Flow dynamic differences between Kawasaki Disease patients with coronary artery aneurysms and ectasia.

BACKGROUND: Untreated Kawasaki Disease (KD) can lead to coronary artery (CA) dilations, such as CA aneurysms (CAA), CA ectasia (CAE), or both (CAA ​+ ​CAE). Currently, therapeutic decisions rely solely on geometric measurements, which have limitations. This study aims to correlate differences in flow dynamics between CAA, CAE, and CAA ​+ ​CAE with clinical outcomes and thrombotic potential.

METHODS: A multicenter retrospective study was performed using a total of 50 dilation models from patients with KD. Dilations were categorized as either CAA (n ​= ​30), CAE (n ​= ​14), or CAA ​+ ​CAE (n ​= ​6). Patient-specific 3D digital models of the CAs were created for each patient. Geometric measurements of each CA were recorded. Flow simulations were conducted and hemodynamic metrics such as time average wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and normalized average wall shear stress divergence (AWSS) were calculated.

RESULTS: CAAs had the largest dilations and entrance diameters. The dilation length and aspect ratio were higher for CAEs. CAAs exhibited consistently low velocity and low TAWSS with extensive regions of co-localized high RRT and OSI, and AWSS source points. CAEs showed elevated RRT in some cases but minimal OSI with little spatial overlap between metrics. CAA+CAEs showed variable and diffuse flow patterns with limited co-localization.

CONCLUSION: Flow dynamics vary significantly across dilation morphologies in KD. Patients with only CAAs present hemodynamic data associated with the highest likelihood of thrombosis. Hemodynamic metrics may serve as mechanistic markers for thrombogenic potential and should be considered alongside anatomical measurements in future risk stratification efforts.