What is the prevalence of lead failure in the malfunction of implantable cardioverter-defibrillators (ICDs)?

Updated: Feb 13, 2017
  • Author: Daniel M Beyerbach, MD, PhD; Chief Editor: Jeffrey N Rottman, MD  more...
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Answer

In July 2007, a higher than expected rate of Sprint Fidelis model 6949 ICD lead fractures were reported. Six patients presented with lead failure 4-23 months after implant. A subsequent database search for similar reports revealed that 33% of affected patients had inappropriate ICD shocks. Analysis of affected leads revealed 33% with high lead impedance and a 35% rate of pace-sense and high-voltage conductor fracture.

The lead manufacturer, Medtronic, Inc, issued an advisory in October 2007 with suggested ICD programming changes aimed at early detection of lead failure and reduction of inappropriate ICD shocks. Medtronic also discontinued sales of the affected leads, which include Sprint Fidelis models 6930, 6931, 6948, and 6949. [54]

A subsequent report found a 3.3% rate (17 of 514) of Sprint Fidelis lead failure 11-35 months after implant. Of the failures in this report, 88% were caused by pace-sense conductor fractures and 12% by high-voltage conductor defects. Of patients with pace-sense conductor fractures, 80% received inappropriate shocks. Notably, impedance monitoring did not prevent inappropriate shocks in two thirds of patients with lead failure. [55]

The Canadian Heart Rhythm Society issued a report on outcomes of the Medtronic Sprint Fidelis family of leads. [56] Lead failure was seen in 1.29% (80 of 6181) of patients at 21 months of observation. Inappropriate shocks were experienced in 56% of patients with lead failure. No deaths were attributed to lead failure. ICD interrogation prior to lead failure revealed evidence of altered lead function in only 10% of failing leads, consistent with the findings of Kallinen et al. [55]

The advisory issued by Medtronic suggested that, in general, the risks of lead replacement surgery outweigh the benefits. [54] Nonetheless, many centers are replacing leads for patients who are pacemaker dependent or who have received prior appropriate ICD shock therapy for treatment of appropriately detected, malignant ventricular arrhythmias. [56]

The Medtronic Sprint Fidelis leads (models 6949, 6948, 6931 and 6930) are subject to an increasing and problematic rate of lead failure. [57]  Specific device programming can enhance lead diagnosis, but many lead failures and the consequences of those failures remain unpredicted. [58]

Diagnostic information tracked and recorded in most devices may be used to distinguish between lead fracture and lead connection problems. [59] Current tools and technologies can be used to address Fidelis lead fractures, including a high success rate for lead extraction in specific centers; however, the optimal treatment strategy is evolving. [60]

A study by Morrison et al that sought to compare all-cause mortality in patients with Fidelis and Quattro leads with those with a nonadvisory lead found that of 2671 study patients, adjusted survival was similar with the Fidelis and Quattro leads. [61]

Other leads may also be problematic. For example, the Riata family of ICD leads were recalled on November 28, 2011, due to premature erosion of the insulation around the electrical conductor wires (ie, insulation failure). [62] The manufacturer (St Jude Medical; now, Abbott) estimated approximately 79,000 Riata leads remained implanted in US patients since 2011. [62]


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