Calcific degeneration of the aortic valve in old age: is the development of flow obstruction predictable?

Abstract

Aortic valve calcification and stenosis become increasingly common with advancing age. This work aimed at assessing whether a time-dependent reduction of aortic valve area is detectable in an unselected elderly population and whether the rate of reduction can be predicted from clinical or biochemical characteristics. A population-based prospective echocardiographic follow-up study. A university hospital. In 1990, randomly selected persons born in 1904, 1909 and 1914 (total n = 501) underwent a Doppler echocardiographic study of aortic valve and biochemical tests of glucose, lipid and calcium metabolism. In 1993, echocardiography was repeated in 333 survivors of the original cohorts. These individuals constitute the present study population. Three-year changes in the aortic valve area and velocity ratio (peak outflow tract velocity/peak aortic jet velocity) determined by Doppler echocardiography. Aortic valve area decreased from a mean of 1.95 cm2 (95% confidence interval of mean, 1.88-2.03 cm2) to 1.78 cm2 (1.71-1.85 cm2) within 3 years (P < 0.001). Concomitantly, the velocity ratio decreased from 0.75 (0.73-0.77) to 0.68 (0.67-0.70) (P < 0.001). The changes in aortic valve area and velocity ratio were unrelated to age, sex, presence of hypertension, coronary artery disease or diabetes, and to all assessed biochemical characteristics. A weak positive statistical association was found between the decrease in aortic valve area and the body mass index at entry (r = 0.16, P < 0.01). A time-dependent reduction of the aortic valve flow orifice can be demonstrated in persons representing the general elderly population. The deterioration of aortic valve function within a span of 3 years is neither clinically nor biochemically predictable. A longer follow-up may be necessary to identify the risk factors of aortic valve stenosis in old age.