High-risk Brugada syndrome: factors associated with arrhythmia recurrence and benefits of epicardial ablation in addition to implantable cardioverter defibrillator implantation

AIMS

This study aims to evaluate the prognostic impact of the arrhythmogenic substrate size in symptomatic Brugada syndrome (BrS) as well as to validate the long-term safety and effectiveness of epicardial radiofrequency ablation (RFA) compared with no-RFA group.

METHODS AND RESULTS

In this prospective investigational long-term registry study, 257 selected symptomatic BrS patients with implantable cardioverter defibrillator (ICD) implantation were included. Among them, 206 patients underwent epicardial RFA and were monitored for over 5 years post-ablation (RFA group), while 51 patients received only ICD implantation declining RFA. Primary endpoints included risk factors for ventricular fibrillation (VF) events pre-ablation and freedom from VF events post-ablation. In the RFA group, BrS substrates were identified in the epicardial surface of the right ventricle. During the pre-RFA follow-up period (median 27 months), VF episodes and VF storms were experienced by 53 patients. Independent risk factors included substrate size [hazard ratio (HR), 1.13; 95% confidence interval (CI), 1.08-1.18; P < 0.001], aborted cardiac arrest (HR, 2.98; 95% CI, 1.68-5.28; P < 0.001), and SCN5A variants (HR, 2.22; 95% CI, 1.15-4.27; P = 0.017). In the post-RFA follow-up (median 40 months), the RFA group demonstrated superior outcomes compared with no-RFA (P < 0.001) without major procedure-related complications.

CONCLUSION

Our study underscores the role of BrS substrate extent as a crucial prognostic factor for recurrent VF and validates the safety and efficacy of RFA when compared with a no-RFA group. Our findings highlight the importance of ajmaline in guiding epicardial mapping/ablation in symptomatic BrS patients, laying the groundwork for further exploration of non-invasive methods to guide informed clinical decision-making.

Outcomes of catheter ablation in high-risk patients with Brugada syndrome refusing an implantable cardioverter defibrillator implantation

AIMS

The aim of this study was to investigate the outcomes of catheter ablation (CA) in preventing arrhythmic events among patients with symptomatic Brugada syndrome (BrS) who declined implantable cardioverter defibrillator (ICD) implantation.

METHODS AND RESULTS

A total of 40 patients with symptomatic BrS were included in the study, of which 18 refused ICD implantation and underwent CA, while 22 patients received ICD implantation. The study employed substrate modification (including endocardial and epicardial approaches) and ventricular fibrillation (VF)-triggering pre-mature ventricular contraction (PVC) ablation strategies. The primary outcomes were a composite endpoint consisting of episodes of VF and sudden cardiac death during the follow-up period. The study population had a mean age of 43.8 ± 9.6 years, with 36 (90.0%) of them being male. All patients exhibited the typical Type 1 BrS electrocardiogram pattern, and 16 (40.0%) were carriers of an SCN5A mutation. The Shanghai risk scores were comparable between the CA and the ICD groups (7.05 ± 0.80 vs. 6.71 ± 0.86, P = 0.351). Ventricular fibrillation-triggering PVCs were ablated in 3 patients (16.7%), while VF substrates were ablated in 15 patients (83.3%). Epicardial ablation was performed in 12 patients (66.7%). During a median follow-up of 46.2 (17.5-73.7) months, the primary outcomes occurred more frequently in the ICD group than in the CA group (5.6 vs. 54.5%, Log-rank P = 0.012).

CONCLUSION

Catheter ablation is an effective alternative therapy for improving arrhythmic outcomes in patients with symptomatic BrS who decline ICD implantation. Our findings support the consideration of CA as an alternative treatment option in this population.

Efficacy and safety of catheter ablation for Brugada syndrome: an updated systematic review

BACKGROUND

Patients with Brugada syndrome (BrS) may experience recurrent ventricular arrhythmias (VAs). Catheter ablation is becoming an emerging paradigm for treatment of BrS.

OBJECTIVE

To assess the efficacy and safety of catheter ablation in BrS in an updated systematic review.

METHODS

We comprehensively searched the databases of Pubmed/Medline, EMBASE, and Cochrane Central Register of Controlled Trials from inception to 11th of August 2021.

RESULTS

Fifty-six studies involving 388 patients were included. A substrate-based strategy was used in 338 cases (87%), and a strategy of targeting premature ventricular complex (PVCs)/ventricular tachycardias (VTs) that triggered ventricular fibrillation (VF) in 47 cases (12%), with combined abnormal electrogram and PVC/VT ablation in 3 cases (1%). Sodium channel blocker was frequently used to augment the arrhythmogenic substrate in 309/388 cases (80%), which included a variety of agents, of which ajmaline was most commonly used. After ablation procedure, the pooled incidence of non-inducibility of VA was 87.1% (95% confidence interval [CI], 73.4-94.3; I2 = 51%), and acute resolution of type I ECG was seen in 74.5% (95% CI [52.3-88.6]; I2 = 75%). Over a weighted mean follow up of 28 months, 7.6% (95% CI [2.1-24]; I2 = 67%) had recurrence of type I ECG either spontaneously or with drug challenge and 17.6% (95% CI [10.2-28.6]; I2 = 60%) had recurrence of VA.

CONCLUSION

Catheter ablation appears to be an efficacious strategy for elimination of arrhythmias or substrate associated with BrS. Further study is needed to identify which patients stand to benefit, and optimal provocation protocol for identifying ablation targets.

