Left Atrial Appendage Thrombus in Patients with Ischemic Stroke as Marker of Atrial Fibrillation?
Wern Yew Ding, MBChB
Atrial fibrillation (AF) is an established risk factor for thromboembolic events, including ischemic stroke. Therefore, identification of patients with this arrhythmia is important to facilitate the implementation of stroke prevention therapy using oral anticoagulation. Nonetheless, as a significant proportion of patients with AF remain asymptomatic, it remains largely under-diagnosed in the general population. Given that the source of emboli in the majority of AF-related strokes originates from the left atrial appendage (LAA), inclusion of this structure in imaging protocols may have a role in aiding the diagnosis of AF.
In a recent retrospective study of consecutive patients with ischemic stroke or transient ischemic attack, Senadeera and colleagues investigated the prevalence of computed tomography angiography (CTA)-detected LAA thrombus during hyperacute stroke imaging and evaluated the association between LAA thrombus and AF. The imaging protocol consisted of non-contrast CT, followed by CT perfusion and CTA from aortic arch to vertex. Two experienced physicians and pre-defined measures were used to assess for LAA thrombus on these scans.