Adjunctive ablation at the mitral isthmus in patients with left ventricular pacing leads: A retrospective multicenter analysis of safety and feasibility

BACKGROUND Vein of Marshall Ethanol Infusion (VOMEI) has benefit in patients with persistent atrial fibrillation (AF) and perimitral atrial flutter, while coronary sinus ablation (CS RFA) improves mitral isthmus (MI) block. Atrial arrhythmias frequently coexist with left ventricular (LV) systolic dysfunction, for which cardiac resynchronisation (CRT) may be indicated OBJECTIVE: To evaluate the safety, feasibility, and outcomes of VOMEI±CS RFA in patients with CRT METHOD: Coding data was used to identify consecutive patients with CRT who underwent VOMEI±CS RFA at two centres. Controls without CRT who underwent contemporaneous VOMEI±CS RFA provided comparison. Clinical and procedural characteristics as well as recurrence within 12 months were recorded for all patients. Lead parameters were compared pre- and post-ablation in patients with CRT, and any lead dysfunction over 43±21months follow up recorded RESULTS: VOMEI was feasible in 94% (94% CRT vs 97% control, P=0.92), and CS RFA in 89% (84% vs 93%, P=0.71). Complications occurred in 5% (6% vs 3%, P=0.54), precluding successful VOMEI without causing patient morbidity. No difference in the need for alternative fluoroscopic projections, balloon-occlusion venography, or MI block achievement was seen. No significant change in LV lead parameters was observed, and only one case of lead dysfunction was seen (phrenic capture, 2%). Arrhythmia recurrence within one year was 42% vs 24% CONCLUSION: VOMEI and CS RFA is feasible and safe in patients with LV leads. Complications are uncommon and preclude VOMEI without causing patient morbidity when they occur, and the risk of clinically significant lead dysfunction is low.