Vein of Marshall Ethanol Infusion Related Lesion Durability: Looking for the Real Scar. Center‐Cluster, Case‐Control Study

Introduction Vein of Marshall ethanol infusion (VOM‐EI) in patients with Atrial Fibrillation (AFib) triggers local injury, which may increase the subsequent radiofrequency catheter ablation (RFCA) success rate in persistent atrial fibrillation (PeAF). The long‐term durability of VOM‐EI induced low‐voltage area (LVA), might condition the success of RFCA after VOM‐EI. We hypothesized that the amount of LVA after VOM‐EI decreases over time. Methods Consecutive patients with recurrent PeAF and no history of previous ablation were enrolled in this prospective, center‐cluster, case‐control study. In the experimental group, RFCA was performed 1 month after VOM‐EI. In the control group, VOM‐EI and RFCA were performed concomitantly. The primary endpoint was the bipolar VOM‐EI LVA measured immediately prior to RFCA. Results We studied 80 consecutive patients who met the inclusion criteria. The two groups did not differ in baseline characteristics. The mean bipolar VOM‐EI‐LVA measured before RFCA was significantly smaller in the 40 patients who underwent VOM‐EI 1 month earlier than in the group of 40 patients who underwent the standard procedure (2.6 ± 2.4 vs. 10.0 ± 7.0 cm 2 , p = 0.012). At a mean follow‐up of 19.6 ± 7.3 months, freedom from AF/AT recurrences was promisingly higher in the investigational group compared to the control group (90.0% vs. 82.5%). Conclusion These data suggest that the endocardial newly‐formed lesion induced by VOM‐EI decreases over time, probably due to progressive resolution of perilesional oedema. These results merit larger studies testing the hypothesis that postponing RFCA 1 month after VOM‐EI may increase its effectiveness in terms of fewer recurrences of atrial fibrillation.