Transapical beating heart septal myectomy learning curve and training of future surgeons: an observational study

Description of the learning curve for transapical beating heart septal myectomy (TA-BSM) helps to understand the potential for wider adaptability. The authors elaborate and examine a competency-based training assessment for TA-BSM that could serve to disseminate septal myectomy expertise.

Data on 177 consecutive patients who underwent the TA-BSM for hypertrophic obstructive cardiomyopathy (HOCM) between April 2022 and June 2023 was collected prospectively, which was registered on ClinicalTrials.gov. Using the cumulative sum analysis, the authors identified two distinct learning phases based on the procedural time. Outcomes of procedural success and major complications were also compared between phases. Assessment through a Likert scale competency-based assessment of a myectomy surgeon after on-site TA-BSM training.

The cumulative sum analysis of procedural time showed two well-differentiated phases: the initial phase (cases 1-44) and the proficiency phase (cases 45-177). After 44 cases, significant improvements in procedural time were observed (113 vs. 134 min; P<0.001). Optimal procedural success (left ventricular outflow tract gradient <30 mmHg and mitral regurgitation grade ≤1+ without mortality or median sternotomy conversion) increased in the proficiency phase (93.2 vs. 79.5%; P=0.018), while complications decreased. The assessment of another surgeon showed consistent agreement in operative decision-making and performance for all evaluated domains.

Competence in TA-BSM was achieved after 44 cases, without sacrificing guideline-desired outcomes. Appropriate training of other septal myectomy surgeons could further expedite this learning curve. This new technique may represent an option for wider dissemination of HOCM surgery worldwide and improve disease management.