Clinical Implication of Left Atrial Appendage Emptying Velocity in Thoracoscopic Ablation of Atrial Fibrillation

Background: There are limited data about predictors of atrial fibrillation (AF) recurrence after totally thoracoscopic ablation (TTA). This study investigated the clinical implication of left atrial appendage emptying velocity (LAAV) in patients undergoing TTA. Methods and Results: Patients who underwent TTA between 2012 and 2015 at a tertiary hospital were prospectively enrolled in this study. LAAV was measured and averaged over five heart beats from preoperative transesophageal echocardiography. The primary outcome was a freedom from recurrent AF or atrial flutter (AFL) detected on 24-h Holter monitoring or an electrocardiogram over a 3-year period after TTA. In all, 129 patients were eligible for analysis in this study. The mean (±SD) patient age was 54.4±8.8 years, and 95.3% were male. During the 3 years after TTA, the overall event-free survival rate was 65.3%. LAAV was an independent predictor of recurrent AF/AFL during the 3-year period after TTA (per 1-cm/s increase, adjusted hazard ratio [aHR] 0.95; 95% confidence interval [CI] 0.91–0.99; P=0.016). Event-free survival was significantly lower among patients with a low LAAV (<20 cm/s; n=21) compared with those with a normal (≥40 cm/s; n=38; aHR 6.11; 95% CI 1.42–26.15; P=0.015) or intermediate (LAAV ≥20 and <40 cm/s; n=70; aHR 2.74, 95% CI 1.29–5.83; P=0.009) LAAV. Conclusions: In patients with AF, LAAV was significantly associated with the risk of long-term recurrence of AF after TTA.