Review of ICD lead failures by Minneapolis Heart Institute Foundation

Researchers at the Minneapolis Heart Institute Foundation have reviewed the last 10 years’ data on the FDA MAUDE database for reports of internal insulation breaches and other implantable cardioverter defibrillator failures. They found that some Abbott ICD leads were more likely than Boston Scientific’s Endotak Reliance leads or Medtronic’s Sprint Quattro Secure leads to fail due to internal insulation breaches, with 93% of Abbott’s (formerly St. Jude Medical’s) Durata pacemaker lead failures being due to insulation breaches. All 11 failures to treat ventricular tachycardia/ventricular fibrillation were caused by high-voltage shorts between the proximal and distal right ventricular coil cables or sensing conductor. Testing showed low values of high-voltage impedance in three of the leads after a shock or an aborted shock or by an alert.
The Minneapolis Heart Institute researchers wrote: “The most serious IBRs are those that disrupt the silicone, abrade the fluorine-based protective coating, and short-circuit conductors to each other or to the shocking coils. These IBRs may be clinically silent or cause detectable malfunctions. A short involving a conductor to a pace-sense electrode may present as noise/oversensing with inappropriate therapy… A short between the proximal superior vena cava … shock coil and the cable to the distal right ventricular … shock coil prevents delivery of a lifesaving shock; this mechanism was responsible for Riata device-related deaths. Thus, it is highly probable that the actual number of Durata leads that have failed due to IBR is substantially higher than the 137 leads in this report. Moreover, we do not know how many additional (high-voltage) failures might have been identified if all Durata leads had been subjected to (high-voltage) shock testing.”
An Abbott response statement read: “The MAUDE database is not a comprehensive representation of product performance. Real-world performance data is a far more accurate view of a product’s performance. Every year our real-world performance data consistently show our cardiac leads are some of the industry’s most durable and reliable leads. They have a strong history of performance and safety and one of the industry’s lowest rates of lead insulation breach.”