Intracardiac echocardiography for verification for left atrial appendage thrombus presence detected by transesophageal echocardiography: the ActionICE II study

Background Transesophageal echocardiography (TEE) remains the gold standard for exclusion of left atrial appendage (LAA) thrombus in patients scheduled for direct electrical cardioversion (DEC) or atrial fibrillation (AF) ablation. Recently, intracardiac echocardiography (ICE) of the pulmonary artery (PA) has been shown to provide excellent LAA images and to be useful in verification of equivocal TEE findings. Hypothesis ICE of the PA may have a role in detecting false-positive TEE results. Methods Twenty-one patients (12 male, age 65 ± 8 years, CHADS2VASC2 score [congestive heart failure, hypertension, age ≥ 75, age 65-74, diabetes mellitus, stroke/TIA/thrombo-embolism, vascular disease, sex female] = 2.2; HAS-BLED score [hypertension, abnormal renal and liver function, stroke, bleeding, labile International Normalized Ratio, elderly, drugs or alcohol] = 1.1), in whom a thrombus in the LAA was detected during TEE before DEC or AF ablation, underwent ICE of the PA. Results On TEE, in 7 (33%) patients, the LAA thrombus was described as “solid” and in the remaining 14 (67%) as “soft.” Disagreement between the TEE and ICE (thrombus in TEE and no thrombus in ICE) was found in 9 (43%) patients. In the solid thrombus group, ICE confirmed thrombi existence in 6 and excluded thrombi in 1 patient. In the soft thrombus group, ICE confirmed thrombi in 6 patients and excluded thrombi in the remaining 8 patients. Of the demographic and clinical variables, only the longstanding persistent type of AF was significantly associated with the presence of an LAA thrombus detected both by TEE and ICE. Conclusions With TEE, a false positive of an LAA thrombus may be indicated, especially when a thrombus is described as soft rather than solid. Our study suggests that ICE may be a valuable option for verification of a TEE-based diagnosis of a thrombus.