Safety and Midterm Outcome of Focal Pulsed Field Ablation for Outflow Tract Premature Ventricular Contractions

BACKGROUND: Pulsed field ablation (PFA) may overcome key limitations of radiofrequency ablation (RFA) when treating premature ventricular contractions (PVCs) in anatomically complex regions (eg, left ventricular summit or intramural outflow tract [OT]). However, the safety and efficacy of PFA in OT PVCs remain to be determined. OBJECTIVES: This study sought to assess the feasibility, safety, and midterm clinical outcomes of focal PFA for outflow tract PVCs. METHODS: In this prospective multicenter study, 80 patients with symptomatic OT PVCs underwent focal monopolar PFA using the CENTAURI generator at 4 European centers. Acute procedural outcome, complications, and mid-term efficacy were assessed. Follow-up at 3 and 6 months included 24-hour Holter electrocardiogram and clinical evaluation. Success was defined as >80% reduction in daily PVC burden off antiarrhythmic drugs. RESULTS: PVCs originated from the right ventricular OT (RVOT) in 61% of cases, with the remainder from the left ventricular OT (LVOT) and left ventricular summit. Acute procedural success was achieved in all. At a median follow-up of 8 months, clinical success was achieved in 88%, and PVC burden was significantly reduced from 21.4% (Q1-Q3: 11.9%-30.0%) before the procedure to 0.0% (Q1-Q3: 0.0%-2%) (P < 0.001) at follow-up. Success rates of ablation at the RVOT, endocardial LVOT, and left ventricular summit were 94%, 89%, and 72%, respectively. Among patients with prior failed RFA, 14 (93%) of 15 experienced no recurrence. One major (ischemic stroke; 1%) and 7 minor (9%) complications occurred. Nitroglycerin was given in 68 (85%) of 80 procedures. During ablation in the great cardiac vein/anterior interventricular vein, coronary vasospasm occurred in 2 (17%) of 12 patients, which resolved with additional nitroglycerin administration. Right bundle branch block occurred during RVOT ablation in 2 patients (1 transient, 1 permanent). CONCLUSIONS: Focal PFA provides high acute success and acceptable mid-term efficacy for OT PVCs, with outcomes comparable to contemporary RFA for RVOT and endocardial LVOT sites. Efficacy was lower for left ventricular summit and intramural substrates. Repeat procedures after failed RFA showed particularly favorable results. Coronary vasospasm occurred when PFA was delivered within the great cardiac vein/anterior interventricular vein, suggesting that venous PFA should be considered only after endocardial and alternative mapping/ablation strategies have been exhausted.