Transesophageal echocardiography-guided cardioversion after cardiac operations

Background. Transesophageal echocardiography (TEE)is often performed during cardiac operations. The needto repeat TEE to exclude left atrial or left atrialappendage thrombus before direct current cardioversion(DCCV) in patients with a recent intraoperativeTEE showing no thrombus is unclear. We sought todetermine the incidence of and risk factors for newthrombus in patients undergoing TEE-guided DCCVafter cardiac operations.

Methods. We reviewed 817 patients referred for TEEguidedDCCV within 30 days of a cardiac operation andan intraoperative TEE. Patients were excluded if theintraoperative TEE showed thrombus or a surgical leftatrial appendage intervention was performed. Univariatelogistic regression identified risk factors for thrombus.

Results. The study included 362 patients (71% male)with a mean age of 69 years. Median time from theoperation to DCCV was 6 days. Thrombus was presentin 13 patients (3.6%) on TEE before cardioversion; DCCVwas cancelled in these patients. Heart failure was associatedwith a significantly higher risk of new thrombusformation (7% vs 2%; odds ratio, 3.26; 95% confidenceinterval, 1.07 to 9.95). Preoperative atrial arrhythmias,duration of perioperative arrhythmias, level of anticoagulation,and time from operation to DCCV were notsignificantly associated with thrombus. Thrombus wasnot associated with 30-day mortality.

Conclusions. Development of new thrombus in patientswith atrial arrhythmias early after cardiac operationsis not uncommon, especially in patients with heartfailure. Patients at high risk for thromboembolic eventsshould undergo TEE before DCCV, even if a recentintraoperative TEE showed no thrombus.