Short-term results of alcohol septal ablation as a bail-out strategy to treat severe left ventricular outflow tract obstruction after transcatheter mitral valve replacement in patients with severe mitral annular calcification

Objectives: To evaluate the outcomes of the early experience of percutaneous alcohol septal ablation in patients with severe left ventricular outflow tract (LVOT) obstruction post transcatheter mitral valve replacement (TMVR). Background: Severe LVOT obstruction with hemodynamic compromise is a complication of TMVR associated with high mortality. Percutaneous alcohol septal ablation has recently been described as a therapeutic option in this setting. Methods: Multicenter retrospective review of clinical outcomes of patients undergoing alcohol septal ablation to treat LVOT obstruction after TMVR for severe mitral stenosis with severe mitral annular calcification. Results: Six patients underwent percutaneous alcohol septal ablation to treat LVOT obstruction post-TMVR at six different centers. Five patients had immediate significant reduction in LVOT obstruction with improvement in hemodynamic status while one had persistent LVOT gradient but hemodynamic instability improved. The first patient died on postoperative day 4 due to complete heart block. One patient had initial improvement in LVOT gradient with recurrence on postoperative day 1 thought to be secondary to septal edema, was treated with surgical removal of the transcatheter valve and resection of the anterior mitral leaflet followed by transatrial TMVR and died 3 weeks later due to multi-organ failure. The remaining four patients improved clinically after alcohol septal ablation, were discharged from the hospital and were clinically stable at 30-day follow-up. Conclusions: Percutaneous alcohol ablation provides acute relief of TMVR-induced LVOT obstruction when septal hypertrophy is a contributing factor. This may be a safer alternative to bail-out surgery in this extremely high-risk patient population.