Role of transesophageal echocardiography guided cardioversion in patients with atrial fibrillation, previous left atrial thrombus and effective anticoagulation

Aims The value of transesophageal echocardiography (TEE) to prevent cardioversion-related thromboembolic events in patients with atrial fibrillation (AF) and left atrial (LA) thrombus is unclear. We compared the embolic risk associated with a strategy of follow-up TEE-guided direct-current cardioversion (DCCV) with that of blind DCCV in patients with AF, pre-existing LA thrombus and effective anticoagulation. Methods and results We identified 67 subjects with TEE-documented LA appendage thrombi from a total of 520 consecutive patients with symptomatic non-rheumatic AF who were referred to us for elective DCCV. All patients received at least 4 weeks of effective warfarin therapy (target international normalized ratio, 2 to 3) before and after DCCV. At time of DCCV, 20 patients had TEE and 47 did not. There were no clinical and echocardiographic differences between the two groups. Thrombus resolution was documented in 18 (90%) patients. After a median follow-up of 4 weeks, two transient ischemic attacks were observed in patients who were blindly cardioverted and one in patients belonging to the TEE group. Sinus rhythm was documented at the time of each thromboembolic event. By multiple logistic regression analysis the TEE strategy was not associated with lower risk of thromboembolism as compared to blind DCCV (odds ratio 1.37; 95% confidence interval, 0.16% to 15.86%; p = 0.20). Conclusion In patients with AF, LA thrombus and effective anticoagulation, there is no difference in the risk of clinical thromboembolism between DCCV with or without follow-up TEE. Benefits of warfarin are related to thrombus resolution and prevention of new thrombus formation.