Histological assessment of the human heart valves and its relationship with age

Abstract

The human heart valves are complex anatomical structures consisting of leaflets with many supporting structures. With advancing age, the microstructure of the components of the valves can change. Knowledge and understanding of the anatomical relationships between the different components of the heart valve structures and their relationship with age is crucial for the development and progression of treatment of valvular disease. The purpose of this study was to determine histological changes of the components of the heart valves and their relationship with age. Fifty hearts taken from cadavers were included to examine the histology of the tricuspid, mitral, pulmonary, and aortic valves. All specimens were stained with Elastic Van Gieson, and picrosirius red to enable the evaluation of elastic and collagen fibers, respectively. There was a gradual increase in elastic and collagen fibers with advancing age, particularly over 40 years, in all valve types. In the case of tricuspid and mitral valves increases in collagen and elastic fibers were observed starting in the fifth decade. Elastic fiber fragmentation was observed in specimens over 50 years. In the case of the pulmonary and the aortic valves, collagen fibers were denser and more irregular in the sixth to seventh decades when compared to younger ages while elastic fibers were significantly increased in the sixth decade. In addition, an increase in fat deposition had an association with aging. These findings provide additional basic knowledge in age-related morphological changes of the heart valves and will increase understanding concerning valvular heart diseases and treatment options.