P992Incidence, predictors, and success of ventricular tachycardia catheter ablation in arrhythmogenic right ventricular cardiomyopathy (ARVC): A long-term cohort study from the Nordic ARVC registry

Background Catheter ablation may reduce ventricular tachycardia (VT) burden in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients. However, little is known about factors predicting need for ablation and various outcomes have been reported. Purpose We sought to investigate predictors and use of VT ablation and to evaluate the post-procedural outcome in ARVC patients. Methods We studied 435 patients from the Nordic ARVC registry including 220 probands with definite ARVC according to the 2010 task force criteria and 215 mutation-carrying relatives identified through cascade screening. Patients were followed until first-time VT ablation, death, heart transplantation, or January 1st 2018. Additionally, patients undergoing VT ablation were further followed from the time of ablation for recurrent ventricular arrhythmias. Results Cumulative use of VT ablation was 4% (95% CI 3%-6%) and 11% (95% CI 8%-15%) after 1 and 10 years. All procedures were performed in probands in whom the cumulative use was 8% (95% CI 5%-12%) and 20% (95% CI 15%-26%). In adjusted analyses restricted to probands, only young age predicted need for ablation. In patients undergoing ablation, risk of recurrent arrhythmias was 59% (95% CI 44%-71%) and 74% (95% CI 59%-84%) 1 and 5 years after the procedure. Despite high recurrence rates, the burden of ventricular arrhythmias was reduced after ablation (p=0.0042). Young age, use of several antiarrhythmic drugs and inducibility to VT immediately after ablation were associated with an unfavorable outcome. Conclusions Twenty percent of ARVC probands developed a clinical indication for VT ablation within 10 years after diagnosis whereas mutation-carrying relatives were without such need. Although the burden of ventricular arrhythmias decreased after ablation, risk of recurrence was substantial.