Risk stratification in individuals with the Brugada type 1 ECG pattern without previous cardiac arrest: usefulness of a combined clinical and electrophysiologic approach

Abstract

AimsRisk stratification in individuals with type 1 Brugada electrocardiogram (ECG) pattern (type 1 ECG) for primary prevention of sudden death (SD).Methods and resultsThree hundred and twenty patients (258 males, median age 43 years) with type 1 ECG were enrolled. No patient had previous cardiac arrest. Fifty-four per cent of patients had a spontaneous and 46% a drug-induced type 1 ECG. One-third had syncope, two-thirds were asymptomatic. Two hundred and forty-five patients underwent electrophysiologic study (EPS) and 110 patients received an implantable cardiac defibrillator (ICD). During follow-up [median length 40 months (IQ20-67)], 17 patients had major arrhythmic events (MAE) (14 resuscitated ventricular fibrillation (VF) and three SD). Both a spontaneous type 1 ECG and syncope significantly increased the risk (2.6 and 3.0% event rate per year vs. 0.4 and 0.8%). Major arrhythmic events occurred in 14% of subjects with positive EPS, in no subjects with negative EPS and in 5.3% of subjects without EPS. All MAE occurred in subjects who had at least two potential risk factors (syncope, family history of SD, and positive EPS). Among these patients, those with spontaneous type 1 ECG had a 30% event rate.Conclusion(1) In subjects with the Brugada type 1 ECG, no single clinical risk factor, nor EPS alone, is able to identify subjects at highest risk; (2) a multiparametric approach (including syncope, family history of SD, and positive EPS) helps to identify populations at highest risk; (3) subjects at highest risk are those with a spontaneous type 1 ECG and at least two risk factors; (4) the remainder are at low risk.

Risk Stratification in Patients With Brugada Syndrome Without Previous Cardiac Arrest

“…21 Delise et al, however, reported that no arrhythmic events occurred in patients with negative inducibility of VF. 10 Makimoto et al reported that the number of extrastimuli in PES using the minimum coupling interval of 180 ms and the inducibility of VF by up to 2 extrastimuli had significant predictive value for future cardiac events. 22 Further discussion of these unresolved issues should be continued.…”

“…Delise et al reported the risk stratification in a similar patient type as in the present study, with a focus on risk combinations. 10 Although FH itself failed to predict arrhythmic events, the authors concluded that a multi-parametric approach that included syncope, FH, and PES+ helped to identify patients at high risk. They also reported that the patients at highest risk were those with at least 2 risk factors in addition to Sp1.…”

Is there a role of MMA T wave alternans test for risk assessment in Brugada syndrome?

“…Risk stratification in BS is still controversial. Implantable cardioverter-defibrillators (ICDs) are inserted to the patients experienced cardiac arrest, syncope and whose ECG showed type I pattern, inducible ventricular arrhythmia with programmed ventricular stimulation (3). A report by Raju et al (4) demonstrated that the majority of individuals experiencing BS sudden death are asymptomatic before their terminal event and 68% of surviving patients has no ICD indication according to current guidelines.…”

Even a Pooled Analysis Does Not Resolve the Debate of Electrophysiology Testing in Brugada Syndrome

“…Third, of the 18 identified studies, only 8 participated and 84% of the study population was pooled from 3 studies. [9][10][11] Fourth, the included studies have little contribution from the high-risk Asian population, and none are authored by one of the Brugada brothers. It is well recognized that their experience strongly endorses risk stratification with PES.…”

“…2 This unique interaction between channelopathy and substrate may, in part, explain the inconsistent findings reported with PES. Considering conflicting literature, [3][4][5][6][7][8][9][10][11] consensus statements suggesting a lesser role, 14 and statistical analysis of the current publication, if and how PES should be incorporated into the algorithm for managing BrS remains unsettled.…”