Cardioversion guided by transesophageal echocardiography: The ACUTE pilot study - A randomized, controlled trial

Background: Electrical cardioversion in patients with atrial fibrillation is associated with an increased risk for embolic stroke. Screening for atrial thrombi with transesophageal echocardiography (TEE) before cardioversion should, in many patients, safely permit cardioversion to be done earlier than would be possible with prolonged conventional, anticoagulation therapy. Objective: To compare the feasibility and safety of TEE-guided early cardioversion with those of conventional management of cardioversion in patients with atrial fibrillation. Design: Randomized, multicenter clinical trial. Setting: 10 hospitals in the United States, Europe, and Australia. Patients: 126 patients who had atrial fibrillation lasting longer than 2 days and were having electrical cardioversion. Intervention: Conventional therapy or early, TEE-guided cardioversion with short-term anticoagulation therapy. Outcome Measures: Feasibility outcome variables were frequency of cardioversion and times to cardioversion and sinus rhythm. Safety outcomes were ischemic stroke, transient ischemic attack, systemic embolization, bleeding, and detected episodes of clinical hemodynamic instability occurring as long as 4 weeks after cardioversion. Results: 62 patients were randomly assigned to receive TEE-guided cardioversion; IEE was done in 56 (90%) of these patients. Atrial thrombi were detected in 7 patients (13%) and led to the postponement of cardioversion. Cardioversion was successful in 38 of 45 patients (84%) who had early cardioversion. No embolization occurred with this strategy. Of the 64 patients receiving conventional therapy, 37 (58%) had cardioversion, which was successful in 28 patients (76%). One patient had a peripheral embolic event. The time to cardioversion was shorter in the TEE group (0.6 weeks [95% Cl, 0.3 to 0.9 weeks] compared with 4.8 weeks [Cl, 3.8 to 5.7 weeks]; P < 0.01). The incidence of clinical hemodynamic instability and bleeding complications tended to be greater in the conventional therapy group. Conclusions: These results suggest that TEE-guided cardioversion with short-term anticoagulation therapy is feasible and safe. The use of TEE may allow cardioversion to be done earlier, may decrease the risk for embolism associated with cardioversion, and may be associated with less clinical instability than conventional therapy. A large multicenter study to confirm these findings is currently under way.