Abstract 259: Outcomes And Success Of Ventricular Tachycardia Ablation In Patients With Implantable Cardioverters Defibrillators

Implantable cardioverter defibrillators (ICDs) have proven efficacy in terminating ventricular tachycardias (VT) by antitachycardia pacing (ATP) or implantable cardioverters defibrillators (ICD) shock and reducing the risk for sudden cardiac death (SCD). However, they do not prevent VT recurrences, and these patients may have a subsequent heart failure or death. For patients with ICDs and failure to antiarrhythmic drug (AAD) therapy the major alternative is catheter ablation (CA). The goal was to assess the outcomes of VT ablation, including inducibility, early VT recurrences and ATP effectiveness after CA in pts with ICDs.

Methods: We analyzed the data of 38 patients, age 43-84 (avg.= 68.76±14.2 years), 33 (90%) males with monomorphic VT and implanted ICD who underwent radiofrequency CA during last 2.5 years (2019 Jan – 2021 July); 32 (82.1%) have failed AAD therapy; 17 (43.6%) patients had an ICD implanted for primary and 22 (56.4%) for secondary prevention; 18 (46.2%) of them had reduced ejection fraction (EF) <35%. The time from ICD implantation to CA was av. 3.61 years.

Results: During first year of follow-up after CA procedure 14 (36.8%) pts experienced an early recurrence of VT, which required the therapy from their ICD device: 5 (35.7%) of them had EF <35%. The inducibility of VT post-CA was identified in 15(39.5%) pts, 8(53.43%) of them with EF <35%. Average time of the reoccurrence of VT was 23.7 days (range 0 – 12.2 months). The frequency of VT storm was significantly lower post-CA comparing to pre-CA: 30 (78.9%) vs 8 (21.1%), p <0.001. The effectiveness of ATP was higher post-CA as 6 (42.9%) vs 6 (19.4%) pre-CA pts have received successful VT termination by ATP and the need for ICD shock was lower: 25(80.6%) pre-CA vs 9 (62.3%) post-CA. The success of ATP was in 2 (11.8%) pts with EF <35% vs 4 (21.1%) in pts with EF ≥35%. Patients with non-ischemic cardiomyopathy (NICM) required less ICD shocks as compared to ICM – 2(12.5%) vs 6 (88.9%), p<0.001.

Conclusions: The inducibility of VT post-CA is higher in patients with lower EF. The frequency of VT storm is significantly reduced post-CA. The success of ATP for VT termination is higher in pts with EF ≥35% and in pts with NICM.