Use of transesophageal echocardiography to guide cardioversion in patientswith atrial fibrillation.

Background: The conventional treatment strategy for patients with atrial fi brillation who are to undergo electrical cardioversion is to prescribe warf arin for anticoagulation for three weeks before cardioversion. It has been proposed that if transesophageal echocardiography reveals no atrial thrombu s, cardioversion may be performed safely after only a short period of antic oagulant therapy. Methods: In a multicenter, randomized, prospective clinical trial, we enrol led 1222 patients with atrial fibrillation of more than two days' duration and assigned them to either treatment guided by the findings on transesopha geal echocardiography or conventional treatment. The composite primary end point was cerebrovascular accident, transient ischemic attack, and peripher al embolism within eight weeks. Secondary end points were functional status , successful restoration and maintenance of sinus rhythm, hemorrhage, and d eath. Results: There was no significant difference between the two treatment grou ps in the rate of embolic events (five embolic events among 619 patients in the transesophageal-echocardiography group [0.8 percent]) vs. three among 603 patients in the conventional-treatment group [0.5 percent], P=0.50). Ho wever, the rate of hemorrhagic events was significantly lower in the transe sophageal-echocardiography group (18 events [2.9 percent] vs. 33 events [5. 5 percent], P=0.03). Patients in the transesophageal-echocardiography group also had a shorter time to cardioversion (mean [+/-SD], 3.0+/-5.6 vs. 30.6 +/-10.6 days; P<0.001) and a greater rate of successful restoration of sinu s rhythm (440 patients [71.1 percent] vs. 393 patients [65.2 percent], P=0. 03). At eight weeks, there were no significant differences between the two groups in the rates of death or maintenance of sinus rhythm or in functiona l status. Conclusions: The use of transesophageal echocardiography to guide the manag ement of atrial fibrillation may be considered a clinically effective alter native strategy to conventional therapy for patients in whom elective cardi oversion is planned. (N Engl J Med 2001;344:1411-20.) Copyright (C) 2001 Ma ssachusetts Medical Society.