Evolution of implantable cardioverter-defibrillator shock therapy in children in the era of optimized ICD programming and remote monitoring.

Aims: Implantable cardioverter defibrillator (ICD) therapy is effective in preventing sudden cardiac death in children. Unnecessary shocks should be avoided. ICD programming strategies and remote monitoring have been proven to be effective in preventing ICD shock therapy in adults; the present study evaluates the effectiveness in children.

Methods and results: Retrospective multi-centre study, including children with transvenous or epicardial ICD implantation. During follow-up data on ICD shocks, programming variables and remote monitoring were collected. One hundred sixteen children were included, median age 13.4 years (min-max 0.3-18) and median follow-up 5.2 years (IQR 3.7-6.6), 53 with an ICD implanted before 2010 and 63 after 2010. The total appropriate and inappropriate annual shock rate decreased from 10.5 to 8% [difference in mean cumulative function (MCF) P = 0.008], 7.8 to 5.8% (MCF P = 0.036), and 4.3 to 2.6% (MCF P = 0.28), respectively, without increase in cardiac-related death. Remote monitoring was associated with a decrease of total shocks (MCF P = 0.013) and appropriate shocks (MCF P = 0.052). The ventricular fibrillation (VF) zone was programmed higher (≥210 bpm) at the time of appropriate vs. inappropriate shocks (86 vs. 79%; P = 0.0016), with no significant change in VF zone programming after 2010 compared to before 2010 (90 vs. 76%; P = 0.142) and in patients with vs. without shocks (79 vs. 89%; P = 0.243).

Conclusion: The incidence of ICD shocks has significantly decreased in children with implantation after 2010, which appears to be multifactorial. A changed programming behaviour and remote monitoring are associated with this decrease and support its use in strategies to prevent unnecessary shocks in children.