Transesophageal echocardiography to guide cardioversion in patients with atrial fibrillation: ACUTE trial update

The Assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) trial was the first randomized prospective study to compare the conventional strategy of 3 weeks of anticoagulation before direct current cardioversion (DCC) for atrial fibrillation (AF) to a transesophageal echocardiography (TEE) guided approach with an expedited course of anticoagulation. This was a multicenter, international study with 70 sites enrolling 1222 patients between 1994-1999. The primary endpoint of composite embolic events and secondary endpoints including bleeding, functional status, prevalence of sinus rhythm, and death were assessed at 8 weeks following randomization. The ACUTE trial demonstrated that the TEE guided approach was safe and effective. There was no difference in the primary outcome of embolic events for the 2 strategies (0.8% TEE group vs. 0.5% conventional group, p =.50). There was a difference between the groups with respect to the number of bleeding events, with minor and major bleeding seen in 2.9% of patients in the TEE guided group and 5.5% in the conventional group (relative risk 0.53, 95% confidence interval 0.30-0.93, p = 0.03). The remaining secondary endpoints did not differ. Clinicians now have a viable alternative approach to cardioversion for patients with AF. Several factors influence the choice of strategies including (1) severity of symptoms and hemodynamic effect; (2) level and chronicity of anticoagulation; (3) risks of bleeding; (4) duration of AF and likelihood of reversion; and (5) risk and likelihood of left atrial thrombi. Future studies, such as ACUTE II are ongoing, with the aim of using low molecular weight heparin to further streamline the TEE guided approach to DCC and shorten hospital stay and costs.