The medical device company's own study shows a problem with wires working free of outer insulation, especially in larger leads.
After the company announced that a review of its Riata defibrillator leads shows about the same rate of "inside-out" abrasion as other studies, the question facing St. Jude Medical is: Now what?
St. Jude on Wednesday will report second-quarter earnings, and analysts are watching whether the company's problems with Riata -- and whether its new Durata leads continue to hold up well -- will affect St. Jude. "It will be interesting on Wednesday to see if all this noise on Riata and Durata had an impact on sales in the quarter," said Thom Gunderson, a senior analyst with Piper Jaffray.
St. Jude launched its study of Riata leads, which connect a defibrillator to the heart, several months ago after it was shown the lead's inner wires can come through the outer silicone insulation. Early results of St. Jude's study released Monday showed externalized wires at a rate "consistent with other published studies."
Officials would not say what they had expected their study to show or how results of their study compare to the expectations. The Little Canada-based medical device company pulled Riata leads off the market in December 2010, and the U.S. Food and Drug Administration issued a recall of the device in December 2011, after St. Jude sent a letter to physicians telling them the problem of "inside-out" abrasion was worse than thought. St. Jude launched its study soon after.
The Riata Lead Evaluation Study involved 724 patients at 20 sites in the United States and Canada and found 24 percent of the larger Riata 8F leads showed inner wires coming through the outer insulation. Externalized wires were found in 9.3 percent of the smaller diameter ST 7F leads. Another 51 patients at three sites in Japan were enrolled in the study; those results are being reviewed and will be reported later.
The inner wires of the Riata leads also are insulated and St. Jude has said that, in many cases, the leads continue to function normally even if the wires have worked free.
"We are now focused on collecting longer-term data in the second phase of this study," said Dr. Mark Carlson, St. Jude's chief medical officer and vice president of clinical affairs for the Cardiac Rhythm Management Division. "Our goal is to provide physicians timely and relevant clinical data to best support their patient-management decisions."
St. Jude's Medical Advisory Board has recommended no changes to existing patient management recommendations, which suggest doctors continue to monitor patients with Riata for signs of lead failure.
The next phase of St. Jude's Riata study will continue for at least two years, looking for signs of electrical malfunction in leads with "externalized" conductors.
In March, Minneapolis cardiologist Dr. Robert Hauser published a study in Heart Rhythm Journal that connected high voltage failures of the Riata lead to at least 20 deaths. Hauser said those failures were not related to the protruding wires.
St. Jude asked for a retraction, saying Hauser's study -- comparing Riata deaths to those connected with a Medtronic lead -- was flawed. Heart Rhythm Journal refused to retract the article.
A single unsubstantiated report in June that St. Jude's Durata lead, which has an extra layer of outer insulation, might have a problem similar to Riata caused the company's stock to drop about 6 percent in one day. St. Jude later proved the problem was not the same. At market close Monday afternoon, St. Jude's stock price was down less than 1 percent.
James Walsh 612-673-7428