Transesophageal Echocardiography in Ischemic Stroke With Atrial Fibrillation

Abstract

BACKGROUND: To clarify differences in clinical significance of intracardiac thrombi in nonvalvular atrial fibrillation-associated stroke as identified by transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE). METHODS AND RESULTS: Using patient data on nonvalvular atrial fibrillation-associated ischemic stroke between 2011 and 2014 from 15 South Korean stroke centers (n=4841) and 18 Japanese centers (n=1192), implementation rates of TEE/TTE, and detection rates of intracardiac thrombi at each center were correlated. The primary outcome was recurrent ischemic stroke at 1 year after the onset. A total of 5648 patients (median age, 75 years; 2650 women) were analyzed. Intracardiac thrombi were detected in 75 patients (1.3%) overall. Thrombi were detected in 7.8% of patients with TEE (either TEE alone or TEE+TTE: n=679) and in 0.6% of those with TTE alone (n=3572). Thrombus detection rates varied between 0% and 14.3% among centers. As TEE implementation rates at each center increased from 0% to 56.7%, thrombus detection rates increased linearly (detection rate [%]=0.11xTEE rate [%]+1.09 [linear regression], P<0.01). TTE implementation rates (32.3%-100%) were not associated with thrombus detection rates (P=0.53). Intracardiac thrombi were associated with risk of recurrent ischemic stroke overall (adjusted hazard ratio [aHR] 2.35, 95% CI, 1.07-5.16). Thrombus-associated ischemic stroke risk was high in patients with TEE (aHR, 3.13; 95% CI, 1.17-8.35), but not in those with TTE alone (aHR, 0.89; 95% CI, 0.12-6.51). CONCLUSIONS: Our data suggest clinical relevance of TEE for accurate detection and risk stratification of intracardiac thrombi in nonvalvular atrial fibrillation-associated stroke.