Key result
RV refractory period difference >60 ms predicts SCD or ICD shock in Brugada syndrome.
Why the study?
The prognostic significance of heterogeneity in the refractoriness of the RV outflow tract and RV apex during electrophysiological study in Brugada syndrome needed investigation.
Does right ventricular refractory period heterogeneity predict sudden cardiac death or appropriate ICD intervention in patients with Brugada syndrome?
Cohort (n=372)
Yes
Does right ventricular refractory period heterogeneity predict sudden cardiac death or appropriate ICD intervention in patients with Brugada syndrome?
Heterogeneity of right ventricular refractory periods (>60 ms difference between RVOT and apex) is a strong independent predictor of life-threatening arrhythmias in Brugada syndrome, providing prognostic value beyond VT/VF inducibility.
May support refined SCD risk stratification in Brugada syndrome; leaves open prospective validation before practice change.
AIMS: To investigate the prognostic significance of heterogeneity in the refractoriness of right ventricular (RV) outflow tract (RVOT) and RV apex at the electrophysiological study (EPS) in Brugada syndrome (BrS). METHODS AND RESULTS: A cohort of BrS patients (primary prevention) from five Italian centres was retrospectively analysed. Patients with spontaneous or drug-induced Type-1 electrocardiogram (ECG) + symptoms were offered an EPS for prognostic stratification. The primary endpoint was a composite of sudden cardiac death (SCD), resuscitated cardiac arrest, or appropriate intervention by the implantable cardioverter-defibrillator (ICD). Three hundred and seventy-two patients with BrS were evaluated (44 ± 15 years, 69% males, 23% with ICD): 4 SCDs and 17 ICD interventions occurred at follow-up (median 48, interquartile range: 36-60 months). Family history of SCD, syncope, and a spontaneous Type-1 ECG pattern were univariate predictors of the primary endpoint in the whole population. In patients undergoing EPS (n = 198, 53%, 44 ± 12 years, 71% males, 39% with ICD), 3 SCD and 15 ICD interventions occurred at follow-up. In this subset, the primary endpoint was not only predicted by ventricular tachycardia/fibrillation inducibility but also by a difference in the refractory period between RVOT and RV apex (ΔRPRVOT-apex) >60 ms. ΔRPRVOT-apex > 60 ms remained an independent predictor of SCD/ICD shock at bivariate analysis, even when adjusted for the other univariate predictors, showing the highest predictive power at C-statistic analysis (0.75, 95% confidence interval 0.63-0.86). CONCLUSIONS: Heterogeneity of RV refractory periods is a strong, independent predictor of life-threatening arrhythmias in BrS patients, beyond VT/VF inducibility at EPS and common clinical predictors.
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Rossi et al. (2022) conducted a cohort in Brugada syndrome (n=372). Difference in refractory period between RVOT and RV apex (ΔRPRVOT-apex) >60 ms was evaluated on Composite of sudden cardiac death (SCD), resuscitated cardiac arrest, or appropriate intervention by the implantable cardioverter-defibrillator (ICD) (C-statistic 0.75, 95% CI 0.63-0.86). A right ventricular refractory period difference >60 ms independently predicted sudden cardiac death or ICD shock in Brugada syndrome patients (C-statistic 0.75; 95% CI 0.63-0.86).
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