It’s more bad news for St. Jude Medical’s (NYSE:STJ) cardiac rhythm management division today as a new study suggests that the company’s next-generation defibrillator wires are susceptible to the issues that spurred the high-profile recall of the Riata leads.
Noted cardiologist and patient safety champion Dr. Robert Hauser’s latest published report found that St. Jude’s newer Durata and Riata ST Optim leads fail to prevent insulation abrasion, which occurs when the leads’ wires poke through their insulation and can lead to device failure.
Hauser found 1 death associated with a high-voltage short in a Riata ST Optim lead. The short was caused by erosion in the insulation due to can abrasion which occurs when the insulated wire rubs against the pulse generator.
The study looked for cases between December 2007 and January 2012 of device failure related to lead abrasion, turning up 15 reports for Riata ST Optim and 37 for Durata leads. All occurred within 4 years of device implant.
Hauser noted that the study is only as good as the data available in the FDA’s MAUDE adverse event reporting database, which is notoriously incomplete.
"Post-market surveillance in the USA relies on a passive reporting system, and thus adverse events are under-reported, particularly by physicians and hospitals," the report states. "Therefore, the number of lead failures in this study likely underestimates the actual number that has occurred."
St. Jude has worked hard to distance its other leads, especially the Durata, from the high-profile Class I recall of the Riata leads in December 2011.
The company has said the Optim coating used with Durata and the next-generation Riata ST Optim is 50 times more abrasion-resistant than silicone coating used in older leads, but Hauser’s study concluded that Optim "does not prevent insulation abrasions" and the failures "may result in lead failure and serious adverse clinical events."
"This is a new and unexpected finding," the report states. "Additional studies are needed to determine the incidence of these failures and their clinical implications."
Earlier this week the FDA ordered St. Jude to run a 3-year surveillance program of its recalled Riata defibrillator leads, plus 3 other leads that are still on the market.
In December 2010 St. Jude started pulling its Riata leads off the shelves over the same concerns, and the FDA slapped the cardiology device maker with a Class I recall on the Riata leads in December 2011 after the company said they failed more frequently than previously reported.
Earlier this year Hauser published a study scouring the MAUDE database for data on the Riata leads, ultimately attributing 22 deaths to short circuits in the devices.
St. Jude contested those findings and demanded that the Heart Rhythm Journal retract the report, which the editors refused to do, spurring accusations from St. Jude CEO Daniel Starks that cross-town rival Medtronic was behind a "whisper campaign" against St. Jude in attempts to prejudice the market.
All the hullabaloo has seen some doctors and investors backing away from St. Jude, which has lost some 13% since late March. STJ shares were relatively flat today, trading up by 0.6% at $38.39 as of about 12:45 p.m.
St. Jude Medical did not respond to requests for comment.