biggest producer of heart devices, raises more questions about the safety of the St. Jude component -- an electrical wire that connects an implanted defibrillator to a patient's heart -- and about how executives of that company have responded to those issues.

St. Jude executives have repeatedly insisted the wire, or "lead," known as the Durata, is safe. Asked about the new study, sponsored by Medtronic, a spokeswoman for St. Jude said in a statement that numerous studies and tests had demonstrated the safety of the insulating material used in the Durata.

"We do not rely on Medtronic to confirm the safety and reliability of material we use in our products," the statement by Amy Jo Meyer said.

Shares of St. Jude fell more than 12 percent Wednesday, to $31.37, after the Food and Drug Administration released a plant inspection report that found significant problems in the company's testing and oversight of the Durata. The stock price represented a three-year low.

The FDA report, which raises the prospect of potential agency action against St. Jude, appears to be the latest misstep by company executives in dealing with questions from investors and doctors about the safety of the Durata and an earlier heart device lead called the Riata, which the company has recalled.

In October, St. Jude executives released the FDA report as part of a filing with the Securities and Exchange Commission but blocked all references in it to the Durata. In taking the unusual action, the company stated that it believed the FDA would make similar redactions when it released the report in response to a Freedom of Information Act request; but the agency did not do so.

Earlier this year, St. Jude's chief executive, Daniel Starks, also criticized a heart device expert, Dr. Robert Hauser, after he raised questions about the safety of the Riata and the Durata. Starks then sought to have a medical journal retract an article written by Hauser. The publication refused.

"It's becoming increasingly difficult to defend Durata," one Wall Street analyst, Lawrence Biegelsen of Wells Fargo Securities, wrote Wednesday in a note to investors in which he downgraded St. Jude stock to hold from buy. He added that the release of the full FDA report is "likely to heighten concerns" among doctors about using the Durata lead.

The Medtronic-sponsored study at issue appeared in the November issue of a scientific journal, Macromolecules, which is published by the American Chemical Society, a professional group.

In it, researchers looked at the durability of two chemically related insulating materials. One material that St. Jude calls Optim is used in the Durata. Medtronic was interested in using the other material, called Pursil 35, in a heart device lead it was developing. Both products belong to a class of materials known as silicone-based polyurethanes.

The products were developed by different companies in an effort to solve a longstanding problem. Over time, insulating materials used in implanted devices are broken down by bodily fluids, exposing them to possible electrical failure and even short-circuits that can prevent a device, like a defibrillator, from working when needed to save a life.

Recent high-profile episodes involving failures of heart devices or their components have involved failures of the insulating materials used in them.

James Runt, a professor at Pennsylvania State University who is a St. Jude consultant, said the Medtronic study struck him as an "outlier" because internal St. Jude studies and external reviews supported the durability of Optim.

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