Prevalence, predictors and complications with defibrillation threshold testing in pediatric patients: Results from...

There are little data about the prevalence and safety of DFT testing in pediatric populations. We analyzed the predictors and outcomes of defibrillation threshold (DFT) testing at the time of implantable cardioverter-defibrillator (ICD) implant and factors associated with inadequate defibrillation safety margin (DSM) in pediatric patients.

We performed a retrospective analysis of initial transvenous ICD implantations in the National Cardiovascular Data Registry (NCDR) ICD Registry of patients ≤21 years. DSM was defined as the lowest successful energy tested <10 J than the maximum output of the ICD. Subjects were followed to hospital discharge.

Of all ICD recipients (n = 3943), DFT testing was performed in 64.0% (n = 2522) though decreased over time. In those with DFT data available (n = 2500), an inadequate DSM occurred in 13.6% (n = 339). After multivariable adjustment, DFT testing was not associated with in-hospital complications or death (OR 0.789, 95% CI 0.579-1.076), but was associated with lower odds of prolonged hospital stay (>3 days) (OR 0.543, 95% CI 0.436-0.677). An inadequate DSM was associated with an increased risk of complications or death (OR 1.893, 95% CI 1.203-2.979) but not with a prolonged hospital stay (OR 1.307, 95% CI 0.878-1.947).

In the largest dataset of DFT testing in pediatric ICD recipients, we found that DFT testing use decreased over time and was not associated with an increase in in-hospital complications in pediatric patients. An inadequate DSM, however, was associated with a higher rate of in-hospital complications or death.