Association Between Left Atrial Appendage Morphology and Function and the Risk of Ischaemic Stroke in Patients with Atrial Fibrillation

Abstract

AF is the most common cardiac arrhythmia and has been identified as an independent risk factor for stroke. The European Society of Cardiology guidelines recommend a thromboembolic event risk assessment based on the CHA2DS2-VASc score. However, stroke also occurs in some patients with a low CHA2DS2-VASc score. Therefore, it is necessary to find new factors to improve thromboembolic risk stratification in AF patients. Over 90% of embolic strokes are caused by thrombi originating from the left atrial appendage (LAA). Thus, certain anatomical or functional parameters of the LAA could potentially be used to predict cardioembolic stroke. Studies have suggested that some of these factors, such as LAA morphology, number of LAA lobes, LAA dimensions, LAA volume, distance from the LAA ostium to the first bend of LAA, LAA orifice diameter, extent of LAA trabeculations, LAA takeoff, LAA flow velocity and LAA strain rate, are independently associated with a higher risk of stroke in a population of patients with AF and improve the performance of the CHA2DS2-VASc score. However, the results are conflicting and, so far, no new parameter has been added to the CHA2DS2-VASc score.

Left atrial appendage occlusion: On the need of a numerical model to simulate the implant procedure

“…It is estimated that over 90% of stroke‐inducing clots are formed in the left atrial appendage (LAA) of those patients affected by atrial fibrillation not related to heart valve pathologies (commonly referred to as non‐valvular atrial fibrillation). For this reason, the LAA is considered the most common site of thrombus formation and cardioembolism 2 . Given this clinical evidence, the LAAO is intended to reduce the risk of strokes originating in this anatomical site.…”

“…For this reason, the LAA is considered the most common site of thrombus formation and cardioembolism. 2 Given this clinical evidence, the LAAO is intended to reduce the risk of strokes originating in this anatomical site. It is a minimally invasive treatment involving self-expandable Nitinol devices 3 conceived in different designs and sizes to better accommodate the LAA morphology.…”

Percutaneous Left Atrial Appendage Occlusion—Current Evidence and Future Directions

“…In patients with AF, the source of cardioembolic stroke in >90% of the cases is thrombi in the left atrial appendage (LAA) as detected by transesophageal echocardiography (TEE) or autopsy studies [4,5]. Blood stagnation, the absence of atrial contractility in patients with AF, and the partly multi-lobed LAA morphologies with highly trabeculated endocardium are major factors contributing to thrombus formation [6,7].…”