Background and aims: Pulmonary vein isolation (PVI) alone achieves modest arrhythmia freedom in persistent atrial #fibrillation (PeAF). Ethanol infusion of the vein of #Marshall (EIVOM) overcomes heat-sink effects, facilitating mitral isthmus (MI) block, and may represent an effective adjunctive ablation strategy. We aimed to quantify the efficacy and safety of EIVOM through a meta-analysis of randomized controlled trials (RCTs).
Methods and results: Systematic review of MEDLINE, Web of Science, and PubMed identified 5 RCTs enrolling 1,179 patients (602 EIVOM, 577 control). The primary endpoint was 12-month freedom from any atrial arrhythmia. Random-effects models generated risk ratios (RR) with 95% confidence intervals (CI). Time-to-event data were pooled using a generic inverse-variance approach to derive hazard ratios (HR). EIVOM-based strategies improved freedom from any arrhythmia (RR 1.16, 95% CI 1.04-1.29; P<0.001; NNT=10) and from AF (RR 1.11, 95% CI 1.05-1.18; P<0.001; NNT=13). Time-to-event analysis demonstrated a sustained reduction in recurrence hazard (HR 0.72, 95% CI 0.64-0.81; P=0.003; I2=0%). Repeat ablation was reduced (RR 0.61; P=0.009). Fluoroscopy time increased (+9.08 minutes; P=0.007), while major complications were comparable (2.5% vs 2.8%; P=0.47). Trial Sequential Analysis confirmed that the cumulative Z-curve crossed the monitoring boundary for benefit for the primary endpoint, indicating that the available evidence is sufficient.
Conclusion: In PeAF, EIVOM-based ablation strategies significantly improve 12-month arrhythmia-free survival and reduce repeat procedures without increasing major adverse events. However, the observed benefit reflects composite ablation sets rather than ethanol infusion in isolation, and the predominance of high-volume expert centres may limit generalizability.
https://academic.oup.com/europace/advance-article/doi/10.1093/europace/euag069/8571854
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