Impact of Multi-Grade Localized Calcifications on Aortic Valve Dynamics under Helical Inflow: A Comparative Hemodynamic Study  
[PERSON]  
1 Faculty of Mechanical Engineering, Department of Mechanical Engineering, Istanbul Technical University, Istanbul 34437, Turkivje; [EMAIL_ADDRESS]  
[PERSON]  
2 Informatics Institute, Department of Computational Science and Engineering, Istanbul Technical University, Istanbul 34469, Turkivje; [PERSON]ADDRESS]  
[PERSON]  
222-285-7012222-285-7012  
Using fluid-structure interaction (FSI) models, [PERSON] et al. [8] studied potential complications associated with calcification patterns in transcatheter aortic valve replacements (TAVR). In another study, FSI models were developed by [PERSON] et al. [10] to examine the role of bio-transport in the calcification and thrombosis of aortic valves. According to their findings, there is a strong relationship between wall shear stress (WSS), flow vortices, and concentration patterns near and far from the leaflets. However, there is limited information regarding the three-dimensional formation of calcifications, the dynamics of leaflet flutter, and other pertinent hemodynamic factors. In numerous studies of FSI modeling of calcified aortic valves, the effect of calcification accounts for an increase in the leaflets' stiffness or thickness with the assumption of a uniform distribution of the leaflets [11; 12]. Using a patient-specific FSI simulation, [PERSON] et al. [11] investigated the effect of leaflet stiffness variation on transvalvular hemodynamics. According to several studies, calcification patterns and their growth are not random. The spatial distribution of calcium deposits on the aortic valve of patients with calcified leaflets was found to follow two identifiable patterns [13]. A coaptation pattern is observed along the coaptation line of the leaflets, while a radial pattern is observed along the attachment line of the leaflets. [PERSON] et al. [14] developed a novel method for reconstructing the 3D geometry of calcium calcification initiation and growth that confirms the findings of [PERSON] et al. [13]. Their research revealed that calcification patterns affected the mechanical flexibility of leaflets and the size of the valve orifice area. The results of the FSI simulations conducted by [PERSON] et al. [4] were used to investigate the hemodynamic effects of 3D patient-specific calcification patterns of the aortic valve. Based on their findings, calcific deposits have a significant influence on flow shear stresses. They paved the way for the further study of the hemodynamic effects of calcification patterns; however, there has been little focus given to other hemodynamic parameters, such as the WSS and change of blood viscosity [15]. In recent years, the analysis of intra-cardiac flow dynamics has attracted considerable interest within the realm of cardiology. Numerous research efforts have examined the complexities of flow patterns within the left ventricle (LV), focusing on aspects such as vortical structures and their clinical implications. For example, some studies use numerical simulations and dynamic mesh techniques to analyze left ventricular flow patterns [16]. [PERSON] et al. [17] employed patient-specific computational fluid dynamics (CFD) models from 3D ultrasound data for comparison across clinical cases. Additional research has also explored phenomena like jet collisions and vortex reversal to understand the underlying hemodynamics [18]. In a healthy heart, the formation of a vortex during the diastolic phase enhances ventricular filling and reduces energy loss [19]. Moreover, in the systolic phase, this vortex aids in the ejection of blood by re-orienting off-center inflow in the direction of the left ventricular outflow tract (LVOT) [18; 20], further reducing energy dissipation and the residence time [21; 22]. Due to the existence of heart-related diseases, the characteristics of intra-ventricular flow could differ from the ideal or typical patterns, leading to compromised cardiac performance [17].