Worse Prognosis in Brugada Syndrome Patients With Arrhythmogenic Cardiomyopathy Features

OBJECTIVES: This study aimed to assess the presence of echocardiographic and electrocardiographic similarities in patients with Brugada syndrome (BrS) and arrhythmogenic cardiomyopathy (AC) and the prevalence and prognostic value of AC structural/electrical features in patients with BrS.

BACKGROUND: BrS and AC are genetic cardiac diseases with high risk for sudden cardiac death. Although BrS and AC display different features, previous reports suggest a phenotypic overlap.

METHODS: We acquired clinical data, electrocardiogram, and transthoracic echocardiography in patients with BrS and AC. We assessed the presence of AC diagnostic criteria according to the 2010 AC task force criteria for right ventricular outflow tract (RVOT), fractional area change, depolarization, and repolarization in the patients with BrS. We compared arrhythmic outcome in BrS patients with and without AC structural/electrical criteria.

RESULTS: A total of 116 BrS and 141 AC patients were included. AC electrical features were present in 28 (24%) BrS patients and structural features in 97 (84%) BrS patients. BrS patients with an RVOT or depolarization AC criterion showed a trend towards worse severe arrhythmia-free survival compared to BrS patients without (p = 0.05). The criterion for RVOT dilation showed high sensitivity and improved detection of arrhythmic BrS patients when added to type 1 electrocardiogram pattern and syncope (area under the curve 0.73 [95% confidence interval: 0.59 to 0.87] vs. area under the curve 0.79 [95% confidence interval: 0.69 to 0.90]); p = 0.009).

CONCLUSIONS: In this large cohort comparison, Brugada syndrome (BrS) and arrhythmogenic cardiomyopathy patients had phenotypic overlap. The presence of arrhythmogenic cardiomyopathy diagnostic criteria in BrS patients was associated with a trend towards higher arrhythmic risk. The right ventricular outflow tract dilation criterion improved detection of arrhythmic BrS patients.