The report of a single Durata defibrillator lead failure that shaved 6% from St. Jude Medical's share price was due to external abrasion, not the "inside-out" abrasion that prompted the company to pull its Riata leads. news

St. Jude Medical (NYSE:STJ) said the Durata lead failure that slashed its share price 2 weeks ago was due to external failure, rather than the "inside-out" abrasion found with its recalled Riata leads.

STJ shares closed down 6% after the report of a single incident of wire externalization in 1 of its next-generation Durata defibrillator leads – the same issue the launched the high-profile recall of the Riata leads.

A voluntary physician report submitted to the FDA's adverse events database said that the Durata's lead wires wore through their insulation and became exposed. The leads were explanted from the patient.

The defect was discovered during an examination and later confirmed after explantation, according to the report. St. Jude said it sent a senior lead engineer to the Florida hospital where the incident occurred to examine the Durata lead.

"Through our investigation, we have identified that the patient had an additional defibrillation lead that had been capped (and was no longer being used)," according to a press release. "Based upon physical examination, our analysis indicates the damage to the Durata lead is consistent with external abrasion from contact with a calcified, or hardened, heart valve or possibly from lead-to-lead contact. External abrasion is a known cause of failure across all cardiac leads in the industry, which is different from the inside-out abrasion seen with externalized conductors observed in some Riata leads."

STJ shares, which closed down 6.0% at $36.24 June 12, the day the news broke, gained 2.6% to close at $37.90 Friday and were up another 0.4% today, hitting $38.09 as of about 10:30 a.m.