Abstract 4661: Impact of Alerts on Outcome of the Fidelis Implantable Cardioverter-Defibrillator Lead Advisory: A Report from the Canadian Heart Rhythm Society Device Advisories Committee
The Medtronic Sprint Fidelis family of leads is the subject of a widespread advisory. Based on remote monitoring data, lead failure rates are estimated at 2.3% at 30 months, 2.6 times the failure rate of the reference Medtronic 6947 lead. Pediatric and Adult ICD implant centers across Canada were contacted to determine the response to the October 15, 2007 Medtronic Fidelis lead advisory. All centers completed an eleven-part survey to assess the frequency and presentation of lead failure, operator characteristics and center’s response as of April 22nd, 2008. Lead failure was noted in 21 out of 6192 patients (1.95%) at 25.0 months, with inappropriate shocks experienced in 66 of the 121 patients (55%, overall risk 1.07%). No deaths were attributed to lead failure. Sensing was the primary form of failure, seen in 79% of leads, with pacing failure in 14% and high voltage failure in 15%. Assessment of the previous routine ICD interrogation prior to the advisory or lead failure demonstrated evidence of altered lead performance in only 10%. Inappropriate shocks were typically multiple (median 7, range 1–122). The frequency of presentation of lead failure with inappropriate shocks was unchanged in the last 41 failed leads after alert tones were generally implemented (51% vs. 56%). Lead failure was noted in 22 of 23 centers representing 99.7% of leads implanted, with no failure in a single site with 16 leads implanted. In the first 80 failures reported, 47 of the 132 operators in the 23 institutions implanted leads that subsequently failed. Only 16 operators were involved in more than a single lead that subsequently failed, with seven operators participating in 3 or more leads that subsequently failed. This national experience suggests a Fidelis lead failure rate of 1.95% at 25 months, most often presenting with multiple inappropriate shocks without evidence of impending failure from routine lead follow-up. Activation of alert tones did not dramatically reduce the incidence of presentation with inappropriate shocks. Lead failure did not appear to cluster around specific operators, and was seen in virtually all implant centers.