Transesophageal Echocardiography for Thrombus Screening Prior to Left Atrial Catheter Ablation

Background: Transesophageal echocardiography (TEE) is useful for detecting left atrial (LA) thrombus prior to percutaneous LA catheter ablation in patients with atrial fibrillation (AF). This study was designed to evaluate clinical predictors of LA thrombus and determine indications for TEE screening prior to LA ablation. Methods and Results: The study consisted of 446 patients with drug-resistant AF who were scheduled to undergo initial LA ablation (age 59 +/- 11 years, 312 males, 136 persistent AF). TEE was performed in all cases within 24h before ablation. We assessed clinical parameters including CHADS2 score and echocardiographic parameters. LA thrombus was detected in 13 cases (2.9%) prior to LA ablation (67 +/- 8 years, 10 males, 12 persistent AF). In multiple logistic regression analysis, advanced age (odds ratio (OR) 1.1, 95% confidence interval (CI) 1.0-1.2; P<0.05), persistent AF (OR 38.1, 95%CI 1.4-988; P<0.05) and structural heart diseases (OR 29.8, 95%CI 2.8-383; P<0.01) were independent positive predictors of LA thrombus prior to ablation, while CHADS2 score and LA volume were not significant predictors. None of the 136 patients with paroxysmal lone AF whose age was below 60 years had LA thrombus prior to ablation. Conclusions: It might be reasonable to omit TEE as a screening examination for LA thrombus prior to LA ablation in younger paroxysmal lone AF patients. (Circ J 2010; 74: 1081-1086)