Po-02-089 empiric vein of marshall ethanol infusion in patients undergoing repeat catheter ablation with durably isolated pulmonary veins

The procedural strategy for patients with recurrent atrial fibrillation (AF) despite isolated pulmonary veins is unknown. Ablative strategies beyond pulmonary vein isolation (PVI) have not consistently shown benefit. Vein of Marshall (VoM) ethanol ablation has a proven benefit in patients with persistent AF undergoing index procedure, however its role in patients with durably isolated pulmonary veins is unknown. To evaluate the benefit of empiric VoM ethanol ablation in addition to posterior wall isolation (PWI) during the repeat procedure in patients with durable pulmonary vein isolation from index procedure. Twenty-three patients (age 67.1 +/- 7.4, 74% males) who received empiric VoM ethanol infusion in addition to PWI (study group) were matched for age, gender, EF and LA size with thirty-four historic patients receiving empiric PWI alone (control group). All patients in the study group underwent endocardial ablation on the mitral isthmus to complete a lateral mitral isthmus line. Additional ablation was based on program and trigger stimulation. Primary outcome was freedom from AF or AT after a blanking period of 3 months using either qualification of symptoms, routine office EKG, wearable or implantable monitor or device (pacemaker or defibrillator). Significant baseline characteristic differences between study vs control group included BMI (35.07 +/- 8.98 vs. 30.85 +/- 5.65, p = 0.033) and incidence of persistent AF (83% vs. 55%, p=0.029). The 1 year AF-free survival for the study and control groups were 20 (86.96%) and 21 (61.76%) patients respectively (p=0.038). Cox proportional hazard regression analysis showed significant reduction in AF or AT recurrence in the study group (HR 0.26, 95% CI 0.074-0.919, p=0.037). Among patients undergoing repeat catheter ablation for recurrent AF with durably isolated pulmonary veins, addition of VoM ethanol infusion increased the likelihood of remaining free from AF or AT at 12 months. The mechanism for increased long-term procedural success with VoM ethanol infusion is unclear. It may be due to ablation of non-pulmonary vein triggers originating from the ligament of Marshall, left atrial parasympathetic denervation, or transmural block across the lateral mitral isthmus with ablation of epicardial connections.