Does adding ethanol infusion in the vein of Marshall (EIVOM) improve rhythm outcomes in persistent atrial fibrillation (AF)? A meta-analysis of randomized controlled trials (RCTs) presented at the ACC.26 provides updated evidence on this adjunctive approach to catheter ablation (CA).

Catheter ablation (CA) remains a standard rhythm control strategy in persistent atrial fibrillation (AF), yet recurrence of atrial tachyarrhythmia limits long-term success. Ethanol infusion in the vein of Marshall (EIVOM) has been evaluated as an adjunct, particularly in procedures centered on pulmonary vein isolation (PVI).

This meta-analysis included six randomized controlled trials (RCTs) with 1,223 patients. Of these, 626 underwent EIVOM with CA (EIVOM+CA) and 597 received CA alone. The primary endpoint was atrial tachyarrhythmia recurrence after a 3-month blanking period. Random-effects models were used to estimate risk ratios (RRs) with 95% confidence intervals (CIs). Prespecified subgroup analyses compared PVI-only strategies with PVI plus linear ablation.

EIVOM+CA was associated with a lower rate of atrial tachyarrhythmia recurrence compared with CA alone (RR 0.77; 95% CI, 0.63 to 0.94; I²=36%). In the PVI-only subgroup, recurrence remained lower with EIVOM+CA (RR 0.68; 95% CI, 0.51 to 0.91; I²=24%). In the PVI plus linear ablation subgroup, the difference was not statistically significant (RR 0.86; 95% CI, 0.62 to 1.19; I²=47%). 

Repeat ablation procedures were less frequent with EIVOM+CA (RR 0.61; 95% CI, 0.44 to 0.84; I²=0%). Vascular access complications were infrequent and did not differ significantly between groups (RR 0.51; 95% CI, 0.17 to 1.53; I²=0%). These findings indicate that EIVOM used with CA is associated with lower recurrence in persistent AF, with variation across ablation strategies and moderate heterogeneity across trials.