Long-Term Outcomes of Brugada Substrate Ablation: A Report from BRAVO (Brugada Ablation of VF Substrate Ongoing Multicenter Registry)

BACKGROUND

Treatment options for high-risk Brugada syndrome (BrS) with recurrent ventricular fibrillation (VF) are limited. Catheter ablation is increasingly performed but a large study with long-term outcome data is lacking. We report the results of the multicenter, international BRAVO (Brugada Ablation of VF Substrate Ongoing Registry) for treatment of high-risk symptomatic BrS.

METHODS

We enrolled 159 patients (median age 42 years; 156 male) with BrS and spontaneous VF in BRAVO; 43 (27%) of them had BrS and early repolarization pattern. All but 5 had an implantable cardioverter-defibrillator for cardiac arrest (n=125) or syncope (n=34). A total of 140 (88%) had experienced numerous implantable cardioverter-defibrillator shocks for spontaneous VF before ablation. All patients underwent a percutaneous epicardial substrate ablation with electroanatomical mapping except for 8 who underwent open-thoracotomy ablation.

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 3 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 ECG, both with and without sodium-channel blockade, after the ablation (hazard ratio, 0.078 [95% CI, 0.008 to 0.753]; P=0.0274). There were no arrhythmic or cardiac deaths. Complications included hemopericardium in 4 (2.5%) patients.

CONCLUSIONS

Ablation treatment is safe and highly effective in preventing VF recurrence in high-risk BrS. Prospective studies are needed to determine whether it can be an alternative treatment to implantable cardioverter-defibrillator implantation for selected patients with BrS.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04420078.

Advances in Ventricular Arrhythmia Ablation for Brugada Syndrome

Three decades have passed since the Brugada syndrome (BrS) clinical entity was introduced in the early 1990s. During the first 2 decades, treatment of patients with BrS was challenging because there were limited treatment options, and an implantable cardioverter-defibrillator was the only choice for high-risk patients with BrS, that is, those who had aborted sudden cardiac death or had previous ventricular fibrillation episodes. In this article, the authors focus on these advances and how to treat patients with BrS with catheter ablation.

Catheter ablation for monomorphic ventricular tachycardia in Brugada syndrome patients: detailed characteristics and long-term follow-up

PURPOSE

Brugada syndrome (BrS) is a risk of sudden cardiac death due to polymorphic ventricular tachycardia and ventricular fibrillation with unusual monomorphic ventricular tachycardia (MVT). Detailed characteristics of MVT and long-term outcome of catheter ablation are still unknown. This study is aimed to identify the detailed characteristics and long-term follow-up of catheter ablation in BrS patients.

METHODS

We evaluated 188 patients who were diagnosed with BrS from March 1999 to March 2018. Of those, patients who developed MVT and underwent catheter ablation were included. We identified eight MVTs in seven BrS patients.

RESULTS

Three of them already had implantable cardioverter-defibrillator, and MVTs were terminated by cardioversion or anti-tachycardia pacing. Four patients presented with MVT originating from the right ventricular outflow tract, one patient had MVT arising from the LV septum, one patient had MVT arising from the tricuspid annulus, and one patient had bundle branch reentry ventricular tachycardia. All MVTs were successfully treated by catheter ablation in the acute phase, and seven of eight (87.5%) were free from ventricular tachyarrhythmia during the long-term follow-up (median, 7.2 years).

CONCLUSIONS

All MVT cases were successfully treated by catheter ablation. We observed high ventricular arrhythmia free rate following catheter ablation during the long-term follow-up period. BrS patients who developed MVT should consider catheter ablation.

Epicardial radiofrequency catheter ablation of Brugada syndrome with electrical storm during ventricular fibrillation: A case report

RATIONALE

Brugada syndrome (BrS) is characterized by ST segment elevation at the J point ≥2 mm in the right precordial electrocardiogram (ECG) leads, in the absence of structural heart disease, electrolyte disturbances, or ischemia. It is a well-described cause of sudden death in young patients, especially in the age of between 30 and 40 years old. Here, we reported an unusual case of electrical storm (ES) of ventricular fibrillation (VF) caused by BrS with complete right bundle-branch block (CRBBB) in a 75-year-old male patient.

PATIENT CONCERNS

A 75-year-old male patient survived sudden cardiac death caused by a ventricular ES. He presented with the cove-shaped ST elevation of 2 mm in lead V1 with typical CRBBB and lacked structural cardiomyopathy and coronary heart disease. The patient suffered ventricular ES again, although the implantable cardioverter defibrillator(ICD) had implanted.

DIAGNOSES

Brugada syndrome with complete right bundle-branch block.

INTERVENTIONS

Implantable cardioverter defibrillator (ICD) implantation was performed. But this therapy could not prevent the recurrence of malignant arrhythmia. Finally, the ES was treated successfully using radiofrequency catheter ablation (RFCA) at the area of the free wall of the right ventricular outflow tract (RVOT) epicardium.

OUTCOMES

During 7 months of follow-up, the patient was asymptomatic and free of arrhythmic events.

LESSONS

As far as we know, the patient is the oldest patient reported to have BrS. RFCA offers an alternative therapy for patients with BrS, especially when ICD shocks are encountered.

Brugada syndrome in childhood: a potential fatal arrhythmia not always recognised by paediatricians. A case report and review of the literature

We report on a youngster followed by his paediatrician from birth until 14 years of age for premature beats, most likely of ventricular origin. The sudden death of his sister provoked a re-assessment of his electrocardiograms (ECG), resulting in the diagnosis of Brugada syndrome and the subsequent implantation of a cardioverter defibrillator. This syndrome is a well known entity in adult cardiology, first described by Brugada and Brugada in 1992. It is considered to be the second most common cause of death in young adults after road traffic accidents. In children, however, the Brugada syndrome is not well known and we believe to be certainly underdiagnosed.