Catheter ablation of ventricular arrhythmias in arrhythmogenic cardiomyopathy - comparison of different approaches and results of genetic testing

Abstract

Abstract Introduction Arrhythmogenic cardiomyopathy (ACM) is a disease characterized by fatty-fibrous remodeling of the myocardium and a high risk of ventricular tachycardia (VT). Catheter ablation is an effective method that prevents VT recurrences. Although the arrhythmogenic substrate in ACM is located dominantly in the epicardium, in some patients VT can be effectively suppressed only by endocardial ablation. Purpose Retrospective analysis of catheter ablation results of VT in patients with ACM and right ventricular involvement. Methods Between 2001-2021, catheter ablation of VT was performed in 51 patients (mean age 43±18 years, 9 women) with a clinical diagnosis of ACM and right ventricular involvement. Pathogenic/likely pathogenic mutation was detected during the genetic testing in 80% of patients. Repeated ablation procedures were necessary to suppress VT (a total of 1.9±1.3 procedures/patient). According to the approach, patients were divided into three groups: A - endocardial ablation only (n=20); B - endocardial ablation first, followed by epicardial approach (n=15); C- primary epicardial approach (n=16). Results The primary epicardial approach (group C) compared to the endocardial approach (group A+B) was associated with better VT free survival (Figure 1, p<0.02) and significantly fewer procedures needed to suppress arrhythmia recurrences (1.1±0.2 vs 2.3±1.5 procedures/patient; p<0.005). Patients in whom an endocardial approach (group A) was sufficient to control arrhythmias were significantly older than patients in whom an epicardial approach (group B) had to be used (52.9±15.1 vs 36.0±16.0 years; p<0.001). The frequency of pathogenic mutations did not differ among groups (A - 83% vs B - 71% vs C - 86%; p=n.s.). The most commonly found mutation was in the gene for plakophilin 2 (51% of all patients). Conclusion Epicardial VT ablation in ACM patients with right ventricular involvement leads to the most effective control of arrhythmias. Endocardial ablation alone may be sufficient to control VT in older patients. The identification of a pathogenic/likely pathogenic mutation does not seem to be relevant for choice of ablation approach.Figure 1