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

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 CHADS-VASc score. However, stroke also occurs in some patients with a low CHADS-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 CHADS-VASc score. However, the results are conflicting and, so far, no new parameter has been added to the CHADS-VASc score.