Background The role of programmed ventricular stimulation (PVS) in identifying Brugada syndrome patients at highest risk for sudden death is uncertain. Methods and Results We performed a systematic review and pooled analysis of prospective observational studies of Brugada syndrome patients without a history of sudden cardiac arrest who underwent PVS. We estimated incidence rates and relative hazards of cardiac arrest or ICD shock. We analyzed individual-level data from 8 studies, comprising 1312 patients who experienced 65 cardiac events (median follow-up of 38.3 months). A total of 527 patients were induced into arrhythmias with up to triple extrastimuli. Induction was associated with cardiac events during follow-up (HR 2.66, 95%CI 1.44–4.92, P<0.001), with the greatest risk observed among those induced with single or double extrastimuli. Annual event rates varied substantially by syncope history, presence of spontaneous type 1 ECG pattern, and arrhythmia induction. The lowest risk occurred in individuals without syncope and with drug-induced type 1 patterns (0.23%, 95%CI 0.05–0.68 [no induced arrhythmia with up to double extrastimuli]; 0.45%, 95%CI 0.01–2.49 [induced arrhythmia]) and the highest risk occurred in individuals with syncope and spontaneous type 1 patterns (2.55%, 95%CI 1.58–3.89 [no induced arrhythmia]; 5.60%, 95%CI 2.98–9.58 [induced arrhythmia]). Conclusions In Brugada syndrome patients, arrhythmias induced with PVS are associated with future ventricular arrhythmia risk. Induction with fewer extrastimuli is associated with higher risk. However, clinical risk factors are important determinants of arrhythmia risk, and lack of induction does not necessarily portend low ventricular arrhythmia risk particularly in patients with high-risk clinical features.

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.