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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Funding from the Swedish Heart-Lung foundation (project number 20230080 and project number 20230742), and the European Union (ERC, MultiPRESS, 101075494). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Approval was granted by the Swedish Ethical Review Authority with the registration number: 2022-01472-01. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.