Long-Term Follow-up of Standard and Small Diameter Implantable Cardioverter Leads

Background: Small-diameter implantable cardioverter-defibrillator (ICD) leads have been introduced into clinical practice to facilitate the implantation procedure. Despite their expected benefits, the reliability of these leads has proven to be questionable. The main purpose of our study is to investigate the impact of ICD lead diameter (≤8 F versus >8 F) on long-term lead durability. Methods: Overall, 206 consecutive patients implanted with a right ventricular ICD lead in the Electrophysiology and Cardiac Pacing Unit of our department from January 2008 to December 2013 were included in this analysis. ICD leads were defined, according to their diameter, as small (≤8 F) and standard (>8 F).The small-diameter leads (n=106) included Linox (Biotronik; n=58) and Durata (St. Jude Medical/Abbot; n=48). The standard-diameter ICD leads (n=100) consisted of Sprint Quattro (Medtronic; n=64) and Endotak (Boston Scientific; n=36). Results: After a median follow-up of 7.3 years, lead failure rate was significantly increased for small-diameter leads compared with standard-diameter leads (6.6% vs 1%; P=0.035). No difference in lead survival probability has been observed between Linox and Durata small-diameter leads (93% vs 92.7%; P=0.71). The majority of lead failures presented as noise (87.5%), without detectable abnormalities on fluoroscopic evaluation. Conclusion: Our single-centre study showed that both Linox and Durata small-diameter ICD are associated to be more susceptible to a greater risk of lead failure as compared to standard-diameter ICD leads. In this perspective, a comprehensive vigilance strategy including home monitoring is warranted for early detection of lead failure.