Novel coating fails to prevent lead abrasions


A preliminary study, by Robert Hauser (Minneapolis Heart Institute Foundation, Minneapolis, USA) and others, published in EP Europace, indicates that a silicone-polyurethane copolymer (Optim, St Jude Medical) designed to prevent implantable cardioverter defibrillator (ICD) lead insulation abrasions fails to prevent such abrasions.

Hauser et al reported that as lead abrasions (eg, can abrasions-contact between a lead and the pulse generator) can result in lead failure, cardiac electronic implantable device (CIED) manufacturers have developed a number of abrasion-resistant coatings that protect the silicone insulation. They wrote: “One such material is a proprietary silicone-polyurethane copolymer trademarked as Optim, which St Jude Medical licensed in 2006 and applied as an overlay to its Riata St Optim and Durata ICD leads.” They added in a previous study, they found that seven deaths (of overall deaths due to Riata and Riata ST leads) were caused by can abrasions and, as a result of this finding, reviewed the FDA’s Manufacturers and User Facility Device Experience (MAUDE) database to identify reports of insulation abrasions with the Riata ST Optim or Durata leads. The authors noted: “The purpose was to determine if Optim protects these devices from abrasions that could cause lead failure, including can and lead-to-lead abrasions that may result in short circuiting during high-voltage shock delivery.”

Of 15 reports for “Riata ST Optim abrasions analysis” from the MAUDE database, eight (53%) can abrasions and three abrasions (20%) were caused by friction with another device–most probably, another lead; and of the 37 reports for the “Durata abrasion analysis”, 12 (32%) were caused by can abrasions and six (16%) abrasions caused by friction with another device.

Hauser et al commented that their results suggested that Optim “does not prevent critical insulation failures in Riata ST Optim and Durata leads that are caused by friction with the can or another device.” They added that it was “equally concerning” that the failures occurred four or less than four years after the lead had been implanted. The authors wrote: “This is a new and unexpected finding since St Jude Medical has recently expressed confidence in the ability of Optim to prevent the insulation abrasions that have observed in Riata, Riata ST, and other silicone leads.”

However, Hauser et al stated that the results of their study “do not support the prophylactic replacement of Riata ST Optim or Durata leads. Likewise our data must be considered preliminary or hypothesis generating.” They added that patients who have a Riata ST Optim lead or a Durata lead should be regularly followed up and the leads should be evaluated visually and with high-resolution fluoroscopy at the time of pulse generator change.

In their conclusion, Hauser et al wrote that studies are needed to determine the incidence and clinical implications of abrasions with Optim-coated leads.

Hauser told Cardiac Rhythm News: “We are concerned that Optim may not be durable over time and that long-term studies will be needed before its reliability is clear.”