Regional function analysis of left atrial appendage using motion estimation CT and risk of stroke in patients with atrial fibrillation.

Aims: The aim of this article is to determine the association between left atrial appendage (LAA) regional dysfunction using image-based motion-estimation computed tomography (CT) (iME) and a prior history of stroke or transient ischaemic attack (TIA) in patients with atrial fibrillation (AF).

Methods And Results: In this single-centre retrospective case-control study, among patients referred for AF ablation who underwent pre-ablation cardiac CT with retrospective ECG gating, we identified 18 patients with a prior history of stroke or TIA at the time of CT scan and 18 age- and gender-matched controls. All the patients were in sinus rhythm at the time of CT scan. Four-dimensional motion vector field was estimated from the CT images using iME. To assess myocardial deformation, area change ratio (A) and area change rate (AR) were calculated over the endocardial surface of the LAA. There was no significant difference in the baseline patient characteristics between the stroke/TIA group and the control group (67.6 ± 8.1 years old, 66.7% male, 16.7% persistent AF). LAA maximum (Amax; 23.8 ± 33.0 vs. 52.9 ± 41.2%, P = 0.02) and pre-atrial contraction area change ratio (ApreA; 13.7 ± 17.7 vs. 30.9 ± 29.2%, P = 0.04) were significantly lower in the stroke/TIA group than in the control group, respectively. The difference in LAA Amax and ApreA remained significant in multivariate analysis (P = 0.03 and P = 0.04, respectively).

Conclusion: LAA regional dysfunction is associated with stroke/TIA in AF patients. Our results offer a basis for a prospective study to determine the role of LAA regional dysfunction by iME in predicting cerebrovascular events such as stroke or TIA.