Determinants of outcome impact of Vein of Marshall Ethanol infusion when added to catheter ablation of persistent atrial fibrillation: A secondary analysis of the VENUS randomized clinical trial.

Abstract

BACKGROUND\nThe VENUS trial demonstrated that adding vein of Marshall (VOM) ethanol infusion to catheter ablation (CA) improves ablation outcomes in persistent atrial fibrillation (AF). There was significant heterogeneity in the impact of VOM ethanol infusion on rhythm control.\n\n\nOBJECTIVE\nTo assess the association between outcomes and: 1) achievement of bidirectional perimitral conduction block, and 2) procedural volume.\n\n\nMETHODS\nVENUS randomized patients (n=343) with persistent AF to CA combined with VOM ethanol, or CA alone. Primary outcome (freedom from AF or tachycardia -AT- longer than 30s after a single procedure) was analyzed by 2 categories: 1) Successful vs no perimitral block. 2) High- (>20 patients enrolled) vs low-volume centers.\n\n\nRESULTS\nIn patients with perimitral block, the primary outcome was reached 54.3% after VOM-CA and 37% after CA alone (P=0.01). Among patients without perimitral block, freedom from AF/AT after VOM-CA was 34.0% and 37.0% after CA (P=0.583). In high volume centers, the primary outcome was reached in 56.4% after VOM-CA and 40.2% after CA (P=0.01). In low volume centers, freedom from AF/AT was 30.77% after VOM-CA and 32.61% after CA (P=0.84). In patients with successful perimitral block from high volume centers, the primary outcome was reached in 59% after VOM-CA and 39.1% after CA in (P=0.01). Tests for interaction were significant (P=0.002 for perimitral block and P=0.04 for center volume).\n\n\nCONCLUSION\nAdding VOM ethanol infusion to CA has greater impact on outcomes when associated with perimitral block and performed in high-volume centers. Perimitral block should be part of VOM procedure.