Canadian Registry of Implantable Electronic Device Outcomes

An advisory related to the Riata and Riata ST leads was announced on November 28, 2011 by St. Jude Medical after these leads had been removed from the market the year before. This advisory described the possibility of conductors within the implantable cardioverter–defibrillator (ICD) lead becoming externalized because of an inside-out abrasion mechanism. This is a novel failure mechanism, not reported with other ICD leads. The implications of this mechanism of lead failure have caused considerable concern, due to the possibility of abnormal electrical conductance between the faulty lead, if left in place, and interaction with another ICD lead, potentially causing further abrasion. In a cross-sectional survey of Riata leads subject to advisory in Canada, we found the rate of electrical failure to be 4.6% overall, with a median follow-up of 5 years. The trajectory of electrical failure, and its relationship to cable externalization, remains an unanswered clinical question. Concern about appropriate management of Riata leads under advisory and whether lead abandonment or lead extraction is more desirable, for leads under revision, also remains an important clinical question. We conducted a comprehensive, national registry in an attempt to address these issues.