Spontaneous type 1 ECG and arrhythmic risk in Brugada syndrome: A meta-analysis of adjusted time-to-event data

Background: Brugada syndrome (BrS) is associated with an increased risk of major arrhythmic events (MAEs), particularly in patients with a spontaneous type 1 electrocardiographic (ECG) pattern. Objective: Because previous meta-analyses used mainly crude or unadjusted data from observational studies, we conducted an updated meta-analysis on the prognostic role of spontaneous type 1 ECG in BrS patients combining adjusted and unadjusted data separately. Methods: We conducted a systematic search of PubMed and Cochrane Central Register of Controlled Trials from inception to May 2024. Studies providing hazard ratios for MAEs associated with spontaneous type 1 ECG in BrS patients were included. Results: Eighteen studies comprising 7238 patients were included, with 10 providing adjusted and 17 providing unadjusted data. Separate pooled analyses using a random-effects model demonstrated a significantly increased risk of MAEs in BrS patients with spontaneous type 1 ECG compared with those without, with a pooled adjusted hazard ratio (aHR) of 2.05 (95% CI 1.38-3.03) and an unadjusted hazard ratio of 2.97 (95% CI 2.04-4.34). Subgroup analysis revealed higher risks in studies with non-Asian populations and those including patients with no history of aborted cardiac arrest (aHR 2.36, 95% CI 1.35-4.11; and aHR 3.56, 95% CI 2.35-5.41, respectively) and a persistent significant risk in studies accounting for syncope as a covariate (aHR 2.01, 95% CI 1.24-3.27). Conclusion: Our analysis indicates that patients with BrS and spontaneous type 1 ECG are at higher risk of MAEs. This is consistent across various subgroups, including asymptomatic individuals.