Adjusted left atrial emptying fraction as a predictor of procedural outcome after catheter ablation for atrial fibrillation

Structural remodeling of the left atrium is a risk factor for recurrent arrhythmia after catheter ablation for atrial fibrillation; however, data are sparse regarding the role of functional left atrial remodeling in predicting procedural outcomes. We evaluated whether left atrial transport function could be used to predict recurrent atrial fibrillation. From July 2008 through August 2010, we enrolled 202 consecutive patients who underwent catheter ablation for atrial fibrillation (paroxysmal=120, persistent=82). Left atrial volumes (LAVs) were measured by means of multislice computed tomography at every 10% of the R-R interval, and measurements were adjusted for body surface area to yield the LAV index (LAVI) at baseline. The left atrial emptying fraction (LAEF) was calculated according to LAV differences. During the mean follow-up period of 10 ± 4 months after a single ablation procedure, atrial fibrillation recurred in 59 patients (paroxysmal=19, persistent=40). Multivariate analysis revealed that persistent atrial fibrillation, early mitral inflow velocity, LAVI_max, LAVI_min, LAEF, LAVI_max/LAEF, and LAVI_min/LAEF were all independent predictors of atrial fibrillation, but the best predictor was LAVI_min/LAEF (β=1.329, P=0.001). The cutoff value was 1.61 (mL/m²)/%, and the sensitivity and specificity were 74.6% and 62.2%, respectively (area under the curve=0.761). Our study shows that adjusted left atrial emptying fraction with use of multislice computed tomography might be a useful, noninvasive method to select patients for ablation.