Ventricular tachycardia ablation in arrhythmogenic right ventricular cardiomyopathy patients with TMEM43 gene mutations.

Introduction: Catheter ablation of VT in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) is often challenging, frequently requiring multiple or epicardial ablation procedures; TMEM43 gene mutations typically cause aggressive disease. We sought to compare VT ablation outcomes for ARVC patients with and without TMEM43 mutations.

Methods: Patients with prior ablation for ARVC-related VT were reviewed. Demographic, procedural, and follow-up data were reviewed retrospectively. Patients with confirmed TMEM43 gene mutations were compared to those with other known mutations or who had no known mutations.

Results: Thirteen patients (10 male, mean age 49 ± 14 years) underwent 29 ablation procedures (median 2 procedures/patient, range 1-6) with a median of 4 targeted VTs/patient (range 1-9). They were followed for a mean duration of 7.3 ± 4.2 years. Gene mutations included TMEM43 (n = 5), PKP2 (n = 2), DSG2 (n = 2), unidentifiable (n = 4). TMEM patients showed more biventricular involvement compared to non-TMEM patients (80% vs. 12.5%, P = 0.032), more inducible VTs during their ablation procedures (mean VTs/patient: 5.8 ± 3 vs. 2.6 ± 1, P = 0.021). Acute and long-term procedural outcomes did not show a significant difference between the two groups, however TMEM patients had worse composite endpoint of death or transplantation (60% vs. 0, P = 0.035; log-rank P = 0.013).

Conclusions: TMEM43 mutation patients were more likely to have biventricular arrhythmogenic substrate and more inducible VTs at EP study. Despite comparable acute VT ablation outcomes, long-term prognosis is unfavorable.