Outcomes of Septal Myectomy Associated With Surgical Volume

Previous studies have reported an inverse relationship between hospital septal myectomy (SM) volume and outcomes, without assessments of surgeon volume and SM outcomes. This Australia and New Zealand-based study sought to appraise the relationships between hospital volume, surgeon volume, and SM outcomes.

Data were collected from the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Database, from the time of inception of the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Database (2001) until 1 January 2021. Hospitals were divided into the lowest (one to three cases), middle (four to six cases), and highest tertiles (more than six cases) based on their annual SM case volume.

This study cohort included 1,132 patients and 115 surgeons. The surgeon volume ranged from one to 91 cases in total. The overall 30-day mortality after SM was 2.2%, and the rate of new-onset complete heart block requiring permanent pacemaker was 7.5%. Concomitant mitral valve repair and mitral valve replacement were performed in 8.1% and 11.7% of patients, respectively. Concomitant mitral valve replacement was associated with increased mortality. Septal myectomy performed at low-volume centres had a significantly higher mortality rate (4.9%) than at the middle- (1.3%, p=0.002) and the high-volume centres (1.1%, p=0.004). Surgeons who performed SM on patients who subsequently died within 30 days of SM had a significantly lower case volume than surgeons who performed SM on patients who were alive.

This study highlights the importance of centre and surgeon case volume in outcomes after SM.