Single-center experience of surgical atrial ablation in case of septal myectomy

Background. Atrial fibrillation is the most common form of arrhythmia in patients with hypertrophic cardiomyopathy. Atrial fibrillation is associated with a significant deterioration in the clinical condition, a high risk of thromboembolic complications in patients with HCM. However, mid-term data on the simultaneous surgical treatment of hypertrophic cardiomyopathy and atrial fibrillation are limited.

Aim. The aim of this study was to evaluate mid-term results of concomitant surgical ablation of atrial fibrillation during septal myectomy in patients with obstructive hypertrophic cardiomyopathy.

Methods. Since 2014 till 2019 55 eligible patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation underwent concomitant surgical ablation and septal myectomy. A left atrial set for performing ablation was chosen in 38 patients (69.1%), maze IV - 17 patients (30.9%). Surgical ablation was performed using an isolated cryoablation energy source or combination with radiofrequency source. The primary endpoint was recurrence of atrial fibrillation, atrial flutter and atrial tachycardia (AF/AFL/AT) in the mid-term follow-up period., Holter monitoring was performed 2 times a year during 24 months of the postoperative period, then 1 time per year.

Results. Median follow-up was 47 months (Q1-Q3: 34-67). Freedom from AF/AFL/AT (primary endpoint) was 73.3% (95% CI: 60.0-86.7%) in 36 months after surgery. Use of a cryoablation energy source was an independent risk factor of arrhythmias (Hazard Ratio 45.56; 95% CI: 1.55-1340.85; p=0.027). Mid-term survival was 88.6% (95% CI: 76.3-94.7%) in 36 months after surgery. Freedom from thromboembolic events was 98.2% (95% CI: 87.7-99.7%) in 36 months after surgery.

Conclusion. Surgical atrial ablation during septal myectomy in patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation is a highly effective procedure in freedom from AF/AFL/AT. In addition, the procedure of surgical ablation allows improving mid-term results in freedom from thromboembolic events.

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