Efficacy of Adjunctive Vein of Marshall Ethanol Ablation for Atrial Fibrillation

Purpose: Vein of Marshall ethanol ablation (VOM-EA) as an adjunct to pulmonary vein isolation (PVI) has been reported to improve freedom from atrial fibrillation (AF) and atrial tachycardia (AT). The purpose of this study was to assess the procedural success rate and clinical efficacy of VOM-EA.

Material and Methods: Patients consecutively underwent PVI with attempted VOM-EA from January 2021 to April 2023 at The Ohio State University Wexner Medical Center. Patients with missing or inadequate electroanatomical maps (EAM) were excluded. Patients were stratified as successful vs unsuccessful VOM-EA, with success defined as retrograde ethanol infusion into the VOM followed by development of a characteristic distribution of low voltage area around the left inferior pulmonary vein on bipolar voltage maps. The primary endpoint was cumulative AF/AT burden based on prolonged cardiac monitoring (30-day mobile cardiac telemetry, implantable loop recorder, or cardiac implantable electronic device interrogation) after the 3-month blanking period. The secondary endpoints were need for antiarrhythmic drugs (AAD), need for cardioversion, and need for repeat catheter ablation at long-term clinical follow up.

Results: VOM-EA was attempted in 262 patients, and among the 231 (88%) patients with adequate EAM, 131 (57%) vs 100 (43%) patients had successful vs unsuccessful VOM-EA. Patient characteristics were similar between groups with overall age 65±9 years, 30% females, LVEF 53±11%, CHA2DS2-VASc 2.9±1.4, 40% with paroxysmal AF, and 56% with a prior cardioversion. Notably, patients with successful vs unsuccessful VOM-EA, had significantly less prior AAD use (84% vs 93%, p=0.019) and prior AF ablations (42% vs 55%, p< 0.050). Among the 185 (80%) patients with post-ablation telemetry, patients with successful vs unsuccessful VOM-EA had a significantly lower cumulative AF/AT burden (4.2±15.5% vs 11.4±28.2%, p=0.039). After mean follow up of 320±210 days, patients with successful vs unsuccessful VOM-EA had significantly less need for AAD (24% vs 38%, p=0.024), but there was no difference in the need for cardioversion or repeat catheter ablation.

Conclusions: VOM-EA is a challenging technique with a 57% procedural success rate, and successful VOM-EA is associated with significantly lower AF/AT burden and need for AAD.