Abstract 17005: Brugada Syndrome: Is There a Difference Between Probands and Relatives?

Abstract

Introduction: Brugada syndrome (BrS) is an inherited arrhythmic disease that is rarely linked to sudden cardiac death (SCD), often associated with SCN5A mutations. Hypothesis: The main objective of this study was to report the demographic, clinical findings and outcomes of a BrS registry in the Maltese Islands, comparing probands and relatives. Methods: Data was collected prospectively in all BrS patients. BrS was defined as per the latest European Society of Cardiology SCD guidelines published in 2022. Patients were placed in two groups (proband vs relative). Results: 120 individuals were included (2.7 per 10,000 individuals) (56.7% male, mean age 44.0±16.5 years at diagnosis, 7.5% athletes). 54 (45.0%) were probands. 61 (50.8%) reported cardiac symptoms. A relevant family history of SCD was present in 55 (46.6%). Follow up period of 49.8 ± 33.3 months. A spontaneous type 1 brugada pattern was the primary method of diagnosis in probands (71.1%), ajmaline provocation in relatives (71.6%) (p<0.001). Probands reported more symptoms (33.1% vs 17.8%, p<0.0001), documented arrhythmias during holter monitoring (29.0% vs 9.3%, p=0.028), and manifested J /ST elevation during stress testing (14.0% vs 5.3%, p=-0.039). The age at diagnosis was similar for probands and relatives. Similar proportions of atrioventricular block (15.7%), prolonged QRS (10.2%), early repolarisation (12.8%), QRS fragmentation (5.6%), low QRS voltages (5.6%) and pathological TWI (8.3%) were observed in both groups. 18 (20.4%) were identified with a SCN5A mutation (P, LP, VUS as per ACMG criteria). 5 patients (4.2%) had a novel variant. 17 (15.3%) were referred for a VT study. 20 (16.7%) had an ICD implanted, more frequent in probands (34.0% vs 3.1%) (p<0.001). 3 were implanted because of OHCA. 27 (22.5%) were implanted with an ILR, commoner in probands (33.3% vs 16.4%, p=0.047). Two patients (10% of ICD subgroup) had an appropriate ICD therapy. One patient is on quinidine because of refractory shocks. Conclusions: The prevalence of BrS in Malta is comparable to other studies. 20.4% (probands) had a SCN5A mutation. The higher incidence of symptoms, arrhythmias, abnormal response during exercise and ICD implantation in probands (vs relatives) may suggest they are a higher risk group.