P1017Thoracoscopic AF ablation is a successful treatment for patients with a giant left atrium

Abstract

Abstract Background Severely enlarged left atrial (LA) volume is associated with a considerable ineffective outcome of ablation for atrial fibrillation (AF). Therefore, in patients with AF and a giant atrial volume catheter ablation is not recommended. However, thoracoscopic AF ablation is being performed in patients with AF and giant LA, but with unknown efficacy. Purpose To determine efficacy of thoracoscopic AF ablation in patients with AF and a giant LA. Methods Patients underwent thoracoscopic AF ablation (paroxysmal AF) plus additional left atrial ablations (persistent AF) and were prospectively followed. Giant LA was defined as left atrial volume index (LAVI)≥50 ml/m2, outcome was also assessed for LAVI≥55 ml/m2. Follow-up was performed with ECGs and 24-hour Holters every three months. After a 3-month blanking period, all AADs were discontinued. Primary outcome was recurrence of any atrial tachycardia ≥30 sec during one year of follow-up. Results Between 2008–2017, 357 patients underwent thoracoscopic AF ablation. At baseline, giant LA was diagnosed in 72 (20.2%) patients (mean LAVI: 59.5±9.6 ml/m2), while 285 (79.8%) had a smaller left atrium (mean LAVI: 36.3±7.8 ml/m2), p<0.001. Giant LA patients were older (mean: 61.7±6.9 vs 59.3±9.0 years, p=0.03) and more often diagnosed with persistent AF (n=60, 83.3%) compared to control (n=164, 57.5%), p<0.001. Sex (female: n=19, 26.4% vs n=79, 27.7%, p=0.82) and history of AF (median: 4.0 [IQR: 2.0–6.0] vs 4.0 [IQR: 2.0–8.0] years, p=0.10) were equally distributed. Freedom of any atrial tachycardia did not differ significantly between both groups (n=43, 59.7% vs n=195, 68.4%, log rank p=0.91), figure. This was similar for the cut-off of LAVI≥55 ml/m2: n=24/43 (55.8%) vs n=214/314 (68.2%), p=0.15). AF recurred in 16 (22.2%) patients with giant LA compared to 55 (19.3%) patients, while atrial tachycardia recurred in 21 (29.2%) vs 56 (19.6%) patients, respectively, p=0.06. Kaplan-Meier analysis of AF recurrence i Conclusion Thoracoscopic AF ablation is an effective therapy in patients with a giant LA. Thoracoscopic AF ablation may therefore be a feasible treatment for patients with a giant LA.