Implementation of lead safety recommendations.

BACKGROUND

The Medtronic Sprint Fidelis (SF) implantable cardioverter defibrillator (ICD; Medtronic Inc., Minneapolis, MN, USA) lead has a higher than expected failure rate. Because of patient safety, Medtronic announced two advisories consisting of (1) adjustments in device settings (October 2007) and (2) installation of a lead integrity algorithm (May 2008). The objective of this study was to evaluate the effect of Medtronic's announcements on patient safety.

METHODS

To comply with the advisories, two clinical evaluations were conducted. The effect of the advisories was assessed by the lead failure rate and the occurrence of inappropriate shocks due to lead failure. Three periods were distinguished in the comparison of event rates: lead implantation to advisory 1 (period A), in-between both advisories (period B), and advisory 2 to follow-up (period C).

RESULTS

Since 2004, 372 patients received a Medtronic ICD and SF lead and were followed from first implant (December 2004) to April 2009. Cumulative incidence rate of lead failure was 3.6%[95% confidence interval (CI) 1.6-5.6] at 21 months and increased to 11.0% (95% CI 6.1-15.9) at 42 months. After implementation of both advisories, the occurrence of inappropriate shocks due to lead failure decreased from 1.5 (95% CI 0.59, 3.00) per 100 lead-years in period A to 0.8 (95% CI 0.02, 4.25) per 100 lead-years in period C.

CONCLUSION

The current study demonstrates that despite an increasing risk for SF lead failure, implementation of the advisories decreased the occurrence of inappropriate shocks due to lead failure. (PACE 2010; 431-436).