Programmed Ventricular Stimulation for Risk Stratification in the Brugada Syndrome: A Pooled Analysis
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.
- Received June 8, 2015.
- Revision received December 9, 2015.
- Accepted December 23, 2015.