Left atrial appendage flow and recurrences of atrial fibrillation after catheter ablation

Low left atrial appendage flow velocity (LAAFV) is a marker of atrial cardiomyopathy and could identify patients with atrial fibrillation (AF) at greater risk of arrhythmic recurrence after catheter ablation.

To assess the role of LAAFV in predicting arrhythmic recurrences after pulmonary vein isolation (PVI).

This is a single-center retrospective study that included consecutive patients referred for cryoballoon PVI due to AF. LAAFV was defined as empty peak velocity in left atrial appendage in a preprocedural (≤48 hours) transesophageal echocardiogram and divided in tertiles for analytical purposes. Primary endpoint was time to any AF recurrence during ≥1 hour. Identification of variables associated with low LAAFV was a secondary endpoint. Reciprocating operating curve was performed to assess the optimal cutoff value and the prediction capability of LAAFV.

152 patients (41.4% females; 66.8 ± 9.0 years; 45.4% paroxysmal AF) were included. Mean LAAFV was 45.6±20.4 cm/s and lower tertile (T3) cutoff value was 33.2 cm/s. In the multivariable analysis, female sex [Adjusted odds ratio (OR): 2.33 (1.07 - 5.12); p=0.034], AF rhythm during examination [adjusted OR: 4.13 (1.69 - 10.05); p=0.002] and left atrial enlargement [adjusted OR: 2.28 (1.01 - 5.20); p=0.049] were associated with LAAFV <t3.

During a median follow up of 33 (31-36) months, 52 (34.2%) patients experienced the primary endpoint. AF recurrence rate divided by LAAFV tertiles is shown in figure 1. LAAFV presented an area under the curve of 0.71 (0.63 - 0.80); p<0.001 in predicting the primary endpoint, and the optimal cutoff value was 41.4 cm/s. A cutoff value of 24.1 cm/s presented a specificity of 0.95 and 61.6 cm/s presented a sensitivity of 0.95. A LAAFV <41.4 cm/s was associated with greater risk of AF recurrence [Hazard ratio (HR): 2.95 (1.64 - 5.33); p<0.001] during the follow up.

LAAFV used both a continous variable or categorized by values under 41.4 cm/s or under T3 was independently associated with AF recurrences in a multivariate analysis (Adjusted HR: 0.96 (0.94 - 0.99); p=0.008, 2.74 (1.19 - 6.28); p=0.012 and 4.62 (1.69 - 12.62); p=0.003, respectively).

Among patients with AF undergoing CA, low LAAFV was associated with more advanced atrial remodeling and showed a good diagnostic performance in predicting AF recurrences.</t3.Figure 1.

Primary endpoint.