Long-term follow-up of asymptomatic Brugada patients with inducible ventricular fibrillation under hydroquinidine

Abstract

To evaluate the long-term efficacy and safety of an electrophysiologically guided therapy, based on a strategy of treatment using hydroquinidine (HQ) among asymptomatic Brugada patients with inducible ventricular fibrillation (VF). In two French reference centres, consecutive asymptomatic type 1 Brugada patients with inducible VF were treated with HQ (600 mg/day, targeting a therapeutic range between 3 and 6 µmol/L) and enroled in a specific follow-up (mean 6.6 ± 3 years), including a second programmed ventricular stimulation (PVS) under HQ. An implantable cardioverter defibrillator (ICD) was eventually implanted in patients inducible under HQ, or during follow-up in case of HQ intolerance, as well as occurrence of arrhythmic events. From a total of 397 Brugada patients, 44 were enroled (47 ± 10 years, 95% male). Of these, 34 (77%) were no more inducible (Group PVS-), and were maintained under HQ alone during a mean follow-up of 6.2 ± 3 years. In this group, an ICD was eventually implanted in four patients (12%), with occurrence of appropriate ICD therapies in one. Among the 10 other patients (22%), who remained inducible and received ICD (Group PVS+), none of them received appropriate therapy during a mean follow-up of 7.7 ± 2 years. The overall annual rate of arrhythmic events was 1.04% (95% confidence interval 0.00-2.21), without any significant difference according to the result of PVS under HQ. One-third of patients experienced device-related complications. Our long-term follow-up results emphasize that the rate of arrhythmic events among asymptomatic Brugada patients with inducible VF remains low over time. Our results also suggest that residual inducibility under HQ is of limited value to predict events during follow-up.