Computational hemodynamic indices to identify Transcatheter Aortic Valve Implantation degeneration

PurposeStructural Valve Deterioration (SVD) is the main limiting factor to the long-term durability of bioprosthetic valves, which are used for Transcatheter Aortic Valve Implantation (TAVI). The aim of this study is to perform a patient-specific computational analysis of post-TAVI blood dynamics to identify hemodynamic indices that correlate with a premature onset of SVD. MethodsThe study population comprises two subgroups: patients with and without SVD at long-term follow-up exams. Starting from pre-operative CT images, we created reliable post-TAVI scenarios by virtually inserting the bioprosthetic valve (stent and leaflets), and we performed numerical simulations imposing realistic inlet conditions based on patient-specific data. The numerical results were post-processed to build suitable synthetic scores based on normalized hemodynamic indices. ResultsWe defined three synthetic scores, based on hemodynamic indices evaluated in different contexts: on the leaflets, in the ascending aorta, and in the whole domain. Our proposed synthetic scores are able to clearly isolate the SVD group. Notably, we found that leaflets OSI individually shows statistically significant differences between the two subgroups of patients. ConclusionThe results of this computational study suggest that blood dynamics may play an important role in creating the conditions that lead to SVD. More-over, the proposed synthetic scores could provide further indications for clinicians in assessing and predicting TAVI valves long-term performance.