Implantable cardiac defibrillator (ICD) in the setting of Tetralogy of Fallot (TOF): Data from the DAI-T4F National Registry

Background TOF is the most frequent congenital heart disease managed by cardiologists, at particularly high risk of sudden cardiac death (SCD). However, few studies have reported long-term outcomes of TOF with ICD. Purpose We aimed to report characteristics and outcomes from a large population of TOF with ICD. Methods Between 2005 and 2016, all TOF implanted with an ICD in 22 centers were enrolled to determine characteristics at implantation and outcomes. Results Overall, 101 patients (43 ± 13 years, 69% males) were enrolled. A majority was implanted for secondary prevention (71%), whereas the remaining (29%) was for primary prevention. Among the latter, risk factors for SCD were: severe pulmonary regurgitation (25%), prior palliative shunt (43%), syncope (21%), inducible ventricular tachycardia (VT) (39%), non-sustained VT (29%), QRS duration ≥ 180 ms (19%), left ventricular significant dysfunction (29%, with ejection fraction ≤ 45%), and sustained supra-VT (46%). After a mean follow-up of 6.0 ± 4 years, 44 (43%) experienced ≥ one appropriate therapy (25% in the primary vs. 51% in the secondary prevention group), giving annual-incidences of 4.95% and 14.1%, respectively ( P  = 0.009). The median time between ICD implantation and the first appropriate therapy was 0.70 years (0.26–3.75), without significant differences between primary and secondary prevention ( P  = 0.27). Overall, ≥ 1 complication occurred in 40 patients (39%), including inappropriate shock ( n  = 26), major pocket hematoma ( n  = 1), lead dysfunction ( n  = 15), infection ( n  = 6), algodystrophia ( n  = 2), device failure needing reintervention ( n  = 3). Eventually, 6 patients received heart transplant (6%), and 9 (9%) died during the course of follow-up. Conclusions TOF and ICDs experience high rates of appropriate therapies, especially in secondary prevention. ICD-related complications remain very high. Selection of candidates for primary prevention remains challenging and can be potentially improved.