The Minneapolis Heart Institute Foundation, an international leader in cardiovascular research, has announced the online publication of a study in EP Europace that raises serious concerns about St. Jude Medical defibrillator leads. The study found that a new copolymer of silicone and polyurethane (Optim™) might not prevent insulation abrasions that can result in electronic malfunction. The paper is authored by Foundation researchers Robert Hauser, Raed Abdelhadi, Deepa McGriff and Linda Retel, and it is another in a series of Foundation publications that have reported significant problems with defibrillator leads, including recalled Riata and Riata ST leads from St. Jude Medical (SJM).
Defibrillators are implanted in patients to prevent sudden cardiac death.
Defibrillator leads deliver energy to the heart in order to stop abnormal, rapid heartbeats that can cause blackouts and death. These leads must be able to function properly during years of service in the body.
The paper “Failure of a Novel Silicone-Polyurethane Co-polymer (Optim) to Prevent ICD Lead Insulation Abrasions” appears on the journal’s web site*.
“Our paper presents data that suggest Riata ST Optim and Durata ICD leads may not be adequately protected from insulation abrasions caused by friction with the pulse generator can or other leads in the heart,” stated Dr. Hauser. “We need studies to determine the incidence of these failures and the implications for patients. At this time we do not believe that patients should be unduly concerned or their leads replaced. We do believe that patients with these leads should be evaluated regularly, as recommended by their physicians.”
This study follows on the heels of a recent FDA order that St. Jude Medical launch new studies focusing on the performance of its Riata and Duranta defibrillator leads.
“We know new leads need to be implanted for years before useful reliability data can be collected,” stated Dr. Hauser. “We are still in the process of gathering information about Optim, so these are not definitive data, and at this point in time we do not see a direct risk to patients.”
The purpose of this study was to determine if Optim, a unique co-polymer of silicone and polyurethane, protects Riata ST Optim and Durata implantable cardioverter-defibrillator leads from abrasions that cause lead failure. The FDA’s Manufacturers and User Device Experience (MAUDE) database search returned 15 reports for Riata ST Optim and 37 reports for Durata leads, which were submitted by SJM based on its analyses of returned leads for clinical events that occurred between December 2007 and January 2012. Eight of 15 Riata ST Optim leads had can abrasions and 3 abrasions were caused by friction with another device, most likely another lead. Twelve Durata leads had can abrasions, and six leads had abrasions caused by friction with another device. The paper concludes that Riata ST Optim and Durata ICD leads have failed due to insulation abrasions and that Optim did not prevent these abrasions, which developed up to four years after implant. The paper recommends that studies are needed to determine the incidence of these failures and their clinical implications.
Minneapolis Heart Institute Foundation