Long-Term Outcomes of Brugada Substrate Ablation: A Report from BRAVO (Brugada Ablation of VF Substrate Ongoing Multicenter Registry)
The treatment options for Brugada syndrome are limited. An ICD (implantable cardioverter-defibrillator) is often implanted and when there are recurrent arrhythmias quinidine is the only available effective drug. However, availability of quinidine is limited in many countries around the world and the drug often comes with significant side effects. In recent years catheter ablation* has gained interest but long-term outcome data are not available. In the present report we report on the long-term outcome of catheter ablation in very symptomatic patients.
The study was performed in Bangkok (Thailand). The lead author of this study, Dr Koonlawee Nademanee has developed the ablation method 15 years ago. It consists of targeted ablation of an area with abnormal electrical signals in the outside layer of the outflow track of the right ventricle (that is the part where the right ventricle connects to the artery that goes to the lungs). It is believed that in this part of the heart fibrosis intermingles with normal tissue, and thereby creating a substrate where arrhythmias can easily originate.
159 Brugada syndrome patients (156 male), all with spontaneous ventricular fibrillation, were included in the study. All but 5 had a defibrillator and 140 had experienced numerous defibrillator shocks for spontaneous VF before ablation. After a single ablation procedure 128 (of 159 patients, 81%) were free of arrhythmia recurrence. This increased to 96% (153 patients) after a second or third procedure in a period of 4 years (± 2.5 years). The sole predictor of a successful procedure was the normalization of the ECG (i.e. disappearance of the Brugada ECG) with and without a drug challenge test after the ablation. The procedure was relatively safely performed with 4 patients (2.5%) with blood in the cavity around the heart (pericardium, which is the site where the catheter has to go in order to reach that particular side of the heart).
In conclusion, in patients with a severe type of Brugada syndrome (i.e. patients with spontaneous VF episodes) ablation therapy is safe and very effective in reducing the number of arrhythmia episodes. In order to judge whether this therapy is as safe as defibrillator treatment a prospective study needs to be performed.
* Catheter ablation – passing a small flexible tube through blood vessels to destroy an area of heart muscle using heat or by freezing.
Layman abstract Article: Nademanee K, Chung FP, Sacher F, Nogami A, Nakagawa H, Jiang C, Hocini M, Behr E, Veerakul G, Jan Smit J, Wilde AAM, Chen SA, Yamashiro K, Sakamoto Y, Morishima I, Das MK, Khongphatthanayothin A, Vardhanabhuti S, Haissaguerre M. Long-Term Outcomes of Brugada Substrate Ablation: A Report from BRAVO (Brugada Ablation of VF Substrate Ongoing Multicenter Registry). Circulation. 2023 May 23;147(21):1568-1578. PMID: 36960730
Abstract prepared by Arthur Wilde (Amsterdam UMC, Amsterdam, the Netherlands) and Lorraine McGlinchey (Irish Heart Foundation)