Pressure Amplification Explains Why Pulse Pressure Is Unrelated to Risk in Young Subjects

Abstract
Pulse pressure rather than diastolic pressure is the best predictor of coronary heart disease risk in older subjects, but the converse is true in younger subjects. We hypothesized that this disparity results from an age-related difference in pressure amplification from the aorta to brachial artery. Data from 212 subjects age r =0.7; P r =0.3; P r =0.1; P =0.2). There was no relationship in either group when the amplification ratio was calculated with nonaugmented central pressure. Amplification is reduced in older subjects because of enhanced wave reflection. In younger, but not older, subjects, amplification declines as diastolic pressure rises. Therefore, peripheral pulse pressure underestimates the effect that diastolic pressure has on central pulse pressure in younger subjects. This may explain why diastolic pressure is a better predictor of risk in this age group and suggests that assessment of central pressure may improve risk stratification further.