Beyond CHA 2 DS 2 -VASc: Hemodynamic and Morphologic Discriminants for Thrombus Formation and Stroke in Atrial...

Stroke is a leading cause of death worldwide, with atrial fibrillation (AF) contributing to up to a third of ischemic strokes. Current clinical risk scores, like the CHA $_2^{}$ DS $_2^{}$ -VASc score, have limited accuracy and do not account for the underlying mechanisms of thrombus formation and stroke. This study investigates the potential of supplementing the CHA $_2^{}$ DS $_2^{}$ -VASc score with information about the form and function of the left atrium (LA) using computational fluid dynamics (CFD)-based flow parameters and morphometrics.

We analyzed 40 patient-specific LA models reconstructed from computed tomography, incorporating a physiologically realistic atrial wall motion derived from an AF motion model. High-fidelity CFD simulations were performed under pathological conditions to compute hemodynamic and morphometric parameters, which were then statistically correlated with thrombus presence or stroke history.

Univariate logistic analysis showed that LA volume, left atrial appendage (LAA) orifice size, and LAA depth correlated strongly with thrombus presence or stroke history (Pseudo $R^2$ = 0.57, 0.55, 0.47, respectively). Additionally, increased LA blood residence time (BRT) showed a strong correlation with thrombus or stroke (Pseudo $R^2$ = 0.61). When combined with CHA $_2^{}$ DS $_2^{}$ -VASc  multivariate logistic regression produced strong Pseudo $R^2$ scores of 0.75, 0.75, and 0.76 for LAA orifice size, LAA depth, and LA BRT, respectively.

These results demonstrate that CFD-based and morphometric parameters can complement the CHA $_2^{}$ DS $_2^{}$ -VASc score, potentially improving the assessment of thrombus formation and stroke risk in AF patients, which could support more personalized treatment options.