Prospective long-term follow-up of silicone-polyurethane–insulated implantable cardioverter-defibrillator leads

BACKGROUND: St Jude Medical (now Abbott) Optim-insulated implantable cardioverter-defibrillator (ICD) leads were expected to overcome problems with insulation abrasion and externalized conductors in earlier models. Long-term follow-up is essential to the evaluation of lead performance. OBJECTIVE: To determine, in a prospective cohort of Optim-insulated ICD leads, the rates of all-cause mechanical failure and its subtypes (conductor fracture, insulation abrasion, externalized conductors, and other mechanical failures) and electrical dysfunction adjudicated as nonmechanical failure. METHODS: Abbott established 3 prospective registries, enrolling 11,155 leads among 10,872 patients beginning in 2006. There was standardized baseline documentation, 6-monthly follow-up, adverse events reporting, and documentation of lead revision or inactivation, study withdrawal, and death or transplant. The Population Health Institute (McMaster University) reviewed database functions, adjudicated all potential mechanical lead failures, and conducted independent data analyses. RESULTS: During a median follow-up of 4.6 years, there were 171 mechanical failures (1.53%, 95.4% freedom from failure by 12 years). There were no significant differences in survival among Durata DF4 and DF1 and Riata ST Optim leads. The year-to-year rate of failure of leads increased over time. There were 69 electrical dysfunctions (0.62%, 98.8% freedom from failure by 12 years) adjudicated as nonmechanical failure. CONCLUSION: During follow-up as long as 12 years (median 4.6 years), Optim-insulated leads had low rates of mechanical failure and electrical dysfunction. Independent analyses provide reliable data on the long-term outcomes essential to analyzing ICD lead performance.