Implantable Cardioverter-Defibrillator Therapy and Implantable Cardioverter-Defibrillator Complications in Idiopathic Ventricular Fibrillation Patients

BACKGROUND: Implantable cardioverter-defibrillator (ICD) therapy is used to prevent sudden cardiac death (SCD) in patients who experienced idiopathic ventricular fibrillation (IVF). Only certain patients with IVF develop recurrence of ventricular arrhythmia (VA). However, all patients with IVF are exposed to the risk of complications. Transvenous ICD (TV-ICD) carries a significant complication risk. The subcutaneous ICD (S-ICD) may offer advantages in this young population. OBJECTIVES: The aim of this study was to analyze ICD therapy in patients with IVF and to assess complications of ICD therapy, comparing S-ICD and TV-ICD. METHODS: Patients were included from the Dutch IVF Registry. First, the occurrence of appropriate ICD therapy (shock/anti-tachycardia pacing) was analyzed. A subgroup was then defined of patients with ICD implantation between 2010 and 2024 to assess inappropriate ICD therapy and other device-related complications. Next, a comparison was made between S-ICD and TV-ICD. RESULTS: Of 415 included patients with IVF, 132 (32%) experienced recurrent VA requiring ICD therapy; subanalysis included 261 patients. There were no significant differences in inappropriate ICD therapy (S-ICD 13% vs TV-ICD 13%; P = 0.976) between S-ICD and TV-ICD. TV-ICD patients had more lead complications compared with S-ICD patients (S-ICD 2% vs TV-ICD 13%; P < 0.001). For the other device-related complications, there were no significant differences between S-ICD and TV-ICD. These results were consistent when corrected for different follow-up duration and age at index event. CONCLUSIONS: VA recurrence occurs frequently, affecting nearly one-third of patients with IVF. Comparing S-ICD and TV-ICD, there were no significant differences in inappropriate ICD therapy. Lead complications were more prevalent with TV-ICD compared with S-ICD.