Predicting favourable outcomes in the setting of radiofrequency catheter ablation of long-standing persistent atrial fibrillation: a pilot study assessing the value of left atrial appendage peak flow velocity.

Background: Catheter ablation is an effective and potentially curative treatment in patients with atrial fibrillation (AF).

Aim: To test the hypothesis that left atrial appendage peak flow velocity (LAV) assessed by echocardiography can accurately predict successful catheter ablation as well as favourable outcome in the setting of long-standing persistent AF.

Methods: This prospective pilot study enrolled 40 patients with long-standing persistent AF (age 60 ± 11 years; persistence of AF 4.2 ± 2 years) who underwent a first catheter ablation procedure using a standardized sequential stepwise protocol. LAV was assessed before the catheter ablation procedure along with classical factors (age, sex, left atrial area, AF cycle length, AF duration and left ventricular ejection fraction), all of which were tested using logistic regression for ability to predict restoration of sinus rhythm during catheter ablation as well as absence of recurrence during a 1-year follow-up.

Results: Eighteen patients (45%) experienced AF termination during the procedure and 18 patients (45%) did not develop any recurrence during the first 12 months. Multivariable analysis demonstrated that high LAV (>0.3 m/s) was the only independent predictor of AF termination (odds ratio 5.91, 95% confidence interval 1.06-32.88; P=0.04) and absence of recurrence at 1 year (odds ratio 4.33, 95% confidence interval 1.05-17.81; P=0.04).

Conclusions: This pilot study demonstrated the feasibility and importance of LAV measurement in the setting of long-standing persistent AF to predict successful catheter ablation and favourable mid-term outcome.