Concomitant atrial fibrillation procedures during septal myectomy: a Society of Thoracic Surgeons Database Analysis

BACKGROUND: Surgical ablation of atrial fibrillation (AF) during septal myectomy (SM) for hypertrophic obstructive cardiomyopathy has limited evaluation. We examined national outcomes and practice patterns for concomitant AF ablation during SM. METHODS: The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried for patients undergoing septal myectomy ± mitral valve surgery from 2014 to 2023. Patients undergoing SM with and without AF were compared. Patients with AF were stratified by surgical ablation vs. no ablation. 1:1 propensity score matching was used to account for baseline differences resulting in balanced groups. The primary outcome was operative mortality. Secondary outcomes included cross-clamp time, postoperative permanent pacemaker implantation, stroke, renal failure, and readmission within 30 days. RESULTS: The study cohort included 3,579 patients. Patients with AF (n=690) had more comorbidities and higher rates of operative mortality, new-onset renal failure, and 30-day readmission than those without AF (n=2889). 380 (55%) patients with AF underwent surgical ablation: pulmonary vein isolation (30.3%), left atrial only (54.3%), and biatrial ablation (15.5%). Paroxysmal AF was most common (n=546, 81.3%), Ablated patients had higher cross-clamp times, mitral valve surgery, and left atrial appendage occlusion (97%) versus non-ablated patients (21.4%). After matching, there was no difference in operative mortality, stroke, pacemaker implantation, new-onset renal failure, or readmission between AF patients who received SA and those who did not. CONCLUSIONS: Without increased risk of operative mortality, 30-day readmission, pacemaker, new-onset renal failure or stroke, concomitant AF ablation with left atrial appendage occlusion should be considered during septal myectomy.