Long-Term Outcomes of Brugada Substrate Ablation
Quick Takes
- Catheter ablation of the epicardial arrhythmogenic substrates is safe and effectively prevents VF recurrences in high-risk patients with BrS.
- In the small number of patients who still had VF recurrences, the VF episodes were infrequent and tolerable.
- These data suggest that patients with BrS without concomitant early repolarization and whose ECG is normalized after ablation will likely be free from VF recurrence and may not need an ICD.
Study Questions:
What are the outcomes of catheter ablation for treatment of high-risk symptomatic Brugada syndrome (BrS)?
Methods:
The investigators enrolled 159 patients (median age 42 years; 156 male) with BrS and spontaneous ventricular fibrillation (VF) in the multicenter, international BRAVO (Brugada Ablation of VF Substrate Ongoing Registry); 43 (27%) of them had BrS and early repolarization pattern. All but five had an implantable cardioverter-defibrillator (ICD) for cardiac arrest (n = 125) or syncope (n = 34). A total of 140 (88%) had experienced numerous ICD shocks for spontaneous VF before ablation. All patients underwent a percutaneous epicardial substrate ablation with electroanatomical mapping except for eight who underwent open-thoracotomy ablation. Study endpoints were death or spontaneous VF episodes. The primary analysis was comparison of VF recurrence rates; patient VF-free survival probabilities and standard error were estimated using the Kaplan-Meier method and were tested by log-rank test.
Results:
In all patients, VF/BrS substrates were recorded in the epicardial surface of the right ventricular outflow tract; 45 (29%) patients also had an arrhythmic substrate in the inferior right ventricular epicardium and three in the posterior left ventricular epicardium. After a single ablation procedure, 128 of 159 (81%) patients remained free of VF recurrence; this number increased to 153 (96%) after a repeated procedure (mean 1.2 ± 0.5 procedures; median = 1), with a mean follow-up period of 48 ± 29 months from the last ablation. VF burden and frequency of shocks decreased significantly from 1.1 ± 2.1 per month before ablation to 0.003 ± 0.14 per month after the last ablation (p < 0.0001). The Kaplan-Meier VF-free survival beyond 5 years after the last ablation was 95%. The only variable associated with a VF-free outcome in multivariable analysis was normalization of the type 1 Brugada electrocardiogram (ECG), both with and without sodium-channel blockade, after the ablation (hazard ratio, 0.078; 95% confidence interval, 0.008-0.753; p = 0.0274). There were no arrhythmic or cardiac deaths. Complications included hemopericardium in four (2.5%) patients.
Conclusions:
The authors report that ablation treatment is safe and highly effective in preventing VF recurrence in high-risk BrS patients.
Perspective:
These registry data report that catheter ablation of the epicardial arrhythmogenic substrates is safe and effectively prevents VF recurrences in high-risk patients with BrS. Furthermore, in the small number of patients who still had VF recurrences, the VF episodes were infrequent and tolerable to the extent that these patients often declined additional ablation procedures. These data suggest that patients with BrS who do not have concomitant early repolarization and whose ECG is normalized after ablation will likely be free from VF recurrence and may not need an ICD; however, prospective studies are needed to validate this concept.
Clinical Topics: Arrhythmias and Clinical EP, Pericardial Disease, Prevention, Implantable Devices, Genetic Arrhythmic Conditions, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias
Keywords: Arrhythmias, Cardiac, Brugada Syndrome, Catheter Ablation, Death, Sudden, Cardiac, Defibrillators, Implantable, Electrocardiography, Pericardial Effusion, Pericardium, Secondary Prevention, Syncope, Thoracotomy, Ventricular Fibrillation
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