Modelling Virchow's Triad to Improve Stroke Risk Assessment in Atrial Fibrillation Patients

Atrial fibrillation (AF) is associated with a significantly increased risk of stroke due to the presence of three prothrombotic mechanisms known as Virchow's triad -blood stasis, endothelial damage and hypercoagulability -which primarily occur in the left atrial appendage (LAA).Insilico evaluation of each factor can improve upon the current empirical stroke risk stratification for AF patients.Computational fluid dynamics simulations were performed on two patient-specific models of the left atrium, one in sinus rhythm (SR) and one in AF to quantify blood stasis and metrics of endothelial damage. Hypercoagulability was assessed by solving reactiondiffusion-convection equations for thrombin, fibrinogen and fibrin -three key clotting proteins, and varying initial concentrations of fibrinogen in accordance with clinical literature. An original grading system is proposed (A = low, B = moderate, C = high risk) for each component of the triad to form a patient-specific risk profile. The SR patient had a risk profile of [A, B, A] showing a low-moderate risk of thrombus formation, while the AF patient had [C, B, C], indicating a very high risk of thrombus formation and increased potential for stroke.This novel modelling approach encapsulates all fundamental mechanisms of thrombus formation and may be used to improve stroke risk assessment for AF patients.PV PV PV LA LAA LAA LAA LA LA LA