Should we implant cardioverter defibrillators in asymptomatic patients with Brugada syndrome?

Abstract Funding Acknowledgements Type of funding sources: None. Background Implantable cardiverter defibrillators (ICD) represent the only effective treatment in prevention of sudden cardiac death (SCD) in patients with Brugada syndrome (BrS). However, according to current ESC Guidelines, ICD implantation is recommended only in secondary prevention, while it should be considered in patients with a spontaneous diagnostic type I ECG pattern and history of syncope. Purpose We aimed to determine the frequency of ventricular tachyarrhythmias during the long-term follow-up among patients with BrS and ICDs implanted in primary or secondary prevention. Methods This retrospective, observational study was conducted in a tertiary center among adult patients with BrS that underwent single or dual chamber ICD implantation from January 2008 to December 2017. The study group was devided into subgroups depending on weather the patients at the time of ICD implantation had documented sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) regardless of the ECG type of BrS (group I), had BrS type I and history of syncope (group II) or had BrS type I and were asymptomatic but assessed as in high risk of SCD due to non-sustained VT episodes, younger age or history of SCD in close family members (group III). We used patients medical records for collecting the data about VT and VF episodes during the follow-up period. Results In the course of ten-year period, ICDs were implanted in 21 adult patients with BrS (66.7% were male). Mean age at the ICD implantation time was 40.3 ± 14.9 years. We analyzed 8 patients from group I, 7 patients from group II, and 6 patients from group III. Mean follow-up period was 82.5 ± 33.3 months. During the obsereved period, VT/VF episodes were appropriately detected in 7 patients from group I (87.5%), in 3 patients from group II (42.86%) and in one patient from group III (16.67%). Kruskal-Wallis test showed that there was a statistically significant difference in the occurrence of ventricular tachyarrhythmias among at least one pair of observed groups (p = 0.031). Using Dunn-Bonferroni post hoc analysis we found statistically significant difference between the patients with malignant arrhythmias and asymptomatic patients (p = 0.03), but not between the other pairs. Conclusion Although asymptomatic patients with BrS are at significantly lower risk of SCD, it is important to identify high-risk patients in the low-risk group. Therefore, creating a tool for calculating the risk of SCD among these patients might be helpfull in everyday clinical practice.