Po-05-094 long term outcomes after bipolar radiofrequency ablation for intraseptal ventricular tachycardias in non-ischemic and ischemic cardiomyopathy – a multi-center experience

Ventricular tachycardia (VT) arising from mid-myocardial substrate of the interventricular septum (IVS) can be challenging for ablation. Bipolar radiofrequency ablation (B-RFA) is a potential option for treating VT of septal origin however there are limited data on outcomes of B-RFA for septal VT comparing individuals with non-ischemic cardiomyopathy (NICM) to those with ischemic cardiomyopathy (ICM). The purpose of this study is to describe the outcomes of B-RFA for septal VT in a multicenter study of patients with NICM and ICM. We included 46 patients (mean age 66 ± 10 years; 95% male; left ventricular ejection fraction 33% ± 12%; 50% with history of prior VT ablation) who underwent B-RFA for VT of septal origin. Septal VTs were determined after failed unipolar ablation or VT substrate mapped by electroanatomic mapping of IVS. Short-term outcomes including non-inducibility of VT after ablation as well as long-term outcomes including recurrent VT, repeat VT ablation and death were evaluated at mean follow-up (FU) of 37 ± 18 months. Of the 46 total patients, 30 patients (65%) had NICM and 16 (35%) had ICM. Noninducibility of the clinical VT immediately after B-RFA was achieved in 27 patients (90%) with NICM vs 16 patients (100%) with ICM. During FU, recurrent VT occurred in 17 patients (37%) overall. Recurrent VT occurred in 14 patients (47%) with NICM vs in 3 patients (19%) with ICM. For those with NICM, 11 patients (37%) underwent repeat VT ablations, including 5 patients (17%) who underwent repeat B-RFA. For those with ICM, 3 patients (19%) underwent repeat VT ablation, and no patients underwent repeat B-RFA. During FU, death occurred in 5 patients (17%) with NICM vs 3 patients (19%) with ICM. B-RFA is an effective strategy for terminating VT of septal origin with a high acute success rate. Recurrent VT after B-RFA and repeat ablations were more common in patients with NICM.