The failure and subsequent recall of two popular brands of implantable cardioverter defibrillator (ICD) leads may have more to do with size than mechanics, Italian researchers suggested.
Compared with 8 French (F) or larger leads, the smaller Sprint Fidelis lead had a significantly higher per-year failure rate (4.8% versus 0.8%, P<0.001), according to Roberto Rordorf, MD, of the department of cardiology at IRCCS Fondazione Policlinico S. Matteo in Pavia, Italy, and colleagues.
Likewise, the smaller-sized Riata/Riata ST leads also failed significantly more often than their 8F or larger counterparts (2.6% versus 0.8%, P=0.001), the researchers reported in the February issue of HeartRhythm.
"The crucial point is whether a small-diameter lead can be robust enough to last over time," they wrote. "When [the results of both lead types are] considered together, small-diameter leads showed almost a five-fold higher risk of failure than did standard-diameter leads."
Lead size was an independent predictor of failure when researchers adjusted their data for potential confounders. Another analysis that included the different lead groups but not the lead size pointed to the Sprint Fidelis and Riata/Riata ST as having six and four times the risk of failure, respectively, as the other models.
Patient age less than 60 years also was an independent predictor of failure, which is not surprising given a higher activity level among younger patients.
Researchers suggested caution when considering implanting a small-diameter lead in a young and active person.