Sex-Related Differences among Adults with Hypertrophic Obstructive Cardiomyopathy Undergoing Transcoronary Ablation of Septal Hypertrophy.

(1) Background: The transcoronary ablation of septal hypertrophy (TASH) is an established therapy for hypertrophic obstructive cardiomyopathy (HOCM). Previous studies on this topic are characterised by a consistent male predominance and show a worse prognosis in females. (2) Methods: This study is a retrospective analysis of all TASH procedures conducted between 2006 and 2021 at a tertiary academic centre. A solution of 75 µm microspheres (Embozene ® , Boston Scientific, Marlborough, MA, USA) was used as an embolising agent. The outcomes of interest were left ventricular outflow tract (LVOT) gradient reduction and symptom improvement among males vs. that among females. Secondarily, we analysed the sex-related differences in procedural safety outcomes and mortality. (3) Results: The study population consisted of 76 patients, with a median age of 61 years. Females comprised 57% of the cohort. We observed no sex-related differences in the baseline LVOT gradients at rest or under provocation ( p = 0.560 and p = 0.208, respectively). Females were significantly older at the time of the procedure ( p < 0.001), had lower tricuspid annular systolic excursion (TAPSE) ( p = 0.009), presented a worse clinical status according to the NYHA functional classification (for NYHA ≥ 3, p < 0.001), and were more often on diuretics ( p < 0.001). We did not observe sex-related differences in absolute gradient reduction at rest ( p = 0.147) and under provocation ( p = 0.709). There was a reduction in the NYHA class by a median value of 1 ( p = 0.636) at follow-up for both sexes. Postprocedural access site complications were documented in four cases (two of which concerned females), and complete atrioventricular block was noted in five patients (three of which concerned females). The 10-year survival rates were comparable between the sexes (85% in females and 88% in males). The female sex was not associated with enhanced mortality according to multivariate analysis after adjusting for the confounding variables (HR 0.94; 95% CI 0.376-2.350; p = 0.895), but we observed age-related differences in long-term mortality (HR 1.035; 95% CI 1.007-1.063; p = 0.015). (4) Conclusions: TASH is safe and effective in both sexes, irrespective of their clinical differences. Women present at an advanced age and with more severe symptoms. An advanced age at the time of the intervention is an independent predictor of mortality.