Abstract 3516: Survival rates as a Guide to ICD Replacement Strategies for Device Recalls: Adding Statistical Insight to Clinical Intuition
Background: With a paucity of data available on which to base decisions, our goal is to model the potential risks and benefits of ICD generator replacement in response to device recalls. The estimated risks are varied through a wide range to determine potential outcomes.
Methods and Results: Using estimates of risk derived from data on 2,915 advisory devices from 17 implanting centers, a decision analysis and Markov model were used to estimate survival according to device replacement decision. Survival rates at five years with and without device replacement were estimated at 60.38% and 60.66%, respectively. This difference was not significantly different on comparative analysis, using variability determined by Monte Carlo simulation. Variation in risk of device failure had a differential effect on survival, with a survival benefit with replacement at 7 years if annual risk of device failure is at least 1.8% (Figure 1a⇓). Little differential effect on survival was seen with variation of arrhythmia risk, non-arrhythmic mortality, and post-procedure infection rate. Combined variation of arrhythmia risk and device failure into a two-way sensitivity analysis is also shown. Most combinations of realistic estimates of risk place the intersection in the area below the line, favoring a non-replacement strategy (Figure 1b⇓).
Conclusions: Survival rates with a generator replacement or non-replacement strategy in response to device recalls are similar and decrease nearly in parallel over time. The main factor with differential effect on survival is risk of device failure, although the level of this risk required to confer a survival advantage to a replacement strategy is quite large.