Background: Brachial artery measures of arterial distensibility have been demonstrated to be independent risk factors for development of heart disease. These measures have been suggested as reflecting the endothelial function or atherosclerotic burden; however, they have not been compared with levels of subclinical atherosclerosis. This study sought to compare measures of brachial artery distensibility to subclinical atherosclerosis as measured by electron beam tomography (EBT).
Methods: Brachial artery pulse waveform data were collected using the DynaPulse 2000A (Pulse Metric, Inc., San Diego, CA). Distensibility measurements were taken on 201 healthy adults and compared with levels of coronary artery calcification (CAC) as measured by EBT. Laboratory values, risk factors, blood pressure (BP), and heart rate measurements were also obtained. We then compared the results of the brachial artery measurements to measures of standard risk factors and CAC.
Results: Multivariate analysis was performed, revealing that brachial artery measures were the strongest predictor of CAC. For women, brachial artery (BA) resistance was the strongest independent predictor of log CAC score (r = 0.373, P =.004). For men, BA distensibility was the only independent predictor of calcium scores (P =.012). We then divided the patients into quintiles of calcium score. Patients in the top quintile had a mean BA distensibility that was significantly higher than those of the lowest quintile (P =.02).
Conclusions: Stiffer vessels with decreased distensibility were seen in subjects with higher levels of coronary artery calcium. Therefore, noninvasive measures of distensibility are useful in measuring subclinical vascular changes related to arteriosclerosis. This noninvasive measure might provide a simple and inexpensive method to identify patients with significant atherosclerotic burden.