Patients undergoing LAAO procedures are primarily at risk for stroke due to what factor?

The primary factor placing patients undergoing Left Atrial Appendage Occlusion (LAAO) procedures at risk for stroke is the presence of an enlarged left atrium. An enlarged left atrium is associated with several factors that promote thrombus (blood clot) formation, which can lead to embolic strokes. The left atrial appendage, in particular, is a common site for thrombus formation, especially in patients with atrial fibrillation.

In the context of atrial fibrillation, the irregular and often rapid heart rhythm can contribute to blood stasis within the left atrium and its appendage, further increasing the risk of clot development. When these clots dislodge, they have the potential to travel to the brain, causing ischemic strokes.

Other factors, such as cardiac output irregularities, anticoagulant use, and atrial fibrillation itself, contribute to the overall risk of stroke but are not the primary factors in this specific context. For example, while anticoagulants are designed to reduce stroke risk, their use alone does not mitigate the underlying risk factors such as the anatomical changes in the left atrium that predispose patients to stroke in the first place. Thus, the enlarged left atrium stands out as the key risk