Prognostic implication of left atrial strain in patients presenting early recurrence of atrial fibrillation after totally thoracoscopic ablation

Funding Acknowledgements Type of funding sources: None. Backgrounds Atrial fibrillation (AF) event during blanking period is a risk factor for late recurrence of AF in patients undergoing AF ablation. The aim of this study was to investigate clinical implications of left atrial (LA) strain for long-term outcome in patients experiencing early AF after totally thoracoscopic ablation (TTA). Methods A total of 128 patients who underwent totally TTA between 2012 and 2015 were enrolled from a tertiary center. Peak longitudinal LA strain was measured preoperatively. Early AF was defined as any AF events detected on 12-lead electrocardiogram or 24-hour Holter monitoring within 3-month blanking period after TTA. The primary outcome was recurrent AF at 5 years after TTA excluding blanking period. Results Of 128 patients, 42 (32.8%) experienced early AF during 3 months of blanking period after TTA. Patients experiencing early AF had a significantly higher risk of 5-year AF recurrence after blanking period compared with those without early AF (72.7% vs. 29.6%; adjusted hazard ratio [HR] 2.99; 95% confidence interval [CI] 1.69–5.27; p<0.001). Among 42 patients experiencing early AF, LA strain ≥18.6% was the only independent predictor of 5-year AF recurrence. Compared with patients with LA strain <18.6%, those with LA strain ≥18.6% had a significantly lower risk of 5-year AF recurrence (17.0% vs. 64.8%, adjusted HR 0.23, 95% CI 0.06–0.96, p = 0.044). Conclusions In patients undergoing TTA, early AF during blanking period was a risk factor of late recurrence. Among patients experiencing early AF, LA strain was an independent predictor for long-term AF recurrence.