Transesophageal Echocardiography for the Prevention of Embolic Complications After Catheter Ablation for Atrial Fibrillation

Background: Thromboembolic complications during left-sided ablations range between 1.5 and 5.4%. Preprocedural TEE has been used to exclude the presence of left atrial thrombi in order to minimize risk. The use of TEE is empiric and it has not been evaluated in contemporary practice.
Methods and Results: A multicenter national survey describing the practice at 11 Canadian teaching hospitals. A total of 2,225 patients underwent elective catheter ablation for symptomatic AF. Transesophageal echocardiography (TEE) was used either routinely or selectively as a preablative strategy in patients. There were 996 patients in a routine preprocedure TEE strategy and 1,190 in a selected TEE strategy; 1 center (n = 39 patients) did not perform TEE. Twelve of 996 (1.2%) in the routine unselected cohort had thrombi identified. TEEs were performed in 200 of 1,190 in the selected cohort; 4 (2.0%) left atrial thrombi were observed; there was no significant difference in the prevalence of thrombi (P = 0.34). A total of 11 embolic events occurred inclusive of all groups. There was no difference in event rates between the 2 strategies (0.6% and 0.4%, P = 0.54). Events were unrelated to AF duration (persistent vs paroxysmal, r = 0.03, N = 2,225, P = 0.9).
Conclusion: The selection criteria employed to perform TEEs did not increase the chance of identifying LA thrombi in a patient cohort with primarily nondilated left atria and paroxysmal AF. The overall thromboembolic event rate was low (0.49%) and was not significantly different between the 2 TEE strategies.