Age-related changes in aortic and mitral valve thickness: Implications for two-dimensional echocardiography based on an autopsy study of 200 normal human hearts

The thicknesses at 3 sites of each aortic cusp (nodule, closing edge and middle part) and 2 sites of both mitral leaflets (closing edge and clear zone) were measured in 200 autopsy specimens of normal hearts, evenly distributed by age and sex. There were no significant correlations between valvular thickness and height, weight, heart weight or body surface area. The mean thickness at each site was not different between men and women but increased significantly with age (p < 0.001). For 3 age groups (< 20, 20 to 59 and ≥ 60 years), the corresponding mean thicknesses (mm) of the aortic nodule were 0.67, 0.87 and 1.42; those for the anterior mitral leaflet were 1.30, 1.60 and 3.20; and those for the posterior mitral leaflet were 0.91, 1.13 and 2.04. For the aortic valve, the nodule was nearly twice as thick as the closing edge (p < 0.001), and the closing edge was at least 25% thicker than the middle part (p < 0.001). Furthermore, the posterior aortic cusp was thicker than the right and left cusps (p < 0.05). For both mitral leaflets, the closing edge was thicker than the clear zone (p < 0.05). Moreover, along the closing edges, the anterior leaflet was thicker than the posterior leaflet (p < 0.05). These observations may be useful in echocardiographic evaluations of aortic and mitral valve sclerosis in elderly patients.