Ageing changes in human heart valves.

Abstract

Eight hundred five patients aged 10-96 years were studied. There was considerable variation between hearts in the same age-groups, but noduli Arantii and slight anterior mitral nodularity were already present in all adult hearts. The histology and location of these endocardial thickenings indicated that they were a reaction to local injury produced by forceful contact between the cusps. At least slight mitral atheromatosis was present in 99% of all patient over 55. As these were frequently the only findings, even in the 10th decade, they form the normal appearance of the valves in old age. Other changes were also common. Those increasing progressively throughout the age range studied were found only in the left side of the heart. In the fibrosa they consisted of mitral atheromatosis, aortic valve calcification preceded by similar atheromatosis, and mitral ring calcification. The 2 former increased steadily with age, they were unrelated to sex, and were thought to result from the hemodynamic forces causing valve closure. The latter increased exponentially with age and was most common in women. Hemodynamic factors did not appear important in pathogenesis. The incidence of diffuse opacity of the posterior mitral cusp and aortic commissural adhesions also rose steadily with age. Both appearances resulted from diffuse fibroelastic hyperplasia of the valve endocardium. This was also thought to be a hemodynamically stimulated reaction, in response to the less forceful blood flow over opening valves. Changes that progress only during middle age, with no further increase after the 65-74 year group, were not considered to be directly related to aging. They included excessive nodular thickening of atrio-ventricular valves senile nodular sclerosis, and mucoid degeneration of mitral valve. The pathogenesis of nodular sclerosis is briefly discussed and its probable relation to chronic pulmonary disease suggested. The etiology of mucoid degeneration is unknown. The low incidence in the elderly indicates that, in man, it is not an involutional process and the slight increase with aging is merely an expression of the increasing incidence of disease processes generally.