Predictors for reduced flow velocity in left atrial appendage during sinus rhythm in patients with atrial fibrillation.

Discontinuation of anticoagulation therapy after catheter ablation (CA) for atrial fibrillation (AF) remains controversial. While decreased left atrial appendage flow velocity (LAAFV) during AF leads to left atrial appendage thrombus and embolic events, some AF patients show decreased LAAFV even during sinus rhythm (SR). We studied 392 patients (256 males, 68 ± 10 years) who exhibited SR during transesophageal echocardiography (TEE) before CA for AF. Clinical factors, transthoracic echocardiography, and blood samples were obtained before TEE. Reduced LAAFV was defined as < 35 cm/s of LAAFV. Reduced LAAFV was observed in 72/392 patients (18%). Reduced LAAFV was significantly associated with high prevalence of non-paroxysmal AF, elevated brain natriuretic peptide (BNP), prior heart failure, high CHADS2 score, high CHA2DS2-VASc score, no beta blocker administration, increased left atrial volume index (LAVI), elevated E/e' ratio, reduced left ventricular ejection fraction and high prevalence of left ventricular hypertrophy. On multivariate analysis, BNP (P = 0.0005, OR 1.045 for each 10 pg/ml increase in BNP, 95% CI 1.018-1.073) and LAVI (P = 0.0045, OR 1.044 for each 1 increase in LAVI, 95% CI 1.013-1.077) were associated with decreased LAAFV. The elevated BNP levels and large LAVI predict decreased LAAFV during SR in patients with AF.