Single-center experience with implantable cardioverter-defibrillators in adults with complex congenital heart disease.

Adults with congenital heart disease are at risk of lethal ventricular arrhythmias and are candidates for implantable cardiac defibrillator (ICD) therapy, yet implant risks, long-term outcomes, and rates of appropriate and inappropriate ICD therapies are not well characterized. We reviewed clinical, implantation, and follow-up data on all transvenous ICDs in adults with congenital heart disease at the Mayo Clinic from 1991 through 2008. Seventy-three adults with congenital heart disease received 85 ICDs. Implantation diagnoses included tetralogy of Fallot (44%) and congenitally corrected transposition of the great arteries (17%). Implantation indication was occurrence of sustained ventricular arrhythmias (secondary prevention) in 36% and prophylactic (primary prevention) in the remainder. There were no major implant-related complications. During follow-up (2.2 ± 2.8 years, range 0 to 15) 11 patients died and 4 patients received heart or heart/lung transplants. An appropriate shock for a ventricular arrhythmia was observed in 19% of patients and an inappropriate shock was observed in 15% of patients. Likelihood of an appropriate shock was associated with increased subpulmonic ventricular pressure. In conclusion, implantation of transvenous ICDs in adults with congenital heart disease is associated with a low risk of implant complications. In this high-risk adult population the rate of inappropriate ICD shocks is low, whereas the likelihood of appropriate therapy for potentially lethal ventricular arrhythmias is high. These data suggest overall benefit of ICD therapy in adults with congenital heart disease.