Alcohol Septal Ablation for Left Ventricle Outflow Tract Obstruction Prevention Before Transcatheter Mitral Valve...

Left ventricle outflow tract obstruction (LVOTO) is the main limitation of transcatheter mitral valve replacement (TMVR) procedure occurring in 7%-9% of cases and responsible of 25% TMVR screen failures.

We aim to assess the alcohol septal ablation (ASA) effect on LVOTO risk before TMVR by multistage cardiac computed tomography (CT).

Patients indicated for TMVR procedure using Sapiens 3 Prosthesis with high LVOTO risk were enrolled in the study. ASA was the first choice technique to reduce this risk based on multiple and staged cardiac CT screening.

Out of 29 consecutive TMVR procedures conducted in our center between March 2021 and April 2023, nine patients presented high LVOTO risk and were enrolled in our study. The main risk factor retained was a reduced predicted NeoLVOT surface 89 mm² [66-135] (< 170 mm²). Most procedures were valve in MAC and all patients underwent at least one ASA. CT control showed a significant increase by 95% in the predicted NeoLVOT surface: 174 mm² [121-240]; p = 0.012 compared to the baseline value. There were no significant paraprosthesis leakage or LVOTO found on TTE according to the MVARC criteria. Cardiac CT showed a larger than predicted final NeoLVOT surface: 215 mm² [175-317]; p = 0.018. One patient died after ASA, and two others during the first year of follow-up. Survivors had significant symptom relief (p = 0.046) and a decreased PASP (38 mmHg [32-47] vs. 54 mmHg [46-62.5]; p = 0.028).

Multistage CT analysis shows that ASA is effective in high LVOTO-risk patients undergoing TMVR.