Prevalence and Rate of Resolution of Left Atrial Thrombus in Patients with Non-Valvular Atrial Fibrillation: A Two-Center Retrospective Real-World Study

Abstract

Background and aim. Thromboembolic events due to left atrial appendage (LAA) thrombosis are the main complication of non-valvular atrial fibrillation (NVAF). Although anticoagulants are effective in patients with NVAF, a minimal residual thromboembolic risk persists. Little is known about the prevalence of LAA thrombus and the rate of resolution after the recommended period of anticoagulation therapy, including vitamin K antagonists (VKA), heparin, and non-vitamin K antagonist oral anticoagulants (NOACs). Methods and results. We aimed to study the prevalence of LAA thrombus in an unselected cohort of patients undergoing transesophageal echocardiogram (TEE), and the determinants of LAA thrombus resolution. We retrospectively analyzed 8888 consecutive TEEs performed over five years in two high-volume centers and included all patients with LAA thrombus. A total of 265 patients (3%) had an LAA thrombus. Among these, 97% presented with AF. Fifty-eight percent of patients were on anticoagulants at least three weeks before the diagnosis. After the LAA thrombus diagnosis, VKAs were prescribed in 52%, heparin in 18.5%, and NOAC in 27% of patients. Among the 183 patients with repeat TEE, performed at (25–75th) 39 days (21–84), 67% showed resolution of the LAA thrombus. Although the rate of thrombus resolution was higher in patients treated with NOACs (NOACs 71%, VKA 66%, Heparin 60%) the difference between anticoagulants was statistically non-significant (VKA, OR 0.9, p = 0.83; NOAC, OR 1.23, p = 0.42; heparin, OR 0.69, p = 0.35). Thus, NOACs were demonstrated to be at least as effective as other anticoagulants in the rate of LAA thrombus resolution. Upon multivariate-adjusted analysis, higher LAA emptying velocities were the only predictor of thrombus resolution. In conclusion, the majority of patients were already on anticoagulants. NOACs could be at least as effective as other anticoagulants, yielding an LAA thrombus resolution in two-thirds of patients. This may have clinical relevance, especially in patients undergoing cardioversion or catheter ablation.

Characteristics, Thrombus Resolution, and Long-Term Outcomes in Patients with Nonvalvular Atrial Fibrillation and Atrial Thrombus

“…In addition, abnormalities in various echocardiographic parameters, such as low LAA emptying velocity (<40 cm/s), high left ventricle (LV) filling pressure, or coexistence of mitral valve disease, might also be predictive of the persistence of atrial thrombus. 39 In the present study, congestive heart failure and a history of ischemic stroke were the independent risk factors of the nonresolution of atrial thrombus. The predictive value of these 2 risk factors was greater than that of the contemporary stroke risk stratification schemes tested.…”

Left Atrial Appendage Thrombosis and Oral Anticoagulants: A Meta-Analysis of Risk and Treatment Response

“…A total of 13 studies involving 922 patients were included in the second meta-analysis. These studies included three in Japan [ 25 , 38 , 40 ], five in European countries [ 30 , 37 , 39 , 43 , 44 ], three in China [ 34 , 36 , 42 ], and two in the United States [ 35 , 41 ]. One of the studies, the X-TRA study, was a multinational large-scale, prospective, single-arm, open-label, multicenter study.…”

Current Status of Left Atrial Appendage Thrombus with Atrial Fibrillation

“…The incidence of LAAT varies greatly owing to the patient's condition, and ranges from 1.2% to 22.6%; however, if adding LAA pre-thrombus conditions such as spontaneous echo contrast, the incidence will further increase. [16] Table 1 [16][17][18][19][20][21][22][23][24][25][26][27][28] summarizes the studies on the incidence of LAAT in AF patients. From August 2016 to December 2021, the incidence of LAAT diagnosed by TEE in AF patients at the Zhoupu hospital was 2.12% (23/1,086 cases).…”