Abstract 17327: Defining the Optimal Timing for Extraction of a Defective Defibrillator Lead: A Simulation Study
Introduction: Several RV defibrillation leads have been withdrawn from the market due to unacceptable failure rates. Often, these leads are extracted to address concerns such as compromised vascular space. However, the optimal timing of extraction is not known. We hypothesized that the optimal timing for lead extraction could be established by simulation of relevant extraction scenarios with appropriately defined procedural risks.
Methods: We performed a Monte Carlo simulation of 100,000 patients with a single defective RV defibrillator lead. Each patient was evaluated yearly from the time of coming to clinical attention, and each underwent appropriately timed procedures (e.g. generator replacement) that were associated with some risk of death. The risk of dying from a lead extraction was presumed to double every 5 years. For each patient, three different clinical scenarios were evaluated: 1) extraction of the defective lead immediately, 2) extraction at the next generator replacement, 3) extraction only when the lead failed. These scenarios were compared against generator replacement alone (i.e. without a defective lead) and against a control scenario in which no procedures were performed. Each patient was followed over time until death from procedural complications or from ”natural causes”. The simulation was performed separately with the risk of dying from lead extraction ranging from 0 to 4%.
Results: The rate of survival was similar with each of the scenarios and was primarily dependent on the baseline risk of lead extraction. For all non-trivial scenarios, early extraction (immediately or with next generator replacement) was associated with decreased survival. For each value of baseline extraction risk, an optimal time for lead extraction was apparent. At this optimal extraction time, survival associated with early extraction surpassed that of extraction at the time of lead failure. This optimal extraction time was delayed with increased baseline risk of extraction.
Conclusion: Early extraction of a defective lead is associated with decreased survival. The optimal timing for lead extraction depends on the baseline risk of extraction with the optimal time being increasingly delayed as the extraction risk increases.
- © 2010 by American Heart Association, Inc.