THE INCREMENTAL ROLE OF IMAGING IN THROMBOEMBOLIC RISK ASSESSMENT FOR PATIENTS WITH ATRIAL FIBRILLATION

Abstract

Background: The CHA2DS2-VASc score is the standard of care in thromboembolic risk assessment for patients with non-valvular atrial fibrillation (AF). Most patients will undergo transthoracic echocardiography (TTE) for further evaluation, and many also having transesophageal echocardiography (TEE) performed prior to cardioversion or ablation. We sought to evaluate the relationship between left atrial (LA) abnormalities detected on TEE and TTE parameters, to determine if imaging may be additive in risk assessment.Methods: Clinical, TEE and TTE data for patients in AF at the time of their study were included in this retrospective analysis. LA/LA appendage (LAA) abnormalities on TEE included the presence of spontaneous echo contrast, sludge, thrombus and LAA emptying velocity 90% in both groups. Median LAVI, septal e’ and E wave velocity in the ≤ 1 vs ≥2 groups were 46ml/m2vs 48ml/m2, 8cm/s vs 6cm/s and 0.8m/s vs 0.8m/s, respectively. Overall, increased LAVI and reduced septal e’ on TTE was associated with TEE LA/LAA abnormalities (p=0.02, p=0.005 respectively). In subgroup analysis, it was found that LAVI and septal e’ was statistically significant in the low CHA2DS2-VASc group (p=0.03, p =0.01), but not in the higher CHA2DS2-VASc group (p=0.21, p=0.30).Conclusion: TEE LA/LAA abnormalities were not infrequently noted in those patients traditionally deemed low risk (CHA2DS2-VASc ≤ 1). LAVI and septal e’ on TTE appear to be associated with LA/LAA abnormalities detected on TEE, which was particularly relevant in lower CHA2DS2-VASc patients and may be additive to conventional clinical risk assessment. Further study is needed to evaluate the role of imaging in AF thromboembolic risk stratification, and whether this translates to prognostic and clinical endpoints.