Low Arrhythmic Risk in Individuals With Brugada ECG Pattern and a Negative dST-Tiso Criterion

Risk stratification in individuals with Brugada electrocardiographic pattern (BrECG) remains challenging. The dST-Tiso ECG criterion, defined as an interval between the onset of coved ST-segment elevation and its return to the isoelectric line >300 ms, has been validated as a predictor of ventricular arrhythmia (VA) inducibility during programmed ventricular stimulation. We aimed to assess the association between this criterion and the arrhythmic risk during follow-up. Consecutive patients with BrECG were prospectively enrolled. The dST-Tiso interval was measured during a manifest type 1 BrECG (spontaneous or drug-induced). The primary endpoint was a composite of sudden cardiac death (SCD) or documented VA, either symptomatic or treated with appropriate implantable cardioverter-defibrillator (ICD) therapy. The cohort included 281 patients (median age 42 years; 64% male; 10% spontaneous type 1; 23% VA-inducible). Among them, 197 (70%) had a negative and 84 (30%) a positive dST-Tiso criterion. Over a median follow-up of 3.2 years, 11 patients (3.9%) reached the primary endpoint: 1 SCD, 5 ICD-treated VA, and 5 self-terminating VA episodes. All events occurred in patients with positive dST-Tiso (log-rank p < 0.001). Within this group, 5 patients had spontaneous and 6 drug-induced type 1 BrECG; 7 had inducible and 4 non-inducible VA. As a continuous variable, the dST-Tiso was also associated with events (hazard ratio per ms: 1.02; 95% CI: 1.01-1.03; p < 0.001). In conclusion, individuals with BrECG and negative dST-Tiso criterion had a very low risk of arrhythmic events. This ECG marker may enhance multiparametric risk stratification.