Asymptomatic Patients With Brugada ECG Pattern: Long-Term Prognosis From a Large Prospective Study

Background: Brugada syndrome poses significant challenges in terms of risk stratification and management, particularly for asymptomatic patients who comprise the majority of individuals exhibiting Brugada pattern ECG (BrECG). The aim of this study was to evaluate the long-term prognosis of a large cohort of asymptomatic patients with BrECG. Methods: Asymptomatic patients with BrECG (1149) were consecutively collected from 2 Italian centers and followed-up at least annually for 2 to 22 years. For the 539 asymptomatic patients (men, 433 [80%]; mean age, 46±13 years) with spontaneous type 1 documented on baseline ECG (87%) or 12-lead 24-hour Holter monitoring (13%), an electrophysiologic study (EPS) was proposed; for the 610 patients with drug-induced-only type 1 (men, 420 [69%]; mean age, 44±14 years), multiple ECGs and 12-lead Holter were advised in order to detect the occurrence of a spontaneous type-1 BrECG pattern. Arrhythmic events were defined as sudden death or documented ventricular fibrillation or tachycardia. Results: Median follow-up was 6 (4-9) years. Seventeen (1.5%) arrhythmic events occurred in the overall asymptomatic population (corresponding to an event-rate of 0.2% per year), including 16 of 539 (0.4% per year) in patients with spontaneous type-1 BrECG and 1 of 610 in those with drug-induced type-1 BrECG (0.03% per year; P<0.001). EPS was performed in 339 (63%) patients with spontaneous type-1 BrECG. Patients with spontaneous type-1 BrECG and positive EPS had significantly higher event rates than patients with negative EPS (7 of 103 [0.7% per year] versus 4 of 236 [0.2% per year]; P=0.025). Among 200 patients who declined EPS, 5 events (0.4% per year) occurred. There was 1 device-related death. Conclusions: The entire population of asymptomatic patients with BrECG exhibits a relatively low event rate per year, which is important in view of the long life expectancy of these young patients. The presence of spontaneous type-1 BrECG associated with positive EPS identifies a subgroup at higher risk. Asymptomatic patients with drug-induced-only BrECG have a minimal arrhythmic risk, but ongoing follow-up with 12-lead Holter monitoring is recommended to detect the appearance of spontaneous type-1 BrECG pattern.