A metric for the stiffness of calcified aortic valves using a combined computational and experimental approach

Calcific aortic valve disease is the most common heart valve disease. It is associated with a significant increase in cardiovascular morbidity and mortality and independently increases the cardiovascular risk. It is then important to develop parameters that can estimate the stiffness of the valve. Such parameters may contribute to early detection of the disease or track its progression and optimize the timing for therapy. In this study, we introduce a metric representing the stiffness of the native aortic calcified valve over a wide range of stenosis severities. Our approach is based on three-dimensional structural finite-element simulations and in vitro measurements. The proposed method is developed first in a pulse duplicator; its clinical applicability is then evaluated in three patients with severe aortic stenosis. Our results indicate that the value of the proposed metric varies considerably between healthy valves and valves with very severe aortic stenosis, from 0.001 to 7.38 MPa, respectively. The method introduced in this study could give useful information regarding the stiffness of the valve leaflets with potential application to the evaluation of aortic sclerosis and aortic stenosis.