Impact of trabeculae on thromboembolic risk in the left atrial appendage

Atrial fibrillation (AF) can lead to thrombosis in the left atrial appendage (LAA), significantly increasing the risk of ischemic events. The LAA is a protrusion of the left atrium, exhibiting considerable morphological variability, including features such as trabeculae, lobes and knees. This study investigates the role of trabeculae on the risk of thrombosis in patient-specific LAA morphologies, through fluid-structure interaction analysis. Four models belonging to the four common patient-specific LAA morphological types (chicken wing, cactus, windsock and cauliflower) were considered. For each model, both sinus rhythm (SR) and atrial fibrillation conditions were simulated and analysed in two scenarios: with and without trabeculae. The findings obtained removing trabeculae showed an increase in blood stasis in the SR condition (due to the absence of the active contraction of the trabeculae) and a decrease in the pathological case (since trabeculae act as a constraint to the LAA expansion).