Transapical beating-heart septal myectomy for Fabry cardiomyopathy with left ventricular outflow tract obstruction: a retrospective case series.

Background: Fabry disease (FD) is an X-linked lysosomal storage disorder characterized by glycosphingolipid accumulation, resulting in multi-organ dysfunction. Cardiac involvement, known as Fabry cardiomyopathy, may rarely present with left ventricular outflow tract (LVOT) obstruction, which is often refractory to pharmaceutical therapy and may require septal reduction therapy (SRT). Herein, we report the first clinical experience of transapical beating-heart septal myectomy (TA-BSM), a novel SRT procedure, in treating severe LVOT obstruction secondary to Fabry cardiomyopathy. Case Description: Four genetically confirmed FD patients with symptomatic LVOT obstruction underwent TA-BSM between October 2022 and September 2024. The cohort comprised two males with classic early-onset FD and two heterozygous females with predominantly cardiac involvement. Preoperative assessments included clinical evaluation, echocardiography, cardiac magnetic resonance (CMR) imaging, and genetic testing. TA-BSM was performed via a small apical puncture without cardiopulmonary bypass (CPB), under transesophageal echocardiography (TEE) guidance. Repeated resections were performed intraoperatively to optimize LVOT gradient, mitral regurgitation (MR), and systolic anterior motion (SAM). All procedures were technically successful without perioperative complications; all patients were discharged in a stable condition on postoperative day 7. At a mean follow-up of 12±8.8 months, all patients showed significant symptomatic improvement, with New York Heart Association (NYHA) functional class improving from III/IV to I/II. Echocardiography during follow-up revealed marked reductions in LVOT gradient (from 111.0±44.3 to 26.5±8.3 mmHg), MR grade (from ≥3+ to ≤2+), SAM grade (from ≥2 to ≤1), and septal thickness (from 26±4.1 to 18±3.9 mm). Conclusions: TA-BSM appears to be a feasible and effective therapeutic option for Fabry cardiomyopathy patients with severe LVOT obstruction refractory to medical therapy. These preliminary findings support the potential role of this novel, minimally invasive SRT technique in this rare patient population.