Po-02-195 adjunctive vein of marshall ethanol ablation for atrial fibrillation: single center experience and procedural learning curve

Retrograde ethanol infusion into the vein of Marshall (EI-VOM) has been demonstrated to be an effective adjunct to pulmonary vein isolation (PVI) for ablation of atrial fibrillation (AF). This study sought to assess the temporal change in procedural volume and associated success rate of VOM ethanol ablation. All patients undergoing PVI with EI-VOM at The Ohio State University Wexner Medical Center from January 2021 to November 2022 were included. Procedural success was defined as successful retrograde infusion of ethanol into the vein of Marshall followed the development of a characteristic distribution of low voltage scar in a semicircular pattern around the left inferior pulmonary vein on high-density electroanatomical mapping. The scar was adjudicated by two blinded high-volume operators. The primary endpoint was procedural success over 6-month intervals. Statistical significance was assessed via Fisher's exact test. 201 patients underwent attempted EI-VOM. Patient characteristics were notable for age 65.2 ± 9.0 years, 56 (28%) females, body mass index 33.1 ± 7.3 kg/m2, left ventricular ejection fraction 52.3 ± 11.3%, and CHA2DS2-VASc 2.9 ± 1.5. 113 (56%) patients had non-paroxysmal AF. 173 (86%) patients had failed antiarrhythmic drugs, 113 (56%) patients had a prior cardioversion, and 105 (52%) patients had a prior catheter ablation for AF. Over 23 months, procedural volume increased from an average of 2 cases/month to 12 cases/month, and the procedural success rate increased from 33% to 68% (p=0.020). Figure 1 demonstrates the case volume and procedural learning curve over time. Notable complications included 1 (0.5%) case of cardiac tamponade requiring pericardiocentesis. VOM ethanol ablation is associated with a significant learning curve, and procedural success rate significantly improves with increased case volume.