A high ankle-brachial index is associated with increased aortic pulse wave velocity: the Czech post-MONICA study

Abstract

Ankle brachial index (ABI) has been increasingly used in general practice to identify individuals with low ABI at high cardiovascular risk. However, there has been no consensus on the clinical significance of high ABI. The aim of our study was to compare aortic stiffness as a marker of cardiovascular risk in individuals with low (<1.0), normal (1.0-1.4), and high ABI (>1.4). A total of 911 individuals from the Czech post-MONICA study (a randomly selected 1% representative population sample, aged 54 ± 13.5 years, 47% of men) were examined. ABI was measured using a handheld Doppler and aortic pulse wave velocity (aPWV) using the Sphygmocor device. Of the 911 individuals, 28 (3.1%) had low ABI and 23 (2.5%) high ABI. There was a U-shaped association between aPWV and ABI. aPWV was significantly higher in individuals with low and high ABI compared with the normal ABI group (11.1 ± 2.8, 8.3 ± 2.3, p < 0.001; 10.8 ± 2.5, 8.3 ± 2.3 m/s, p < 0.001, respectively). In a model adjusted for age, sex, systolic, diastolic, mean blood pressure and examiner, aPWV remained increased in both extreme ABI groups compared with the normal ABI group. In logistic regression analysis, aPWV together with glucose level, male sex, and a history of deep venous thrombosis were independent predictors of high ABI, while cholesterol was not. This is the first study showing increased aortic stiffness in individuals with high ABI, presumably responsible for increased left ventricular mass described previously in this group. These findings suggest increased cardiovascular risk of high ABI individuals.