A report involving a failed Durata defibrillator lead has been published in an online journal, renewing concerns that St. Jude Medical’s newest device that connects a defibrillator to the heart with wires may suffer some of the same problems as the Little Canada company’s failed and recalled Riata leads.

The report, published Monday in the journal Pacing and Clinical Electrophysiology, involves the case of a 55-year-old man who complained of his defibrillator vibrating. A new defibrillator was implanted, and testing showed the device failed to deliver a high-voltage jolt. Although the cause of the failure is unknown, the report’s author theorizes that it may be due to an abrasion problem similar to the Riata leads.

“Lead insulation defects have been well documented in the Riata family of leads,” said the report’s authors, Dr. Matthew A. Goldstein, Dr. Marwan Badri, Dr. Dusan Kocovic and Dr. Peter R. Kowey. “This case again demonstrates a similar mechanism of lead failure in one Durata lead. The prevalence of this complication is not known, but continued evaluation and surveillance will be important.”

On Tuesday, officials from St. Jude pointed out that the report is based on a single failed lead, that the actual cause is unknown and that the overwhelming data in thousands of cases show Durata to be safe. Dr. Mark Carlson, chief medial officer for the company’s Implantable Electronic Systems Division, said several years of data from multiple registries show Durata to be extremely safe and durable — at rates showing better than 98 percent after five years.

“So, our data, I would put up there with anybody’s,” Carlson said. “Our data makes the point. Not me.”

St. Jude has been touting the safety and reliability of Durata for years, but doctors and industry watchers have reacted quickly to any signs of possible Durata trouble. That is because St. Jude pulled Durata’s predecessor, Riata, off the market in late 2010, following safety concerns arising when inner wires were found to have worked their way through the lead’s insulation. The U.S. Food and Drug Administration a year later classified Riata concerns as a recall.

Since then, a study by Minneapolis cardiologist Dr. Robert Hauser connected at least 20 patient deaths to Riata leads.

Nothing has definitively indicated that Durata has had similar problems to the Riata lead. But, in January, the FDA sent a warning letter to St. Jude regarding manufacturing processes at the California facility where Durata is manufactured. FDA inspectors cited concerns over such things as the number of tests performed on Durata leads and the facility’s record keeping.

According to St. Jude, the warning letter will not affect sales of existing St. Jude products. It also will not delay approval requests for other new, non-cardiac rhythm products from St. Jude, the company said. The letter did not raise any safety concerns about the Durata lead, other St. Jude leads or any other St. Jude products, St. Jude said.

In November, after it was discovered that the FDA had raised concerns over Durata, St. Jude’s share price fell nearly 13 percent. Tuesday’s news appears to have had little effect on St. Jude’s stock price. Shares closed at $42.52 — down about 2 percent from the previous day.

Mixed reaction

Analysts’ reaction to what this latest news means for St. Jude has been, and continues to be, mixed.

In a note to investors sent May 31, Glenn Novarro of RBC Capital Markets gave a heads-up about the expected report and said it would be difficult for St. Jude Medical’s share price to keep going up “given the risk of Durata failures and prospects for further share loss.”

On that same day, however, Wedbush analyst Tao Levy gave St. Jude stock an “outperform” rating, saying in a note: “The controversy … has negatively impacted the company’s share price and financial results. For now, we believe this overhang will remain, but is beginning to lose some steam, thus enabling investors to refocus on St. Jude’s healthy pipeline.”

In an interview Tuesday with the Star Tribune, analyst Rajeev Jashnani of UBS said the report “throws a bit more fuel onto the fire. A bit. Not a lot.”

He pointed out that there are hundreds of thousands of Durata leads out there and that about 11,000 are being studied in long-term, well-controlled registries. In that context, he said, “One lead doesn’t really have that much of an impact.”

But, Jashnani added: “That being said, that doesn’t mean there is not going to be any impact in the marketplace.”

St. Jude has lost market share to its defibrillator competitors, he said, in large part because of concern over the now-recalled Riata leads and continuing concerns that Durata may share a similar defect.

St. Jude officials have repeatedly said that they will continue to rely on data from an ongoing review of Durata to overcome continuing jitters on the part of some. Jashnani said that if the data continue to be favorable to St. Jude overall, “next year, you should begin to see a rebound.”