Impact of vein of Marshall ethanol infusion on left atrial function: an MRI study

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Previous data suggested that left atrial (LA) function may be impaired by extensive atrial fibrillation (AF) ablation. Ethanol infusion of Vein of Marshall (EI-VOM) as an adjunctive therapy to pulmonary vein isolation is an emerging therapeutic strategy that has shown to improve efficacy in persistent AF ablation procedures and mitral isthmus line. The impact of EI-VOM scar formation on LA function has not been addressed. Purpose To analyse the effect of EI-VOM on LA function, evaluated by magnetic resonance imaging (MRI) strain parameters. Methods Twelve patients referred for de novo persistent AF or any repeat procedure were included. MRI was performed previous (baseline) and 3-month after AF ablation. MRI images were analyzed off-line with specialized post-processing software. LA volumes, LA strain parameters, including LA global longitudinal strain (GLS), LA reservoir (LASr), conduit (LAScd) and contractile (LASct) strain; LA ejection fraction (LAEF), LA passive emptying function (LAPEF) and LA active emptying function (LAAEF) were measured from SSFPs two-chamber cine sequences. Results Two patients were excluded due to absence of VOM and failed ethanolization. Ten patients (83%) underwent both MRI studies (64 [55-71]years; 80% men; de novo ablation of persistent AF (50%)). Six patients received additional mitral isthmus line and three posterior wall isolation. Mean baseline indexed LA volume was 62.7ml/m2 [47-73]. Baseline LA strain and EF parameters were: LA GLS 17.16±15.3, LASr 17.80±14.9%, LAScd -5.96±3.7%, LASct -10.35±9.5%; LAPEF 5.89±9.8, LAAEF 23.87±17.0 and LAEF 27.6±18.3%. At 3-months follow-up, no AF recurrences were detected. No differences were found regarding LA volume (57.6ml/m2 [42-64], p=0.671), strain parameters (LA GLS Δ0.62, p=0.903; LASr Δ0.02, p=0.991; LAScd Δ-0.84, p=0.563; LASct Δ0.54, p= 0.874) and LAEF parameters (LAPEF Δ4.82, p=0.592; LAAEF Δ3.03, p=0.903; and LAEF Δ7.0, p=0.213). Conclusions EI-VOM appears as a safe adjunctive strategy in AF ablation in terms of LA function. The present study did not show impairment in the main MRI strain parameters.