Alcohol septal ablation in hypertrophic obstructive cardiomyopathy: do sex, mitral valve leaflet length and septal thickness affect the outcome?

Purpose This retrospective cohort study aimed to assess whether basal septal wall thickness (BSWT), anterior (AML) and posterior (PML) mitral leaflet length, or sex were associated with remaining left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing alcohol septal ablation (ASA). Methods 154 patients that underwent ASA at the Karolinska University Hospital in Stockholm, Sweden, between 2009 and 2021, were retrospectively included. Anatomical and hemodynamic parameters were collected from invasive catheterization before and during ASA, and from echocardiography (ECHO) examinations before, during, and at one-year follow-up after ASA. Linear and logistic regression models were used to assess the association between sex, BSWT, AML, PML, and outcome defined as remaining LVOTO ( > 30 mmHg) after ASA. Results The median follow-up was 364 days (IQR 334-385 days). BSWT > 23 mm (n=13, 12%) was associated with remaining LVOTO at follow-up ( p=0.004 ). Elongated MVLL (either AML or PML) was present in 125 (90%) of the patients. Elongated AML (>24 mm) was present in 67 (44%) of the patients, although AML length was not associated with remaining LVOTO at follow-up. Elongated PML (>14 mm) was present in 114 (74%) and not associated with remaining LVOTO at follow-up. No significant sex differences were observed regarding remaining LVOTO. Conclusion ECHO measurement of BSWT can be used effectively for patient selection for successful ASA and for identification of patients with a risk of incomplete resolution of LVOTO after ASA.