Central pressure: variability and impact of cardiovascular risk factors: the Anglo-Cardiff Collaborative Trial II.

ABSTRACT

Pulse pressure varies throughout the arterial tree, resulting in a gradient between central and peripheral pressure. Factors such as age, heart rate, and height influence this gradient. However, the relative impact of cardiovascular risk factors and atheromatous disease on central pressure and the normal variation in central pressure in healthy individuals are unclear. Seated peripheral (brachial) and central (aortic) blood pressures were assessed, and the ratio between aortic and brachial pulse pressure (pulse pressure ratio, ie, 1/amplification) was calculated in healthy individuals, diabetic subjects, patients with cardiovascular disease, and in individuals with only 1 of the following hypertension, hypercholesterolemia, or smoking. The age range was 18 to 101 years, and data from 10 613 individuals were analyzed. Compared with healthy individuals, pulse pressure ratio was significantly increased (ie, central systolic pressure was relatively higher) in individuals with risk factors or disease (P<0.01 for all of the comparisons). Although aging was associated with an increased pulse pressure ratio, there was still an average+/-SD difference between brachial and aortic systolic pressure of 11+/-4 and 8+/-3 mm Hg for men and women aged >80 years, respectively. Finally, stratifying individuals by brachial pressure revealed considerable overlap in aortic pressure, such that >70% of individuals with high-normal brachial pressure had similar aortic pressures as those with stage 1 hypertension. These data demonstrate that cardiovascular risk factors affect the pulse pressure ratio, and that central pressure cannot be reliably inferred from peripheral pressure. However, assessment of central pressure may improve the identification and management of patients with elevated cardiovascular risk.