If last month’s recall by Medtronic (Minneapolis) of its Sprint Fidelis leads was a “kick in the shins” — as one expert called it at the time — to the implantable cardioverter defibrillation (ICD) market, then St. Jude (St. Paul, Minnesota) may receive the biggest bruise.

Medtronic pulled its Fidelis family of ICD leads — thin wires connecting the defibrillator to the heart — in October because they may break inside the body (Medical Device Daily, Oct. 16, 2007).

Since the recall, St. Jude’s Riata leads have come under heavy scrutiny as rumors quickly began to surface about the devices being next in line for a recall.

An editorial published Monday in the medical journal Pacing and Clinical Electrophysiology (PACE) doesn’t do the company any favors as it details four cases of the Riata leads poking holes through patients’ hearts rather than remaining attached to the heart wall.

“There is a legitimate concern that the problem may be more than physician misadventure and that there may be an inherent design flaw, at least in some of the models of the Riata lead,” Stephen Vlay, MD, an associate editor of the journal and a cardiologist and heart-rhythm specialist at Stony Brook University (Stony Brook, New York), wrote in the editorial.

According to Vlay, sometimes the lead perforation is not caught until it is well beyond the right ventricular free wall. Furthermore, he noted, the movement continues until it protrudes out several centimeters into adjacent tissue.

“This factor seems to distinguish it from a small perforation in which only the tip of the lead penetrates the right ventricular wall,” Vlay wrote.

Kathleen Janasz, a St. Jude spokeswoman, told Medical Device Daily that St. Jude has three active registries monitoring nearly 6,000 patients implanted with Riata leads and that “the rate of any incidence is very, very low” and that the incidence of perforation is far lower than what has been reported in the medical literature.

St. Jude responded to the editorial by submitting its own article expected to be published in PACE’s December issue, touting Riata’s performance and safety. The company said the rate of perforation with Riata is below or at the low end of what has been reported in clinical literature.

“We take a conservative approach in evaluating the performance of our products,” said Mark Carlson, MD, one of three authors of the company’s rebuttal article.

While perforation is a well-known risk in all transvenous lead implant procedures, Carlson said St. Jude’s Riata lead performance is strong as confirmed by data from both product return analysis as well as the company’s active registries.

“Based on its specific design elements and data analysis to date, we are confident that our Riata Optim family of defibrillation leads, which have been well received by the clinical community, will have the highest reliability yet,” Carlson said.

Still, shares of St. Jude dropped Monday in response to the PACE editorial. The stock fell $1.72, or 4.4%, to $37.30 in afternoon trading on greater than average volume. Shares have ranged between $32.40 and $48.10 over the last 52 weeks.

The perforation rate of the Riata lead was discussed late last month during a Bear Stearns conference call hosted by med-tech analyst Rick Wise (MDD, Oct. 31, 2007). During the call, Eric Fain, president of St. Jude’s cardiac rhythm management division, told listeners not to credit recent rumors that the Riata is in line for recall.

Fain highlighted three main factors contributing to lead perforation: lead design; patient-specific factors including the patient’s medical condition and what medications they are using; and implant technique.

St. Jude cites a 0.086% perforation rate in patients implanted with its Riata leads among returned products and reported incidents involving 121,000 implanted Riata leads in the U.S. Specifically, the company reports an incidence of 0.057% for 86,000 Riata 8 French leads and 0.157% for 35,000 implanted 7 French leads.

In April, Massachusetts General Hospital (Boston) reported a 3.8% rate of perforations — five out of 130 — with certain models of Riata leads.

However, that study was just a single-site experience and should be interpreted from that perspective, according to Jagmeet Singh, MD, director of the cardiac resynchronization therapy program at Massachusetts General Hospital and assistant professor of medicine at Harvard Medical School (Boston).

“We looked at about 130 Riata leads and 111 Sprint Fidelis leads and we found that there was a higher perforation risk to the tune of 3.8% in the Riata lead side as opposed to 0% in the Sprint Fidelis lead,” Singh said last month during the Bear Stearns call.

While it may be too early to know for sure, the safety issues raised over Riata could turn out to be worse for the company than Medtronic’s recent recall was for that firm, according to Alex Arrow, analyst with Lazard Cappital Markets.

“In St. Jude’s case, the lead problem of reportedly puncturing holes in cardiac tissue, instead of shorting out like Medtronic’s, has the potential to be worse because it could cause damage to the patient, rather than just failing to prevent it like the Medtronic problem,” Arrow wrote in a note to investors Monday.

However, Wachovia Capital Markets analyst Larry Biegelsen said the issue is not new and can be resolved.

“So far, the perforation issue with the Riata lead does not appear to be hampering St. Jude’s ability to capture share,” he wrote in a note to clients.

Biegelsen also said that increased awareness of the problem will likely will lead to a higher rate of incident reports.