## 4 Discussion
In scenarios of pronounced calcification, the leaflet tips are subjected to exceptionally high shear stresses. As expected, varying calcification patterns instigate distinct flow behaviors and vorticity intensities, subsequently affecting shear stress magnitudes and distributions, especially adjacent to the leaflets--a phenomenon affirmed by our results. The aortic side experiences significantly reduced WSS in contrast to the ventricular side, with the difference amplifying as calcification escalates. In alignment with prior studies highlighting the aortic side (or fibrosa) to be more susceptible to calcification than the ventricle side (or ventricular) [4; 10; 55], our results support this finding, substantiating that diminished TAWSS levels on the aortic side foster calcite particle deposition on the fibrosa layer. Thrombosis tends to form in regions with low flow or stasis, where shear stresses are reduced [56; 57; 58]. Given these insights, it is beneficial to have a high probability of elevated shear stress close to the leaflet. Conversely, a decreased probability of such stress is undesirable, as regions with diminished shear stress have a greater risk of thrombus formation [58]. OSI values are generally lower on the ventricle side compared to the aortic side, which experiences more oscillatory flow due to vortex formation and retrograde flow. A slight but negligible increase in OSI values is observed for helical flow. RRT values are lower on the ventricular side due to transit blood flow, and similarly, helical flow RRT values decrease due to enhanced blood washout in the Valsalva sinus region. Simultaneously observing higher values of RRT in the attachment line on the ventricle side of the healthy valve, which is consistent with the findings presented by [PERSON] et al. [10], we also noted an escalation of RRT values in the vicinity of the aortic root with increasing calcification; this is crucial as certain clinical data highlight the potential for thrombus formation within the attachment region of transcatheter aortic valves [59]. Calcification notably elevates transWSS values, especially in leaflet tip regions, with distinct patterns and variations arising across different calcification grades and regions. Enhanced transWSS is prominently observed along the coaptation line and is influenced by both leaflet flutter and helical flow. Notably, asymmetrical calcification patterns cause unstable fluctuations, impacting stress variations and lateral load components. We found nuanced shifts in helical flow characteristics with increasing calcification severity; specifically, higher grades of calcification suppress the helicity while increasing its intensity in the ascending aorta. Aortic helical flow, commonly seen in healthy individuals, stems from the cardiovascular system's innate ability to optimize fluid transport processes [60]. Localized calcification disrupts the naturally formed helicity in the flow field of the aortic domain, potentially affecting blood transport efficiency and contributing to further cardiovascular disease progression. A deeper exploration of the helical flow patterns is undertaken through helicity descriptors. Our results indicate that helicity has favorable physiological implications, as it promotes efficient blood transportation, minimizes flow disruptions, and reduces the accumulation of blood stasis behind the leaflets and aortic sinuses. Finally, investigating the vortical structure formations, distinct vortex rings become evident as the valve opens, with their complexity growing as flow increases. We found that calcification noticeably impacts these vortex formations. In healthy valves, symmetrical vortex rings are evident, while in the presence of calcification, these rings become distorted. The increasing presence of small vortices with rising calcification grades further obscures these vortex structures.